Muscle Anatomy and Physiology

Flashcards based on muscular system anatomy, types of muscles, contraction mechanisms, and muscle movements.

There are three types of muscles: skeletal, cardiac, and __.

smooth

Cardiac muscle is __ and is found only in the heart.

involuntary

Skeletal muscles are characterized by their __ appearance due to striations.

striated

Muscle fibers are surrounded by connective tissue layers: endomysium, __, and epimysium.

perimysium

The __ is the smallest contractile unit of a muscle fiber.

sarcomere

The process that explains how muscles contract is known as the __ theory.

sliding filament

Muscles can contract in different ways: isotonic, isometric, and __.

isokinetic

Muscle fatigue is often caused by __ debt, which is the amount of oxygen needed after exercise to return to resting state.

oxygen

A motor unit consists of a single motor neuron and all of the muscle fibers it __.

innervates

During muscle contraction, the __ moves toward the origin of the muscle.

insertion

The __ is the type of muscle contraction that leads to a muscle shortening.

concentric

Flexion is a movement that __ the angle of a joint.

decreases

Skeletal muscle must be stimulated by a __ to contract.

nerve

The gaps between nerve and muscle fibers are known as __ clefts.

synaptic

Muscles that resist or reverse the action of a prime mover are called __.

antagonists

Stretching and contracting of a muscle fibers without shortening is known as __ contraction.

isometric

During graded responses, a twitch is a single brief jerky __ caused by a brief stimulus to the muscle.

contraction

Isotonic

constant muscle tension with a change in length, seen when walking/jumping/squatting etc.

Concentric

occurs when a muscle contracts and shortens, generation force to move a load

Eccentric

occurs when a muscle lengthens under tension, working to accelerate a joint at the end of a movement

Isometric

a change in muscle tension with no change in muscle length, seen when pushing against an immovable object or attempting to lift something that is too heavy

Isokinetic

contraction of the same speed, typically to a beat/machine