Nervous System

Question 1

Functions of the NS

Answer 1

• sensory receptors monitor changes in and out of the body
• processes and interprets sensory input
• dictates a response by activating effector organs

Question 2

Afferent vs efferent

Answer 2

A- sensory signals picked up by sensory receptors

E- motor signals are carried away from the CNS

Question 3

Somatic body region vs visceral

Answer 3

S- structures external to the ventral body cavity

V- viscera within the ventral body cavity

Question 4

4 subdivisions of the PNS

Answer 4

somatic sensory
visceral sensory
somatic motor
visceral motor

Question 5

What are the general somatic senses? (somatic sensory division)

Answer 5

receptors are widely spread throughout

-touch, pain, temp, proprioceptive senses

Question 6

What are the special somatic senses? (somatic sensory division)

Answer 6

receptors are confined to small area

-hearing, balance, vision

Question 7

What are the general visceral senses? (visceral sensory)

Answer 7

• stretch, pain, temp, nausea, hunger

- felt in digestive and urinary tracts and reproductive organs

Question 8

What are the special visceral senses? (visceral sensory)

Answer 8

-taste, smell

Question 9

What is the role of the somatic motor division?

Answer 9

signals contraction of skeletal muscle

-voluntary control

Question 10

What is the role of the visceral motor division?

Answer 10

• regulates contraction of smooth and cardiac muscle

- controls function of visceral organs

Question 11

What makes up the ANS?

Answer 11

the visceral motor division of the NS

Question 12

What are the 2 cell types that make up nervous tissue?

Answer 12

neurons- transmit electrical signals

neuroglia- support cells (4 in CNS, 2 in PNS)

Question 13

What are the special characteristics of a nerve cell/ neuron?

Answer 13

Longevity
Do not divide- neural stem cells are an exception
High metabolic rate- require abundant O2 and glucose

Question 14

How long does it take a neuron to die without O2?

Answer 14

5 minutes

Question 15

Role of dendrites?

Answer 15

• increase SA for receiving synaptic communication

- transmit electrical signal towards the cell body

Question 16

Axons transmit impulses _______ the cell body

Answer 16

away from

Question 17

How does axon diameter affect the conduction of impulses?

Answer 17

larger diameter= faster impulses

smaller diameter= more resistance= slower impulses

Question 18

What are the most abundant type of neuron?

Answer 18

multipolar

Question 19

What neurons make up majority of sensory neurons?

Answer 19

unipolar

Question 20

Sensory (afferent) neurons transmit impulses _______ the CNS

Answer 20

toward

Question 21

Motor (efferent) neurons transmit impulses _______ the CNS ____ the effector organ

Answer 21

away from

to

Question 22

Most motor neurons are _____polar

Answer 22

multi

Question 23

What are interneurons?

Answer 23

association neurons

• multipolar
• btwn. sensory and motor
• confined to CNS

Question 24

Satellite cells vs. schwann cells

Answer 24

surround neuron cell bodies within ganglia

surrounds axons in the PNS to form myelin sheaths

Question 25

What cells wrap multiple cell processes around different axons in the CNS to produce myelin sheaths?

Answer 25

Oligodendrocytes

Question 26

Function of bear cilia?

Answer 26

help circulate CSF | -located on ependymal cells

Question 27

What cells increase blood flow to active regions of the brain and take up/ release ions to control environment?

Answer 27

Astrocytes

Question 28

MS is when the immune system attacks __________ in the ______

Answer 28

myelin sheaths | CNS

Question 29

Endoneurium? Perineurium? Epineurium?

Answer 29

endo- surrounds axon peri- surrounds fascicle of axons epi- surrounds whole nerve

Question 30

Afferent PNS fibres (nerves) respond to ______ and carry info ______ the CNS

Answer 30

sensory stimuli | to

Question 31

Efferent PNS fibres (nerves) transmit _______ from the CNS to ______ and _______

Answer 31

motor stimuli | glands and muscles

Question 32

Nerves of the CNS are composed of ________

Answer 32

interneurons

Question 33

Monosynaptic reflex

Answer 33

- simplest and fastest | - knee jerk

Question 34

Polysynaptic reflex

Answer 34

-withdrawal reflex | single interneuron btwn. motor and sensory

Question 35

How does neuronal regeneration occur?

Answer 35

- in the PNS, macrophages invade and destroy the axon distal to the injury - axon filaments grow peripherally from the injury site - in the CNS, neuroglia never form bands to guide regrowing axons - no effective regeneration to spinal cord and brain

Question 36

Where are sensory, motor, and interneurons located?

Answer 36

dorsal ventral central