RESPIRATORY SYSTEM:  

1. Know the locations of the major anatomical structures of the nasal cavity. a. Roof of the Nasal Cavity b. Floor of the nasal cavity- formed by the hard palate c. Medial wall of the nasal cavity- formed by the nasal septum 

i. Perpendicular plate of the ethmoid bone, vomer, septal cartilage and nasal crests of the maxillary and palatine bones  

d. Lateral wall of the nasal cavity- this plane is uneven d/t nasal conchae (superior, middle, inferior) 

 2. Understand the structure and functions of the nasal conchae (turbinates). 

a. Superior, middle, inferior nasal conchae  Curve inferomedial 

b. Divide the nasal cavity into four air passages (spheno-ethmoidal recess, superior nasal meatus, middle nasal meatus, inferior nasal meatus) 

  

3.

Know the major cartilages of the larynx and the location of the hyoid bone. a. Hyoid bone: u-shaped bone that lies between the mandible and thyroid cartilage; suspended by stylohyoid ligaments; corresponds to level C3 of vertebrae; provides attachment area for anterior neck muscles; keeps airway open b. Major Cartilages of the larynx:  

i. Thyroid, arytenoid, cricoid, epiglottis, vestibular folds, vocal folds  

4.

Know the location of the vestibular and vocal folds. a. Vestibular Folds: known as the “false” vocal cords containing the vestibular ligament b. Vocal Folds: “true” vocal cords that are whiter in color compared to their neighbor the vestibular folds  

 5. Know the basic anatomy of the trachea and its major branches to the alveoli. 

a. Trachea extends from inferior larynx into the thorax; adults roughly 2.5 cm diameter; trachealis muscle is smooth muscle connecting tracheal ring ends posteriorly  b. Terminates at sternal angle into Left and Right primary/main bronchi > secondary bronchi > tertiary bronchi > bronchioles > alveoli 

  

6. Know the two pleural membranes of the lungs. a. Parietal (lines thoracic wall) and visceral (lines lungs)  

7. Know the location of the diaphragm, and its basic function and the name and origin of the nerve that innervates it. 

a.  Diaphragm is the muscle that separates the thoracic cavity from the abdominal cavity and consist of a right and left muscular dome. It is the primary muscle responsible for inspiration.  b. Diaphragm is innervated by phrenic and sensory nerves. 

 8. Know the three main arteries and their major branches supplying the nasal cavity. 

1. Opthalmic (internal carotid branch) i. ethmoidal > *anterior and posterior ethmoidal arteries* (nasal cavity, septum) *most extensive arteries in nasal cavities 

2. Facial (external carotid branch) i. superior labial artery (nasal septum and ala) ii. Lateral nasal branches of facial artery (nose dorsum, ala) 

3. Maxillary (external carotid branch) i. sphenopalatine artery (nasal cavity) through sphenopalatine foramen 

i. Descending palatine artery > Greater palatine artery (hard palate)  

 9. Know the significance of the complex of veins along the lateral wall of the nasal cavity in terms of erectile tissue. 

a. Anastomosing veins (primarily at middle and inferior nasal concha) act as erectile tissue that can become swollen, blocking nasal cavity 

i. Vasoconstrictors or corticosteroids may be required to reduce swelling.  10. Know where the olfactory nerve enters the nasal cavity and its basic function. 

a. Olfactory nerve enters nasal cavity at cribriform plate of ethmoid bone and joins with olfactory bulb b. olfactory neuron cell bodies are embedded in olfactory epithelium covering nasal cavity roof (cribriform plate of ethmoid bone) and superior nasal concha c. Detect different orders; olfactory neurons can regenerate (decreases with age)  

11. Know three major branches of the trigeminal nerve, and those branches that enter the nasal cavity 

1. Opthalmic (V1): routed through superior orbital fissure i. Enters nasal cavity via frontal nerve and nasociliary nerve ii. Also enters paranasal sinuses 

2. Maxillary (V2): routed through foramen rotundum i. Enters nasal cavity via infraorbital nerve and pterygopalatine ganglion ii. Also enters paranasal sinuses 

3. Mandibular (V3) --> routed through foramen ovale and goes through mandibular and mental foramens 

i. does NOT enter nasal cavity  

12. Know the two basic sets of muscles of the pharynx and their actions. a. Constrictor (superior, middle, and inferior): constrict the pharynx during swallowing and propel food bolus into the esophagus b. Elevator: elevate the larynx and pharynx, help with swallowing and speech 

  

  13. Know the extrinsic and intrinsic muscles of the larynx and their actions. 

a. Extrinsic (sternohyoid, sternothyroid, thyrohyoid, inferior constrictor, omohyoid): move entire larynx. Help with swallowing/speech b. Intrinsic (posterior and lateral cricoarytenoid): move laryngeal parts; change length and tension of vocal folds 

 14. Know the two major nerves of the larynx and from which cranial nerve they branch. 

a. Intrinsic muscles mostly supplied by recurrent laryngeal nerve (branch of CN X);  b. Cricothyroid muscle supplied by external laryngeal nerve  

  Terms to Know and Understand:   

1. Nasal Cavity: bilateral cavities entered through the nares that open posteriorly into the nasopharynx through the choanae 

a. Nasal Septum: bilateral nares separated by midline septum; partially bone b. Septal Nasal Cartilage c. Nasal Conchae or Turbinates 

i. Superior Nasal Concha ii. Middle Nasal Concha 

iii. Inferior Nasal Concha d. Superior Meatus e. Middle Meatus f. Inferior Meatus g. Ciliated pseudostratified columnar epithelium h. Paranasal Sinuses 

i. Frontal Sinus 

ii. Ethmoidal Sinus iii. Sphenoidal Sinus iv. Maxillary Sinus  

i. Opthalmic Artery: i. Anterior Ethmoidal Artery: arises from the ophthalmic artery and travels through the anterior ethmoidal foramen located along the medial wall of the orbit.  

1. Provides a blood supply to dura mater, anterior ethmoidal air cells, frontal sinus, nasal septum, and the lateral nasal wall  

ii. Posterior Ethmoidal Artery: arises from the ophthalmic artery and travels through the posterior ethmoidal foramen located along the medial wall of the orbit.  

1. Provides blood supply to dura mater, posterior ethmoidal air cells, and the nose 

j. Maxillary Artery: one of the two terminal tranches of the external carotid artery; arises from parotid gland and has three parts. 

i. Maxillary Artery Three Parts:  1. Mandibular Part, pterygoid part, pterygopalatine part 

ii. Sphenopalatine Artery: 1. Arises from the pterygopalatine part of the maxillary artery traveling anteriorly through the sphenopalatine foramen and into the nasal cavity giving off the posterior lateral nasal arteries. Continues inferior to the sphenoid bone and ends at the nasal septum giving off posterior septal branches supplying Kiesselbach’s area.  

k. Facial Artery: arises from the external carotid artery and travels over the mandible and superiorly along the line of the nasolabial fold 

i. Provides blood supply to the face, palate, and tonsils ii. Superior Labial Artery: arises from the facial artery close to the angle of

the mouth 1. Has a nasal septum branch  2. Provides blood for the upper lip, nasal septum and ala of the nose (lower lateral wing of the nose) 

iii. Lateral Nasal Artery: 1. Branch of facial artery 

l. Kiesselbach’s Plexus or “Little’s Area” i. nasal septum area rich in capillaries in which all 5 arteries (anterior and posterior ethmoidal arteries, sphenopalatine artery, palatine artery, superior labial artery) supplying the septum anastomose 

m. Olfactory Nerve (I): i. Perforate the cribriform plate of the ethmoid bone and enter the nasal cavity 

ii. Axons reside in the olfactory mucosa where they respond to odorous stimuli and relay odorous information to the brain via the olfactory bulb and nerve  

n. Trigeminal Nerve (V): 

i. Sensory root emerges from the trigeminal ganglion and the motor root from the trigeminal motor nucleus in the pons 

ii. Sensory fibers convey general sensations from the anterior two thirds of the tongue, skin of the face, and mucous membranes of the nasal and oral cavities 

iii. Motor fibers supply the muscles of mastication iv. Opthalmic Nerve V1: passes from the trigeminal nerve ganglion through

the superior orbital fissure and innervates the skin of the forehead, upper eyelid, nasal mucous membranes and sinuses 

v. Maxillary Nerve V2: passes from the trigeminal nerve ganglion through the foramen rotundum and into the pterygopalatine fossa and innervates the cheek, upper lip, lower eyelid, mucous membranes of the palate, teeth, gingiva, nasal cavity and maxillary sinus  

vi. Mandibular Nerve V3: formed by the union of the motor root of the trigeminal ganglion and passes through the foramen ovale as well as the mandibular and mental foramen; motor fibers supply muscles of mastication; sensory fibers supply the skin of the lower lip and jaw extending above the ear as well as mucous membranes of the tongue, floor of the mouth, lower teeth, and gingiva of the mandibular alveolar arch 

2. Pharynx: a. Coanae or Internal Nares b. Constrictor Muscles 

i. Superior Constrictor ii. Middle Constrictor 

iii. Inferior Constrictor c. Elevator Muscles 

3. Larynx: a. Thyroid Cartilage: 

i. Largest of the 9 cartilage structures that make up the laryngeal skeleton ii. Contains the Larynx iii. Prominence is referred to as the Adam’s apple 

b. Cricoid Cartilage: i. Ring of hyaline cartilage contributing to the formation of the larynx ii. Only cartilaginous band that extends around the trachea 

c. Arytenoid Cartilage: i. Provides attachment for the vocal fold in the larynx and assists in their movement 

ii. Base articulates with cricoid cartilage d. Epiglottis:  

i. Cartilaginous flap that projects obliquely upwards and dorsally from the larynx 

ii. During swallowing, elevation of the hyoid bone causes it to depress preventing food from entering the trachea  

e. Vestibular Fold (False Vocal Cord): extend between the posterior aspect of the laryngeal prominence and arytenoid cartilages 

i. Play little to no part in voice production but play more of a protective role 

f. Vocal Fold (True Vocal Cord): project medially into the laryngeal cavity i. Source of sounds that come from the larynx by producing audible vibrations when their free margins are closely apposed during phonation and air is forcibly expired  

ii. Each fold contains a vocal ligament and vocalis muscle  g. Extrinsic Muscles: 

i. Sternohyoid: 1. Inserts on the lower border of the hyoid bone, medial to the omohyoid 2. Depresses and stabilizes the hyoid bone and larynx; aids in swallowing and speech  

ii. Sternothyroid: 1. Inserts via the oblique line of the thyroid cartilage 2. Depresses and stabilizes the larynx for speech and swallowing  

iii. Thyrohyoid:  1. Insertion is the lower border of the hyoid bone 2. Depresses and stabilizes the hyoid and elevates the larynx during swallowing  

iv. Inferior Constrictor: 1. Inserts at the pharyngeal raphe or posterior to the larynx 2. Contracts to push the bolus of food downwards into the esophagus during swallowing  

v. Omohyoid: 1. Inserts on the lower border of the hyoid bone lateral to the sternohyoid 2. Depresses and stabilizes the hyoid and larynx for swallowing and speech 

h. Intrinsic Muscles: i. Posterior Cricoarytenoid: 

1. Posterior muscular process of arytenoid cartilage 2. Opens rima glottis by pulling the vocal ligaments laterally and anteriorly 

ii. Lateral Cricoarytenoid: 1. Lateral part of the cricoid cartilage arch 2. Medially rotates and adducts the vocal cords bringing them towards the midline 

i. Thyrohyoid Membrane:  i. Thin fibroelastic membrane which joins the thyroid cartilage with the hyoid bone  

ii. Divided into median and lateral ligaments  j. Vagus Cranial Nerve (X): 

i. Emerges on lateral medulla, exiting the cranium via jugular foramen; descends in the carotid sheath to the cardiac plexus, esophagus, and esophageal hiatus 

ii. Supplies sensory innervation or general somatic sense from the ear and skull; special visceral sense from the root of the tongue, epiglottis, and aortic body 

iii. Motor innervation to viscera and smooth muscle of the thorax and abdomen and special visceral motor innervation to pharyngeal and laryngeal muscles  

iv. Superior Laryngeal Nerve: 1. Arises as a branch of the vagus nerve descending on either side of the pharynx; divides into external and internal laryngeal nerves 2. Connects the cricothyroid muscle to the vocal cords 3. Internal laryngeal nerve pierces the thyrohyoid membrane and supplies the epiglottis, base of the tongue, and laryngeal mucosa with sensory innervation 

v. Recurrent Laryngeal Nerve: 1. Crosses under then posterior to the subclavian artery or aortic arch and ends in the larynx 2. Provides sensory innervation to the lower half of the larynx, upper trachea, esophagus 3. Provides motor innervation to all the muscles of the larynx, smooth muscle of the trachea and esophagus 

4. Trachea: a. Cartilage Rings or Tracheal Cartilages:  

i. 16-20 incomplete C-shaped rings made of hyaline cartilage ii. Help maintain patency of the trachea during inspiration  iii. Inferior most tracheal cartilage ring is located where the trachea bifurcates

into the right and left main bronchi iv. Rings are absent along the posterior trachea, but the posterior ends are

linked together by smooth muscle that form the trachealis muscle  b. Elastic Connective Tissue c. Trachealis Muscle  

5. Bronchi: a. Main (primary) Bronchi:  

i. Right and left pass inferolaterally from the bifurcation of the trachea  b. Secondary (lobar) Bronchi: 

i. Two on left and three on right each supplies a lobe of the lung  c. Tertiary (segmental) Bronchi: 

i. Supply the bronchopulmonary segments d. Terminal Bronchioles: 

i. Proceed after the tertiary bronchi  e. Respiratory Bronchioles f. Alveoli:  

i. Gas exchange occurs 6. Lungs:  

a. Lobes (3R, 2L) b. Pleura: 

i. Visceral Pleura 

ii. Parietal Pleura iii. Pleural Cavity 

 7. Diaphragm: 

a. Phrenic Nerve

         

  

 CARDIOVASCULAR: 

1. Know the basic structure of the human heart, specifically the pericardium, chambers, valves (names, locations and functions), fibrous skeleton, and major arteries and veins.  

a. Pericardium Layers (Innermost Layer to Outermost Layer):  i. Visceral Pericardium: deepest layer lying directly against the heart muscle; separated from the parietal pericardium by the pericardial cavity. The cavity contains serous fluid allowing the heart to move freely within the sac.  

ii. Parietal Pericardium:  the more superficial layer of the pericardial sac that lines the fibrous pericardium. 

iii. Fibrous Pericardium: tough, fibrous, outermost layer made of dense, irregular, connective tissue. It is continuous with the central tendon of the diaphragm.  

b. Chambers & Valves:  i. Right Atrium: deoxygenated blood enters from the coronary sinus, anterior veins of the right ventricle and the inferior and superior vena cava. Interior of the R atrium has a smooth posterior wall where the veins return the blood, muscular wall composed of pectinate muscles, & right AV orifice via which the right atrium discharges blood into the right ventricle: 

1. Right AV (Tricuspid) Valve: blood enters R ventricle through this valve. Anchored in place via chordae tendineae or “heart strings” that are connected to the heart muscle via the papillary muscles on internal surface of right ventricular wall.   

ii. Right Ventricle: makes up the largest part of the anterior surface of the heart, a small part of the diaphragmatic surface, and almost the entire inferior boarder of the heart. Main function is to pump deoxygenated blood to the pulmonary trunk. 

1. Pulmonary (Semilunar) Valve: blood enters pulmonary trunk from left ventricle through this valve. Located at the apex of the conus arteriosus. Has semilunar cusps.  

iii. Left Atrium:  forms most of the base of the heart and receives oxygenated blood from the four pulmonary veins (right and left superior and inferior) entering its posterior wall.  

1. Mitral (Bicuspid) Valve: blood enters the left ventricle via the mitral valve which has two cusps (anterior and posterior) and is located posterior to the sternum at the level of the 4th costal cartilage.   

iv. Left Ventricle: forms the apex of the heart and nearly all its left pulmonary surface and border and most of the diaphragmatic surface. The left ventricle is the largest, most muscular portion of the heart.  

1. Aortic (Semilunar) Valve: is located posterior to the left side of the sternum at the level of the 3rd intercostal space. Pumps blood from the left ventricle into ascending aorta 

“Lub” = AV valves (close first); “Dub” = semilunar valves  

  

c. Fibrous Skeleton: made of dense, regular connective tissue  i. Sits between atria and ventricles  

ii. 4 separate rings of tissue  iii. Acts as frame for attachment of cardiac muscles – term “skeleton” iv. Anchors heart valves – keeps them open  v. Acts as electrical insulator between atria and ventricles 

vi. Cardiac muscle fiber bundles arranged around fibrous skeleton d. Major Arteries and Veins:  

i. Inferior Vena Cava- return deoxygenated blood to Right Atrium ii. Superior Vena Cava- Return deoxygenated blood to right atrium  

iii. Ascending Aorta/ Aortic Arch- sends blood away from the heart via the left ventricle  

iv. Descending Aorta- area of aorta after the arch that sends blood away from the heart to the lower half of the body 

1. Becomes the “descending abdominal aorta” once passes through diaphragm  

v. Pulmonary Veins- returns oxygenated blood to the heart from the lungs; pumps into left atrium; 4 pulmonary veins 

vi. Pulmonary arteries – pulmonary trunk splits to two pulmonary arteries carrying deoxygenated blood from right ventricle to the lungs 

    

2. Understand the conducting system of the heart.  Heart is autorhythmic organ. 

a. SA Node initiates the heartbeat. The signal begins at the SA node (pacemaker) in the right atrium and travels through the walls of the right atrium via cardiac muscle (myogenic conduction) that transmits the signal rapidly from the SA node to the AV node. The AV node is located near the opening of the coronary sinus. AV node delays muscle impulse as it travels from atria to ventricles – separation of contraction of atria from contraction of ventricles. From there the AV node distributes the signal to the ventricles via the AV bundle (Bundle of His) through the fibrous skeleton of the heart and along the membranous part of the Interventricular septum. The AV bundle then divides into the right and left bundle branches that proceed on each side of the septum and further separate into the subendocardial branches (I.e. purkinje fibers). The purkinje fibers on the right simulate the muscle of the IV septum, anterior papillary muscle, and the wall of the right ventricle. The purkinje fibers on the left simulate the IV septum, anterior and posterior papillary muscles, and the wall of the left ventricle.  

3. Understand the innervation of the heart.  a. The heart is supplied by autonomic nerve fibers from the cardiac autonomic plexus.  

i. Not under conscious control b. The sympathetic supply is from the presynaptic fibers with cell bodies in the intermediolateral cell columns (lateral horns) of the superior five for six thoracic segments of the spinal cord. Sympathetic control increases the rate and force of the hearts contraction. Prepare body for intense activity. Cardio-acceleratory center in medulla oblongata of the brain > spinal cord > sympathetic preganglionic axon > cervical sympathetic ganglion > sympathetic post-ganglionic axon > cardiac nerve > innervate SA node, AV node, and myocardium > Positive Chronotropic (increase rate) and positive inotropic (increase force) 

c. Parasympathetic supply of the heart is from the presynaptic fibers of the vagus nerve (CN X). These cell bodies are located near the SA and AV nodes along the coronary arteries. Parasympathetic control slows the heart rate, reduces force of contraction, and constricts the coronary arteries. Cardio-inhibitory center in medulla oblongata > impulses along the vagus nerve (CN X) > parasympathetic preganglionic axon > parasympathetic postganglionic axon > innervate SA node and AV node > Negative chronotropic effect (decrease rate) 

4. Understand the blood supply (arteries and veins) of the heart.  a. Major Arteries and Veins: (see #1 above) b. Coronary Arteries:  

i. Left and Right coronary arteries branch from the ascending the aorta.  ii. The right coronary artery arises from the right anterior aortic sinus and

runs in the coronary sulcus. The RCA descends into the coronary sulcus and gives off the right marginal branch. The RCA then turns to the left and continues in the coronary sulcus on the posterior aspect of the heart. At the crux (cross) of the heart, the RCA gives rise to the AV nodal branch that supplies the AV node. The RCA then gives off the large posterior IV branch that descends in the posterior IV sulcus toward the apex of the heart. The posterior IV branch supplies both ventricles and sends perforating interventricular septal branches to the IV septum.  

1. RCA supplies: right atrium, most of the right ventricle, diaphragmatic surface of left ventricle, part of IV septum, SA node, AV node 2. Simplified Description of RCA: 

a. Right coronary artery (RCA). The right coronary artery supplies blood to the right ventricle, the right atrium, and the SA (sinoatrial) and AV (atrioventricular) nodes, which regulate the heart rhythm. The right coronary artery divides into smaller branches, including the right posterior descending artery and the acute marginal artery. Together with the left anterior descending artery, the right coronary artery helps supply blood to the middle or septum of the heart. 

iii. The left coronary artery arises from the left anterior aortic sinus of the ascending aorta. At the left end of the coronary sulcus, left of the pulmonary trunk, the LCS divides into the anterior IV branch and a circumflex branch. The anterior IV branch of the LCA passes along the IV sulcus to the apex of the heart. It then anastomoses with the posterior IV branch of the RCA. The anterior IV branch supplies both ventricles and the IV septum. The anterior IV artery gives rise to the lateral branch that descends on the anterior surface of the heart. The smaller circumflex branch of the LCA follows the coronary sulcus around the left border of the heart. The left circumflex branch of the LCA terminates in the coronary sulcus on the posterior aspect of the heart before reaching the crux.  

1. The LCA supplies: left atrium, most of left ventricle, part of right ventricle, most of IV septum, SA node 2. Simplified Description of LCA: 

a. Left main coronary artery (LMCA). The left main coronary artery supplies blood to the left side of the heart muscle (the left ventricle and left atrium). The left main coronary divides into branches: 

i. The left anterior descending artery branches off the left coronary artery and supplies blood to the front of the left side of the heart. 

ii. The circumflex artery branches off the left coronary artery and encircles the heart muscle. This artery supplies blood to the outer side and back of the heart. 

5. Know the major arteries and veins of the Thoracic Cavity, Neck, Head, & Upper Limb Lecture. 

a. Circle of Willis (around Sella Turcica)   i. Made up of:  

1. Posterior Cerebral Arteries- bilateral divisions of the basilar arteries; supply inferior surface and occipital  2. Posterior Communicating Arteries- connects the internal carotid and posterior cerebral artery 

a. **connects anterior and posterior sources of blood supply in the brain  

3. Internal Carotid Arteries- terminal branches become the a. Anterior Cerebral Artery: supply medial and superior surfaces and the frontal lobe b. Middle Cerebral Artery: supply lateral surface and temporal   

4. Anterior Communicating Arteries: connects the right and left anterior cerebral arteries 

b. Aorta (Thoracic Cavity/ Head/ Neck Region):  i. Ascending Aorta ii. Aortic Arch 

1. Right Brachiocephalic Trunk: a. Right Subclavian Artery: 

i. Axillary Artery- changes name after the 1st rib ii. Brachial Artery- change name at the inferior

boarder of the teres major muscle; this artery further bifurcates at the level of the elbow into the- 

1. Radial Artery 2. Ulnar Artery 

b. Right Common Carotid Artery: (comes up through cervical region and bifurcates at about level of hyoid bone) 

i. Internal Carotid Artery- blood supply primarily to brain 

1. Basilar Artery- bilateral convergence of internal carotid arteries once through the  

ii. External Carotid Artery- blood supply to nasal cavity, orbits, and face 

1. Facial Artery- deep to mandible and then lies over its anterior surface 2. Superficial Temporal Artery 3. Maxillary Artery 

a. Meningeal Artery- ascends through foramen spinosum between skull and dura matter  

2. Left Common Carotid (same bifurcation as Right- see above) i. Internal Carotid Artery ii. External Carotid Artery 

3. Left Subclavian Artery (same bifurcation as Right- see above iii. Descending Abdominal Aorta: (called this once passes through

diaphragm) 1. Common Illiac Arteries 

a. Internal Illiac Artery- runs deeply mostly to the reproductive organs b. External Illiac Artery- passes inguinal ligament and becomes the- 

i. Femoral Artery- palpated distal to inguinal ligament  

c. Veins:  i. Superior Vena Cava- formed by union of left brachiocephalic and right brachiocephalic vein 

1. Brachiocephalic Vein- formed via internal jugular vein and subclavian vein  2. External Jugular Vein originates from the subclavian vein  

6. Understand the connections between these vessels in terms of blood flow away from the heart (arteries) and towards the heart (veins).  7. Understand the types of connections (anastomoses, terminal vessels, collateral) 

a. Anastomoses:  communicating connections between multiple branches of an artery that provide detours for blood flow in case the usual pathway is obstructed by compression, joint position, pathology, or surgical ligation b. Collateral Circulation : If main channel is occluded, smaller alternate channels can usually increase in size, to provide alternate circulation pathway 

i. Ensures blood supply to structures distal to the blockage ii. Require time to develop—usually insufficient to compensate for sudden

occlusion or ligation iii. There are areas where collateral circulation does not exist or is inadequate

to replace main vessel c. (true) Terminal (end) arteries : arteries that do not anastomose with adjacent arteries 

i. Occlusion of terminal artery disrupts blood supply to the structure or segment of an organ it supplies 

1. (i.e.) occlusion of terminal arteries of the retina will result in blindness  

ii. Functional terminal arteries  (not true terminal arteries): arteries with ineffectual anastomoses that supply segments of the brain, liver, kidney, spleen, and intestines 

1. Example: coronary arteries--> carries oxygenated blood to a single organ--> if occluded, results in myocardial infarction and death of myocardial cells 2. Lack anastomoses  

8. Know areas where specific vessels can be accessed for cannulation. a. Common sites for IV insertion: 

i. Median cubital vein ii. Basilic Vein iii. Cephalic Vein 

b. Common Sites for Central Lines: “Great Vessels” i. Superior and inferior vena cava, brachiocephalic vein, internal jugular, subclavian, iliac, common femoral veins 

c. Most common site for arterial cannulation i. Distal radial artery 

1. superficial course 2. low rate of complications 

Terms to Know and Understand:   Pericardium- a double walled membrane that encloses the heart and the base of the great vessels. Composed of 2 layers—fibrous and serous layers. Functionally fixes heart to the mediastinum, provides protection from infection and lubrication  Fibrous pericardium- The tough fibrous layer that is the outermost/superficial layer of the pericardium and blends with the central tendon of the diaphragm. Holds heart in place. Made up of dense, irregular connective tissue. Appears as white tissue.  Parietal pericardium- the more superficial layer of the serous pericardium  Visceral pericardium- the deepest layer of the pericardium/deepest layer of serous pericardium; lies directly against the heart muscle. Separated from the parietal pericardium by the pericardial cavity, despite being part of a continuous structure. 

Heart   Right atrium- blood enters from the coronary sinus, anterior veins of right ventricle and the inferior and superior vena cavas. Pumps blood through the right atrioventricular valve (tricuspid)  Right ventricle- received non oxygenated blood from the right atrium and pumps it into the pulmonary trunk via the pulmonary semilunar valve (pulmonic)  Left atrium- receives oxygenated blood from the left and right pulmonary veins. Pumps blood through the bicuspid atrioventricular valve (mitral)  Left ventricle- receives oxygenated blood from left atrium. Largest, most muscular chamber of the heart. Pumps blood into the aortic root through the aortic semilunar valve  Tricuspid valve- located between right atrium and ventricle; anchored to inner surface of right ventricle by chordae tendineae aka “heart strings”  Bicuspid (mitral) valve- located between left atrium and left ventricle  Papillary muscles- conical shaped muscles attached to the ventricular wall. At their apex, chordae tendinae attach these muscles to the mitral and tricuspid valves (atrioventricular

valves). 3 located in right ventricle, 2 in left ventricle; papillary muscles contract to prevent inversion or prolapse of these valves on systole (ventricular contraction)  Chordae tendineae- tendons attaching the mitral and tricuspid valves to papillary muscles to their respective ventricles. Prevent prolapse of the valves into the atrium during ventricular contraction.  Pulmonary semilunar valve- located between the right ventricle and the pulmonary trunk  Aortic semilunar valve- located between the left ventricle and the aortic root. The left and right coronary artery’s orifices are in the right and left coronary leaflet  Sinoatrial node- pacemaker of the heart, located within the right atrium, near the entry of the superior vena cava. Initiate heartbeat – part of parasympathetic nervous system. Impulses spread to both atria and to the AV node via internodal pathways.  Atrioventricular node- connected to the SA node via internodal pathways. Delays the impulse slightly to prevent the atria and ventricles from contracting at the same time.  Sends signal to AV bundle.  Atrioventricular bundle (bundle of His)- located in the interventricular septum, pathway bifurcates after this point into the left and right bundles  Purkinje cells- the nervous fibers distribute the impulse into the myocardium of the left and right ventricles.  Cardiac Autonomic plexus- Collection of sympathetic postganglionic nerves and parasympathetic preganglionic nerves innervating the heart. Split into two parts—the superficial part is located below the arch of the aorta, and between the arch and the pulmonary trunk. The deep part lies between the arch of the aorta and the bifurcation of the trachea.  Cardio-accelerator- located in the medulla oblongata and spreads + inotropic and + chronotropic signals along sympathetic nerves. Acts on SA node, AV node, and myocardium.  Cardio-inhibitor- located in the medulla oblongata and spreads – chronotropic signals along the vagus nerve (CN X). Acts on SA node and AV node.  Ascending aorta- lumen immediately above the aortic semilunar valves leading to aortic arch.  Coronary arteries- branch off the ascending aorta within the pericardium but immediately above the aortic semilunar valve. Orifices for left and right coronary arteries located in the left and right aortic valve coronary leaflets (also called left and right sinus) when valve is open  Right coronary artery- travels along anterior side of heart between right atrium and right ventricle. Branches into right marginal artery (anterior side) and posterior interventricular artery (posterior side)   Right marginal artery- last bifurcation of the RCA and extends anteriorly toward the apex of the heart  Posterior interventricular artery- branch off the right coronary artery and runs along the posterior interventricular sulcus  Left coronary artery- travels mainly along posterior side of heart. Divides into circumflex artery and anterior interventricular artery.  Circumflex artery- arises from the left coronary artery and follows the coronary sulcus around the left border of the heart to the posterior side. Supplies blood to left atrium and left ventricle. 

Anterior interventricular artery- arises from the left coronary artery. Passes along anterior interventricular sulcus to apex of heart.   Right anterior sinus - Located within right coronary leaflet. Right coronary artery emerges here  Left anterior sinus- Located within left coronary leaflet. Left coronary artery emerges here   End artery- Carry oxygenated blood to a single organ or structure. They lack an interconnection (a.k.a. Anastomosis) with other arteries. The lack of anastomosis with other arteries means that if the end artery occluded there will be no other arteries able to supply blood to that organ or structure.   Functional end artery- Subtype of end artery (ex. Coronary arteries, renal arteries). These arteries form a tiny, weak anastomosis with adjacent arteries that is not sufficient to compensate the blood supply if the one of them is blocked.  Aneurysm- Balloon like enlargement in the wall of a vessel. Occurs in ascending aorta or aortic arch. Requires surgery. Could burst.  Dissection- tear in the wall of a blood vessel between endothelial layers that allows blood to be pushed between the layers and pool, usually extending the dissection. Does not tear through all layers of vessel. Occurs in ascending aorta or aortic arch. Diverts oxygenated blood delivery from organs. 

Coronary veins   Great cardiac vein- the far-left end of the coronary sinus. Lies along anterior interventricular artery.  Middle cardiac vein right posterior vein of the heart that enters the cardiac sinus near its entry into the right atrium. Lies along posterior interventricular artery.  Small cardiac vein- posterior and inferior vein that enters the coronary sinus immediately before it empties into the right atrium. Lies along lateral side of right ventricle.  Coronary sinus- main vein of the heart—all 3 coronary veins empty here. Runs from left to right in the posterior part of the coronary sulcus to the right atrium. Lacks smooth muscle—not capable of changing diameter. Blood enters the right atrium superior and medial to the inferior vena cava.  

Arteries: pulsate; thicker arterial walls  Aortic arch: curved portion of aorta following ascending aorta  Brachiocephalic trunk: first arterial branch off aortic arch. Branches into right subclavian artery and right common carotid artery.   Right common carotid artery: Branch off brachiocephalic artery. Come up through cervical region. Bifurcate at about level of hyoid bone into external and internal carotid arteries.  Right subclavian artery: Branch off brachiocephalic artery. Runs deep to the clavicle.  Left common carotid artery: Middle artery branching off aortic arch.  Left subclavian artery: left-most artery branching off aortic arch  External carotid artery: branch off common carotid artery. Provides blood supply in nasal cavity  Internal carotid artery: Arise in neck from common carotid arteries and travel toward brain. Paired internal carotid arteries entering the cranial cavity with the carotid plexus of sympathetic nerves through the carotid canals in the temporal bone. The internal carotids course anteriorly through the cavernous sinuses, with the abducent nerves (CN VI) and in

close proximity to the oculomotor (CN III) and trochlear (CN IV) nerves. Terminal branches of these arteries are the anterior and middle cerebral arteries.  Vertebral arteries: Begin in the root of the neck as branches of the first part of the subclavian arteries, pass through the transverse foramina of the first six cervical vertebrae, and perforate the dura and arachnoid to enter the skull through the foramen magnum. The intracranial vertebral arteries join to form the basilar artery  Basilar artery: Formed by intracranial joining of vertebral arteries. Continues running up through the pontocerebellar cistern to the superior border of the pons, where it ends by splitting into the two posterior cerebral arteries.   Cerebral arterial circle (circle of Willis):  located at base of brain around portion of the skull called sella turcica (containing pituitary gland). Anastomosis between the four arteries (2 vertebral and 2 internal carotids) that helps equalize blood pressure in the brain. Circle of Willis formed by: 

o posterior cerebral arteries: supply the inferior surface and occipital pole o middle cerebral arteries: supply the lateral surface and temporal pole o anterior cerebral arteries: supply most of the medial and superior surfaces and the frontal pole o anterior communicating artery o internal carotid arteries o posterior communicating arteries 

Axillary artery: After right subclavian artery in axial region.  Brachial artery: After axillary artery in brachial region. At level of elbow – brachial artery splits to radial and ulnar.  Radial artery: Formed from splitting of brachial artery. Most common site for arterial cannulation (distal radial artery)--superficial course, low rate of complications.   Ulnar artery: Formed from splitting of brachial artery  Descending thoracic aorta: Aorta continuing down through thoracic cavity.   Descending abdominal aorta: Aorta continuing down - deemed abdominal once passing through diaphragm. Lies next to inferior vena cava. Splits into common iliac artery.   Common iliac artery: formed by branches of descending abdominal aorta. Splits into internal and external iliac artery.  External iliac artery: Continues past the inguinal ligament; to then become femoral artery.  Internal iliac artery: Runs deep to reproductive organs.  Femoral artery: Arises from the external iliac artery. Has walls that consist mainly of smooth muscle circularly arranged (can change diameter). Palpated along the anteromedial side of the thigh, just distal to the inguinal ligament. 

Veins: Collapsible; thinner walls; return blood to the heart   Superior vena cava: CVC insertion “Great vessel” formed by union of left brachiocephalic and right brachiocephalic vein. Tip of PICC line ends up in SVC. Large vein characterized by wide bundles of longitudinal smooth muscle and well-developed tunica adventitia. Receives venous return from the upper half of the body, above the diaphragm.  Inferior vena cava: CVC insertion “Great vessel”. Lies next to descending abdominal aorta. Large vein characterized by wide bundles of longitudinal smooth muscle and well-developed tunica adventitia. Carries deoxygenated blood from the lower and middle body

into right atrium. Formed by joining of right and left common iliac veins, usually at the level of the fifth lumbar vertebra.  Brachiocephalic vein: (a.k.a innominate vein) CVC insertion “Great vessel” formed by joining subclavian vein along with internal jugular vein at the level of the sternoclavicular joint. Within superior mediastinum; drains territories of the arms, head, and neck respectively.  Internal jugular vein: CVC insertion “Great vessel”; paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. Runs in the carotid sheath with the common carotid artery and the vagus nerve. Begins in the posterior compartment of the jugular foramen, at the skull base.  External jugular vein: Joins subclavian vein along the neck posterior to the internal jugular vein. Receives the greater portion of the blood draining from the exterior of the cranium and the deep parts of the face.  Anterior jugular vein: Paired blood vessel that drains the anterior aspect of the neck. Emerges from the confluence of the superficial submandibular veins beneath the chin and drains into the external jugular vein or subclavian vein.  Subclavian vein: CVC insertion “Great vessel” and deep vein of the neck. Superior to the axillary vein. Originates at the outer border of the first rib. Travels within the subclavian groove, then runs laterally to the medial border fo the anterior scalene.  Axillary vein: inferior to subclavian vein. Conveys blood from lateral aspect of thorax, the axilla, and upper limb toward the heart. Origin at lower margin of the teres major muscle and a continuation of the brachial vein.  Brachial veins: Paired brachial veins. Split into radial and ulnar veins inferiorly. Brachial vein travels from the cubital fossa superiorly to become the axillary vein  Common iliac vein: CVC insertion “Great vessel”. Join left and right common iliac veins in the abdomen at the level of the fifth lumbar vertebra, to form the inferior vena cava. The pair drain blood from the pelvis and lower limbs. Both common iliac veins are accompanied along their course by common iliac arteries.  External iliac vein: large veins that connect the femoral veins to the common iliac veins. Origin at the inferior margin of the inguinal ligaments and they terminate when they join the internal iliac veins (to form the common iliac veins)  Internal iliac vein: (a.k.a. hypogastric vein) Begins near the upper part of the greater sciatic foramen, passes upward behind and slightly medial to the internal iliac artery, and at the brim of the pelvis, joins with the external iliac vein to form the common iliac vein  Femoral vein: CVC insertion “Great vessel”. A direct continuation of the popliteal vein just proximal to the knee. It ascends to the inguinal region, where it passes posterior to the inguinal ligament as the external iliac vein to enter the abdomen. Functions to drain the lower limbs. 

   Complete Anatomy Definitions Aortic Arch: 

1.    Brachiocephalic Trunk: Supplies right upper limb and head. Bifurcates into: a.     Right common carotid b.    Right subclavian artery: shorter vessel than left subclavian artery. 

2.    Left common (will split) carotid: Ascend through neck to reach head. Bifurcate into: 

a.     Internal carotid: ascend through carotid canal; course medially within temporal bone to ascend near sella tercica; split to branches that supply blood to middle and anterior and superior aspects of brain 

b.    External carotid: provide blood to neck and face structures; splits into:                                            i.     Facial artery (supplies face-“curly” route) 

External Carotid Terminates as: ii.     Superficial temporal artery: lateral aspect of head iii.     Maxillary artery: course deep to mandible, supply muscles, nasal, oral cavities, inferior orbit 

1.    Middle meningeal artery: ascends on lateral aspect of head to supply meninges; passes through the foramen spinosum of the skull; between skull and dura mater; frequently damaged in head trauma at terion 

3.    Left subclavian arteries: Branch up and out of thorax toward left upper limb a.     Vertebral artery (left and right sides of body); Ascend up through transverse foramen in cervical vertebra beginning at C6; base of skull course medially. Ascend up through foramen magnum into skull. Vertebral arteries join to form the basilar artery. 

i.     Basilar artery supplies cerebellum, brainstem, occipital lobe _______________________________________________________   Circle of Willis (cerebral arterial circle): loop of arteries at base of brain; allows for redundant blood supply or backup blood supply known as collateral circulation. If one vessel becomes blocked, there is an alternate path around the circle. Blood not automatically compensated (i.e. stroke, aneurysm); aids in slow filling or slow occlusion of vessels 

1.     Internal carotid arteries (right and left sides): supply anterior and lateral aspects of brain; anterior blood supply. Branches into: a.     Middle cerebral artery: laterally to parietal and temporal lobes b.     Anterior cerebral artery: anterior toward frontal lobe 

 **Connected by anterior communicating artery: connect left and right anterior blood supply 2.     Vertebral arteries: ascend up through foramen magnum with spinal cord; then merge together to form basilar artery; posterior blood supply 

a.     Basilar artery: midline, unpaired artery formed by junction of right and left vertebral arteries; terminates as posterior cerebral artery: 

                                               i.     Posterior cerebral artery: back toward occipital lobe **Communication between anterior blood supplied by internal carotid arteries and posterior blood supplied by vertebral arteries accomplished by posterior communicating artery             Posterior communicating artery: Connect posterior cerebral artery to internal carotid near junction of middle and anterior cerebral arteries  _______________________________________________________   Right subclavian artery: remains as such up until it passes the lateral border of the first rib 

·       Then becomes the Axillary artery (armpit): course down past clavicle, anterior to the scapula 

·       Progresses to the brachial artery at inferior border of teres major muscle ·       Progresses down until it passes the cubital fossa, deep to or near the pronator teres (medial boundary of cubital fossa) where it splits to the radial artery (lateral radius) and the ulnar artery (medial ulna) 

·       Anastomose at superficial palmar arterial arch _______________________________________________________    Abdominal aorta ·       Terminates toward end of lumbar vertebrae at its bifurcation of two common iliac arteries 

·       Common iliac arteries branch into ·       Internal iliac artery: passes over brim of pelvis into pelvic cavity; passes through obturator foramen to supply medial part of thigh and through greater sciatic foramen to supply gluteal region, posterior thigh, and pelvic floor; visceral branches supply organs within pelvis ·       External iliac artery: anterior extension; along pelvic brim; main continuation progresses to be the femoral artery which supplies lower limb, branches superiorly to the iliac crest, groin, and anterior abdominal wall 

  NERVOUS SYSTEM: 

1. Know the basic components and functions of the peripheral nervous system. a. The peripheral nervous system consists of both nerve cell bodies and nerve fibers outside of the CNS that connect with the CNS via peripheral structures. It has two components: somatic nervous system and the autonomic nervous system. The somatic nervous system provides general sensory and motor innervation to all parts of the body, except the viscera in the body cavities, smooth muscle, and glands. It is made up of somatic motor fibers that carry neural impulses away from the CNS to voluntary skeletal muscles, and of somatic sensory fibers that transmit sensations from sensory receptors to the central nervous system or spinal cord. The autonomic nervous system consists of two components as well: the sympathetic division and parasympathetic division. The autonomic nervous system mediates most of physiologic arousal (I.e. rapid heartbeat, tremors, sweating). The sympathetic nervous system works to mobilize the body to respond to emergencies via the “fight or flight” response. The parasympathetic division helps us conserve energy via “rest and digest” response.  b. From PowerPoint: 

i. The PNS is divided into 2 components: Sensory (afferent) division carries info to the CNS while the motor (efferent) division carries info away from the CNS. Both motor and sensory can be divided into somatic and visceral regions of the body. Somatic = outer regions/voluntary muscles of limbs while visceral = inner regions (digestive, circulatory system organs, involuntary organs). Visceral = autonomic NS.   

 2. Understand the differences between sensory and motor as they pertain to the peripheral nervous system. 

a. Somatic, sensory, afferent neurons carry information from the body towards the CNS. The sensory neurons transmit exteroceptive sensations (pain, temperature, touch, and pressure) from the skin as well as proprioceptive sensations from the muscles, tendons, and joints. The sensory neurons innervate unilateral areas of the skin called dermatomes.     b. Somatic, motor, efferent division carries information from the central nervous system to the skeletal muscles of the body. The unilateral muscle masses receiving innervation from the somatic motor fibers are called myotomes. Each skeletal muscle is usually innervated by the somatic motor fibers of several spinal nerves.  c. Visceral, sensory, afferent neurons are within the autonomic nervous system innervate the viscera of the body cavities. They make up the afferent component of autonomic reflexes and the conductors of pain impulses from internal organs while also regulating visceral functions.  d. Visceral, efferent, motor neurons are within the autonomic nervous system and work to stimulate smooth, involuntary muscle in the walls of the blood vessels and organs, cardiac muscle, and glands. These nerve fibers are further organized into two divisions: sympathetic and parasympathetic.  e. Special sensory (afferent) pathways exist for hearing, balance, vision, olfaction, and taste 

 3. Know the anatomical differences between the somatic and autonomic systems. 

i. Somatic motor neuron has single motor neuron that extends all the way from CNS to target organ. Autonomic motor NS has intermediate autonomic ganglion. Autonomic motor NS has preganglionic neuron before autonomic ganglion and postganglionic neuron. There is a single sensory neuron for both somatic and autonomic divisions. Axon of preganglionic neuron has cell body in CNS, axon is myelinated, it synapses with cell body of postganglionic neuron inside the autonomic ganglion. The postganglionic axon is unmyelinated b/c its distance is considerably shorter 

 4. Know the two divisions of the autonomic nervous system and their anatomical and functional differences. 

 a. From PowerPoint: 

i. The autonomic NS is divided into parasympathetic and sympathetic divisions. The parasympathetic is rest and digest and sympathetic is fight or flight. Autonomic tone is established where both work at the same time to maintain a balance between the two. For example, the parasympathetic operates the heart around 70 bpm but if those nerves are cut, rate will increase to intrinsic rate of 100 bpm. Neither division is inhibitory or excitatory. For example, sympathetic stimulates hr and rr but will decrease functions of digestive and urinary systems.   

b. From Book: i. The efferent nerve fibers and ganglia of the ANS are organized into two systems or divisions that often innervate the same structures, having different, but coordinated effects: 

1. Sympathetic division a. The effects of sympathetic stimulation are catabolic to prepare the body for flight or fight 

2. Parasympathetic division a. The effects of parasympathetic stimulation are anabolic to promote normal function and conserving energy 

 5. Know the pathways for preganglionic axons away from the sympathetic autonomic ganglion. (Spinal nerve route, Sympathetic nerve route, Splanchnic Nerve Route) 

 a. From PowerPoint: b. Axons that form the sympathetic division are going to exit the spinal cord as part of the spinal nerves T1 to L2. Their cell bodies are located in the lateral horn gray matter. Preganglionic axons travel along anterior root then into spinal nerve then enter into right and left sympathetic trunks. Each trunk is a chain of sympathetic trunk ganglia, which are autonomic ganglia that are connected by a bundle of axons. There are 3 cervical ganglia, a single sympathetic trunk ganglia for each spinal nerve T1 to L2 and then 5 inferior ganglia L3-S2.  c. Sympathetic trunk lies along anterior side of neck of ribs. In the trunk the ganglia are anteriolateral to the bodies of the lumbar vertebrae. To reach the sympathetic trunk, preganglionic axon travels thru white ramus communicans b/c preganglionic portion is myelinated. 3 routes that it then follows: spinal nerve route where preganglionic axon comes out and synapses with cell body of postganglionic neuron then exits the gray ramus communicans. In the sympathetic route the axon comes out and travels superiorly or inferiorly and then synapse with postganglionic axon in another sympathetic route. For the Splanchnic route: nerves come pass through sympathetic system without synapsing and continues as splanchnic nerves passing out of T5 to T12.   

i. There are 3 cervical ganglia, T1-L2 each have a single sympathetic trunk ganglia, and 5 inferior ganglia L3-S2.  

 6. Know the basic composition of an autonomic plexus. (collections of sympathetic postganglionic axons and preganglionic parasympathetic axons) 

 

a. From PowerPoint: i. the autonomic plexuses are collections of sympathetic postganglionic axons and preganglionic parasympathetic axons. They do not actually interact or synapse with each other.  

ii. Only know the plexus that we talk about: the Celiac Plexus (Solar Plexus) arises from Celiac ganglion 

1. The celiac plexus is the largest plexus of the sympathetic NS and part of the abdominal aortic plexus. It consists of sympathetic postganglionic axons from celiac ganglion and preganglionic axons from vagus nerve. Sterile needles are inserted around L1 just inferior to 12th rib. There are complications that could arise such as damage to aorta, kidney or lungs.   

 7. Know the major components of a typical vertebra. 

a. From PowerPoint - Typical vertebra consists of: i. Body (anteriorly) 

ii. Vertebral arch: from this arise 7 processes 1. Spinous process (posteriorly) x1 2. Transverse processes (posterior laterally from the junctions of the pendicles and laminae) x2 3. Articular Processes: (arise from junctions of the pedicles and laminae)x4 

a. Two superior b. Two inferior c. Each with articular surface  

b.  From Book: Typical vertebra consists of vertebral body, vertebral arch, and seven processes.  

i. The vertebral body is the anterior, more massive part of the vertebra that gives strength to the vertebral column and supports body weight. In life, most of the superior and inferior surfaces of vertebral bodies are covered with hyaline cartilage, which are remnants of the cartilaginous model from which the bone develops, except at the periphery, where there is a ring of smooth bone, the epiphysial rim.  

ii. The vertebral arch lies posterior to the vertebral body and is formed by right and left pedicles and laminae. The pedicles are short, stout processes that join the vertebral arch to the vertebral body. The pedicles project posteriorly to meet two broad, flat plates of bone, called laminae, which unite in the midline. The vertebral arch and the posterior surface of the vertebral body form the walls of the vertebral foramen. The succession of vertebral foramina in the articulated column forms the vertebral canal, which contains the spinal cord, meninges, fat, spinal nerve roots, and vessels. The indentations formed by the projection of the body and articular processes superior and inferior to the pedicles are vertebral notches. 

1. The superior and inferior vertebral notches of adjacent vertebrae combine to form the IV foramina, which give passage to spinal nerve roots and accompanying vessels and contain the spinal ganglia.  

iii. Seven processes arise from the vertebral arch of a typical vertebra: 1. One median spinous process project posteriorly (and usually inferiorly) from the vertebral arch at the junction of the laminae 2. Two transverse processes project posterolateral from the junctions of the pedicles and laminae 3. Four articular processes—two superior and two inferior—also arise from the junctions of the pedicles and laminae, each bearing an articular surface 

8. Know the vertebral regions: a. Cervical Vertebrae (7): 

i. Body: small and wider from side to side than anteroposteriorly; superior surface is concave between adjacent processes; inferior surface is convex 

ii. Vertebral foramen: large and triangular iii. Transverse processes: foramina transversaria; small or absent in C7;

vertebral arteries and accompanying venous and sympathetic plexuses pass through foramina (except C7); anterior and posterior tubercles 

1. Vertebral arteries travel through C6 (sometimes C7 and up) iv. Articular processes: superior facets directed superoposteriorly; inferior

facets directed infero-anteriorly  v. Spinous process: C3-C5 short and bifid; process of C6 is long but that of

C7 is longer 1. Bifid process: divided into 2 clefts. Only found in cervical vertebrae 

vi. Atlas (C1): Ring-like; somewhat kidney-shaped when viewed superiorly or inferiorly; no spinous process or body; consists of two lateral masses connected by anterior and posterior arches; concave superior articular facets form atlanto-occipital joints with the occipital condyles; flat inferior facets meet with the C2 vertebra to form lateral atlanto-axial joints 

vii. Axis (C2): Strongest cervical vertebra; distinguishing feature is the dens, which projects superiorly from its body and provides a pivot around which the atlas turns and carries the cranium; articulates anteriorly with the anterior arch of the atlas and posteriorly with the transverse ligament of the atlas 

b. Thoracic Vertebrae (12) i. Body: heart-shaped; bears one or two bilateral costal facets for articulation with head of rib 

ii. Vertebral Foramen: circular and smaller than those in cervical and lumbar regions 

1. Contains spinal cord, spinal nerves, and epidural space iii. Transverse process: long and strong; extends posterolaterally; length

diminishes from T1-T12; those of T1-T10 have transverse costal facets for articulation with tubercle of rib 

iv. Articular processes: superior articular facets directed posteriorly and slightly laterally; inferior articular facets directed anteriorly and slightly medially  

v. Spinous process: long; slopes postero-inferiorly, overlapping sub-adjacent vertebral body 

c. Lumbar Vertebrae (5) i. Body: massive; kidney-shaped when viewed superiorly; larger and heavier than those of other regions 

ii. Vertebral foramen: triangular; larger than in thoracic vertebrae and smaller than in cervical vertebrae 

iii. Transverse processes: Long and slender; accessory process on posterior surface of base of each process 

iv. Articular processes: superior articular facets directed postero-medially; inferior articular facets directed anterolaterally; mammillary process on posterior surface of each superior articular process 

v. Spinous process: short and sturdy; hatchet-shaped d. Sacrum (5) 

i. Five fused sacral vertebrae to form the sacrum ii. Sacral hiatus: lies at apex of coccyx and it provides convenient access to

caudal ending of epidural space, especially in children.  iii. Posterior sacral foramina 

1. Foramen-opening in bone. Posterior sacral foramina are openings in bone- S2 is easiest to access because medial to the posterior superior iliac spine as benchmark look for dimples for injections of anesthesia 

e. Coccyx (4) coccygeal segments i. Four vertebrae are remnants of the skeleton of the embryonic tail-like caudal eminence; the distal three vertebrae fuse during middle life to form the coccyx, a beak-like bone that articulates with the sacrum 

f. Major differences amongst the vertebral regions:  i. Cervical vertebrae are the smallest vertebrae outside of the coccyx. The first cervical vertebra is called the atlas, and the second is the axis. These two vertebrae are highly modified to support and provide rotation for the head. The atlas includes a wide lateral mass on each side containing concave regions that articulate with the skull's occipital condyles, which are each of two large, convex processes that allow attachment of the spine to the skull by articulating with the first cervical vertebra of the spine. The axis carries a unique structure, a knob called the dens, that contributes to complex articulation with the atlas. The atlas allows nodding "yes," and the axis allows rotating the head to indicate "no." Cervical vertebrae are the only ones to have a transverse foramen in each transverse process. Together these openings permit passage of vertebral arteries. Thoracic vertebrae possess long, thin, downward-pointing spinous processes, as well as long transverse processes. On the T1–T10 vertebrae, these processes include facets, or hinge-like joints, and the superior articular process of the subsequent vertebrae, which are known as costal facets and articulate with the ribs. Lumbar vertebrae are large, with thick bodies and heavy processes. They possess facets facing in two directions, providing articulation that strengthens the lower vertebral column.   

9. Know the major ligaments of the vertebral column: a. Posterior longitudinal ligament: reinforce vertebral column; largely parallel to the anterior; posterior side of the vertebral bodies, so it lies within the vertebral column; 2 layers spanning multiple vertebrae b. Anterior longitudinal ligament: reinforce vertebral column; wide band along anterior side of vertebral bodies; extends from C1 – upper edge of sacrum; primarily attaching to intervertebral discs and edges of vertebral bodies; multiple layers that span to connect vertebrae c. Ligamentum flavum: high content of elastic fibers; allowing stretch and recoil to original length; connect neighboring vertebrae along upper regions of the vertebral arch on the right and left sides; thickness increases from the cervical, to thoracic, to lumbar regions; lumbar puncture is possible between the spinous processes of the lumbar vertebrae when the back is flexed—spreads the spinous processes apart to expose this ligament d. Interspinous Ligament: each connects one spinous process to the next; narrow in thoracic region; thicker and paired in lumbar region e. Supraspinous Ligament: lie along dorsal tips of the spinous processes; deeper fibers merge with those of the interspinous ligament where it becomes thinner in the lumbar region  

10. Know the basic structure of the spinal cord and a spinal nerve: a. Spinal cord 

i. In transverse sections of the spinal cord, the gray matter appears roughly as an H-shaped area embedded in a matrix of white matter. The struts (supports) of the H are horns; therefore, there are right and left posterior (dorsal) and anterior (ventral) gray horns. Three membranous layers—pia mater, arachnoid mater, and dura mater—constitute the meninges. The meninges and the CSF surround and protect the CNS. The spinal cord is covered on its outer surface by the innermost meningeal layer, the pia mater. The CSF is located in the subarachnoid space between the pia and the arachnoid mater. External to the pia and arachnoid is the thick, dura mater. The dura of the spinal cord is separated from the vertebral column by the epidural space. All 31 pairs of spinal nerves arise from the spinal cord and exit through the intervertebral foramina in the vertebral column. 

ii. From Book: 1. The spinal cord is a cylindrical structure that is slightly flattened anteriorly and posteriorly. It is protected by the vertebrae and their associated ligaments and muscles, the spinal meninges, and the CSF. The spinal cord begins as a continuation of the medulla oblongata, the caudal part of the brainstem. In the newborn, the inferior end of the spinal cord usually is opposite the IV disc between the L2 and the L3 vertebrae. In adults, the spinal cord usually ends opposite the IV disc between the L1 and the L2 vertebrae; however, its tapering end, the conus medullaris, may terminate as high as T12 or as low as L3. The spinal cord occupies the superior two thirds of the vertebral canal. The spinal cord is enlarged in two regions for innervation of the limbs: the

cervical enlargement from C4-T1 and the lumbosacral enlargement extending from the L1-S3 segments of the spinal cord.  

b. Spinal nerve: i. A typical spinal nerve arises from the spinal cord by nerve rootlets, which converge to form two nerve roots. The anterior (ventral) root consists of motor fibers passing from nerve cell bodies in the anterior horn of the spinal cord gray matter to effector organs located peripherally. The posterior (dorsal) root consists of sensory (afferent) fibers that convey neural impulses to the CNS from sensory receptors in various parts of the body. The posterior root carries general sensory fibers to the posterior horn of the spinal cord. The anterior and posterior roots unite at the intervertebral foramen to form a spinal nerve, which immediately divides into two rami: a posterior ramus and an anterior ramus. As branches of a mixed spinal nerve, the anterior and posterior rami also carry both motor and sensory nerves, as do all their branches.  

1. The posterior rami supply nerve fibers to synovial joints of the vertebral column, deep muscles of the back, and the overlying skin. 2. The anterior rami supply nerve fibers to the much larger remaining area, consisting of anterior and lateral regions of the trunk and the upper and lower limbs arising from them. 

ii. A typical spinal nerve includes the following components: somatic sensory fibers and motor fibers; visceral motor fibers; connective tissue coverings; vasa nervorum 

iii. From book: 1. Multiple rootlets attach to the posterior and anterior surfaces of the spinal cord and converge to form posterior and anterior roots of the spinal nerves. The part of the spinal cord to which the rootlets of one bilateral pair of roots attach is a segment of the spinal cord. The posterior roots of the spinal nerves contain afferent (sensory) fibers from skin, subcutaneous and deep tissues, and, often, viscera. The anterior roots of spinal nerves contain efferent (motor) fibers to skeletal muscle, and many contain presynaptic autonomic fibers. The cell bodies of somatic axons contributing to the anterior roots are in the anterior horns of gray matter of the spinal cord, whereas the cell bodies of axons making up the posterior roots are outside the spinal cord in the spinal ganglia at the distal ends of the posterior roots. The posterior and anterior nerve roots unite at their points of exit from the vertebral canal to form a spinal nerve. 

iv. Spinal Nerve: 1. Posterior and anterior rootlets projecting medially from the spinal cord 2. Rootlets combine to form roots 

a. Roots combine to form the spinal nerve 3. Posterior rootlets combine into posterior root 

a. Dorsal side: posterior root ganglion (collection of sensory nerve cell bodies that lie outside of the CNS) 

b. Sensory information travels along the posterior side toward the spinal cord 

4. Anterior rootlets combine into anterior root a. Motor information travels out away from the spinal cord through the anterior roots to the rest of the body 

5. Posterior and anterior roots combine to form a spinal nerve a. 31 pairs of spinal nerves b. All exit vertebral column through the intervertebral foramina  

11. Be able to define a plexus and know the four principal plexuses: a. Plexus:  

i. a network of interconnecting anterior rami of spinal nerves on each side of the body; each plexus divides into a number of nerves that have specific destinations. The repeating branching of the anterior rami ensures that individual axons in a single ramus travel through a lot of different branches and the nerves that eventually arise from the plexus consist of axons from many different anterior rami. This is good because damage to a single spinal nerve may not necessarily result in complete loss of muscle function for whichever muscle it innervates or for complete loss of sensation from the skin region.  

b. 4 Plexuses:  i. Cervical:  

1. Cervical plexus: arises from anterior rami of C1-C4. The cervical plexus lies deep to the sternocleidomastoid and internal jugular vein. Two branches are important for an anesthetist: superficial branches that go to the skin of the neck, external ear, mastoid process and occipital area, and those that make up the phrenic nerve (C3, C4, and C5 of the brachial plexus) that innervates the diaphragm.  

ii. Brachial: 1. Brachial plexus: arises from anterior rami of spinal nerve C5 to T1. Nerves arising from the brachial innervate muscles, skin, and joints of the upper limb. The brachial plexus enters the posterior triangle of the neck between the anterior scalene muscle and Middle scalene muscle. 

iii. Lumbar:  1. Lumbar Plexus: arises from anterior rami of spinal nerves L1-L4  

a. Femoral Nerve: L2-L4. Sensory: Skin of anterior and upper lateral thigh. Motor: iliacus, pectineus, quadriceps femoris, and sartorius muscles b. Obturator Nerve: L2-L4. Sensory: skin of medial thig; hip and knee joints. Motor: obturator externus, medial adductor thigh muscles 

iv. Sacral and Coccygeal:  

1. Sciatic nerve largest nerve of human body: L4,L5,S1,S2,S3. Articular branches to hip joint and muscular branches to flexors of knee (hamstring muscles) and all muscles in leg and foot 

a. Tibial nerve branch of sciatic: sensory: skin of posterior leg, planter skin, knee and foot joints b. Common fibular (peroneal) nerve branch of sciatic nerve. Sensory: skin of anterior distal third of leg, dorsum of foot, and toes, knee joint. Motor: biceps femoris muscle, anterior and lateral muscles of leg, extensor dithorium brevis muscle of foot. 

TERMS TO KNOW:  Sensory (afferent)- carries information to the central nervous system. Travels along posterior side toward spinal cord. Posterior root ganglion: collection of sensory nerve cell bodies.  Motor (efferent-) carries information away from the central nervous system. Motor information travels out and away from spinal cord through the anterior roots to the body.   Somatic-outer region of the body (the skin and voluntary muscles of trunk, limbs  Visceral- inner region body, internal organs, involuntary muscles in these systems  Somatic motor- voluntary control of skeletal muscles  Somatic sensory- sensory info from skin, joints, skeletal muscles, senses  Visceral sensory-sensory info from viscera  White ramus communicans-preganglionic myelinated axon travels through the white rami to reach sympathetic trunk  Gray ramus communicans-Contain postganglionic nerve fibers (unmyelinated) exiting sympathetic chain to target organ/gland  Autonomic nervous system- involuntary control of smooth and cardiac muscle and glands 

o Parasympathetic- rest digest and read o Sympathetic-fight or flight 

Preganglionic neuron (cell body and axon)- fibers from the CNS from brain or spinal cord that synapse at the autonomic ganglion. Myelinated. White rami communicans.   Autonomic ganglion- the autonomic system has an intermediate autonomic ganglion.  Postganglionic axon- after the autonomic ganglion. Unmyelinated. Shorter distance. Gray rami  Myelinated versus unmyelinated axons- myelin sheath for conduction of nerve impulses fast over longer distances, bulk of somatic nerves are myelinated. White matter includes myelinated axons, gray matter consists of unmyelinated nerve fibers.   Vertebra: 

o Body (largest on lumbar vertebra) o Vertebral foramen: Opening formed by the vertebra through which the spinal cord passes o Vertebral canal: the actual canal the spinal cord is in o Vertebral arch 

Pedicle  Lamina 

o Transverse process o Spinous process 

o Transverse foramen (cervical only) o Costal facet (thoracic only) o Intervertebral foramen: opening between the vertebrae through which spinal nerves exit 

Vertebral Ligaments: o Anterior longitudinal ligament: A wide band along the anterior side of the vertebral bodies o  Posterior longitudinal ligament: Parallel to the anterior ligament, the posterior ligament lies along the posterior side of the vertebral bodies within the vertebral canal. o  Ligamentum flavum: Connect neighboring vertebrae along the upper regions of the vertebral arch (laminae) on the right and left sides. Large number of elastic fibers present. Will pass through ligamentum flavum when doing a lumbar puncture. o Interspinous ligament: Each connects one spinous process to the next. Thicker in lumbar region versus thoracic o Supraspinous ligament: lies along dorsal tips of the spinous processes. The deeper fibers merge with those of the interspinous ligament. 

Vertebral Regions: o Cervical (7)  o Atlas (C1)  o Axis (C2)  o Thoracic (12)  o Lumbar (5)  o Sacrum and Coccyx: 

Sacral hiatus: a posterior gap at the bottom of the sacrum and a convenient entrance point to the epidural space.   Posterior sacral foramina: Openings on posterior side of sacrum for injections (S2 easiest) 

Spinal Cord & Spinal Nerve: o Epidural space o Dura mater o Subdural space o Arachnoid mater o Subarachnoid space o Pia mater o White matter o Gray matter o Anterior root o Posterior root o Posterior root ganglion o Posterior ramus: A branch formed from the spinal nerve. Innervates the dorsal back muscles and skin. o Anterior ramus: Innervates anterior and lateral regions of the trunk, upper o limbs, and lower limbs. 

o Paravertebral space: For unilateral injection of nerve block for abdominal, thoracic, and breast surgery. A wedge-shaped region with the tapering edge of the wedge directed laterally. 

Plexuses: network of interconnected anterior rami of spinal nerves on each side of the body  Cervical Plexus: arises from anterior rami of C1-C4. The cervical plexus lies deep to the sternocleidomastoid and internal jugular vein. Two branches are important for an anesthetist: superficial branches that go to the skin of the neck, external ear, mastoid process and occipital area, and those that make up the phrenic nerve (C3, C4, and C5 of the brachial plexus) that innervates the diaphragm.      Brachial Plexus: arises from anterior rami of spinal nerve C5 to T1. Nerves arising from the brachial innervate muscles, skin, and joints of the upper limb. The brachial plexus enters the posterior triangle of the neck between the anterior scalene muscle and Middle scalene muscle.  Lumbar Plexus: arises from anterior rami of spinal nerves L1-L4  

o Femoral Nerve: L2-L4. Sensory: Skin of anterior and upper lateral thigh. Motor: iliacus, pectineus, quadriceps femoris, and sartorius muscles o Obturator Nerve: L2-L4. Sensory: skin of medial thing; hip and knee joints. Motor: obturator extermus, medial adductor thigh muscles 

Sacral and coccygeal plexuses Arises from anterior rami of L4-S4 (s5): o Sciatic nerve largest nerve of human body 

 L4,L5,S1,S2,S3. Articular branches to hip joint and muscular branches to flexors of knee (hamstring muscles) and all muscles in leg and foot 

o Tibial nerve branch of sciatic: sensory: skin of posterior leg, planter skin, knee and foot joints o Common fibular (peroneal) nerve branch of sciatic nerve. Sensory: skin of anterior distal third of leg, dorsum of foot, and toes, knee joint. Motor: biceps femoris muscle, anterior and lateral muscles of leg, extensor dithorium brevis muscle of foot. 

Sympathetic trunk (sympathetic chain)- Each trunk is a chain of sympathetic trunk ganglia (autonomic ganglia) connected by bundles of axons.  Splanchnic nerves: axons pass out from T5 to T12. Route of sympathetic nerve where the preganglionic axons continues until a prevertebral or collateral ganglia before synapsing with the postglanglionic neuron.   Prevertebral (collateral) ganglia: sympathetic ganglia that lie between the paravertebral ganglia and the target organ/gland.   Autonomic plexuses: collections of sympathetic postganglionic axons because these pass to the sympathetic trunks shortly after entering the rami, and preganglionic parasympathetic axons.  

 CRANIAL NERVES SECTION: 

  Pneumonic Devices: 

o OOOT TAF VG VAH  o Ol d Opie Occasionally Tries Trigonometry And Feels Very Glossy Vague And Hypoactive o Some Say Marry Money, But My Brother Says, Big Brains Matter More! 

Sensory, Motor, Both  Olfactory Nerve I: 

o Sensory Only o Special sense of smell. Olfactory nerve is a bundle of small hair-like follicles that come off the olfactory bulb which arises from the olfactory tract. The bulbs sit on both sides of the crista gali. The actual olfactory nerves pass through the cribriform plate of the ethmoid bone.   

Optic Nerve II: o Sensory Only o Special sense of vision. Optic chiasm- where two eyes “cross” and communicate with one another. Some of the visual information crosses from one side of our brain to the other side of the brain. Then to optic tract which sends all the visual information from one side of the visual field to one side of our brain.   o Optic nerves travel through the optic canal (anterior part of our skull)  o Takes visual info from one eye posteriorly, the chiasm is where it crosses and then the tract carries it back further to the visual cortex (hit back of your head and “see stars”).   

Oculomotor cranial nerve III: o Motor Only function. It has both general somatic efferent and general visceral efferent fibers. o Motor function- controls movement of 4 out of the 6 extraoccular muscles and a muscle to lift the eyelid.  o Parasympathetic function- constriction of the pupil (decrease amount of light), and lens accommodation (maintain focus on an object). o Course- the oculomotor nerve proceeds anteriorly, passing above the superior cerebellar artery, and lateral to the sella turcica to reach the muddle cranial fossa, passing within the lateral wall of the cavernous venous sinus. In the iddle cranial fossa, immediately prior to entering the bony orbit, it gives rise to a superior and inferior branch. These branches enter the bony orbit via the superior orbital fissure.  

Superior branch- conveys general somatic efferent fibers to levator palpebrae superioris and superior rectus  Inferior branch gives off 3 further branches- 1st innervates the medial rectus. 2nd innervates the inferior rectus and 3rd has a somatic and parasympathetic component and conveys general somatic efferent fibers to the inferior oblique. The 3rd branch also gives rise to the branch of the oculomotor nerve to the ciliary ganglion which provide parasympathetic innervation to the constrictor pupillae and the ciliary muscle.   clinical note: Ptosis is a condition where there is a damage with the oculomotor supplying the levator palpebrae superioris. This results in drooping of the upper eyelid.  Cranial nerve III palsy is a damage to the oculomotor nerve results in the paralysis of the targeted extraocular muscles. The eye takes a ‘down and out position’ and there will be ptosis as well as a dilated pupil due to the failure of the parasympathetic function of the nerve. 

Trochlear Nerve IV:  

o Motor Only o Controls movement of 1 out of the 6 extra ocular muscles. Originates posteriorly off the brain stem. Very long intracranial route- very thin and often times can get compressed. Passes through superior orbital fissure. Target is the superior oblique muscle which is controlled by the trochlea which is a strong tendon like structure. Moves our eye down and out. (If nerve damage the eye will look more medially) 

Trigeminal Nerve V: o Motor and Sensory Function o Motor is muscles of mastication. Sensory is the dominant sensory nerve of our head. Cutaneous sensation to the face, surface of the eye, nasal and oral cavities and the general sense (is it hot or cold? Texture? NOT taste) to the anterior 2/3 of the tongue.   o Opthalmic Division V1: o Maxillary Division V2: o Mandibular Division V3: o Trigeminal ganglion (collection of cell bodies outside of the CNS) is where all of sensory cell bodies are located.   

Abducens Nerve VI: o Motor Only o most straightforward nerve. Moves 1 out of the 6 extraocular muscles. Near the internal carotid artery. It passes through the superior orbital fissure. Reaches the lateral rectus muscle- when contracts it pulls our eye laterally. Abducts the eye- takes it away from midline. Eye drifts medially/cross eyed with damage. 

Facial cranial nerve VII- has both motor and sensory functions. It carries three types of fibers: special sensory fibers, general somatic fibers and general visceral fibers. It also carries proprioceptive fibers from the muscle it innervates. The special sensory fibers innervate the anterior 2/3 of the tongue to provide taste. The general somatic fibers carry information to supply the muscles of facial expression. The general visceral fibers innervate the sublingual and submandibular glands. 

o Motor and Sensory o Parasympathetic function 

Mucous production in Sublingual gland, and submandibular gland  Tear production in lacrimal gland 

o Course- the cell bodies of the special sensory (taste) are located in the geniculate ganglion, located in the facial canal of the petrous temporal bone. The general somatic fibers originate from the motor nucleus in the tegmentum of the pons while the general visceral fibers originate from the superior salivary nucleus of the pons.  

The facial nerve comes out as 2 roots from the cerebellopontine angle. The sensory and parasympathetic roots coming out from the more lateral aspect of the cerebellopontine angle (the nervous intermedius) and the motor axons coming out from the more medial aspect of the cerebellopontine angle (primary root).  The facial nerve then runs laterally within the posterior cranial fossa and enters the internal acoustic meatus. It takes a sharp turn in this space. The bend is the geniculum of the facial nertve where the geniculate ganglion is located. In addition, white travelling through the temporal bone, the facial

nerve gives rise to a few branches: the greater petrosal nerve, nerve to stapedius and the chorda tympani.  The facial nerve then emerges from the skull via the stylomastoid foramen of the temporal bone. After leaving the stylomastoid foramen, the facial nerve gives rise to the posterior auricular nerve. The posterior auricular nerve provides motor innervation to the posterior auricular muscle and the occipital belly of the occipitofrontalis muscle. It then gives rise to a small branch which provides motor innervation to the posterior belly of the digastric muscle and the stylohyoid muscle.  The facial nerve then enters the parotid gland and generates two major branches within the substance of the parotid gland- the temporofacial branch and the cervicofacial branch.  The facial nerve ultimately generates 5 terminal branches, which innervate the muscles of facial expression. Pneumonic to remember these branches- “To Zanzibar By Motor Car.”  

Temporal branches- provide somatic motor innervation to the musculature in the region of the forehead, temple and the supraorbital region  Zygomatic branches- provide somatic motor innervation to the musculature in the infra-orbital region, lateral aspect of the external nose and the superior labial region  Buccal branches- provide somatic motor innervation to the muscles of the cheek, the superior lip and the lateral aspect of the oral fissure  Marginal mandibular branches- provide somatic motor innervation of the musculature of the inferior lip and the musculature of the chin  Cervical branches- provide somatic motor innervation to the platysma  

Clinical Note: Bell’s palsy is a condition of unknown etiology where there is an acute inflammatory lesion of the facial nerve. This condition is presented with a unilateral lower motor nerve lesion of the face on the affected side: paralysis of affected side of the face, hyperacusis and loss of taste on the anterior 2/3 of the tongue.  Clinical Note #2: Ramsay-hunt syndrome is a syndrome characterized by a similar presentation with additional symptoms such as vesicular rash in the external auditory canal and the mucous membrane of the oropharynx. This condition is cause by herpes zoster infection causing an inflammation to the facial nerve.    

Vestibularchochlear VIII: o Sensory Only o Special sense of hearing and balance. 2 divisions of this nerve. One for hearing and one for balance. Originates in posterior cranial fossa and courses in parallel to cranial nerve VII which also passers through the internal acoustic meatus. It has a double barreled appearance compared to CN VII. Terminates within the temporal bone. Targets are in our inner ear- vestibular portion (balance/motion) in our ear and the cochlea (hearing).   

Glossopharyngeal cranial nerve IX – has both motor and sensory as well as parasympathetic functions (parorid gland) although it is principally a sensory nerve. It targets two structural areas- the glossus (the tongue) and the pharynx. 

o Motor, Sensory, and Parasympathetic  o The general sensory fibers of this nerve supply the pharynx, muddle ear, carotid body, carotid sinus and posterior 1/3 of the tongue to provide the general sensation of these areas. Stimuli detected here and at the back of the tongue can evoke the gag reflex, where the back of the throat contracts and can even cause vomiting.  o The special sensory fibers supply the posterior 1/3 of the tongue to provide taste sensation to the area.  o The glossopharyngeal nerve also gives motor supply to the stylopharyngeus muscle which is involved in swallowing. o Preganglionic sympathetic fibers provide parasympathetic innervation to the parotid salivary gland. o Another important function of the glossopharyngeal nerve is to monitor blood pressure and oxygen levels going to our brain. It does this by giving rise to a small nerve that supplies sensory innervation to the carotid body and the carotid sinus. The carotid sinus is a dilated portion of the internal carotid artery and it contains baroreceptors (“baro” means pressure) so its able to monitor BP within the internal carotid blood vessel. The carotid body lies beside the carotid sinus and it contains chemoreceptors which can detect changes in oxygen levels. The glossopharyngeal nerve then relays this info about BP and O2 levels to the brain. o Course- the afferent fibers carry info from the receptor for the pharynx, middle ear, carotid body, carotid sinus and posterior 1/3 of the tongue to the brain. Within the brain the glossopharyngeal nerve receives or sends fibers through the motor and sensory nuclei. The glossopharyngeal nerve emerges from the lateral aspect of the medulla. It then courses within the posterior cranial fossa to pass through the jugular foramen to the base of the skull. Extracranially, the glossopharyngeal nerve runs along beside the internal carotid artery. o Clinical Note: the cranial nerve IX is responsible for the sensory aspect of the gag reflex as it supplies the sensory innervation to the pharynx. Damage to the glossopharyngeal nerve will lead to inability to induce the gag reflex and this will predispose to respiratory aspiration. 

Vagus Nerve X: o Motor, Sensory, and Parasympathetic  o Motor- soft palate muscles, pharyngeal and laryngeal muscles. Sensory- general sense to the inferior pharynx and larynx as well as the thoracic and abdominal organs. Parasympathetic- thoracic and abdominal viscera up to 2/3 of the transverse colon. This nerve is the “wanderer”- has the largest area of distribution of any of the cranial nerves. Exits the skull via the jugular foramen alongside cranial nerves IX and XI. Runs parallel to the common carotid artery and internal jugular vein but sends off branches along the way. Supplies muscles of the soft palate- helps block off entrance into the nasal cavity so food and liquid goes down into the throat and not up into the nose. Supplies constrictor muscles of the pharynx. Innervates the larynx. Sensation to inferior aspect of our pharynx- gag reeks combines aspects of glossopharyngeal nerve (gag) and vagus nerve (vomit). Vagus nerve receives sensory info from organs in

thoracic and abdominal cavities. Vagus nerve provides parasympathetic- rest and digest.   o Cardiac Plexus o Pulmonary Plexus o Esophageal Plexus o Abdominal Aortic Plexus 

Spinal Accessory Nerve XI: o Motor Only o Sternocleidomastoid and trapezius muscle  o Enters foreman magnum and exits jugular foramen 

Hypoglossal Nerve XII: o Motor Only  o Extrinsic and intrinsic muscle of the tongue o Enters foreman magnum and exits hypoglossal canal 

 Topic: Cranial Nerves, Nerve Blocks and Dermatomes Objectives: 

1. Cranial Nerve: location and function (is it a sensory, motor or combination nerve) 2. Regional Nerve blocks 3. Understand dermatomes 4. Know the difference between regions of skin innervated by dermatomes and cutaneous fields. 

 Terms to Know and Understand: 

1. Be able to label the trigeminal nerve, trigeminal ganglion, 3 trigeminal branches and sensory distribution of trigeminal branches on a diagram  2. Label the openings in the skull (supraorbital foramen, infraorbital foramen, mental foramen) and cranial nerves 3. Trigeminal nerve and its branches (as pertaining to the covered nerve blocks) 4. For all nerve blocks covered in lecture, know what it can be used for, and the general area of administration: 

a. Cervical b. Trigeminal nerve block c. Ophthalmic nerve block d. Maxillary nerve block 

i. From power point:  ii. An infraorbital maxillary nerve block can be done and that will 

anesthetize all the parts of the maxillary nerve not just the infraorbital, however, the terminal branch of the maxillary nerve is called infraorbital once it actually reaches the infraorbital fossa. There are two types of approach you can either do the extraoral or the intraoral. The point of both of these is to administer enough anesthetic by the infraorbital nerve to achieve the outcome that you want. The nerve blocks are going to be better than a local infiltration especially when you're dealing with laceration repairs in this area because if you are doing a local infiltration it's 

going to take more medication and you can distort the area that you are trying to repair. 

e. Mandibular nerve block i. From Power point 

ii. Can anesthetize the entire side of the mandible including the muscles of mastication. 

1. Route 1 :Apply the anesthetic in between the zygomatic arch and the coronoid process 2. Route 2: Go through the inferior alveolar nerve (enters the mandibular condyle in the inner side of the mandible toward the top of the ramus, will exit through the mental foramen) 

iii.  f. Lumbar, Femoral, Sciatic, Brachial, Obturator  

5. Dermatome 6. What is a dermatome map, reasons why it may not be accurate (see intersegmental anastomoses and cutaneous field) 

a. From Power Point b. Intersegmental anastomosis are the connections between predominantly posterior spinal roots of neighboring nerves. As a result, a sensory Axon from one posterior root could actually enter the root of a superior or an inferior spinal nerve. Its great when you have these nice maps of dermatomes but what those don't take into account are these little connections that can happen and they can kind of blur the lines of where those maps are actually showing you the sensory input from. 

7. Intersegmental anastomoses 8. Referred pain 9. Cutaneous field