muscle tissue fibers
The bundles of muscle tissue that form a muscle.
muscles
Muscles are bundles of parallel muscle tissue fibers. As there fibers contract (shorten in length) they pull whatever they are attached to closer together. This may move two bones closer together or make an opening more narrow. A muscle contraction occurs
cardiac muscle
The involuntary muscle found in the heart.
involuntary muscles
Muscles under the control of the subconscious regions of the brain. The smooth muscles found in internal organs and cardiac muscles are examples of involuntary muscle tissue.
skeletal muscle
A voluntary muscle that is attached to bones by a tendon.
smooth muscle
An involuntary muscle found in internal organs such as the digestive organs or blood vessels.
voluntary muscles
Muscles that a person can consciously choose to contract. The skeletal muscles of the arm and leg are examples of this type of muscle.
fascia
Connective tissue that wraps muscles. It tapers at each end of a skeletal muscle to form tendons.
motor neurons
Nerves that carry activity instruction from the CNS to muscles or glands out in the body; also called efferent neurons.
myoneural junction
The point at which a nerve contacts a muscle fiber.
striated muscle
Another name for skeletal muscle referring to its striped appearance under the microscope.
tendon
The strong connective tissue cords that attach skeletal muscles to bones.
visceral muscle
The muscle found in the walls of internal organs such as the stomach.
myocardium
The middle layer of the muscle. It is thick and composed of cardiac muscle. This layer produces the heart contraction.
biceps
An arm muscle named for the number of attachment points. Bi- means two and biceps have two heads attached to the bone.
extensor carpi
A muscle named for its action, extension.
external oblique
A muscle named for the direction of its fibers, on an oblique angle.
flexor carpi
A muscle named for its action, flexion.
gluteus maximus
A muscle named for its size and location: gluteus means rump area and maximus means large.
rectus abdominis
A muscle named for its location and the direction of its fibers: rectus means straight and abdominis means abdominal.
sternocleidomastoid
Muscle named for its attachments, the sternum, clavicle, and mastoid process.
action
The type of movement a muscle produces.
antagonistic pairs
Pair of muscles arranged around a joint that produce opposite actions.
insertion
The attachment of a skeletal muscle to the more movable bone in the joint.
origin
The attachment of a skeletal muscle to the less movable bone in the joint.