Neuromuscular Junction

What is necessary for the myosin to release the actin?

• ATP

• Calcium

• ADP

• Sodium

What is a crossbridge?

• Where myosin binds to actin

• Where the calcium crosses into the cytoplasm

• Where calcium binds with troponin

• Where titin and myosin are connected

What does the myosin do to the actin?

• Nothing

• Pushes on it

• Pulls on it

• Breaks it into pieces

What does the sarcoplasmic reticulum do?

• Stores sodium

• Stores ATP

• Releases sodium

• Stores calcium

What is the name of the place where a nerve meets a muscle fiber

• Nerve junction

• Neuromuscular junction

• Muscle junction

• Crossbridge

How does the sarcomere shorten (contract) ?

• The myosin filaments contract

• The actin filaments contract

• The myosin is pulled by the actin

• The actin is pulled by the myosin

___ and ___ are regulatory proteins bound to actin.

• Myosin and actin

• Glycogen and hemoglobin

• Calcium and oxygen

• Troponin and tropomyosin

Skeletal Muscle contraction is initiated when the ________ sends a message to the muscle cell.

• Muscle cell

• Gland

• Neuron

• None of the above

The neurotransmitter that signals muscle contraction is...

• Calcium

• Actin

• Myosin

• Ach (acetylcholine)

The functional unit of the muscle cell is the:

• Sarcomere

• Myofilament

• Osteon

• Muscle fiber