Muscle Tissue and Skeletal Muscle Anatomy

A comprehensive set of flashcards reviewing vocabulary related to muscle tissue and skeletal muscle anatomy, designed to aid in exam preparation.

Muscle Tissue

Makes up approximately 1/2 of the body’s mass and has the ability to transform ATP into directed mechanical energy.

Types of Muscle Tissue

Three types: Skeletal, Smooth, Cardiac.

Skeletal Muscle

Voluntary, striated, and multinucleate muscle tissue.

Smooth Muscle

Involuntary, smooth, and uninucleate muscle tissue.

Cardiac Muscle

Involuntary, striated, and uninucleate muscle tissue.

Striations

The alternating light and dark bands found in skeletal and cardiac muscle.

Intercalated Discs

Specialized connections between cardiac muscle cells that facilitate synchronized contraction.

Muscular System

Primarily involves skeletal muscle, which facilitates body movement and acts with the skeleton as a system of levers.

Major Functions of Skeletal Muscle

Movement, posture stabilization, respiration, and heat production.

Excitability

Property of skeletal muscle to respond to a stimulus.

Contractility

Ability of muscle to shorten.

Extensibility

Ability of muscle to stretch.

Elasticity

Ability of muscle to return to its normal shape after being stretched.

Conductivity

Ability of muscle to transmit electrical impulses.

Gross Anatomy of Skeletal Muscle

Includes hundreds of thousands of muscle fibers along with connective tissue, blood vessels, and nerve fibers.

Muscular Fascia

Connective tissue that surrounds skeletal muscles.

Tendon

Connective tissue that attaches muscle to bone.

Epimysium

Connective tissue that wraps around the whole muscle.

Perimysium

Connective tissue that encloses a fascicle within a muscle.

Endomysium

Connective tissue that surrounds each muscle fiber or cell.

Neuromuscular Junction

The synapse between a motor neuron and a muscle fiber.

Motor Unit

Consists of a single motor neuron and all the muscle cells it innervates.

Precise Movements

Require smaller motor units with fewer muscle cells.

Large Force Movements

Require larger motor units with many muscle cells.

Skeletal Muscle Fiber

Single muscle cell also known as a muscle fiber.

Sarcolemma

The plasma membrane of a muscle fiber.

Sarcoplasm

The cytoplasm of a muscle fiber.

Sarcoplasmic Reticulum

Specialized smooth endoplasmic reticulum in muscle cells that stores calcium.

Myofibrils

Organelles in muscle fibers made of myofilaments.

Myofilaments

The contractile proteins within myofibrils, primarily actin and myosin.

Troponin/Tropomyosin

Proteins that regulate contraction in muscle by controlling the interaction of actin and myosin.

Triad

Structure formed by a T-tubule and two terminal cisternae of the sarcoplasmic reticulum.

Thick Filament

Filament composed mainly of myosin that forms the A band in muscle fibers.

Thin Filament

Filament composed mainly of actin that forms the I band in muscle fibers.

Actin Active Site

The site on actin where myosin heads bind during muscle contraction.

Myosin Heads

Part of the thick filament that interacts with actin during muscle contraction.

Titin

Elastic filament that stabilizes myosin and contributes to muscle elasticity.

Muscle Fiber Structure

Includes several organelles and structures necessary for muscle contraction.

Connective Tissue Purpose

Provides structure and support for muscle fibers, enables nerve and blood supply.

Central Nervous System Role

Signals muscle contractions through motor neuron activity.

Blood Supply

Provides glucose, oxygen, and ATP essential for muscle contraction.

Skeletal Muscle Contraction

Involves the interaction of actin and myosin facilitated by calcium ions.

Mechanism of Contraction

Involves the shortening of sarcomeres within muscle fibers.

Thermoregulation

The process of producing heat through muscle activity to maintain body temperature.