Muscular System Functions & Mechanisms Quiz

<p>It binds to troponin, causing exposure of actin's binding sites (A)</p> Signup and view all the answers

<p>It transmits action potentials from motor neurons to muscle fibers (C)</p> Signup and view all the answers

<p>H Zone (D)</p> Signup and view all the answers

<p>Through myosin cross-bridges pulling actin filaments (C)</p> Signup and view all the answers

<p>Greater force of contraction (B)</p> Signup and view all the answers

<p>It provides energy for myosin to detach and reattach to actin. (B)</p> Signup and view all the answers

<p>Subsequent stimuli produce greater contraction strength before relaxation occurs. (D)</p> Signup and view all the answers

<p>A muscle fiber either fully contracts or does not contract at all in response to a stimulus. (C)</p> Signup and view all the answers

<p>Anaerobic respiration (glycolysis) (B)</p> Signup and view all the answers

<p>Isometric contraction (A)</p> Signup and view all the answers

<p>Flexion (C)</p> Signup and view all the answers

<p>Depletion of ATP and oxygen (D)</p> Signup and view all the answers

<p>It stores and releases calcium ions. (A)</p> Signup and view all the answers

Myosin heads attach to actin, pull, release, and reattach during muscle contraction.

ATP provides energy for myosin to detach and reattach to actin during contraction.

Structure that stores and releases Ca²⁺ ions needed for muscle contraction.

A single, brief contraction in response to a single stimulus.

Occurs when a second stimulus is given before muscle has relaxed, leading to a stronger contraction.

A muscle fiber either contracts fully in response to a stimulus or not at all; no partial contractions.

A type of muscle contraction where the muscle contracts but does not change length.

Fatigue results from depletion of ATP, oxygen, lactic acid accumulation, and ion imbalances.

Muscles enable movement, maintain posture, stabilize joints, and produce heat.

Muscles contract through shortening, and can stretch and return thanks to elasticity.

Three layers: Epimysium (surrounds whole muscle), Perimysium (surrounds fascicles), Endomysium (surrounds fibers).

The sarcomere includes A Band (myosin), I Band (actin), H Zone (myosin only), M Line (center), Z Disk (ends).

Muscle > Fascicle > Muscle Fiber > Myofibrils > Myofilaments (Actin & Myosin).

Action potential triggers ACh release, binding to receptors for muscle contraction.

Muscle tension is created through contraction and increased frequency of action potentials strengthens it.

Actin slides over myosin during contraction; regulated by tropomyosin and troponin with Ca²⁺ involvement.

A sustained muscle contraction due to rapid, repeated stimuli.

ATP production without oxygen, quick but less efficient, produces lactic acid.

ATP production using oxygen, more efficient but slower process.

Muscle changes length while contracting, like lifting weights.

Decreasing the angle between two body parts, e.g., bending the elbow.

Increasing the angle between two body parts, e.g., straightening the elbow.

Moving a limb toward the body's midline.

Moving a limb away from the body's midline.

Muscles enable movement, maintain posture, stabilize joints, and produce heat.

Outer connective tissue layer that surrounds the entire muscle.

Connective tissue surrounding individual fascicles (bundles of muscle fibers).

Connective tissue surrounding individual muscle fibers (cells).

Muscles contract by shortening in response to neural signals, generating force.

Muscles help stabilize joints and maintain posture.