Chapter 12: Muscle Physiology

These flashcards cover key terms and concepts related to muscle physiology, including different types of muscles, contraction mechanisms, and energy systems.

Efferent Nervous System

The branch of the nervous system that carries signals away from the central nervous system to effectors (muscles and organs).

Skeletal Muscle

Striated and voluntary muscle that attaches to bones and is primarily examined in this chapter.

Cardiac Muscle

Striated and involuntary muscle that makes up the heart wall.

Smooth Muscle

Non-striated and involuntary muscle located in internal organs and blood vessels.

Fascicles

Bundles of muscle fibers within skeletal muscle.

Fascia

A sheet of fibrous connective tissue that covers muscles.

Epimysium

Outer layer of connective tissue that surrounds the entire muscle.

Sarcoplasm

The liquid component within a muscle fiber.

Myofibrils

Small thread-like structures within muscle fibers that are the contractile elements.

Sarcoplasmic Reticulum (S.R.)

Fluid-filled sacs that encircle myofibrils, storing calcium and releasing it during muscle contraction.

Sliding Filament Mechanism

The process by which skeletal muscles shorten as thick and thin filaments slide past each other.

Calcium's Role in Contraction

Calcium ions increase in the sarcoplasm to trigger muscle contractions by changing the shape of troponin-tropomyosin complex.

Power Stroke

The action of myosin heads pulling thin filaments towards the center of the sarcomere during muscle contraction.

Excitation-Contraction Coupling

The process by which an action potential triggers muscle cell contraction.

Isotonic Contraction

A muscle contraction in which the muscle changes length while the tension remains constant.

Isometric Contraction

A muscle contraction where tension is produced without a change in muscle length.

Myogram

A record of muscle contraction that depicts different periods of muscle activity.

Twitch Contraction

A brief contraction of all muscle fibers in a motor unit in response to a single impulse.

Glycolysis

The metabolic pathway that breaks down glucose into pyruvic acid, providing ATP for muscle contraction.

Aerobic Cellular Respiration

The process of producing ATP with the presence of oxygen, yielding more energy and involving the Krebs Cycle.

Oxygen Debt

The extra oxygen consumed post-exercise to restore depleted oxygen supplies in the body.