Lecture 5 PQs

Question 1

True or False: CN are peripheral nerves

Answer 1

True

Question 2

What type of neurons are the motor branches on the CN?

Answer 2

multipolar

Question 3

What type of neurons are the somatosensory branches on the CN?

Answer 3

pseudounipolar

Question 4

What type of neurons are the special sensory on the CN most of the time?

Answer 4

bipolar

Question 5

What are the layers of a peripheral nerve from out to in? What do they consist of in each layer?

Answer 5

(OUT)Epineurium- groups of fascicles; contains blood vessels
Perineurium- groups of axons
(IN) Endoneurium- nerve fiber

Question 6

Which CNs have both sensory and motor pathways?

Answer 6

CN V, VII, IX, X

Question 7

Where can the olfactory sensory receptor cells be located?

Answer 7

Olfactory Epithelium

Question 8

What is the function of basal stem cells in the olfactory epithelium?

Answer 8

regulate new olfactory receptors

Question 9

How does CN 1 get through the skull to the olfactory bulb in the sensory pathway?

Answer 9

via small foramina aka cribriform plate

Question 10

What are the cortices that the olfactory tract project to?

Answer 10

amygdala, entorhinal cortex, hippocampus, prefrontal cortex, insula, temporal lobe

Question 11

Which CNs open and close the lids?

Answer 11

open lids- CN 3

Close lids-CN 7

Question 12

What structures are in the fibrous outer layer?

Answer 12

sclera and cornea

Question 13

What structures are in the vascular middle layer?

Answer 13

choroid, ciliary body, and iris

Question 14

What structures/layers are in the retinal inner layer?

Answer 14

7 layers:
pigment epithium -> photoreceptor layer (contains rods and cones)-> outer and inner nuclear layers-> outer and inner synaptic layers->ganglion cell layer
Other structures:
optic disc and macula lutea

Question 15

what is the function of the lens?

Answer 15

to bend light to focus on image on retina

Question 16

Where is the vitreus body/humor located?

Answer 16

between lens and retina

Question 17

What is in the anterior cavity of the eye?

Answer 17

aqeuous humor- filters plasma and nourishes lens and cornea

Question 18

In the optic pathway, where do the neurons end following the synapse of 2nd neuron and before the 3rd neuron synapse?

Answer 18

majority terminate at lateral geniculate of thalamus

minority travel to superior colliculus and pretectal nucleus in midbrain

Question 19

F/u question from previous question; after the superior colliculus and pretectal nucleus, where do the nerves travel to next?

Answer 19

superior colliculus -> primary and supplementary visual areas and numerous brainstem areas
pretectal nucleus-> primary and supplementary visual areas and parasympathetic nuclei controlling pupils

Question 20

Right visual field input

Answer 20

Left temporal and right nasal retinal input

Question 21

Left visual field

Answer 21

Right temporal and left nasal retinal input

Question 22

Left primary visual cortex

Answer 22

Right visual field

Question 23

Right primary visual cortex

Answer 23

Left visual field

Question 24

Oculumotor innervates what eye muscles? What are their actions?

Answer 24

Medial rectus - adduction
Superior rectus- elevation and intorsion
Inferior rectus-depression and extorsion
inferior oblique- extorsion and elevation

Question 25

Trochlear innervates what eye muscles? What are their actions?

Answer 25

Superior oblique - intorsion and depression

Question 26

Abducens innervates what eye muscles? What are their actions?

Answer 26

lateral rectus - abduction

Question 27

What muscles are in the superior and inferior divisions of the Oculomotor pathway?

Answer 27

Superior: superior rectus and levator palpebrae Inferior: inferior rectus medial rectus and inferior oblique

Question 28

Which regions does the somatosensory branch of V1 trigeminal nerve bring sensation to?

Answer 28

forehead, upper eyelid, cornea, nose

Question 29

Which regions does the somatosensory branch of V2 trigeminal nerve bring sensation to?

Answer 29

lower eyelid, cheeks, temples, upper lip region, and upper teeth

Question 30

Which regions does the somatosensory branch of V3 trigeminal nerve bring sensation to?

Answer 30

part of external ear, lower lip, chin, anterior 2/3 of tongue, lower teeth

Question 31

In the motor pathway what muscles does the mandibular branch of CN V innervate?

Answer 31

masseter, temporalis, medial and lateral pterygoid muscles and tensor tympani

Question 32

motor trigeminal nuclei

Answer 32

gives rise to efferent to muscles of mastication

Question 33

principle sensory trigeminal nuclei aka main sensory nuclei

Answer 33

afferent to discriminate touch, light touch, proprioception to face, and dental pressure

Question 34

mesencephalic trigeminal nuclei

Answer 34

afferent proprioception to jaw

Question 35

spinal trigeminal nuclei

Answer 35

afferent crude touch, pain, temperature of face

Question 36

5 major branches to muscles of facial expression

Answer 36

temporal, zygomatic, buccal, mandibular, and cervical

Question 37

what reflex would cause bilateral eye blinking? what cranial nerves are involved?

Answer 37

corneal reflex; CN V and IV

Question 38

what reflex functions to prevent aspiration of solid foods? what cranial nerves are involved?

Answer 38

gag reflex; CN IX and X