Muscle Contraction and Neuromuscular Junction

Flashcards covering key vocabulary related to muscle contraction and neuromuscular junction processes.

Sarcolemma

The cell membrane of a muscle cell.

Triad

A structure formed by the transverse tubule and two terminal cisterns of the sarcoplasmic reticulum.

Myofibrils

Long threads that run parallel to the length of a muscle fiber; they contain the thick and thin filaments.

H zone

The region in the center of the A band where thin filaments do not overlap with thick filaments.

I band

The light band in muscle striations, containing only thin filaments.

Cross-bridges

Connections that are formed between myosin heads and binding sites on actin filaments during muscle contraction.

Neurotransmitter

A chemical substance, such as acetylcholine, released from nerve endings to transmit impulses to muscle cells.

End Plate Potential (EPP)

A local depolarization at the neuromuscular junction caused by the binding of neurotransmitters to receptors on the muscle cell membrane.

Wave of depolarization

An electrical signal that travels along the sarcolemma and into the T-tubules, initiating muscle contraction.

Neuromuscular Junction

The junction between a motor neuron and a skeletal muscle fiber.