Anatomy and Physiology 2A Chapter 9

These flashcards cover essential vocabulary and concepts related to anatomy and physiology of muscle tissue.

Myo

Prefix that refers to muscle.

Sarco

Prefix that refers to flesh or muscle.

Skeletal Muscle

A type of muscle that is under voluntary control, has striations, and is responsible for moving bones.

Cardiac Muscle

Involuntary muscle found in the heart, responsible for pumping blood.

Smooth Muscle

Involuntary muscle found in walls of hollow organs, responsible for movement within these organs.

Excitability

The ability of muscle tissue to respond to stimuli.

Contractility

The ability of muscle tissue to shorten and generate force.

Extensibility

The ability of muscle tissue to be stretched without being damaged.

Elasticity

The ability of muscle tissue to return to its original shape after being stretched.

Insertion

The attachment point of a muscle on the bone that moves.

Origin

The attachment point of a muscle on the bone that remains fixed during contraction.

Tendon

A fibrous connective tissue that attaches muscle to bone.

Aponeurosis

A flattened tendon that connects muscle to muscle or muscle to bone.

Sarcolemma

The plasma membrane of a muscle cell.

Sarcoplasm

The cytoplasm of a muscle cell.

Myofibril

A long, thread-like structure within a muscle fiber that contains the filaments necessary for contraction.

Sarcomere

The basic contractile unit of muscle fiber.

Myosin myofilament

Thick filaments made primarily of myosin, which interact with actin for muscle contraction.

Actin myofilament

Thin filaments made primarily of actin that slide over myosin during muscle contraction.

Sarcoplasmic Reticulum

An organelle in muscle cells that stores calcium ions and releases them during muscle contraction.

T-tubule

A structure that allows electrical signals to move into the interior of muscle fibers.

Triad

A structure formed by two terminal cisternae and one T-tubule, which helps in muscle contraction.

Sliding Filament Model

A theory that explains muscle contraction as the sliding of actin filaments over myosin filaments.

Motor unit

A motor neuron and the muscle fibers it innervates.

Muscle Twitch

A single, quick contraction of muscle fibers.

Wave summation

The increase in muscle contraction strength due to the presence of successive stimuli.

Fused tetanus

A sustained muscle contraction without any relaxation due to rapid stimulation.

Isotonic contraction

Muscle contraction where the muscle changes length while maintaining the same tension.

Isometric contraction

Muscle contraction where the muscle length does not change but tension increases.

Muscle Tone

The continuous and passive partial contraction of the muscles.

Anaerobic pathway

A way of generating ATP without the use of oxygen.

Aerobic pathway

A way of generating ATP with the use of oxygen.

Muscle Fatigue

The decline in ability of a muscle to generate force.

Excess Postexercise Oxygen Consumption (EPOC)

The amount of oxygen required after physical exercise to restore the muscles to their resting state.

Slow Oxidative fibers

Muscle fibers that are resistant to fatigue and are suited for endurance activities.

Fast Oxidative fibers

Muscle fibers that have a moderate resistance to fatigue and are suited for intermediate activities.

Fast Glycolytic fibers

Muscle fibers that fatigue quickly and are suited for short bursts of high-intensity activities.

Load

The weight or resistance against which a muscle works.

Recruitment

The process of activating more muscle fibers to increase strength of contraction.

Peristalsis

The wave-like muscle contractions that move food through the digestive tract.

Varicosities

Enlarged regions along the axon of certain neurotransmitter-releasing neurons that release neurotransmitters.

Caveolae

Small invaginations in the cell membrane of smooth muscle cells that help in signal transduction.

Dense bodies

Structures within smooth muscle cells that anchor the actin filaments.

Calcium source in smooth muscle

Calcium ions required for contraction primarily come from the extracellular fluid.