physiology ch 7 Flashcards
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
muscle action potentials have faster conduction velocity than neurons
what is the step in contraction, 1-5… calcium is quickly pumped back into the sarcoplasmic reticulum using a calcium pump (SERCA)
5
what is the step in contraction, 1-5…calcium enters the sarcoplasm surrounding the myofibrils
3
what is the step in contraction, 1-5… calcium release channels of the sarcoplasmic reticulum are opened
2
what is the step in contraction, 1-5…calcium binds to troponin C, causing the removal of tropomyosin from actin binding sites
4
what is the step in contraction, 1-5…action potential traveling along t-tubules activate DHP receptors
1
what are the locations of smooth muscle?
blood vessels, uterus, bronchi, trachea, stomach, and intestines
what is the ability of skeletal muscle to conduct electrical charges along the membrane called?
a. elasticity
b. excitability
c. contractility
d. extensibility
excitability
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
acetyle-CoA
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
large amounts of summation are needed to get a muscle to threshold
what are the locations of skeletal muscle?
external anal + urethral sphincters, connects bones of appendicular skeleton, face, eye, ear, diaphragm, upper esophagus, connects bones of axial skeleton
Acetylcholine binds to ______ receptors on the skeletal muscle motor endplate.
a. muscarinic
b. alpha adrenergic
c. beta adrenergic
d. nicotinic
nicotinic
synaptic endplate of alpha motor neuron sequence of events… vesicles fuse with neural cell membrane and ACH is emptied into synaptic cleft
5
synaptic endplate of alpha motor neuron sequence of events… freed ACH vesicles migrate to active zones and dock at release sites
4
synaptic endplate of alpha motor neuron sequence of events… voltage gated calcium channels on either side of dense bars open
2
synaptic endplate of alpha motor neuron sequence of events… neuron action potential arrives at nerve terminal
1
synaptic endplate of alpha motor neuron sequence of events… influx of calcium activates calcium calmodulin dependent protein kinase which phosphorylates synapsin proteins
3
what is the ability of skeletal muscle to conduct electrical charges along the membrane called?
a. contractility
b. elasticity
c. irritability
d. extensibility
contractility
Which is an enzyme housed in the synaptic cleft that breaks down acetylcholine?
a. carbonic anhydrase
b. acetylcholinesterase
c. phosphofructokinase
d. choline acetyltransferase
acetylcholineterase
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
6
muscle contraction sequence of events… tropomyosin is removed from the actin binding site
2
muscle contraction sequence of events… calcium is removed from troponin C and tropomyosin covers actin binding site to stop the muscle contraction
7
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
4
muscle contraction sequence of events… myosin head tilts, pulling actin filament closer to M line as ADP and Pi are released
5
muscle contraction sequence of events… calcium enters the sarcoplasm and binds to troponin C
1
muscle contraction sequence of events… myosin binds to actin
3
Which are features of cardiac muscle?
intercalated discs, autorhythmic, irregular/branched shape, cross striations, gap junctions
what is the ability of skeletal muscle to lengthen or stretch beyond beyond normal resting length?
a. elasticity
b. extensibility
c. contractility
d. excitability
extensibility
what are the features of single unit smooth muscle?
gap junctions, single/centrally located nucleus, apindle/fusiform shape, involuntary
what is the ability of skeletal muscle to shorten when adequately stimulated called?
a. excitability
b. elasticity
c. extensibilioty
d. contractility
contractility
synaptic + post synaptic events at NMJ sequence of events… the muscle action potential spreads along sarcolemma and into the t-tubules
5
synaptic + post synaptic events at NMJ sequence of events… threshold is reached and voltage gated sodium channels deeper in the subneural cleft open
4
synaptic + post synaptic events at NMJ sequence of events… ACH binds to a nicotinic receptor in the subneural cleft
2
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
3
synaptic + post synaptic events at NMJ sequence of events… ACH diffuses acrodd the synaptic space and into the mouth of the subneural clefts
1
Ability of skeletal muscle to recoil and return to original length after being stretched?
a. extensibility
b. contractility
c. excitability
d. elasticity
elasticity
what are features of skeletal muscle?
cross striations, elongated/cylindrical shape, voluntary, multiple nuclei
ACH production sequence of events… ACH is released into synaptic cleft, where it activates nicotinic receptors causing an end plate potential in the muscle
5
ACH production sequence of events… Acetylcholine is absorbed into the vesicles and stored
3
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
2
ACH production sequence of events… Empty vesicles are produced in the Golgi apparatus of the motor neuron and shipped to the synaptic endplate
1
ACH production sequence of events… Neuronal action potential arrives, triggering the influx of calcium and the exocytosis of the synaptic vesicles
4
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
6
