ch. 9 Muscular System Overview

These flashcards cover key vocabulary and concepts from the muscular system lecture, focusing on anatomy and physiology.

Sarcolemma

The cell membrane of a muscle cell that exhibits electrical excitability.

Skeletal Muscle Tissue

Muscle tissue responsible for voluntary movements and attached to bones.

Cardiac Muscle Tissue

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

Smooth Muscle Tissue

Involuntary muscle tissue found in walls of hollow organs, responsible for involuntary movements.

Electrical Excitability

The ability of a muscle cell or neuron to generate and propagate electrical signals.

Resting Membrane Potential

The electrical charge difference across the membrane of a cell at rest, typically around -70 mV.

Action Potential

A rapid change in membrane potential that allows for the transmission of electrical signals along neurons and muscle fibers.

Myo-

A prefix meaning 'muscle'.

Contractility

The ability of muscle fibers to shorten and generate force.

Extensibility

The ability of muscles to stretch without being damaged.

Elasticity

The ability of muscles to return to their original length after being stretched.

Peristalsis

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

Neuromuscular Junction

The synapse where a motor neuron connects to a muscle fiber.

Epimysium

The connective tissue layer that surrounds the entire muscle.

Perimysium

The connective tissue that surrounds bundles of muscle fibers (fascicles).

Endomysium

The connective tissue that surrounds individual muscle fibers.

Myofibrils

Long, thread-like structures in muscle fibers that contain the contractile proteins.

Sarcoplasmic Reticulum

The specialized endoplasmic reticulum in muscle cells that stores calcium ions.

T-tubules

Invaginations of the sarcolemma that help transmit electrical signals deep into the muscle fiber.

Origin and Insertion

Attachment points of muscles: origin is the fixed point while insertion is the movable point.