Cranial Nerves

Question 1

Give acronym and name of 12 cranial nerves

Answer 1

On Old Olympus Towering Tops A Fat Voracious Viewed A Hop

1. Olfactory = smell
2. Optic= vision
3. Oculomotor= 4/ 6 extrinsic eye muscles
4. Trochlear= Extrinsic Eye Muscles
5. Trigeminal= sensory fibres to the face and motor fires to the chewing muscles
6. Abducens= controls eye muscles that turn eye laterally
7. Facial= facial expression
8. Vestibulocochlear= hearing and balance
9. Glosopharyngeal= tongue and pharynx
10. Vagus= from medulla - acetylcholine slows heart breathing
11. Accessory= accessory part of vagus nerve
12. Hypoglossal= moves muscles under tongue

Question 2

Origin of the Olfactory Nerves I

Answer 2

Olfactory Receptor Cell

Question 3

Optic Nerves II origin

Answer 3

Retinal Ganglion Cells

Question 4

Oculomotor nerves origin

Answer 4

1. oculomotor nucleus:
   - Superior Oblique M
   - Levator Palpebrae Superioris
   - Superior Rectus M
2. Edinger Westphal nucleus–> Ciliaris

Question 5

Trochlear Nerves IV nerve origin and innervation

Answer 5

ORIGIN: Trochlear nerve nucleus (midbrain)–> Superior oblique muscles

Question 6

Trigeminal Nerves V

Answer 6

Trigeminal sensory nucleus consists of 3-subnuclei:
1-CHIEF (PRINC) SENSORY NUCLEUS= lies in pontine tegmentum (mid-pon), receives touch sensation.

2-SPINAL NUCLEUS= ext caudally through medulla and upper cervical spinal cord to become cont with substantial gelatinous

(apex of the posterior grey column, one of the three grey columns of the spinal cord, is capped by a V-shaped or crescentic mass of translucent, gelatinous neuroglia)

receives pain and temp sensation from face and scalp

3- MESENCEPHALIC NUCLEUS in midbrain, receives proprioception
(deep) sensation from head

Question 7

Abducens Nerve VI Origin and innervation

Answer 7

ORIGIN: abducens nerve nucleus–> lateral rectus muscle (at junction between pons and medulla)

Question 8

Facial nerves VII is made up of what 2 components?

Answer 8

Facial nerve proper and Intermediate Nerve (Wrisberg)

Question 9

Origin of Facial Nerve V

Answer 9

1. MOTOR-> facial nerve nucleus (Ms of facial expression)
2. Parasympathetic–> Superior Salivatory Nucleus (Sublingual, submandibular & Submental Glands)
3. SENSORY–> geniculate ganglion (taste an 2/3 of tongue)

Question 10

NUCLEUS OF ORIGIN and functions of nerves in Vestibulocochlear Nerves VIII

Answer 10

COCHLEAR NERVE
NOO: spiral ganglia, lying in IAM
F: carries hearing info from organ of corti to cochlear nuclei

VESTIBULAR NERVE
NOO: vestibular ganglion,, lying in internal acoustic meatus
F: carries balance sensationf rom utricle , saccule and semicircular canals (membranous labrynth)

Question 11

Glossopharyngeal nerves XI

Answer 11

1. Origin: medulla
2. Innervation: mucous mem and tonsils, pharynx, post 1/3 tongue, pharyngeal muscles, carotid sinus and body
3. function: taste from post 1/3 tongue- afferent limb of gag swallow and cardiac reflexes

4/ DF: loss of taste neuralgia

Question 12

Vagua nerves X

Answer 12

1. origin: medulla
2. INNERVATION
   - muscles of larynx, pharynx and soft palate
   - parasympathetic inn of thoracic and abdomina viscera
3. function:
   - muscles of larynx, pharync and soft palate
   - sensation converted from the heart, lungs, digestive tract, carotid sinus and body
   - efferent limb of gag and swallow reflex
4. DF:
   - loss gag and swallow reflect
   - loss of carotid sinus
   - occulocardiac reflex; dysphagia

Question 13

Accessory Nerves XI

Answer 13

origin: medulla
2. INNERVATION: sternocleidomastoid M and trapezius
3. FUNCTION: Motor fucniton SCM & T
4. DF: muscle weakness

Question 14

HYPOGLOSSAL NERVES XII

Answer 14

1. ORIGIN medulla
2. INNERVATION: muscles of tongue except palatoglossus
3. FUNCITON: movement tongue
4. DF:
   - unilateral lesions can cause paresis, atrophy, farrowing, fibrillation, and fasciculation on affected half
   - on protrusion tongue deviates towards the affected side due to unopposed action of the contralateral GENIOGLOSSUS
5. FLACCID PARALYSIS
   - dysphagia
   dysarthria
   -dyspenea
   - difficulty chewing food