BIO 168 Unit 7: Muscular System

Flashcards covering key vocabulary and concepts related to the muscular system, particularly focusing on the sarcomere and myofilaments.

Sarcomere

The functional unit involved in contraction and movement of skeletal muscle tissue.

Myofibrils

Long, cylindrical structures filled with tightly packed myofilaments, containing many sarcomeres.

Sarcoplasmic reticulum

Modified endoplasmic reticulum in muscle tissue that stores calcium ions.

T-tubules

Invaginations of the sarcolemma that extend deep into muscle cells, facilitating the transmission of action potentials.

Triad

A structure formed by one T-tubule sandwiched between two terminal cisternae of the sarcoplasmic reticulum.

Actin

Thin myofilaments that play a crucial role in muscle contraction.

Myosin

Thick myofilaments that interact with actin to produce muscle contraction.

Tropomyosin

A regulatory protein that blocks myosin binding sites on actin and is unblocked when troponin changes shape.

Troponin

A globular protein that changes shape when bound to calcium, allowing muscle contraction to occur.

Dystrophin

A protein that attaches thin actin to the sarcolemma, maintaining the integrity of muscle fibers.