Cranial nerves 2

Question 0

Vestibular branch route

Answer 0

Semicircular canals, the saccule + utricle of inner ear -> vestibular ganglion -> vestibular nuclei in pons + medulla

Question 1

CNVIII

Answer 1

Vestibulocochlear Nerve
sensory nerve
2 branches
Vestibular branch (carries impulses for equilibrium) and cochlear branch (Carries impulse for hearing)

Question 2

Cochlear branch

Answer 2

Spiral organ (organ of corti) -> spiral ganglion -> auditory meatus -> medulla -> thalamus (medial genuculate nuclei, inferior colliculus midbrain) -> primary auditory area (41, 42)

Question 3

Injury to vestibular branch

Answer 3

Vertigo - a subjective feeling that one’s own body or the environment is rotating
Ataxia - muscular incoordination
Nystagmus - involuntary rapid movement of the eyeball

Question 4

Injury to cochlear branch

Answer 4

tinnitus - ringing in ears

Deafness

Question 5

CN IX

Answer 5

Glossopharyngeal nerve

sensory, motor and autonomic

Question 6

CN IX sensory

Answer 6

1. Taste buds on posterior 1/3 of tongue
2. Proprioceptors from some swallowing mm
3. baroreceptors in carotid sinus that monitor BP
4. Chemoreceptors
5. External ear to convey touch, pain, heat and cold
   - > superior and inferior ganglia -> jugular foramen -> medulla

Question 7

CN IX motor

Answer 7

nuclei in medulla ->jugular foramen -> stylopharyngeus mm

Question 8

CN IX Autonomic

Answer 8

inferior salivary nucleus in medulla ->otic ganglion -> parotid gland (facial nerve goes through but Glossopharyngeal innervates it)

Question 9

Injury to CN IX

Answer 9

Dysphagia -difficult to swallow
Aptyalia - no saliva 
Loss of sensation in throat
Ageusia - no taste
Glossopharyngeal neuralgia - posterior pharynx, tonsils, back of tongue, middle ear, can be triggered by chewing, swallowing, talking, sneezing, touching the tonsils an applicator

Question 10

CN X

Answer 10

Vagus nerve
Autonomic
Motor and sensory

Question 11

CN X sensory

Answer 11

Skin of external ear
a few taste buds in epiglottis and pharynx
proprioceptors in mm of neck and throat
baroreceptors and chemoreceptors
mainly from visceral sensory receptors in most organs of Thoracic and abdominal cavities that convey sensations (ie hunger, fullness, discomfort)
-> superior + inferior ganglia -> jugular foramen ->medulla

Question 12

CNX motor

Answer 12

axons from medulla to jugular foremen -> pharynx, larynx, soft palate (swallowing, vocalization, coughing)

Question 13

CNX autonomic

Answer 13

axons of autonomic motor neurons start in medulla and supply the lung, heart (cardiac), glands of the GI tract, smooth mm of respiratory passageways, esophagus, stomach, gallbladder, small intestine, most of large intestine

Question 14

injury to CNX

Answer 14

vagal paralysis
dysphagia
tachycardia

Question 15

CN XI

Answer 15

accessory nerve

motor nerve

Question 16

CNXI motor

Answer 16

motor axons from anterior grey horn of first 5 segments of c/spine (C1-C5) -> Ascend through foramen magnum -> exit through jugular foramen -> SCM + trapezium

Question 17

CN XI injury

Answer 17

Paralysis to SCM + Trapezius

Question 18

CNXII

Answer 18

Hypoglossal nerve (motor)

Question 19

CN XII motor

Answer 19

hypoglossal nucleus ->hypoglossal canal -> mm of tongue

Question 20

Injury to CN XII

Answer 20

difficulty chewing
dysarthria (slur speech)
dysphagia (swallow)
the tongue, when protruded, curls toward the affected side and that side atrophies

Question 21

Development of the nervous system

Answer 21

• begins in the 3rd week of gestation
• starts with a thickening of the ectoderm called the neural plate
• neural plate folds inward + forms a longitudinal groove, called the neural groove
• raised edges of neural plate are called neural folds
• as the whole thing grows it forms a tube (neural tube)

Question 22

layers of walls of neural tube

Answer 22

• outer/marginal layer cells = white matter of nervous system
• middle/mantle layer cells = gray matter
• inner/ependymal layer cells = lining of central canal (spinal cord) and ventricles of brain

Question 23

what is the mass of tissue between the neural tube and skin ectoderm?

Answer 23

Neural crest becomes posterior (dorsal) root ganglia of spinal nerves

• spinal nerves
• ganglia of cranial nerves
• cranial nerves
• ganglia of autonomic nervous system
• adrenal medulla
• meninges