Muscle Contraction

Put these in the correct order

• ACh binds to receptors on the sarcolemma

• Motor neuron is stimulate

• Ca2+ ions diffuse into synaptic end bulb

• Synaptic vesicles release ACh into synapse

• Action potential travels down the axon

Reorder the following in the correct sequence

• The muscle cell depolarizes as Na+ moves in

• Ca2+ ions attach to troponin

• The action potential travels deep into muscle via t-tubules

• T-tubules stimulate the sarcoplasmic reticulum to release Ca2+

• The action potential travels across the sarcolemma

Reorder the following in the correct sequence.

• troponin changes shape

• tropomyosin moves exposing actin binding sites

• myosin heads rotate creating a power stroke

• ATP bonds to myosin head causing it to release from actin

• myosin heads attach to binding sites

The cell membrane of muscle cells.

This structure stores/releases calcium ions when a muscle is stimulated.

These allow the action potential to travel deep within muscle fibers.

Ca2+ binds with ​ (a)   which changes shape and causes ​ (b)   to reveal the binding sites on ​ (c)   .

• troponin
• tropomyosin
• actin
• myosin
• t tubule
• sarcolemma

The​ (a)   "heads" connect to the binding sites on ​ (b)   and rotate to pull the thin filaments toward the ​ (c)   . To detach, the myosin heads require a molecule of ​ (d)   to be used.

• myosin
• actin
• M-line
• ATP
• ADP
• Ca2+
• Z-disk

Match the following structures in the image

• C

• perimysium

• A

• endomysium

• E

• fascicle

• D

• epimysium

• B

• muscle fiber