Nerves/NERVOUS SYSTEM

Question 1

List the first 4 cranial nerves, numerically and by function

Answer 1

I. olfactory (sensory); smell
II. optic (sensory); sight
III. oculomotor (motor); eye/eyelid rotation and pupil size
IV. trochlear (motor); vertical eye movement

Question 2

List Cranial Nerves 5-8

Answer 2

V. trigeminal (both); chewing, facial sensations, scalp, cornea, teeth
VI. abducens (motor); eyeball movement
VII. facial (both); facial expression, salivation, taste, tearing, blinking (ie. bell’s palsy and motor arm of corneal reflex)
VIII. vestibulocochlear aka auditory (sensory); cochlear branch: hearing and vestibular branch: balance

Question 3

List Cranial Nerves 9-12

Answer 3

IX. glossopharyngeal (both); swallowing, gag/BP reflex, saliva secretion, taste
X. vagus aka “wanderer nerve” (both); inside of thoracic/abdominal organs & voice box, baroreceptor reflex
XI. accessory (motor); head movement, shoulder shrugging, swallowing
XII. hypoglossal (motor); speech/swallowing

Question 4

Define the Blood Barrier’s formation and function

Answer 4

It is formed by astrocytes; prevents harmful chemicals/waste products from entering brain but medications cant cross this barrier

Question 5

Explain the spinal cord’s function

Answer 5

it processes reflexes without brain involvement and provides the sensory pathway (periphery to brain), motor pathway (brain to periphery) and the reflex center (involuntary stim. response to external environment )

Question 6

Explain the spinal cord’s tracts

Answer 6

ascending : sensory (spinothalamic/dorsal column/spinocerebellar)
descending: motor (pyramidal/extrapyramidal)

Question 7

Where is the spinal cord located?

Answer 7

in the CNS extending from the foramen magnum to L1; the cervical, thoracic, and lumbar make up the vertebrae

Question 8

Will a lumbar puncture harm the spinal cord?

Answer 8

No, because the spine ends at L1 and spinal taps needles are inserted in the L3 and L4

Question 9

What is the phrenic nerve and its function?

Answer 9

stimulates diaphragm contraction which means if damaged, it will affect proper breathing (vent may be needed)

Question 10

Define the Hypothalamus’s function(s)

Answer 10

regulates body temp, water balance, metabolism etc; can have an effect on heart rate, BP, resps.

Question 11

where is the Hypothalamus’ located?

Answer 11

in the diencephalon which is between the L & R hemispheres

Question 12

What is the Medulla Oblongata and where is it found?

Answer 12

brain stem structure that relays sensory and motor info and controls heart rate, BP, and resps.; aka “vital center”; it is found at the end of the brainstem below the pons

Question 13

Define how the “left brain” or left hemisphere helps us

Answer 13

It is helps us with language, speech, analyzing external environment, mathematical abilities, and reasoning

Question 14

What is the axon and where can it be found?

Answer 14

A long extension of neuron (found in the CNS) that transmits signals away from the cell body

Question 15

What are some axon parts?

Answer 15

nodes of Ranvier: not covered by myelin, appear the myelinated axon intervals

Myelin sheath: fatty, white material insulating/protecting the the axon

Neurilemma: membrane-like material surrounding the axon

Question 16

Define a reflex

Answer 16

it is an involuntary response to a stimulus at the spinal cord’s level (spinal reflexes)

Question 17

Efferent vs. Afferent

Answer 17

afferent aka sensory neuron: impulse influenced from receptor along afferent to spinal cord

efferent aka motor neuron: impulse carried by efferent to a muscle

Question 18

What is the Sympathetic Nervous System and its indicators?

Answer 18

“fight or flight” response during confrontation or duress; pupil dilation, intestinal movement decrease, kidneys slow down (no pee), bronchodilation, increased resps. and BP, adrenaline rush

Question 19

What is the Parasympathetic Nervous System and its indicators?

Answer 19

“rest and digest” response during relaxation and rest; intestinal movement, voiding, regular resps and BP, sex,

Question 20

What are the receptors of the ANS divisions?

Answer 20

cholinergic: found in PNS and SNS and activated by ACh; nicotinic and muscarinic
adrenergic: found in SNS and bound by epi and norepinephrine; beta 1 and 2, alpha 1 (opens lungs, heart rate and BP increase)

Question 21

Where are sympathetic neurons located? where are parasympethetic neurons located?

Answer 21

SNS: neurons in thoracic and lumbar (organ supply via postganglionic neurons)
PNS: neurons found in craniosacral & stimulate cranial nerves/organs, ganglia (group of nerve cells) found parallel to spinal cord or near/in effector organ

Question 22

What are 2 neurotransmitters of the SNS?

Answer 22

ACh and noreipinephrine

Question 23

What is a ganglion?

Answer 23

group of nerve cell bodies linked by synapses, found between two neurons

Question 24

What are the ganglion components?

Answer 24

preganglionic fiber: neuron 1’s axon, comes before ganglion
postganglionic fiber: neuron 2’s axon (leaves/after the ganglion)

Question 25

True or False: postganglionic receptors for the PNS are muscarinic

Answer 25

True