Muscle Terminology 1

the dynamic motion or movement produced when the muscles contract

the part of the muscle attached to the moving point

the part of the muscle attached to the stable point

muscles that:
- usually originate and insert on the axial skeleton
- position the head
- position the vertebral column
- move the ribs
- compress the abdomen

muscles that stabilize the pectoral and pelvic girdles and move the upper and lower limbs.

bundle of muscle cells (muscle fibers)

fascicles are parallel to the long axis of the muscle;
terminates at either end in a broad tendon;
example: biceps brachii

parallel fascicle with a thicker belly (central body);
terminates at either end in a broad tendon;
example: biceps brachii

fascicle forms an oblique angle to the tendon (like a feather)

short pennate fascicles run down one side of the tendon;
example: extensor digitorum longus

short pennate fascicles run down both sides of the tendon;
example: rectus femoris

muscle where the tendon branches within the muscle and short pennate fascicles are attached to each tendon branch;
example: deltoid

long fascicles of muscles based over a broad area that converge, coming together at a common attachment site;
example: pectoralis major

circular muscle;
fascicles are concentrically arranged around an opening or recess;
examples: orbicularis oris (around mouth), orbicularis oculi (around eye)

collagenous sheets or ribbons that resemble flat, broad tendons;
may cover the surface of a muscle and assist in attaching superficial muscles to another muscle or structure

cords of dense regular tissue that attach skeletal muscles to bone;
the collagen fibers run along the longitudinal axis of the bone

the arrangement of fascicles determines range and power;
example: parallel muscle - longer fascicles produce greater range of movement;
example: multipennate muscle - more fascicles produce more power

rigid structure that moves at a fixed point called the fulcrum;
anatomically, the bone is the lever and the joint is the fulcrum

the fixed point upon which a lever moves;
anatomically, the joint is the fulcrum and the bone is the lever

the force applied to the lever to move a load or weight or counteract a resistance;
anatomically, muscle contraction is the applied force

the load or weight being moved by the applied force to a lever

lever in which the fulcrum is between the applied force and the resistance;
common example: seesaw;
anatomical example:
fulcrum: atlanto-occipital joint;
force: splenius capitis;
weight: head

lever in which the resistance is between the applied force and the fulcrum;
common example: wheelbarrow;
anatomical example:
fulcrum: metatarsophalangeal joints (ball of foot);
force: gastrocnemius;
weight: body mass on middle of foot during plantar flexion while standing

lever in which the applied force is between the resistance and the fulcrum;
common examples: baseball bat, tweezers;
anatomical example:
fulcrum: elbow;
force: biceps brachii;
weight: forearm and hand

(white line) tendinous band that runs along the midline of the rectus abdominis

the action produced at a joint by a group of muscles working together;
a muscle in the group may play the role of agonist, antagonist, synergist, or fixator in order to perform the action;
example:
group action: flex forearm at elbow;
agonist: biceps brachii;
antagonist: triceps brachii;
synergist: brachialis, brachioradialis;
fixator: deltoid, pectoralis major, etc.

the muscle that contracts to produce the action;
it is the muscle whose contraction is chiefly responsible for producing the particular movement

agonist

the muscle that relaxes when the agonist contracts

the muscle that also contracts to help the agonist

the muscle that contracts in order to stabilize the joint