Module 3

Question 1

What do the nervous system do?

Answer 1

Coordinates voluntary and involuntary actions and transmits signals to and from different parts of the body

Question 2

What does afferent mean?

Answer 2

Carrying information towards the CNS (sensory)

Question 3

What does efferent mean?

Answer 3

Carrying information away from the CNS (somatic and autonomic)

Question 4

What are the two divisions of the nervous system?

Answer 4

PNS and CNS

Question 5

What makes up the CNS?

Answer 5

brain and spinal cord

Question 6

What makes up the PNS?

Answer 6

Nerve tissue outside the CNS (cranial nerves and branches, spinal nerves and branches, ganglia)

Question 7

What is a neuron?

Answer 7

basic signaling units of the nervous system

Question 8

What are glia?

Answer 8

Support cells known to communicate with neurons and provide biochemical support

Question 9

Which part of the neuron receives incoming signals from neighboring cells?

Answer 9

Dendrites

Question 10

Which part of the neuron carries outgoing signals from the integrating center?

Answer 10

Axon

Question 11

What is the control center of the neuron?

Answer 11

Soma (cell body)

Question 12

What is the name of the region where an axon terminal communicates with its postsynaptic target cell?

Answer 12

Synapse

Question 13

What is a nerve?

Answer 13

A bundle of peripheral neurons

Question 14

Why cant the axon produce proteins?

Answer 14

It lacks ribosomes and ER, proteins are produced in the soma and transported down the axon

Question 15

If a substance was being transported toward the cell body, what is this called?

Answer 15

Retrograde transport

Question 16

If a substance was being transported away from the cell body, what is this called?

Answer 16

Anterograde transport

Question 17

Kinesins are an example of ___ transport, and dynein’s are an example of ___ transport.

Answer 17

Anterograde (move toward + charge), Retrograde (move toward - charge)

Question 18

The space containing extracellular matrix that holds the pre and post synaptic cells is called ____.

Answer 18

Synaptic cleft

Question 19

What is the moto that synapses tend to go by?

Answer 19

Use it or lose it

Question 20

What is myelin?

Answer 20

Layers of phospholipid membrane wrapped around an axon

Important in structural stability of axon, insulation of axon and speeding up electrical signals

Question 21

Which glial cell produces myelin the CNS, and which glial cell produces myelin the PNS?

Answer 21

CNS: Oligodendrocytes
PNS: Schwann cells

Question 22

Which disorder results from demyelination in the CNS?

Answer 22

MS

Question 23

What are the 6 types of glial cells and their functions?

Answer 23

Oligodendrocytes: myelin producers in CNS
Schwann cells: myelin producers in PNS
Satellite: supportive capsule around cell bodies of neurons (PNS)
Astrocytes: take up and release chemicals at synapses, provide neurons with substrate, main ECF homeostasis, surrounds vessels (CNS)
Microglia: CNS immune cells
Ependymal: line cerebrospinal fluid, circulate cerebrospinal fluid

Question 24

What types of diseases are likely to occur if microglia remain activated past a certain time period or pass a certain threshold?

Answer 24

Alzheimer’s, ALS

Question 25

Which division of the nervous system is more likely to repair neurons and why?

Answer 25

PNS. Schwann cells create a tube to guide the regenerating axon

Question 26

What does the Nernst equation describe?

Answer 26

Describes the membrane potential that would result if the membrane were completely permeable to only one ion

Question 27

What does the Goldman-Hodgkin-Katz equation describe?

Answer 27

Predicts the membrane potential that results from the contribution of all ions that can cross the membrane

Question 28

What alters membrane potential?

Answer 28

Change in K+ concentrations or change in permeability to ions (Na+, K+, Ca2+, Cl-)

Question 29

The ease with which ions flow through a channel is known as ___.

Answer 29

the channels conductance

Question 30

Which gated channel opens in response to physical forces and is found in sensory neurons? a) Voltage-gated b) Mechanically-gated c) Chemically-gated

Answer 30

b) mechanically-gated

Question 31

Which gated channel responds to ligands? a) voltage b) mechanical c) chemical

Answer 31

c) chemical

Question 32

which gated channel responds to changes in the cells membrane potential? a) voltage b) mechanical c) chemical

Answer 32

a) voltage

Question 33

A mutation in a channel is called ____. What can this mutation do to the channel?

Answer 33

Alter permeation Change channel activation Change channel inactivation

Question 34

What conditions can result from channelopathies?

Answer 34

cystic fibrosis, muscle disorders, congenital insensitivity to pain

Question 35

What are the two sources of resistance in a cell?

Answer 35

membrane resistance | internal resistance of cytoplasm

Question 36

What determines how far current will flow in a cell before the energy is dissipated?

Answer 36

Resistance

Question 37

What is a graded potential?

Answer 37

Electrical signal that travel over short distances and lose strength as they travel

Question 38

What induces an action potential?

Answer 38

a graded potential large enough that causes a large depolarization

Question 39

What is an action potential?

Answer 39

brief, large depolarization that travel for long distances without losing strength (rapid signal over long distance)

Question 40

Where do graded potentials typically occur? | Where do action potentials typically occur?

Answer 40

GP: soma+dendrites AP: axon

Question 41

What generates the graded potential?

Answer 41

Chemically gated ion channels or closure of leak channels

Question 42

What causes graded potential to lose strength as they travel through the cell?

Answer 42

Leak channels | Cytoplasmic resistance

Question 43

Which part of the neuron must a graded potential reach to initiate an action potential?

Answer 43

trigger zone (axon hillock)

Question 44

Why is the movement of an action potential dominoes-like?

Answer 44

The movement of an AP results in sequential opening of voltage gated ion channels in each adjacent area of the axon creating a uniform depolarization

Question 45

The movement of AP along an axon is referred to as ___.

Answer 45

Conduction