ppt 2 brain and CNS (Cranial nerves)

lachimolala

afferent fibers are_____ fibers, that carry information away or toward brain?

afferent fibers are sensory fibers, that carry information toward the brain

efferent fibers are____ fibers, that carry information away or toward brain?

efferent fibers are motor fibers, that carry information away from the brain

which of the 12 cranial nerves are only afferent (sensory) (3) what is each responsible for?

• Olfactory I- smell/olfaction

• Optic II- vision

• Vestibulocochlear VIII-hearing/balance

which of the 12 cranial nerves are only efferent (motor) (5) what is each responsible for?

• oculomotor III- most eye movement

• trochlear IV- superior oblique eye muscle

• abducens VI- lateral eye movement (external rectus)

• spinal accessory XI- trapezius +sternocleidomastoid

• hypoglossal XII- tongue movement

which of the 12 cranial nerves are only BOTH afferent and efferent (4) what are they responsible for?

• trigeminal V- facial sensation, chewing, teeth, sinsuses

• facial VII — muscles of facial expression; taste anterior tongue; salivary/lacrimal glands

• glossopharyngeal IX——swallowing (pharyngeal muscules); taste posterior tongue 1/3; sensation tongue/pharynx

• Vagus X- motor to pharynx/larynx, sensory ro heart lungs bronchi and GI tract

where does the olfactory nerve leave the cranium

cribiform plate

where does the optic nerve leave the cranium

optic canal

what nerves leave the superior orbital fissue (4)

• oculomotor III

• trochlear IV

• abducens VI

• opthalamic V1

the maxillary nerve V2 leaves the cranium via

foramen rotundum

the Mandibular nerve leaves cranium via

foramen ovale

which nerves leave internal acoustic meatus

• Facial VII

• Vestibulocochlear VIII

which nerves leave via the jugular foramen

• glossopharngeal IX

• Vagus X

• spinal accessory XI

the Hypoglossal nerve XII leaves cranium via

hypoglossal canal

why is the spinal accessory nerve unique (1) where does it enter and exit cranium(2) what muscles does it innervate(3)

1. the spinal accessory nerve is unique because it originates is spinal nerve rootlets c1-c6 and medulla. Unlike most nerves originating from brain stem

2. it enters cranium through foramen magnum and exits through jugular foramen

3. innervates sternocleidomastoid muscle and trapezius

what are the types of fiber classifications for cranial nerves ? (6)

1.Somatomotor

2.Visceromotor

3.Somatosensory

4.Viscerosensory

5.Specialsensory - special sense organs (vision, hearing/balance, smell and taste)

6.Pharyngeomotor (pharngeal arch)

Somatomotor nerves innervate ____ muscles derived from ______ of the head

ex.? (2)

Somatomotor nerves innervate skeletal muscles derived from somites of the head

ex. 1.Extrinsic eye muscles

2. Muscles of the tongue

what are extrinsic eye muscles? are they voluntary? pharyngeal arch derived? what 3 nerves innervate them?

1. extrinsic eye muscles are muscles outside the eyeball that move the eye

2. extrinsic eye muscles are voluntary

3. SOMITE derived

4. extrinsic eye muscles are innervated by

• Oculomotor nerve III

• Trochlear nerve IV

• Abducens nerve VI

muscles of the tongue are innervated by which nerve? voluntary or involuntary? somite or pharyngeal arch derived?

• muscles of the tongue are innervated by hypoglossal nerve XII

• voluntary

• somite derived

pharengeomotor nerves innervates muscles derived from _____ arches give an example of a muscle with this innervation and example of a nerve with this fiber type

• pharngeal arches

• stylopharyngeous

• glossopharyngeal n

does sensory mean the same as afferent or efferent?

afferent

does motor mean the same as afferent or efferent

efferent

What does the dorsal hollow nerve cord develop into? It is a structure from what stage of human development?

Brain & spinal cord (central nervous system)

Embryonic structure

The notocord is replaced by____

What does it do?

Replaced by vertebral column

The notocord supports development