Somato - CN 1

Question 1

Cranial nerve nuclei

Answer 1

Located in mesencephalon, metencephalon & myelencephalon
Sites of synapse for first order sensory neurons
Location of cell bodies for LMN

Question 2

Cranial nerve ganglia

Answer 2

Sensory ganglia
Autonomic ganglia

Question 3

Sensory ganglia

Answer 3

Sites of neuron cell bodies for first order sensory neurons (GSA & SSA)

Question 4

Autonomic ganglia

Answer 4

Sites for synapse for parasympathetic motor pathways

Question 5

Somatic efferent pathway

Answer 5

Coricobulbar tract
2 neurons
UMN in primary motor cortex
LMN in cranial nerve motor nucleus

Question 6

UMN somatic efferent pathway

Answer 6

Synapses in cranial nerve motor nucleus
Abt half of axons cross to the contralateral side

Question 7

LMN somatic efferent pathway

Answer 7

Synapses with skeletal muscle at neuromuscular junction

Question 8

Nerves involved in eye movement

Answer 8

III IV and VI
Oculomotor
Trochlear
Abducent

Question 9

Cranial nerve pathways - visceral efferent

Answer 9

Part of parasympathetic NS
Cranial nerves III, VII, IX, X
Each has its own parasympathetic nucleus in brainstem
Each has a ganglion near target organ

Question 10

Effects of III in visceral efferent pathways

Answer 10

Pupil constricts & cilliary muscle relaxes

Question 11

CN VII in visceral efferent pathways

Answer 11

Nasal, lacrimal, salivary glands secretion

Question 12

CN IX in visceral efferent pathways

Answer 12

Mouth waters, salivary gland secretes

Question 13

CN X in visceral efferent pathways

Answer 13

Heart slows down
Decreased blood flow to skeletal muscle
Increased blood flow to GI tract
Increased peristalsis to proximal colon

Question 14

Are there any sympathetic nerve fibers in cranial nerves?

Answer 14

No
Sympathetic nerves all arise form thoracic spinal cord
Sympathetic nerves do innervate structures in head but presynaptic neurons are in intermediolateral horn of thoracic spinal cord

Question 15

Effects of SNS

Answer 15

Pupil dilation
Cilliary body relaxation
Inhibition of gland secretion

Question 16

Cranial nerve pathways - general somatic afferent

Answer 16

CN V, VII, IX, X
Sensory information from the face, skeletal muscles, oral cavity, cornea, teeth
Each nerve has its own sensory ganglion

Question 17

First & second & third order neurons in somatic afferent paths

Answer 17

1st - sensory neurons synapse in trigeminal nuclei
2nd - cross and ascend to the thalamus (trigeminalthamalic)
3rd - ascend to primary sensory cortex

Question 18

CN Responsible for sensation in lips

Answer 18

Trigeminal nerve

Question 19

General visceral afferent

Answer 19

V - meninges
IX - rostral pharynx, middle ear, carotid body, meninges
X - caudal pharynx, larynx, meninges

Question 20

Pathway for GVA

Answer 20

Similar to GSA
Cell body in ganglion
Synapse in spinal trigeminal nucleus
2nd order neurons project to thalamus (trigeminothalamic)
3rd order neurons project to somatosensory cortex

Question 21

Special sense

Answer 21

Special somatic afferent
Special visceral afferent

Question 22

Special somatic afferent

Answer 22

Vision
Hearing and balance

Question 23

Special visceral afferent

Answer 23

Taste
Olfaction

Question 24

Nerve responsible for brain freeze

Answer 24

Glossopharyngeal

Question 25

Taste receptors

Answer 25

Special visceral afferent (located just in head) VII, IX, X Sweet, salty, bitter, sour, savory

Question 26

Taste receptors

Answer 26

Secondary sensory receptors 3 types of specialized receptors Grouped together, distributed in papillae on tongue

Question 27

Type 1 taste receptors

Answer 27

Salty - Na channels

Question 28

Type 2 taste receptors

Answer 28

Sweet, bitter, umami (g protein receptor activates Na channel)

Question 29

Type 3 taste receptor

Answer 29

Sour, H+ channel (depolarizes the cell)

Question 30

Taste pathways

Answer 30

CN VII, IX, X Cell bodies in sensory ganglia Synapse in nucleus of solitary tract 2nd order neurons project to the thalamus 3rd order neurons project to the gustatory cortex pathway DOES NOT cross midline

Question 31

2nd order taste pathway

Answer 31

Project into thalamus

Question 32

3rd order taste pathway

Answer 32

Project into the gustatory cortex

Question 33

Gustatory cortex

Answer 33

Located on the lateral frontal lobe Different tastes localized to specific areas Representation can change based on experience

Question 34

Comparative gustatory neurophys

Answer 34

dogs are not sensitive to salty taste Cats are taste blind to sweet Dogs have receptors that detect meat & fat Dogs & cats can taste water Cats have receptors for ATP in meat

Question 35

# of tastebuds in dogs and cats

Answer 35

Dogs - 1700 Cats - 470

Question 36

Cranial nerve I

Answer 36

Olfactory Arises from telencephalon Smell

Question 37

Criteria for orderants

Answer 37

Volatile - high vapor pressure Capable of binding a receptor in nose Water & high lipid soluble