Muscular System Flashcards

Flashcards to review key vocabulary and concepts related to the muscular system, including muscle structure, sarcomere components, and the process of muscle contraction.

Muscle Actions

Producing body heat, contracting to allow movements, and constricting organs and blood vessels.

Sarcomeres

The functional units of skeletal muscle; shorten to cause muscle contraction.

Actin

The thin filament within a sarcomere; myosin attaches to it during muscle contraction.

Z-Line

Part of a sarcomere where actin anchors.

Myosin

The thick filament within a sarcomere; resembles a golf club head and attaches to actin during muscle contraction.

A-Band

The entire span of the thick filaments (myosin) in one sarcomere.

Tropomyosin

A protein that covers the attachment sites on actin, preventing myosin from attaching during muscle relaxation.

Calcium Ions

Ions responsible for removing tropomyosin from actin, allowing myosin to attach and initiate muscle contraction.

Neuromuscular Junction

Point where action potentials terminate, releasing acetylcholine (aCh).

Acetylcholine (aCh)

Neurotransmitter released at the neuromuscular junction to initiate muscle contraction.

Sarcoplasmic Reticulum

Organelle that releases calcium ions upon stimulation by sodium ions, triggering muscle contraction.