Nervii cranieni
12 Pairs of Cranial Nerves Part of the Peripheral Nervous System Originate from the brain, not the spinal cord Bundles of nerves: sensory and/or
motor(somatic or parasympathetic) Ipsilateral innervation Name includes:
Number Word
4 Classification - Cranial Nerves1. Sensory nerves:
carry somatic sensory information: touch, pressure, vibration, temperature, and pain
2. Special sensory nerves: carry sensations:
smell, sight, hearing, balance3. Motor nerves: – axons of somatic motor neurons
4. Mixed nerves: – mixture of motor and sensory fibers
Summary: Cranial Nerves
Summary: Cranial Nerves
CN I
CN III
CN V
CN VII
CN IX
CN XI
CN II
CN IV
CN VI
CN VIII
CN X
CN XII
Nerv olfactiv
Primary function- special sensory (smell)
Origin receptors of olfactory epithelium
Pathway - olfactory foramina in cribriform plate of ethmoid
Destination - olfactory bulbs Smell Apply odors to each nostril Traumatic anosmia – loss of sense
of smell
• Structures– Olfactory bulbs:located on either
side of crista galli– Olfactory tracts: axons of
postsynaptic neurons, leading to cerebrum
Nerv optic Vision Visual acuity Map field of vision Optic chiasm Sensory only: vision Runs from the retina to the optic chiasm to the thalamus
Nerv optic
Primary function: special sensory (vision)
Origin: retina of eye
Pathway: optic canals of sphenoid
Destination: diencephalon via optic chiasm
• Structures– Optic chiasm: where sensory fibers converge , and cross to
opposite side of brain– Optic tracts: reorganized axons, leading to lateral geniculate
nuclei
Nerv oculomotor Primary function:
motor (eye movements) Origin:
mesencephalon Pathway:
superior orbital fissures of sphenoid
Destination: somatic motor:
superior, inferior, and medial rectus muscles
inferior oblique muscle levator palpebrae superioris muscle
visceral motor: intrinsic eye muscles
Problems: diplopia; uneven eyes
Nerv oculomotor
• Structures• Oculomotor nerve: controls 4 of 6 eye-movement
muscles, delivers autonomic fibers to ciliary ganglion
• Ciliary ganglion: controls intrinsic muscles of iris and lens
Nerv oculomotor
Disorders can result in eye paralysis, diplopia or ptosis.
Nerv trohlear
Primary function: motor (eye movements)
Origin: mesencephalon
Pathway: superior orbital fissure of
sphenoid Destination:
superior oblique muscle
Nervul trigemen Primary function:
mixed (sensory and motor) to face Origins:
ophthalmic branch (sensory): orbital structures nasal cavity skin of forehead, upper eyelid, and eyebrow part of nose
– maxillary branch (sensory): • lower eyelid• upper lip, gums, and teeth• cheek and nose • palate and part of pharynx
– mandibular branch (sensory): • lower gums, teeth, and lips• palate and part of tongue
– mandibular branch (motor): • motor nuclei of pons
Nervul trigemen• Pathways:
– ophthalmic branch: • superior orbital fissure
– maxillary branch: • foramen rotundum
– mandibular branch: • foramen ovale
• Destinations:– sensory nerves: sensory nuclei-pons– motor nerves of mandibular branch:
• muscles of masticationTrigeminal nerves:
largest cranial nerveswith 3 major branches
Semilunar ganglion:contains cell bodies of sensory neurons
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Nervul trigemen Three Branches V1 Ophthalmic
division: sensory V2 Maxillary: sensory V3 Mandibular:
Sensory for the face
Motor (somatic) nerves for chewing
Originates in the pons
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Nervul trigemen
Medical Example: Trigeminal Neuralgia
AKA:Tic Douloureux It is characterized by sudden attacks of
pain that are typically brief, lasting only seconds to two minutes.
These attacks are severe and described as intense, stabbing or electrical shock-like.
Nervul abducens
Primary function: motor (eye movements)
Origin: pons
Pathway: superior orbital fissures of sphenoid
Destination: lateral rectus muscle
Nervul facial Primary function:
mixed (sensory and motor) to face
Origins: sensory: taste receptors on
anterior 2/3 of tongue motor: motor nuclei of pons
• Pathway: – internal acoustic canals to facial canals (stylomastoid
foramina)• Destinations:
– sensory: sensory nuclei of pons– somatic motor: muscles of facial expression– visceral motor: tear and nasal mucous glands, submandibular
and sublingual salivary glands
Originates in the pons
Structures Facial nerve branches:
temporal zygomatic buccal mandibular cervical branchesGeniculate ganglia: hold cell bodies of sensory neurons
Pterygopalatine ganglia: postganglionic fibers innervate
glands (lacrimal, nasal cavity, and pharynx)
Submandibular ganglia: innervate salivary glands
Medical Example: Facial Nerve Palsy
AKA: Bell’s Palsy Causes paralysis of
facial muscles which leads to tearing and drooling.
Loss of taste on one side of tongue.
Nervul glosofaringian
• Primary function: mixed (sensory and motor) to head and neck
• Origins:–sensory:
• posterior 1/3 of tongue• part of pharynx and palate• carotid arteries
–motor: • motor nuclei of medulla oblongata
• Pathway: –jugular foramina between occipital and temporal bones
Figure 14–24
Nervul vestibulocohlear Primary function: special sensory
vestibular branch: balance and equilibrium
cochlear branch: hearing
Origin: receptors of inner ear– internal acoustic canals of temporal bones
• Destination: – vestibular and cochlear nuclei of pons and medulla
oblongata• Structures– Vestibular branch:originates at receptors of vestibule
(balance), connects to vestibular nuclei of pons and medulla oblongata
– Cochlear branch:originates at sensors of cochlea (hearing), connects with cochlear nuclei of pons and medulla oblongata
Nervul vestibulocohlear
Nervul glosofaringian Destinations:
sensory: sensory nuclei of medulla oblongata
somatic motor: nerves involved in swallowing
visceral motor: parotid salivary gland
• Structures– Superior and inferior ganglion:
• sensory neurons of tongue and pharynx– Otic ganglion:
• synapse visceral motor fibers
Nervul vag
Primary function: mixed (sensory and motor) of thorax and abdomen
•Origins:–sensory:
• part of pharynx• auricle and external acoustic
canal• diaphragm• visceral organs of thoracic, and
abdominopelvic cavities–motor:
• motor nuclei in medulla oblongata
Pathway: jugular foramina between occipital and temporal bones
Originates in the medulla
Nervul vag• Destinations:
– sensory: • sensory nuclei and autonomic
centers of medulla oblongata– visceral motor:
• palate, pharynx• digestive, respiratory, and
cardiovascular systems in thoracic and abdominal cavities
• Structures– Vagus nerves:branch and radiate
extensively– Jugular ganglion and inferior nodose
ganglion: hold sensory neurons
Nervul accesor Primary function:
motor to muscles of neck and upper back Origin:
motor nuclei of spinal cord and medulla oblongata
Pathway: jugular foramina between occipital and
temporal bones• Destinations:
– internal branch: • voluntary muscles of palate, pharynx, and
larynx– external branch:
• sternocleidomastoid and trapezius muscles
Structures Spinal root: motor fibers
that originate in anterior gray horns of first 5 cervical segments of spinal cord
Cranial root: motor fibers that originate in medulla oblongata
– Internal branch:joins the vagus nerve
– External branch:controls muscles of neck and back
Nervul accesor
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Medical Example: Accessory Nerve Palsy
Spinal accessory nerve injury can cause drooping shoulder, muscle atrophy, limited elevation of
shoulder, and winged scapula
Nervul hipoglos
Primary function: motor (tongue
movements) Origin:
motor nuclei of medulla oblongata
Pathway: hypoglossal canals of
occipital bone Destination:
muscles of tongue during speech and
swallowing
Originates in the medulla
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Nervul hipoglos
Injury deviates tongue to injured side when protruded.
Reflexe craniene Monosynaptic and polysynaptic reflex
arcs Involve sensory and motor fibers of
cranial nerves Clinically useful to check cranial
nervous system
Examples of Cranial Reflexes
The End