Muscle Terms

terms

Flexion

closing the angle at a joint

extension

opening the angle at a joint

abduction

movement away from the midline of the body

adduction

movement toward the midline of the body

rotation

turning of a body part on its own axis

circumduction

circular movement from a central point

pronation

turning downward

supination

turning upward

eversion

turning outward

inversion

turning inward

dorsiflexion

bending backward

plantar flexion

bending the sole of the foot

acetylcholine

a neurotransmitter that stimulates contraction of skeletal muscles

actin

one of the two contractile proteins in muscle cells; the other is myosin

agonist

a muscle that carries out a given movement

antagonist

the muscle that opposes an agonist;it must relax when the agonist contracts

cardiac muscle

involuntary muscle that makes up the heart wall

fascia

the fibrous sheath of connective tissue that covers a muscle ; called deep fascia to differentiate it from the superficial fascia that underlines the skin

fascicle

a small bundle, as of muscle or nerve fibers

insertion

in a given movement, the point where a muscle is attached to a moving part of the skeleton

muscle

an organ that produces movement by contracting; also the tissue that composes such organs

myosin

one of the two contractile proteins in muscle cells ; the other is actin

neuromuscular junction (NMJ)

the point of contract,or synapse, between a branch of motor neuron and a muscle cell

origin

in a given movement, the point where a muscle is attached to a stable part of the skeleton

prime mover

the main muscle involved in a given movement

skeletal muscle

voluntary muscle that moves the skeleton and maintains posture

smooth muscle

involuntary muscle that makes up the wall of hollow organs, vessels, and ducts; visceral muscle

synergist

a muscle that assists a prime mover to produce a given movement

tendon

a fibrous band of connective tissue that attaches a muscle to a bone

tonus

a state of steady, partial muscle contraction that maintains firmness; muscle tone