Lecture 12: Brain and Cranial Nerves e.) Cranial Nerves

Accessory Nerve XI: Orgin

cranial root: motor nuclei in medulla spinal root: spinal cord (C1 - C5 segments)

Hypoglossal Nerve XII: Pathway

hypoglossal canals of occipital bone

Vagus Nerve X: Primary Function

mixed (sensory and motor) of thorax and abdomen

Facial Nerve VII: Primary Function

mixed (sensory and motor) to face

Glossopharyngeal Nerve IX: Primary Function

mixed (sensory and motor) to head and neck

Hypoglossal Nerve XII: Primary Function

motor (tongue movements)

Hypoglossal Nerve XII: Origin

motor nuclei in medulla oblongata

Accessory Nerve XI: Primary Function

motor to muscles of neck and upper back

Hypoglossal Nerve XII: Destination

muscles of tongue

Trigeminal Nerve V: Pathway

ophthalmic branch: superior orbital fissure maxillary branch: foramen rotundum mandibular branch: foramen ovale

Vestibulocochlear Nerve VIII: Origin

receptors of inner ear

Trigeminal Nerve V: Destination

sensory nerves: sensory nuclei in pons motor nerves of mandibular branch: muscles of mastication

Vagus Nerve X: Origins

sensory: part of pharynx auricle and external acoustic canal diaphragm visceral organs of thoracic, and abdominopelvic cavities motor: motor nuclei in medulla oblongata

Glossopharyngeal Nerve IX: Origins

sensory: posterior 1/3 of tongue part of pharynx and palate carotid arteries motor: motor nuclei in medulla oblongata

Vagus Nerve X: Destination

sensory: sensory nuclei and autonomic centers in medulla oblongata motor: palate, pharynx digestive, respiratory, and cardiovascular systems in thoracic and abdominal cavities

Glossopharyngeal Nerve IX: Destination

sensory: sensory nuclei in medulla oblongata somatic motor: muscles involved in swallowing visceral motor: parotid salivary gland

Facial Nerve VII: Destination

sensory: sensory nuclei in pons somatic motor: muscles of facial expression visceral motor: lacrimal and nasal mucous glands submandibular and sublingual salivary glands

Facial Nerve VII: Origins

sensory: taste receptors on anterior 2/3 of tongue motor: motor nuclei in pons

Oculomotor Nerve Destination

somatic motor: superior, inferior, and medial rectus muscles inferior oblique muscle levator palpebrae superioris muscle visceral motor: intrinsic eye muscles

Vestibulocochlear Nerve VIII: Primary Function

special sensory vestibular branch: balance and equilibrium cochlear branch: hearing

Vestibulocochlear Nerve VIII: Destination

vestibular and cochlear nuclei in pons and medulla oblongata

How to identify Cranial Nerves?

Each one is identified by: primary function, origin, pathway, destination

What are the 12 Cranial nerves

I) Olfactory II) Optic III) Oculomotor IV)Trochlear V) Trigeminal VI) Abducens VII) Facial VIII) Vestibulocochlear IX) Glossopharyngeal X) Vagus XI) Accessory XII) Hypoglossal

What are the three cranial nerves for special senses?

I, II, VIII for smell sight hearing and balance

What are the motor cranial nerves?

III, IV, VI, XI, XII

Trigeminal Nerve V

Primary function: mixed (sensory and motor) to face Origins: ophthalmic branch (sensory) maxillary branch (sensory) mandibular branch (mixed)

Trochlear Nerve IV

Primary function: motor (eye movements) Origin: midbrain Pathway: superior orbital fissure of sphenoid Destination: superior oblique muscle

Oculomotor Nerve (III)

Primary function: motor (eye movements) Origin: midbrain Pathway: superior orbital fissures of sphenoid

Abducens Nerve VI

Primary function: motor (eye movements) Origin: pons Pathway: superior orbital fissures of sphenoid Destination: lateral rectus muscle

Optic Nerve (II)

Primary function: special sensory (vision) Origin: retina of eye Pathway: optic canals of sphenoid Destination: diencephalon via optic chiasm

Olfactory Nerve (I)

Primary function: special sensory (smell) Origin: receptors of olfactory epithelium Pathway: olfactory foramina in cribriform plate of ethmoid Destination: olfactory bulbs

Facial Nerve Branches

Temporal Zygomatic Buccal Mandibular Cervical

What are the mixed cranial nerves?

V, VII, IX, X

Vestibulocochlear Nerve VIII: Pathway

internal acoustic canals of temporal bones

Facial Nerve VII: Pathway

internal acoustic canals to facial canals (stylomastoid foramina)

Accessory Nerve XI: Destination

internal branch: voluntary muscles of palate, pharynx, and larynx external branch: sternocleidomastoid and trapezius muscles

Accessory Nerve XI: Pathway

jugular foramina between occipital and temporal bones

Glossopharyngeal Nerve IX: Pathway

jugular foramina between occipital and temporal bones

Vagus Nerve X: Pathway

jugular foramina between occipital and temporal bones