Exam 1

Question 1

What is most directly responsible for the falling (repolarizing) phase of the AP?

Answer 1

There permeability of K+ increases greatly while that to Na+ decreases

Question 2

What would occur if the concentration of ATP were depleted in a typical nerve cell?

Answer 2

Resting membrane potential would become less negative

Question 3

Acetylcholine is the main neurotransmitter released by:

Answer 3

Preganglionic sympathetic neurons and motor neurons

Question 4

An action potential in a neuronal membrane differs from a graded potential in that:

Answer 4

an action potential is propagated without decrement whereas a graded potential decrements with distance

Question 5

A threshold stimulus applied to a excitable membrane is one that is just sufficient to

Answer 5

Trigger an action potential

Question 6

A presynaptic synapse:

Answer 6

is any synapse between an axon terminal and another axon’s terminal that can be either excitatory or inhibitory

Question 7

What is true about the initial segment of an axon

Answer 7

Its threshold potential is more negative than that of the cell body and dendrites

Question 8

What is the major inhibitory neurotransmitters in the CNS

Answer 8

Gamma-aminobutyric acid

Question 9

Alzheimer’s disease is thought to involve primarily

Answer 9

Loss of cholinergic neurons

Question 10

T or F? The absolute refractory period of an excitable membrane roughly corresponds to the period when sodium channels are opening and inactivated

Answer 10

True

Question 11

The diffusion potential due to the concentration gradient for Na+ across a nerve cell membrane

Answer 11

favor its movement into the cell at the resting membrane potential

Question 12

Ependymal Cells

Answer 12

CNS

Producing CSF

Question 13

Microglia

Answer 13

CNS

Remove debris

Question 14

Oligodendrocytes

Answer 14

CNS

Myelinate CNS axons

Question 15

Astrocytes

Answer 15

CNS

Maintain BBB

Question 16

Schwann cells

Answer 16

PNS
Surrond axons in PNS;
Myelinate

Question 17

Satellite Cells

Answer 17

Surrond neuron cell bodies in ganglia

Question 18

Absolute refractory period

Answer 18

No stimulus of any strength can produce action potential due to inactivation of Na+ channels

Question 19

Relative Refractory Period

Answer 19

Strong stimulus can produce another action potential but with a smaller amplitude

Question 20

Depolarizing

Answer 20

becomes more positive

Question 21

Repolarizing

Answer 21

becomes more negative (back to resting potential)

Question 22

Hyperpolarizing

Answer 22

Refractory period where no new AP can be generated

Question 23

EPSP

Answer 23

Transient postsynaptic membrane depolarization by presynaptic release of neurotransmitter
*ACh and glutamate-gated channels

Question 24

IPSP

Answer 24

Transient hyper polarization of postsynaptic membrane potential caused by presynaptic release of neurotransmitter
*glycine and GABA-gated channels

Question 25

Olfactory pathways

Answer 25

Nose directly to the cortex

Question 26

Equilibrium Pathways

Answer 26

project to the cerebellum with a branch to the cortex via the thalamus

Question 27

All other pathways

Answer 27

pass through the thalamus before they project to their relevant cortical area

Question 28

Isometric

Answer 28

Constant Muscle Length

Question 29

Isotonic

Answer 29

Constant tension after transitional period