Chap 4 - Nervous System

Question 1

appendages that receive signals from other cells

Answer 1

Dendrites

Question 2

where the cell body transitions to the axon, and where action potentials are initiated

Answer 2

Axon hillock

Question 3

occurs via neurotransmitter release from the presynaptic cell and the binding of these neurotransmitters to the postsynaptic cell

Answer 3

Chemical communication

Question 4

occurs via ion exchange and generation of membrane potentials down length of the axon

Answer 4

Electrical communication

Question 5

highly specialized cells responsible for conduction of impulses

Answer 5

Neurons

Question 6

long appendage down which an action potential travel

Answer 6

Axon

Question 7

location of the nucleus as well as organelles such as the endoplasmic reticulum and ribosomes

Answer 7

Soma

Question 8

is the end of the axon from which neurotransmitters are released

Answer 8

Synaptic bouton

Question 9

are exposed areas of myelinated axons that permit saltatory conduction

Answer 9

Nodes of Ranvier

Question 10

consists of the nerve terminal of the presynaptic neuron, the membrane of the postsynaptic cell, and space between the two

Answer 10

Synapse

Question 11

space between the nerve terminal of the presynaptic neuron and the membrane of the postsynaptic cell

Answer 11

Synaptic cleft

Question 12

An insulating substance that prevents signal loss and coats many axons

Answer 12

Myelin

Question 13

create myelin in the CNS

Answer 13

Oligodendrocytes

Question 14

create myelin in the PNS

Answer 14

Schwann cells

Question 15

formed by bundle of multiple neurons in the PNS

Answer 15

nerves

Question 16

formed by bundle of multiple axons in the CNS

Answer 16

tracts

Question 17

Mass of INDIVIDUAL neuron cell bodies w/in a tract in the CNS

Answer 17

nuclei

Question 18

Mass of neuron cell bodies of the same type w/in a nerve in the PNS

Answer 18

ganglia

Question 19

Cells that support neurons; includes Astrocytes, microglia, etc.

Answer 19

Glial Cells

Question 20

Nourish neurons and form blood-brain barrier, which controls transmission of solutes from bloodstream into nervous tissue

Answer 20

Astrocytes

Question 21

line the ventricles of the brain and produce cerebrospinal fluid, which physically supports the brain and serves as a shock absorber

Answer 21

Ependymal cells

Question 22

Phagocytic cells that ingest and break down waste products and pathogens in the CNS

Answer 22

Microglia

Question 23

neural structure that initiates the action potential

Answer 23

axon hillock

Question 24

What maintains resting membrane potential and what is the approximate voltage

Answer 24

Na+/Ka+ ATPase and -70mV

Question 25

continuously pumps potassium into the cell and sodium out of the cell

Answer 25

Na+/Ka+ ATPase

Question 26

cause depolarization of the neuron

Answer 26

excitatory signals

Question 27

cause polarization of the neuron

Answer 27

inhibitory signals

Question 28

integration of multiple signals near each other in time

Answer 28

temporal summation

Question 29

addition of multiple signals near each other in space

Answer 29

spatial summation

Question 30

is used to propagate signals down to the axon

Answer 30

action potential

Question 31

Value at which action potential is triggered if axon hillock receives enough excitatory input to be depolarized

Answer 31

threshold voltage

Question 32

strong ______ promotes migration of sodium into cell

Answer 32

electrochemical gradient

Question 33

Restoration of the resting membrane in neurons from being depolarized by active and passive processes

Answer 33

repolarization

Question 34

raising membrane potential, Vm, from its resting potential

Answer 34

depolarization

Question 35

lowering membrane potential, Vm, from its resting potential

Answer 35

hyperpolarization

Question 36

Window where axon is hyperpolarized

Answer 36

refractory period

Question 37

Window where cell requires a larger than normal stimulus to fire an action potential

Answer 37

relative refractory period

Question 38

Window where cell is unable to fire another action potential

Answer 38

absolute refractory period

Question 39

Ion responsible for fusion of neurotransmitter vesicles with the nerve terminal membrane

Answer 39

Calcium

Question 40

Enzymatic degradation, reuptake or diffusion results in:

Answer 40

halting of neurotransmitter’s action

Question 41

Sodium channel opens first at ___ mV; is regulated by _____ and causes ____

Answer 41

-50; inactivation; depolarization

Question 42

Potassium channel opens second at ___ mV; is regulated by _____ and causes ____ then ____

Answer 42

+35; closing at low potentials; repolarization then hyperpolarization

Question 43

______ neurons Ascend in the spiral cord toward the brain
______ neurons Exit the spinal cord on their way to the rest of the body

Answer 43

Afferent
Efferent