ANATOMY AND PHYSIOLOGY
MUSCLE SYSTEM QUIZ 1
NAME ________________________________________________________ DATE ___________________
What does the sliding filament theory explain?
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Step 1: A muscle contraction starts in the brain, where signals are sent along the
(1. CIRCLE ONE: myosin
motor neuron ) where there are vesicles that contain the neurotransmitter
(2. CIRCLE ONE: acetycholine cholinesterase ). This neurotransmitter reaches the receptors on the
(3. CIRCLE ONE: sarcolemma sarcoplasm ) which causes an impulse.
Step 2: The impulse travels down the membrane and into the transverse tubules where it causes calcium to be
released from the sarcoplasmic reticulum.
Step 3: Calcium binds to a structure on the actin that causes it to change shape.
Step 4: The change in shape allows myosin heads to form cross-bridges between the actin and the myosin.
Step 5: Energy from (4. CIRCLE ONE: acetycholine ATP) is used to create a "power stroke" between the two
filaments. The (5. CIRCLE ONE: actin myosin ) filament then slides inward and shortens, or contracts, the
whole muscle.
The Neuromuscular Junction.
MATCH the part with
the letter indicated at right.
_____6. T tubule
A
..
B
.
_____7. actin
_____8. neuron
_____9. myosin
_____10. cross bridge
C
D
E