Muscle Anatomy and Function

These flashcards are designed to help students study key terms and concepts related to muscle anatomy and physiology, focusing on definitions and functions of various muscle types and structures.

Agonist

The primary muscle responsible for a particular movement; also known as the prime mover.

Antagonist

The muscle that opposes the action of the agonist, often lengthening or stretching during the movement.

Synergists

Muscles that work together to assist the agonist in performing a movement.

Fixators

Muscles that stabilize a joint to allow a specific movement to occur.

Motor Unit

A motor neuron and all of the muscle fibers it innervates.

Fast Twitch Fibers

Muscle fibers that contract quickly and are used for short bursts of speed or power but fatigue rapidly.

Slow Twitch Fibers

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

Recruitment

The process of activating more motor units to increase the strength of muscle contraction.

Myoglobin

A protein in muscle cells that binds oxygen and is important for aerobic respiration.

Aponeurosis

A flat, fibrous connective tissue that connects muscles to the parts they move.

Erector Spinae

A group of muscles that run along the spine and are responsible for keeping the body upright.

Hypertrophy

The increase in muscle size resulting from exercise or strength training.

Atrophy

The decrease in muscle size due to disuse or injury.

Lineal Alba

A fibrous structure that runs vertically down the midline of the abdomen.

Quadriceps

A group of four muscles located at the front of the thigh responsible for knee extension.

Hamstrings

A group of three muscles located at the back of the thigh responsible for knee flexion.

Tendon

A fibrous connective tissue that attaches muscle to bone.

Sarcoplasmic Reticulum

A specialized endoplasmic reticulum involved in muscle contraction.

Calcium

An important ion that triggers muscle contraction.

Biceps Brachii

A muscle in the upper arm that has two heads and is primarily responsible for flexing the elbow.