Download Muscular System (Human): Key Words

Muscular System (Human): Key Words
Cardiac muscle
Skeletal muscle
Smooth muscle
Abductor A muscle that moves a bone
(or limb) away from the body’s midline.
Adductor A muscle that moves a bone
(or limb) toward the body’s midline.
Biceps A muscle with two heads: biceps
brachii in the upper arm and biceps
femoris in the thigh.
Brachialis A muscle in the upper arm.
Brevis The shortest of similarly named
muscles, such as peroneus brevis.
Buccinator A cheek muscle involved in
chewing.
Cardiac muscle Involuntary striated
muscle, found only in the heart.
Deltoid The triangular shoulder muscle.
Depressor A muscle that results in
downward movement.
Diaphragm The muscular sheet that
separates the thorax and abdomen. It
contracts and flattens during inspiration,
and relaxes and becomes dome-shaped
during expiration.
Extensor A muscle that increases the
angle of a joint.
Fascia Connective tissue formed into
layers. One type, deep fascia, forms
sheaths around individual muscles.
Fascicle (or Fasciculus) A bundle of
muscle or nerve fibers.
Flexor Decreases the angle of a joint.
Gastrocnemius A muscle in the calf.
Gluteus One of the three paired muscles
in the buttocks. Gluteus maximus is the
body’s largest muscle.
Insertion The point of attachment of a
muscle that is relatively movable when
the muscle contracts.
Involuntary muscle Muscle that is not
under conscious control. See also
Smooth muscle; Cardiac muscle.
Levator Results in upward movement.
Masseter A cheek muscle used to chew.
Maximus The largest among similar
muscles, such as gluteus maximus.
Minimus The smallest of similar
muscles.
Muscle Tissue that shortens to
make part of the body move. There are
three types: skeletal, cardiac, and
smooth. Skeletal and cardiac muscle
have striped fibers. Only skeletal muscle
is under conscious control.
Myocardium Cardiac muscle forming
the middle layer of the heart wall.
Orbicularis A muscle with fibers that run
in a circular direction, for example
orbicularis oculi (around the eye) or
orbicularis ori (around the mouth).
Origin The point of attachment of a
muscle that remains relatively fixed when
the muscle contracts.
© Diagram Visual Information Ltd.
Pectoral muscles The chest muscles:
pectoralis major and pectoralis minor.
Peristalsis Waves of muscular
contraction that propel substances
through passageways, such as the
alimentary canal.
Peroneus Peroneus longus and
peroneus brevis are muscles arising from
the fibula.
Pronator Turns the palm downward.
Rectus A muscle with straight fibers,
such as rectus femoris in the thigh.
Rhomboideus A rhomboid-shaped
muscle, such as rhomboideus major and
rhomboideus minor in the upper back.
Rotator A muscle that moves a bone
around its longitudinal axis.
Sartorius A muscle at the front of the
thigh: the longest muscle in the body.
Skeletal muscle (or Voluntary muscle)
Muscle attached to bones, consisting of
striated (striped) fibers, and under
conscious control.
Smooth muscle (or Unstriated muscle
or Involuntary muscle) Muscle without
striped fibers that automatically operates
internal organs such as the stomach,
bladder, and blood vessels.
Soleus A broad flat muscle in the calf.
Sphincter A ring-shaped muscle that
contracts to close an orifice.
Sternocleidomastoid A neck muscle
extending from the mastoid to the
clavicle that rotates the neck and flexes
the head.
Striated muscle Muscle with striped
fibers, especially skeletal muscle.
Tendons Bands of fibrous connective
tissue joining muscles to bones.
Tensor A muscle that increases rigidity.
Teres A round muscle, such as teres
major and teres minor in the shoulder.
Tibialis One of two muscles in the calf
attaching the tibia to the metatarsals.
Transversus A muscle with fibers at
right angles to the midline, for example
transversus abdominis.
Trapezius A trapezoid-shaped muscle
over the back of the neck and shoulder.
Triceps A muscle with three heads,
especially triceps brachii in the upper
arm.
Unstriated muscle Muscle without
striped fibers. See also Smooth muscle.
Vastus A term denoting a huge muscle,
such as vastus lateralis in the thigh.
Voluntary muscle See Skeletal muscle.