Question 1

How far do most postsynaptic potentials travel before they die out.

Accepted Answer

A)  to the axon hillock 
B)  to the terminal buttons 
C)  no more than a couple of millimeters 
D)  about 50 millimeters 
E)  both B and D

Question 2

Na+ ions are encouraged to move into neurons by

Accepted Answer

A)  nonrandom assignment. 
B)  electrostatic pressure. 
C)  the sodium-potassium pump. 
D)  selective ion channels. 
E)  nonrandom movement.

Question 3

Discuss the synthesis, packaging, transport, and release of conventional small and large types of neurotransmitters.

Accepted Answer

The answer of Discuss the synthesis, packaging, transport, and release...

Question 4

Pump mechanisms in the cell membrane of neurons pump __________ ions out of the neuron to maintain the membrane potential.

Accepted Answer

The answer of Pump mechanisms in the cell membrane of...

Question 5

Second messengers are formed in the

Accepted Answer

A)  presynaptic neuron. 
B)  postsynaptic neuron. 
C)  synaptic cleft. 
D)  vesicles. 
E)  mitochondria.

Question 6

After a neuron fires, the resting potential is re-established by the

Accepted Answer

A)  sodium-potassium pump. 
B)  random movement of ions. 
C)  refractory period. 
D)  electrostatic gradient. 
E)  EPSPs.

Question 7

Ionotropic receptors are linked to

Accepted Answer

A)  ribosomes. 
B)  neurotransmitters. 
C)  ligand-activated ion channels. 
D)  vesicles. 
E)  G proteins.

Question 8

Nitric oxide

Accepted Answer

A)  is a soluble gas neurotransmitter. 
B)  is considered to be an unconventional neurotransmitter. 
C)  participates in retrograde synaptic transmission. 
D)  all of the above 
E)  both A and B

Question 9

Sodium-potassium pumps are

Accepted Answer

A)  integrators. 
B)  refractory. 
C)  transporters. 
D)  excitatory. 
E)  inhibitory.

Question 10

With respect to the maximum speed of axonal conduction in motor neurons, cats are to humans as

Accepted Answer

A)  50 is to 100 meters per second. 
B)  80 is to 100 meters per second. 
C)  25 is to 100 meters per second. 
D)  82 is to 100 meters per second. 
E)  100 is to 60 meters per second.

Question 11

Nondirected synapses

Accepted Answer

A)  involve the release of neurotransmitter molecules diffusely into the extracellular fluid. 
B)  include string-of-beads synapses. 
C)  involve the movement of neurotransmitter molecules across gap junctions. 
D)  both A and B 
E)  both B and C

Question 12

The brief period of time immediately after the initiation of an action potential when it is absolutely impossible to initiate another one in the same neuron is called the

Accepted Answer

A)  threshold of excitation. 
B)  threshold of inhibition. 
C)  absolute refractory period. 
D)  IPSP. 
E)  relative refractory period.

Question 13

Neuropeptides are synthesized in the cell body on

Accepted Answer

A)  ribosomes. 
B)  the Golgi complex. 
C)  vesicles. 
D)  mitochondria. 
E)  microtubules.

Question 14

Which neurotransmitters are often released from string-of-beads axons?

Accepted Answer

A)  monoamines 
B)  amino acids 
C)  glutamate and GABA 
D)  soluble gases 
E)  peptides

Question 15

The one enzyme whose function is to deactivate a specific neurotransmitter once it has been released into the synapse is

Accepted Answer

A)  dopamine. 
B)  L-DOPA. 
C)  acetylcholine. 
D)  acetylcholinesterase. 
E)  a G protein.

Question 16

By binding to nicotinic cholinergic receptors, this drug produces paralysis and death:

Accepted Answer

A)  atropine. 
B)  chlordiazepoxide. 
C)  curare. 
D)  morphine. 
E)  belladonna.

Question 17

By binding to nicotinic receptors, __________ produces paralysis and death, which is why it is used on poison darts.

Accepted Answer

The answer of By binding to nicotinic receptors, __________ produces...

Question 18

Neurotransmitter molecules are often packaged in vesicles by

Accepted Answer

A)  Golgi complexes. 
B)  ribosomes. 
C)  buttons. 
D)  peptides. 
E)  microtubules.

Question 19

The end of the rising phase of an action potential occurs when the

Accepted Answer

A)  sodium channels close. 
B)  sodium channels open. 
C)  potassium channels open. 
D)  potassium channels close. 
E)  both A and D

Question 20

In neurons without axons, conduction occurs entirely in the form of

Accepted Answer

A)  passive, decrementally conducted potentials. 
B)  action potentials. 
C)  all-or-none potentials. 
D)  saltatory conduction. 
E)  excitation.

Exam 4: Neural Conduction and Synaptic Transmission