Chapter 9: Skeletal Muscle Tissue

A set of vocabulary flashcards based on Chapter 9 of Skeletal Muscle Tissue covering major terms and definitions.

Skeletal muscle tissue

Voluntary, striated muscle tissue found attached to bones.

Cardiac muscle tissue

Involuntary, striated muscle tissue found in the heart.

Smooth muscle tissue

Involuntary, nonstriated muscle tissue found in the walls of hollow organs.

Functions of skeletal muscle

Include producing body movement, maintaining posture, supporting soft tissues, guarding entrances/exits, maintaining temperature, and storing nutrients.

Epimysium

The dense layer of collagen fibers surrounding a skeletal muscle.

Muscle fascicle

A bundle of muscle fibers surrounded by perimysium.

Skeletal muscle fiber

An individual muscle cell, surrounded by endomysium.

Sarcolemma

The plasma membrane of a skeletal muscle fiber.

Sarcoplasm

The cytoplasm of a skeletal muscle fiber.

Myofibril

A cylindrical structure running the length of a skeletal muscle fiber.

Sarcomere

The contractile unit of skeletal muscle.

Myofilaments

Filaments within a sarcomere, including thin filaments (actin) and thick filaments (myosin).

Transverse tubules

Extensions of the sarcolemma that form passages through muscle fiber and transmit action potentials.

Sarcoplasmic reticulum

Specialized smooth endoplasmic reticulum that stores and releases calcium around myofibrils.

Action potential

An electrical impulse that sends a signal across the muscle fiber.

Depolarization

The phase during which voltage-gated sodium channels open, causing sodium to enter the cell.

Repolarization

The phase where voltage-gated sodium channels close and potassium exits the cell, making the inside more negative.

Neuromuscular junction (NMJ)

The synapse where a motor neuron contacts a skeletal muscle fiber.

Motor unit

A group of muscle fibers controlled by the same motor neuron.

Calcium ions

Ions that play a crucial role in muscle contraction by binding to troponin.

Myosin heads

Molecular structures that bind to actin during muscle contraction, facilitating the sliding filament mechanism.