Anatomy Ch 7 Muscle Flashcard

Front

What is the role of the sarcoplasmic reticulum in muscle contraction?

Back

The sarcoplasmic reticulum stores calcium ions and releases them in response to action potentials, which is essential for muscle contraction.

Front

What is muscle recruitment?

Back

Muscle recruitment is the process of increasing muscle tension by activating more motor units.

Front

Which protein blocks the active sites on actin in a resting muscle?

Back

Tropomyosin blocks the active sites on actin, preventing muscle contraction when the muscle is at rest.

Front

What happens to the H zone during muscle contraction?

Back

The H zone disappears during muscle contraction as the actin filaments slide over the myosin filaments.

Front

What is oxygen debt?

Back

Oxygen debt refers to the amount of oxygen required during the recovery period to restore normal pre-exertion conditions after exercise.

Front

What is the function of myosin in muscle contraction?

Back

Myosin is a motor protein that interacts with actin to produce muscle contraction through cross-bridge cycling.

Front

Define the term 'motor unit'.

Back

A motor unit consists of a motor neuron and all the muscle fibers it innervates, working together to produce muscle contraction.

Front

What is the sliding filament theory?

Back

The sliding filament theory explains how muscles contract by the sliding of actin and myosin filaments past each other, shortening the sarcomere.

Front

What is the role of troponin in muscle contraction?

Back

Troponin binds to calcium ions and causes a conformational change that moves tropomyosin away from actin's active sites, allowing contraction.

Front

Explain the term 'isometric contraction'.

Back

Isometric contraction occurs when muscle tension increases without changing the muscle length, such as holding a weight steady.