Nerves

How many spinal nerves are there?

62

How many cranial nerves are there?

24

What is the difference between tracts & nerves?

Nerves are peripheral & tracts are central

What are the 3 connective tissue layers of nerves?
(In order of outside —> inside)

Epineurium, Perineurium, Endoneurium

Where does sensory input enter the spinal cord?

The back

Where do the 12 cranial nerve pairs attach?

First 2 on the forebrain, last 10 on brainstem

Cranial Nerve (I)

Olfactory Nerve
Sensory
Smell
Person is asked to identify an odor w/eyes closed and one nostril
Pierces Cribriform Plate & Uncus

Cranial Nerve (II)

Optic Nerve
Sensory
Vision
Snellen Eye Chart
Covered in meninges

Cranial Nerve (III)

Oculomotor Nerve
Motor
Moves Eye & constricts pupil (superior, inferior, & medial rectus, and the inferior oblique)
Shine light into pupil to see if there is a response
Exits superior orbital fissure, Enters the Edinger-Westphal

Cranial Nerve (IV)

Trochlear Nerve
Motor
Moves superior oblique (cheaters muscle)
Field of Gaze Test (follow finger with eyes)
Exits superior orbital fissure (smallest but longest cranial nerve)

Cranial Nerve (V)

Trigeminal Nerve
Mixed
Sensory to face, controls muscles of mastication, and blink/corneal reflex
Touch cornea w/cotton from side
Put fingers on temples and have patient bite down
Nucleus located in midbrain, pons, and medulla [entire brain stem] (Largest cranial nerve)
3 Branches (ophthalmic, maxillary, mandibular)

Cranial Nerve (VI)

Abducens
Motor
Controls lateral rectus
Field of Gaze Test
Exits superior orbital fissure

Cranial Nerve (VII)

Facial Nerve
Mixed
Controls facial expression, lacrimal & salivary glands, and senses anterior taste (sour, salty & sweet)
Motor part exits the stylomastoid foramen
5/6 Branches (temporal, zygomatic, buccal, mandibular, cervical, posterior auricular)

Cranial Nerve (VIII)

Vestibulocochlear Nerve
Sensory
Balance, equilibrium & hearing
Travels through internal acoustic meatus

Cranial Nerve (IV)

Glossopharyngeal Nerve
Mixed
Senses bitter test and controls tongue & pharynx
Test for swallowing and gag reflex (say “ah”) [innervates parotid salivary gland]
Fibers emerge from medulla and exit jugular foramen (also branches to carotid sinus)

Cranial Nerve (X)

Vagus Nerve “the wanderer”
Mixed
Controls PARASYMPATHETIC heart rate, breathing, digestive function, voice box, and receives sensory info from viscera (internal organs)
Only cranial nerve to extend below head/neck into thorax and abdomen

Cranial Nerve (XI)

Spinal Accessory Nerve
Motor
Controls trapezius & sternocleidomastoid
Ask patient to shrug shoulders against resistance
Exits jugular foramen

Cranial Nerve (XII)

Hypoglossal Nerve
Motor
Controls tongue (swallowing & speech)
Have tongue hold tongue against cheek against outside resistance
Exits hypoglossal canal

Anosmia

Lack of Smell

The Zesty Bitches Make Cum Particularly Arousing

Temporal Zygomatic Buccal Mandibular Cervical Posterior Auricular
5/6 branches of facial nerve

Superior vs Inferior Colliculi

Superior = Visual Reflex
Inferior = Startle/Auditory Reflex

LR6SO4
————
      3

Lateral Rectus = 6, Superior Oblique = 4, Rest = 3

Trigeminal Nerve AKA

Gasserian Ganglion

Trigeminal Neuralgia

Face pain also called tic douloureux

Bell’s Palsy

unilateral facial paralysis due to damage to facial nerve

Bitter Back 9

Taste for bitter on posterior third of tongue

Oh, oh, oh to touch and feel very good v——, ah heaven!

Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducens
Facial
Vestibulocochlear
Glossopharyngeal
Vagus
Accessory
Hypoglossal

Mnemonic for type of cranial nerves

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