Muscle Terminology & Nomenclature Flashcards
Agonist
A muscle that is a prime mover or primarily responsible for the movement
Antagonist
A muscle that counteracts the action of the prime mover. This muscle will relax or stretch when the agonist contracts.
Synergist
A muscle that works to assist a prime mover (Agonist) to create movement or stabilize a joint where the movement is occurring.
Atrophy
When a muscle is wasting or decreasing in size.
Hypertrophy
When a muscle increases in size or even overgrows.
Hypotonicity
An abnormal decrease in resting muscle tone. Usually indicates a long standing problem. The muscle will feel soft and squishy to the touch.
Hypertonicity
An abnormal increase in resting muscle tone. Usually indicates an issue involving inflammation and irritation to a peripheral nerve (such as spinal joint dysfunction). Upon palpation, the muscle will feel extremely tight and often with spasms.
Extrinsic
A muscle whose origin begins in one system and insertion crosses or bridges another system as in the axial skeletal system to an appendicular system.
Intrinsic
A muscle whose origin begins in one system and the insertion ends in the same system.
Origin
The proximal end of the muscle, which is usually closest to the body. It serves as an anchor for movement during the contraction phase.
Insertion
The distal end of the muscle, which has crossed at least one joint and attached to a movable part. Upon contraction of the muscle (shortening), movement will occur.
Expaxial
Muscles positioned dorsal to the transverse processes of the spinal column
Hypaxial
Muscles positioned ventral to the transverse processes of the spinal column.
Major
Greater in size or function
Minor
Lesser in size or function
