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.