1. An ____________ travels down the _____ to the ___________
action potential
axon
axon terminal
Previous Step: An action potential travels down the axon to the axon terminal
(2) _______________________ in the axon terminal open and ________ enters
Voltage-gated calcium channels
calcium
Previous Step: Voltage gated calcium channels in the axon terminal open and calcium enters
(3) ______________ release ________________ via ___________ into the ___________
synaptic vesicles
acetylcholine
exocytosis
synaptic cleft
Previous Step: synaptic vesicles release acetylcholine (Ach) via exocytosis into the synaptic cleft
(4) Ach binds to ___________________ on the ____________
a chemically gated ion channel
motor end plate
Previous Step: Ach binds to it's receptor (a chemically gated ion channel) on the motor end plate
(5) The _____________ opens
ion channel
Previous Step: The ion channel opens
(6) ________ enters and __________ exits through the ___________, but _______ enters to a greater extent than ________ exits
Sodium
potassium
ion channel
sodium
potassium
Previous Step: Sodium enters and potassium exits through the ion channel, but sodium enters to a greater extent than potassium exits
(7) _____________ occurs as the membrane potential becomes _____________
Depolarization
less negative
Previous Step: Depolarization occurs as the membrane potential becomes less negative
(8) This triggers an ____________ which is ____________ along the ___________ via the opening of ___________________
action potential
propagated
sarcolemma
voltage gated sodium channels
Previous Step: This triggers an action potential which is propagated along the sarcolemma via the opening of voltage gated sodium channels
(9) The sarcolemma is __________ as _____________________ close and ____________________open allowing _________to exit the cell
repolarized
voltage-gated sodium channels
voltage-gated potassium channels
potassium
Previous Step: The sarcolemma is repolarized as voltage gated sodium channels close and voltage gates potassium channels open allowing potassium to exit the cell
(10) The action potential is propagated down the ________ of the ____
T-tubules
triads
Previous Step: The action potential is propagated down the T-tubules of the triads
(11) The action potential causes voltage-sensitive tubule proteins to change shape and opens ___________ in the ___________ of the _______________________
calcium channels
terminal cisterns
sarcoplasmic reticulum
Previous Step: The action potential causes voltage-sensitive tubule proteins to change shape and opens calcium channels in the terminal cisterns of the sarcoplasmic reticulum
(12) ________ enters the _______ and binds to ________ thereby removing the blocking action of ___________
Calcium
sarcoplasm
troponin
tropomyosin
Previous Step: Calcium enters the sarcoplasm and binds to troponin thereby removing the blocking action of tropomyosin
(13) This exposes binding sites for ______ on the _____________
myosin
actin filaments
Previous Step: This exposes binding sites for myosin on the actin filament
(14) _______ binds to _____ forming a ________ and _________ begins
Myosin
actin
cross bridge
contraction
Previous Step: Myosin binds actin forming a cross bridge and contraction begins
(15) A __________ occurs as myosin pivots and bends at the hinge region resulting in myosin pulling on actin
power stroke
Previous Step: A power stroke occurs as myosin pivots and bends at the hinge region resulting in myosin pulling on actin
(16) In the presence of ____, myosin detaches from actin
ATP
Previous Step: In the presence of ATP, myosin detaches from actin
(17) The _________ return to the "cocked position"
myosin heads