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