A muscle is made of many (a)   (one subunit down from a muscle).

A myofibril is made of many (a)   (one subunit down from a myofibril).

Which myofilament is thick? (a)  

Which myofilament is thin? (a)  

Together, actin and myosin make up a (a)   .

A group of fascicles is a (a)   .

Each muscle fiber is made of smaller, long and skinny proteins called (a)   .

A muscle fiber, like all cells, has smaller subparts (ex. Nucleus) called (a)   .

The cell membrane of a muscle fiber is called the (a)   .

(a)   are the binding sites on the outside of a muscle fiber that receive neurotransmitters.

Because a motor neuron and muscle fiber do not physically touch, axon terminals release chemical messages to bridge the synaptic cleft. These chemical messages are known as

(a)  

The specific neurotransmitter that is released by the axon terminal at a neuromuscular junction is called

(a)  

The release of acetylcholine triggers a skeletal muscle fiber to (contract or relax)?

(a)  

What is the smallest unit of a muscle to contract?

(a)  

Actin is the thin myofilament. Myosin is the thick myofilament. Myosin has “hands” that bind to (a)   .

Which myofilament is attached to the Z line?

(a)  

Which part of a sarcomere contains only thick filaments?

(a)  

Which part of a sarcomere contains only thin filaments?

(a)  

Which part of the sarcomere is the boundary between sarcomeres?

(a)  

Which part of the sarcomere contains both actin and myosin?

(a)  

Which part of the sarcomere is the line down the middle of myosin?

(a)