Chapter 6 - Vocab 1: Intro to Muscles

aponeurosis

a broad, flat sheet of dense connective tissue to which muscles attach

antagonist

a muscle that reverses a particular movement

involuntary

cannot be consciously controlled; controlled through the action of the nervous system

tendon

dense fibrous tissue which attaches muscle to bone

hypertrophy

enlargement of muscles from overuse

smooth (visceral) muscle

found in walls of hollow organs which act to move substances within the body; involuntary; spindle-shaped; uninucleate, non-branching

cardiac muscle

found only in the heart which serves to move blood through rhythmic contractions; striated; involuntary; uninucleate; branching

muscle fibers

groupings of muscle cells that compose muscle tissue

prime mover (agonist)

muscle that has the major responsibility for causing a particular movement when many muscles are working together at the same time

flexor

muscle that produces a movement that decreases the angle between a muscle's origin and insertion

extensor

muscle that produces a movement that increases the angle between a muscle's origin and insertion

skeletal (striated) muscle

muscle tissue attached to bones which aid in movement of the body and have a striped appearance; voluntary; sausage-shaped; multinucleate, non-branching

voluntary

muscle under conscious control

synergist

muscles that help stabilize a movement; they help prime movers accomplish a movement efficiently

tendonitis

painful swelling of a tendon usually caused by repetitive motions that stress the tendons near a joint (ex. tennis elbow)

myosin

protein found in thick filaments of skeletal muscle fibers and acts as a kind of molecular motor that is able, with actin, to make movement in the form of muscle contraction

actin

protein found in thin filaments of skeletal muscle fibers

atrophy

reduction in size of muscle tissue from lack of use

insertion

site of muscle attachment on the movable bone or surface in a joint.

origin

site of muscle attachment to the immovable bone in a joint. (Muscle movement brings movable bone towards the origin).

fixator

specialized synergists that act to hold bones still, as in maintaining body posture control

sprain

stretching or tearing of a ligament

strain

stretching or tearing of a muscle or tendon

contraction

the general ability of a muscle to shorten in length and develop tension in a process that requires energy.

action

the movement caused by a muscle contraction, usually of skin or bone

muscle tone

the state of balanced muscle tension that makes normal posture, coordination, and movement possible

muscle

tissue composed of fibers that can contract, causing movement of an organ or part of the body

rules of muscle contraction

1. For every contraction there is an equal and opposite relaxation, because muscles work in pairs. 2. Muscles can only pull. 3. Muscle contraction requires energy.