Blood Vessels Blood Vessels
Intracellular Fluid (ICF): Fluid located Intracellular Fluid (ICF): Fluid located within the cell; cytosolwithin the cell; cytosol
Extracellular Fluid (ECF): Fluid outside Extracellular Fluid (ECF): Fluid outside of body cells; plasma and interstitial of body cells; plasma and interstitial fluidfluid
Interstitial Fluid (IF): The portion of Interstitial Fluid (IF): The portion of extracellular fluid that fills the extracellular fluid that fills the microscopic spaces microscopic spaces betweenbetween the cells the cells of tissues; tissue fluidof tissues; tissue fluid
Bulk FlowBulk Flow Filtration and reabsorption of fluids Filtration and reabsorption of fluids
due to pressure (osmotic/hydrostatic) due to pressure (osmotic/hydrostatic) differences differences
Balance of pressures = net filtration Balance of pressures = net filtration pressure (NFP) pressure (NFP)
Starling's Law of the CapillariesStarling's Law of the Capillaries - - movement of fluid between plasma movement of fluid between plasma and the interstitial fluid is in a state and the interstitial fluid is in a state of near equilibrium at the arterial and of near equilibrium at the arterial and venous ends of a capillary venous ends of a capillary
Blood hydrostatic pressure (BHP)= Blood hydrostatic pressure (BHP)= pressure of blood acting against the pressure of blood acting against the capillary walls forcing fluids out of capillary walls forcing fluids out of capillaries capillaries
Interstitial fluid hydrostatic pressure Interstitial fluid hydrostatic pressure (IFHP) = pressure acting outside the (IFHP) = pressure acting outside the capillaries pushing fluid in capillaries pushing fluid in
Blood colloid osmotic pressure Blood colloid osmotic pressure (BCOP)= pressure as a result of (BCOP)= pressure as a result of moving fluid into capillaries due to moving fluid into capillaries due to attraction to non diffusible solutes attraction to non diffusible solutes (i.e. plasma proteins)(i.e. plasma proteins)
EdemaEdema - filtration exceeds reabsorption - filtration exceeds reabsorption resulting in increased interstitial fluid resulting in increased interstitial fluid volume; causes include: volume; causes include:
Increased blood hydrostatic pressure in Increased blood hydrostatic pressure in capillaries (cardiac failure, blood clots)capillaries (cardiac failure, blood clots)
Decreased concentration of plasma Decreased concentration of plasma proteins (burns, malnutrition, kidney dis.)proteins (burns, malnutrition, kidney dis.)
Increased permeability of capillaries Increased permeability of capillaries Increased extracellular fluid volume Increased extracellular fluid volume Blockage of lymphatic vessels (radical Blockage of lymphatic vessels (radical
mastectomy)mastectomy) Edema is not detectable in tissues until IF Edema is not detectable in tissues until IF
is increased 30% above normalis increased 30% above normal
Blood flows from high pressure (arterial)Blood flows from high pressure (arterial)to low pressure (venous).to low pressure (venous).Arteries-arterioles-capillaries-venules-veinsArteries-arterioles-capillaries-venules-veins
Pressure: aorta: 90-130mmHgPressure: aorta: 90-130mmHgarteries: 80-120arteries: 80-120arterioles: 60-80arterioles: 60-80capillaries: 20-40capillaries: 20-40venules: 10-20venules: 10-20veins: 5-10veins: 5-10vena cava: 0-5vena cava: 0-5
NFP = (BHP+IFOP) NFP = (BHP+IFOP) -- (BCOP+IFHP) (BCOP+IFHP)
Arterial end:Arterial end:
NFP=(35+1)-(26+0)=(36)-(26)=10 mmHgNFP=(35+1)-(26+0)=(36)-(26)=10 mmHg
Venous end:Venous end:
NFP=(16+1)-(26+0)=(17)-(26)= -9 mmHgNFP=(16+1)-(26+0)=(17)-(26)= -9 mmHg
Definition of TermsDefinition of Terms ResistanceResistance =the opposition to flow and is =the opposition to flow and is
a measure of the amount of friction blood a measure of the amount of friction blood encounters as it passes through vessels.encounters as it passes through vessels.
Blood viscosityBlood viscosity
Total blood vessel lengthTotal blood vessel length
Blood vessel diameterBlood vessel diameter
..
Blood PressureBlood Pressure =the force per unit =the force per unit area exerted on a vessel wall by the area exerted on a vessel wall by the blood contained within it (expressed in blood contained within it (expressed in mm Hg).mm Hg).
Arterial blood pressureArterial blood pressure Systolic pressureSystolic pressure Diastolic pressureDiastolic pressure Pulse pressurePulse pressure Mean arteriole pressureMean arteriole pressure
Capillary blood pressureCapillary blood pressure
Venous blood pressureVenous blood pressure
Venous Blood PressureVenous Blood Pressure
Muscular pumpMuscular pump
Respiratory Respiratory pumppump
Factors affecting Blood Factors affecting Blood PressurePressure
Cardiac OutputCardiac Output Increased CO = increased BPIncreased CO = increased BP Decreased CO = decreased BPDecreased CO = decreased BP
Peripheral ResistancePeripheral Resistance Increased vasoconstriction = increased BPIncreased vasoconstriction = increased BP Increased vasodilation = decreased BPIncreased vasodilation = decreased BP
Blood VolumeBlood Volume Increased blood volume = increased BPIncreased blood volume = increased BP Decreased blood volume = decreased BPDecreased blood volume = decreased BP
Maintaining BP Maintaining BP (Short-term: neural)(Short-term: neural)
Vasomotor centerVasomotor center BaroreceptorsBaroreceptors ChemoreceptorsChemoreceptors Hypothalamus Hypothalamus
and cerebral and cerebral cortexcortex
Peripheral Peripheral chemoreceptorschemoreceptors
Maintaining BP Maintaining BP (Short-term: chemical)(Short-term: chemical)
Adrenal medulla Adrenal medulla hormone hormone (Adrenalin)(Adrenalin)
Atrial natriuretic Atrial natriuretic peptide (ANP)peptide (ANP)
Antidiuretic Antidiuretic hormone (ADH)hormone (ADH)
Angiotensin IIAngiotensin II Nitric oxideNitric oxide AlcoholAlcohol EndothelinEndothelin
Maintaining BP (Long-Maintaining BP (Long-term)term)
Renal RegulationRenal Regulation High blood pressure due to increased blood High blood pressure due to increased blood
volume causes decreased reabsorption in volume causes decreased reabsorption in kidneys resulting in a decrease in blood kidneys resulting in a decrease in blood volume and a lowering of blood pressure.volume and a lowering of blood pressure.
Renin-angiotensin II mechanism=when Renin-angiotensin II mechanism=when artery blood pressure drops, renin triggers artery blood pressure drops, renin triggers angiotensin II production which causes angiotensin II production which causes vasoconstriction and increased blood vasoconstriction and increased blood pressurepressure
Blood flowBlood flow =the volume of blood =the volume of blood flowing through a vessel, an organ, flowing through a vessel, an organ, or the entire circulation in a given or the entire circulation in a given periodperiod
Blood pressure:Blood pressure:Heart pumps blood through vessels. Blood Heart pumps blood through vessels. Blood
flow is under pressure due to resistance in flow is under pressure due to resistance in the systemthe system
F=F= P PRR
F= blood flowF= blood flowP= pressureP= pressureR= resistance R= resistance Blood flow is directly proportional to Blood flow is directly proportional to
changes in blood pressure.changes in blood pressure.Blood flow is inversely proportional to Blood flow is inversely proportional to
peripheral resistance.peripheral resistance.
Systolic: Ventricles ejecting blood into Systolic: Ventricles ejecting blood into the aortathe aorta
Diastole:: ventricles relaxing, pressure Diastole:: ventricles relaxing, pressure drops in aortadrops in aorta
Difference between the two is called Difference between the two is called pulse pressure.pulse pressure.
What is the pulse pressure on a normal What is the pulse pressure on a normal BP of 120/80?BP of 120/80?
40mm/Hg40mm/Hg
Pulse pressure is increased in Pulse pressure is increased in conditions like arteriosclerosis.conditions like arteriosclerosis.
Total peripheral resistance is Total peripheral resistance is controlled by arterioles. BP is controlled by arterioles. BP is controlled by arterioles.controlled by arterioles.
Arteries and veinsArteries and veins
1- Tunica intima: inside layer of the vessel.1- Tunica intima: inside layer of the vessel.
in veins= valvesin veins= valves
2- Tunica media: smooth muscle is thicker 2- Tunica media: smooth muscle is thicker in arteries and thinner in in arteries and thinner in veins. Can dilate and veins. Can dilate and constrict. constrict.
- vasoconstriction and - vasoconstriction and vasodilationvasodilation
3- Tunica adventitia: outer layer. Thicker in 3- Tunica adventitia: outer layer. Thicker in veinsveins
Capillaries:Capillaries:- Extensions of the inner layer of the Extensions of the inner layer of the
arteriole: endothelium (simple squamous)arteriole: endothelium (simple squamous)- ContinuousContinuous: skin, muscles and blood brain : skin, muscles and blood brain
barrierbarrier- FenestratedFenestrated: openings called pores that : openings called pores that
permeable to fluid and small solutes.permeable to fluid and small solutes.
Found in small intestine (absorption), Found in small intestine (absorption), endocrine glands (hormone release) and endocrine glands (hormone release) and kidneys (filtration of blood)kidneys (filtration of blood)
- SinusoidsSinusoids: liver, bone marrow and spleen: liver, bone marrow and spleen
Very leaky.Very leaky.
Capillary Transport Capillary Transport MechanismsMechanisms
Pulse PointsPulse Points
Vascular anatomy:Vascular anatomy:Arterial:Arterial:Major branches off of aorta:Major branches off of aorta:Aortic sinus (ascending): right and left Aortic sinus (ascending): right and left
coronary arterycoronary arteryArch of aorta:Arch of aorta:1- Brachiocephalic trunk which 1- Brachiocephalic trunk which
bifurcates into right subclavian a. bifurcates into right subclavian a. and the right common carotid a.and the right common carotid a.
2- Left common carotid a.2- Left common carotid a.3- Left subclavian a.3- Left subclavian a.
Descending aorta:Descending aorta:Thoracic aorta lies anterior to the Thoracic aorta lies anterior to the
vertebral column and above the vertebral column and above the diaphragmdiaphragm
Branches are:Branches are: pericardial a. pericardial a. esophageal a.esophageal a.posterior intercostal a.posterior intercostal a.
Abdominal aorta lies below the Abdominal aorta lies below the diaphragm.diaphragm.
Branches are: celiac a. Branches are: celiac a. - left gastric a.- left gastric a.- hepatic a.- hepatic a.- splenic a. (tortuous)- splenic a. (tortuous)
Phrenic a.: diaphragmPhrenic a.: diaphragm
Superior mesenteric a.: Superior mesenteric a.:
jejunum, ileum, cecum, ascending colon jejunum, ileum, cecum, ascending colon and transverse colon.and transverse colon.
Inferior mesenteric a.: Inferior mesenteric a.:
descending, sigmoid colon and rectumdescending, sigmoid colon and rectum
Renal and suprarenal a.:Renal and suprarenal a.:
supplies blood to the paired kidneys and supplies blood to the paired kidneys and adrenal glandsadrenal glands
Gonadal a.:Gonadal a.:
Male: spermatic a. that descend Male: spermatic a. that descend through the inguinal canal to supply through the inguinal canal to supply blood to the testes.blood to the testes.
Female: ovarian a.Female: ovarian a.
Middle sacral a.: long slender a. Middle sacral a.: long slender a. descending anterior to the lumbar descending anterior to the lumbar vertebra and sacrum to supply blood vertebra and sacrum to supply blood to sacrum and coccyx.to sacrum and coccyx.
Abdominal aorta will bifurcate into left Abdominal aorta will bifurcate into left and right common iliac arteries. and right common iliac arteries.
- These further divide into:These further divide into:- internal iliac a.- internal iliac a.- external iliac a.- external iliac a.
Internal iliac a.:Internal iliac a.:iliolumbar a.: ilium and back musclesiliolumbar a.: ilium and back musclessuperior and inferior gluteal a.: superior and inferior gluteal a.: buttocksbuttocksinternal pudendal a.: external genitaliainternal pudendal a.: external genitaliamiddle rectal a.: rectummiddle rectal a.: rectum
External iliac a.:External iliac a.:
- main blood supply to lower limb- main blood supply to lower limb
- Between the pubis symphysis and the ASIS - Between the pubis symphysis and the ASIS it becomes the femoral a.it becomes the femoral a.
Femoral a.:Femoral a.:
- superficial circumflex iliac a.: groin- superficial circumflex iliac a.: groin
- deep femoral a.: muscles of thigh and - deep femoral a.: muscles of thigh and hip hip jointjoint
- deep geniculate a.: distal end of thigh- deep geniculate a.: distal end of thigh
Popliteal a.: knee joint Popliteal a.: knee joint
- Will bifurcate into anterior and posterior - Will bifurcate into anterior and posterior tibial a. tibial a.
Posterior a. branches into fibular a. Posterior a. branches into fibular a. (largest branch)(largest branch)
Ant. tibial a. becomes dorsalis pedis a. Ant. tibial a. becomes dorsalis pedis a. (pedal pulse)(pedal pulse)
Arm, head and neck.Arm, head and neck.Subclavian a.:Subclavian a.:
- vertebral a.: through transverse - vertebral a.: through transverse foramina into brain through foramen foramina into brain through foramen magnum.magnum.
- becomes single basilar a. along - becomes single basilar a. along the ventral aspect of the the ventral aspect of the brainstembrainstem
- basilar a. divides into two post. - basilar a. divides into two post. cerebral a.cerebral a.
- becomes part of the Circle of - becomes part of the Circle of Willis at Willis at base of brainbase of brain
- thyrocervical a.: thyroid and - thyrocervical a.: thyroid and parathyroid glands pharynx and parathyroid glands pharynx and trachea.trachea.
Common carotid a.: branch into internal Common carotid a.: branch into internal and external carotid a. and external carotid a.
External carotid a.: External carotid a.:
- superior thyroid a.- superior thyroid a.
- lingual a.- lingual a.
- facial a.- facial a.
- occipital a.- occipital a.
Internal carotid a.:Internal carotid a.:- Ophthalmic a.Ophthalmic a.- Post. communicating a. (circle of Post. communicating a. (circle of
Willis)Willis)
Terminate in the anterior and middle Terminate in the anterior and middle cerebral arteries. These vessels cerebral arteries. These vessels supply blood to the motor, sensory supply blood to the motor, sensory and speech cortices of the brain.and speech cortices of the brain.
Arm:Arm:
Subclavian a. give rise to axillary a.Subclavian a. give rise to axillary a.
- humoral - humoral circumflex a.circumflex a.
Axillary becomes brachial a. (BP)Axillary becomes brachial a. (BP)
- deep brachial a. supplies - deep brachial a. supplies tricepstriceps
At the elbow the brachial a. divides At the elbow the brachial a. divides into ulnar and radial a. (pulse).into ulnar and radial a. (pulse).
Major VeinsMajor Veins
Superior vena cavaSuperior vena cava braciocephalicbraciocephalic external/internal jugularexternal/internal jugular vertebralvertebral subclaviansubclavian axillaryaxillary cephaliccephalic
brachialbrachial basilicbasilic median cubitalmedian cubital ulnarulnar RadialRadial
inferior vena cava inferior vena cava
splenic hepatic splenic hepatic
renal renal
superior mesenteric superior mesenteric
inferior mesentericinferior mesenteric
common iliaccommon iliac external/internal iliac external/internal iliac femoral femoral great saphenous great saphenous popliteal popliteal anterior/posterior anterior/posterior tibial tibial fibular fibular dorsal digitaldorsal digital
Clinical cornerClinical corner AneurysmAneurysm - a balloon-like outpocketing of an artery wall - a balloon-like outpocketing of an artery wall
that places the artery at risk for rupture that places the artery at risk for rupture Microangiopathic lesionMicroangiopathic lesion - an abnormal thickening of a - an abnormal thickening of a
capillary basement membrane due to the deposit of capillary basement membrane due to the deposit of glycoproteins glycoproteins
PhlebitisPhlebitis - inflammation of a vein accompanied by painful - inflammation of a vein accompanied by painful throbbing and redness of the skin throbbing and redness of the skin
HypotensionHypotension (low BP) and (low BP) and hypertensionhypertension (high BP) (high BP) AngiogenesisAngiogenesis - formation of new blood vessels - formation of new blood vessels ClaudicationClaudication - pain and lameness or limping caused by - pain and lameness or limping caused by
defective circulation of the blood in vessels of the limbs defective circulation of the blood in vessels of the limbs (Intermittant)(Intermittant)
OcclusionOcclusion - the closure or obstruction of the lumen of a - the closure or obstruction of the lumen of a structure such as a blood vessel structure such as a blood vessel
Hypovolemic shockHypovolemic shock - large-scale blood loss followed by - large-scale blood loss followed by "thready" pulse"thready" pulse
White coat hypertensionWhite coat hypertension!!! !!!