Cranial Nerves ppt 16

Question 1

Mnemonic for the cranial nerves

Answer 1

Oh once one takes the anatomy final very good vacations are heavenly

Question 2

What are the corticobulbar fibers?

Answer 2

serve as the source of upper motor neuron innervation of lower motor neurons in cranial nerve nuclei

Question 3

What cranial nerve and muscles have corticobulbar innervation?

Answer 3

• Muscles of mastication (CN V)
  • Muscles of facial expression (CN VII) - (partially bilateral)
  • Palate, pharynx, and larynx (CN X)
  • Tongue (CN XII)
  • Sternocleidomastoid and trapezius muscles (CN XI)

Question 4

CNI - Olfactory

Answer 4

Function: Smell

Origin: Olfactory bulb- cribriform plate-olfactory epithelium

Damage: Anosmia

Question 5

CNII- Optic

Answer 5

Function: Vision

Origin: Retina-optical canal-optic chiasma- thalamus

Damage: Blindness, anopsias, papilledema, optic atrophy

Question 6

CNIII- Oculomotor

Answer 6

Function: Movements of eye.

Origin: ventral midbrain- orbital fissures- eye

Damage: Eye rotates down and out. Ptosis. double vision

Question 7

Eye Movement Mnemonic

Answer 7

LR6 SO4 AO3

Question 8

Fibers of CNIII

Answer 8

• Somatic motor fibers to four of the six extrinsic eye muscles (inferior oblique and superior, inferior, and medial rectus muscles)
• Parasympathetic (autonomic) motor fibers to sphincter pupillae, and to ciliary muscle, controlling lens
• Sensory (proprioceptor) afferents

Question 9

CNIV- Trochlear

Answer 9

Function: Superior oblique muscle

Origin: Midbrain-orbital fissure- eye

Damage: Double vision. Cannot move eye down and out

Question 10

CNV1- Trigeminal Ophthalmic division

Answer 10

Function: Sensory forehead and eyes

Origin: Pons- orbital fissure- face

Question 11

CNV2- Trigeminal Maxillary

Answer 11

Function: Sensory Checkbones, nose

Origin: Pons- Forament rotundum- face

Question 12

CNV3- Trigeminal Mandibular

Answer 12

Function: Sensory jaw chin (ant. 2/3 tongue touch). muscle of mastication

Origin: through the foramen ovale

Question 13

Trigeminal Neuralgia

Answer 13

painful afflictions known caused by a disorder of the fifth cranial (trigeminal) nerve.

Question 14

CNVI- Abducens

Answer 14

Functions: Lateral Rectus Muscle

Origin: Pons-supirior orbital fissure- eye

Damage: eye rotates medially

Question 15

CNVII- Facial

Divisions

Answer 15

Temporal
Zygomatic
Buccal
Mandibular
Cervical

Question 16

CNVII- Facial

Answer 16

Function: muscles of facial expression. Tears
TASTE ant 2/3 taste

Origin: Pons-internal acoustic meatus- face

Question 17

CNVII Facial

Innervation

Answer 17

• Corticobulbar innervtion of facial motorneurons to muscles of the upper face is bilateral.
• Muscles of the mouth, is only contralateral only.

Question 18

Bell’s palsy

Answer 18

Paralysis or severe weakness of the nerve that controls the facial muscles on the side of the face

Eyelid droops
corner of mouth sags dry-eye syndrome

Question 19

CNVIII- Vestibulocochlear

Answer 19

Function: vest- equilibrium. cochlear- hearing

Origin: pons medulla border- internal acoustic meatus, inner ear

Damage: deafness, nystagmus, nausea, vertigo

Question 20

CN IX- glossopharyngeal nerve

Answer 20

Function: (post 1/3 touch and taste) Tongue and pharynx

Origin: Medulla- jugular foramen- throat.

Damage: impair swallowing and taste.

Question 21

CNX Vagus

Answer 21

Function: a lot

Origin: Medula- jugular foramen- neck- thorax and abdomen

Damage: hoarseness or mute, difficulty swallowing and impaired digestive system motility.

Question 22

CNXI Accessory

Answer 22

Function: Trap and SCM

Origin: Spinal cord- foramen magnum- jugular foramen- back and neck

Damage: Head trun to injury side, no shrugging

Question 23

CNXII Hypoglossal

Answer 23

Function: Motor tongue

Origin: medulla- hypoglossal canal- tongue

Damage- tongue deviation to affected side.