bio 212

Question 1

what is the opening of too few sodium channels for generating the sodium-channel positive feedback loop considered?

Answer 1

subthreshold stimulus

Question 2

parkinson’s disease appears to target ____ cells within ____

Answer 2

dopaminergic; basal nuclei

Question 3

where is the cell body for a preganglionic sympathetic neuron?

Answer 3

in the lateral horn of the spinal cord

Question 4

at the neuromuscular junction, which step happens LAST when an action potential reaches the axon terminal?

Answer 4

acetylcholine binds with receptors on the motor end plate

Question 5

which of the following is NOT a mechanism to remove calcium from the cytoplasm of smooth muscle cells?

Answer 5

calcium-induced calcium release channels in the sarcoplasmic reticulum

Question 6

if hypokalemia persists in the body,

Answer 6

the cell membrane would be hyperpolarized compared to normal resting membrane potential, resting membrane potential would be closer to threshold than normal

Question 7

in response to stepping on a nail, the crossed-extensor reflex causes

Answer 7

extension of the leg opposite the side of receptor activation

Question 8

which of the following statements concerning propagation of action potentials is TRUE?

Answer 8

saltatory conduction occurs only in myelinated fibers

Question 9

which of the following would consist of white matter?

Answer 9

axon tracts in the spinal cord

Question 10

graded potentials summate in a postsynaptic neuron in response to simultaneous stimulation by the neurotransmitters glutamate, serotonin, and acetylcholine released by three separate presynaptic neurons. this summation is classified as:

Answer 10

spatial summation

Question 11

which of the following statements is NOT true?

Answer 11

graded potentials and action potentials are all-or-none

Question 12

which of the following is a role for ATP in skeletal muscle contraction?

Answer 12

to allow myosin to detach from actin

Question 13

two neurons, A and B, synapse onto a third neuron, C. if neurotransmitter from A opens monovalent cation channels and neurotransmitter from B opens K+ channels, which of the following statements is true?

Answer 13

simultaneous action potentials in A and B will cause less depolarization of neuron C than if only neuron A fired an action potential

Question 14

which of the following ion channels must open for a cardiac autorhythmic cell to depolarize to threshold for an action potential?

Answer 14

both funny channels and t-type calcium channels

Question 15

atropine blocks muscarinic receptors. which of the following would result from the use of this drug?

Answer 15

a small volume of viscous saliva would be produced

Question 16

creatine phosphate is used to convert

Answer 16

ADP to ATP

Question 17

cardiac contractile cells do not undergo tetanus because of voltage-gated ____ channels?

Answer 17

calcium

Question 18

in a synapse, the influx of calcium into the axon terminal is responsible for which of the following?

Answer 18

fusion of vesicles to the membrane and exocytosis of neurotransmitter

Question 19

where are gap junctions found?

Answer 19

both cardiac and single-unit smooth muscle

Question 20

which of the following contains only sensory neurons

Answer 20

dorsal root

Question 21

what is the primary role of myosin ATPase?

Answer 21

it makes energy available for the power stroke

Question 22

a contraction that generates force and moves a load is known as ____, whereas one that generates force without movement is known as

Answer 22

isotonic/isometric

Question 23

which of the following characteristics of an action potential does NOT result directly from the refractory period?

Answer 23

the “peak” level of depolarization reached

Question 24

a person with a heart rate of 40 beats per minute has no P waves but has normal QRS complexes on the eCG. what is the best explanation?

Answer 24

SA node is not working

Question 25

the myosin in smooth muscle can interact with action only when the light chain:

Answer 25

is phosphorylated

Question 26

in a clinical setting, drugs which stimulate ____ receptors would be used to open the airways when treating people suffering from asthma or nasal congestion

Answer 26

beta-2

Question 27

the time between action potentials is directly determined by the ____ the graded potentials at the axon hillock

Answer 27

amplitude (size) of

Question 28

for an unmyelinated axon, conduction velocity is primarily determined by the:

Answer 28

diameter of axon

Question 29

which of the following is NOT true of EPPs and EPSPs?

Answer 29

EPPs occur in smooth muscle, cardiac muscle and glands

Question 30

which of the following does NOT contain smooth muscle?

Answer 30

heart

Question 31

in order to prevent unwanted motor action (skeletal muscle activity) in a patient, one realistic treatment option is for the doctor to prescribe a muscarinic antagonist

Answer 31

this is false

Question 32

when a monovalent cation channel opens in a synapse, which of the following is TRUE?

Answer 32

sodium moves faster than potassium because of both sodium's concentration and electrical gradients

Question 33

paxil and prozac are SSRIs, which help treat depression by

Answer 33

slowing or blocking the re-uptake of serotonin from the synaptic cleft

Question 34

in terms of blood flow through the heart, place these structures in order returning to the heart from the lungs

Answer 34

a. left atrium (6) b. left ventricle (1) c. aorta (3) d. right atrium (2) e. right ventricle (5) f. pulmonary artery (4)

Question 35

which of the following does NOT affect the amount of tension in a whole skeletal muscle (like the biceps)?

Answer 35

stimulating variable portions of each motor unit

Question 36

the chordae and tendineae are needed for appropriate functioning of the

Answer 36

bicuspid or mitral valve

Question 37

a person suffers from a chronically dry mouth. what type of drug would be best to treat this disorder?

Answer 37

parasympathetic agonist

Question 38

which of the following is NOT true about the sympathetic nervous system?

Answer 38

it emerges from the cranial and sacral regions of the CNS

Question 39

which of these synapses does NOT have acetylcholine as its primary neurotransmitter?

Answer 39

synapse of a postganglionic sympathetic neuron onto a smooth muscle cell

Question 40

weightlifting can result in a dramatic increase in skeletal muscle mass. this increase in muscle mass is primarily attributable to which of the following?

Answer 40

synthesis of more contractile proteins