AHS 22002 Clinical Kinesiology - Muscular Structure and Function

Flashcards covering the key concepts from the lecture on muscular structure and function, including definitions and differing types of muscle functions.

Muscle

A bundle of red contractile fibers held together by a sheath of connective tissue.

Agonist

The muscle responsible for producing desired motion at a joint.

Antagonist

Muscle that produces action opposite the agonist.

Synergist

A muscle that works with one or more other muscles to enhance a motion.

Reciprocal Inhibition

When a muscle is contracting, its antagonist is relaxing (inhibited).

Co-Contraction

The agonist and antagonist contract at the same time to provide stability.

Active Insufficiency

Due to excessive shortening of the muscle, the force the muscle produces is decreased.

Passive Insufficiency

The inactive antagonist is not long enough to allow full range of motion of the agonist.

Golgi Tendon Organ

Sensory receptor that detects tension within the muscle; functions to inhibit muscle action.

Muscle Spindle

Sensory receptor that detects changes in the length of the muscle and the speed of the change.

Isotonic Contraction

Contraction in which tension remains constant as the length changes.

Isometric Contraction

Contraction involving force production without a change in length.

Isokinetic Contraction

Contraction where the speed of the joint movement is kept constant.

Tonic Muscles

Muscles that maintain joint stability by providing large amounts of compression.

Phasic Muscles

Muscles that provide movement and react quickly to immobilization.

Myoneural Junction

Where the nerve cell comes into contact with the muscle fiber.

Motor Unit

The final common pathway consisting of the alpha motor neuron, axon, and muscle fibers.

All or None Law

When a muscle fiber is stimulated by a nerve to contract, it will contract maximally.

Tenodesis

Grip created through passive insufficiency of the long finger tendons.