physiology ch 7

Question 1

All of the following are true concerning muscle action potentials when compared to neuron action potentials EXCEPT?
a. each muscle end plate potential typically increases the local membrane to threshold
b. muscle action potentials have faster conduction velocity than neurons
c. muscle action potentials have a longer duration of action potential than neurons
d. muscle action potentials have a more negative resting membrane potential than neurons

Answer 1

muscle action potentials have faster conduction velocity than neurons

Question 2

what is the step in contraction, 1-5… calcium is quickly pumped back into the sarcoplasmic reticulum using a calcium pump (SERCA)

Answer 2

5

Question 3

what is the step in contraction, 1-5…calcium enters the sarcoplasm surrounding the myofibrils

Answer 3

3

Question 4

what is the step in contraction, 1-5… calcium release channels of the sarcoplasmic reticulum are opened

Answer 4

2

Question 5

what is the step in contraction, 1-5…calcium binds to troponin C, causing the removal of tropomyosin from actin binding sites

Answer 5

4

Question 6

what is the step in contraction, 1-5…action potential traveling along t-tubules activate DHP receptors

Answer 6

1

Question 7

what are the locations of smooth muscle?

Answer 7

blood vessels, uterus, bronchi, trachea, stomach, and intestines

Question 8

what is the ability of skeletal muscle to conduct electrical charges along the membrane called?
a. elasticity
b. excitability
c. contractility
d. extensibility

Answer 8

excitability

Question 9

acetylcholine is made from ___, a product of the breakdown of glucose, fatty acids, or amino acids?
a. acetate
b. acetyl-CoA
c. choline
d. ATP

Answer 9

acetyle-CoA

Question 10

All of the following are true concerning muscle action potentials when compared to neuron action potentials EXCEPT?
a. each muscle end plate potential typically increases the local membrane to threshold
b. large amounts of summation are needed to get a muscle to threshold
c. muscle action potentials have a longer duration of action potential than neurons
d. muscle action potentials have a more negative resting membrane potential than neurons

Answer 10

large amounts of summation are needed to get a muscle to threshold

Question 11

what are the locations of skeletal muscle?

Answer 11

external anal + urethral sphincters, connects bones of appendicular skeleton, face, eye, ear, diaphragm, upper esophagus, connects bones of axial skeleton

Question 12

Acetylcholine binds to ______ receptors on the skeletal muscle motor endplate.
a. muscarinic
b. alpha adrenergic
c. beta adrenergic
d. nicotinic

Answer 12

nicotinic

Question 13

synaptic endplate of alpha motor neuron sequence of events… vesicles fuse with neural cell membrane and ACH is emptied into synaptic cleft

Answer 13

5

Question 14

synaptic endplate of alpha motor neuron sequence of events… freed ACH vesicles migrate to active zones and dock at release sites

Answer 14

4

Question 15

synaptic endplate of alpha motor neuron sequence of events… voltage gated calcium channels on either side of dense bars open

Answer 15

2

Question 16

synaptic endplate of alpha motor neuron sequence of events… neuron action potential arrives at nerve terminal

Answer 16

1

Question 17

synaptic endplate of alpha motor neuron sequence of events… influx of calcium activates calcium calmodulin dependent protein kinase which phosphorylates synapsin proteins

Answer 17

3

Question 18

what is the ability of skeletal muscle to conduct electrical charges along the membrane called?
a. contractility
b. elasticity
c. irritability
d. extensibility

Answer 18

contractility

Question 19

Which is an enzyme housed in the synaptic cleft that breaks down acetylcholine?
a. carbonic anhydrase
b. acetylcholinesterase
c. phosphofructokinase
d. choline acetyltransferase

Answer 19

acetylcholineterase

Question 20

muscle contraction sequence of events… myosin binds to new ATP, setaching from actin binding site. hydrolyzes the ATP to ADP and Pi as it ectends forward to bind to new actin site

Answer 20

6

Question 21

muscle contraction sequence of events… tropomyosin is removed from the actin binding site

Answer 21

2

Question 22

muscle contraction sequence of events… calcium is removed from troponin C and tropomyosin covers actin binding site to stop the muscle contraction

Answer 22

7

Question 23

muscle contraction sequence of events… myosin detatches from actin as it binds ATP. hydrolyzes ATP to ADP and Pi, extends forward and rebinds to anew actin site

Answer 23

4

Question 24

muscle contraction sequence of events… myosin head tilts, pulling actin filament closer to M line as ADP and Pi are released

Answer 24

5

Question 25

muscle contraction sequence of events... calcium enters the sarcoplasm and binds to troponin C

Answer 25

1

Question 26

muscle contraction sequence of events... myosin binds to actin

Answer 26

3

Question 27

Which are features of cardiac muscle?

Answer 27

intercalated discs, autorhythmic, irregular/branched shape, cross striations, gap junctions

Question 28

what is the ability of skeletal muscle to lengthen or stretch beyond beyond normal resting length? a. elasticity b. extensibility c. contractility d. excitability

Answer 28

extensibility

Question 29

what are the features of single unit smooth muscle?

Answer 29

gap junctions, single/centrally located nucleus, apindle/fusiform shape, involuntary

Question 30

what is the ability of skeletal muscle to shorten when adequately stimulated called? a. excitability b. elasticity c. extensibilioty d. contractility

Answer 30

contractility

Question 31

synaptic + post synaptic events at NMJ sequence of events... the muscle action potential spreads along sarcolemma and into the t-tubules

Answer 31

5

Question 32

synaptic + post synaptic events at NMJ sequence of events... threshold is reached and voltage gated sodium channels deeper in the subneural cleft open

Answer 32

4

Question 33

synaptic + post synaptic events at NMJ sequence of events... ACH binds to a nicotinic receptor in the subneural cleft

Answer 33

2

Question 34

synaptic + post synaptic events at NMJ sequence of events... sodium, with positive charge enters the muscle cell motor endplate through the ACH gated channels creating an endplate potential

Answer 34

3

Question 35

synaptic + post synaptic events at NMJ sequence of events... ACH diffuses acrodd the synaptic space and into the mouth of the subneural clefts

Answer 35

1

Question 36

Ability of skeletal muscle to recoil and return to original length after being stretched? a. extensibility b. contractility c. excitability d. elasticity

Answer 36

elasticity

Question 37

what are features of skeletal muscle?

Answer 37

cross striations, elongated/cylindrical shape, voluntary, multiple nuclei

Question 38

ACH production sequence of events... ACH is released into synaptic cleft, where it activates nicotinic receptors causing an end plate potential in the muscle

Answer 38

5

Question 39

ACH production sequence of events... Acetylcholine is absorbed into the vesicles and stored

Answer 39

3

Question 40

ACH production sequence of events... AcetylCoA from metabolism of glucose, fatty acids or amino acids is combined with choline (from diet) using acetylcholine transferase in the cytoplasm of the nerve terminal

Answer 40

2

Question 41

ACH production sequence of events... Empty vesicles are produced in the Golgi apparatus of the motor neuron and shipped to the synaptic endplate

Answer 41

1

Question 42

ACH production sequence of events... Neuronal action potential arrives, triggering the influx of calcium and the exocytosis of the synaptic vesicles

Answer 42

4

Question 43

ACH production sequence of events... Acetylcholine is broken down into acetate ions and choline by acetylcholinesterase. The choline and the vesicle are recycled into the nerve terminal

Answer 43

6