BSC 2085 Lab 7 – Muscular System Vocabulary

A comprehensive set of vocabulary flashcards covering muscle structure, movement terminology, muscle-naming conventions, tissue types, and key anatomical terms from Lab 7.

Muscle fiber

A single muscle cell that contracts when stimulated by a motor neuron.

Fascicle

A bundle of muscle fibers grouped together within a muscle.

Perimysium

Connective-tissue sheath that surrounds each fascicle.

Endomysium

Delicate connective tissue filling the spaces between individual muscle fibers; its extensions form tendons.

Epimysium

Tough outer connective-tissue layer that encloses all fascicles of a muscle.

Origin (of a muscle)

Muscle attachment to the immovable or less movable bone.

Insertion (of a muscle)

Muscle attachment to the movable bone.

Agonist (prime mover)

The primary muscle responsible for a specific movement.

Antagonist

Muscle that opposes or reverses the action of an agonist.

Synergist

Muscle that contracts at the same time as the agonist to assist its action.

Fixator

Muscle that stabilizes a bone at the origin of an agonist to allow efficient movement.

Flexion

Bending a joint to decrease the angle between two bones.

Extension

Straightening a joint to increase the angle between two bones.

Dorsiflexion

Flexing the foot toward the shin.

Plantar flexion

Extending the ankle so the toes point downward.

Abduction

Movement away from the midline of the body.

Adduction

Movement toward the midline of the body.

Supination

Turning the palm anteriorly (upward).

Pronation

Turning the palm posteriorly (downward).

Protraction

Moving a body part anteriorly in the transverse plane.

Retraction

Moving a body part posteriorly in the transverse plane.

Elevation

Raising a body part superiorly.

Depression

Lowering a body part inferiorly.

Inversion

Turning the sole of the foot inward.

Eversion

Turning the sole of the foot outward.

Circumduction

Circular movement combining flexion, extension, abduction, and adduction.

Opposition

Movement of the thumb to touch the fingertips; basis of tool use.

Rotation

Moving a bone around its own longitudinal axis.

Rectus (fiber direction)

Muscle fibers that run straight or parallel to the body’s midline.

Transverse (fiber direction)

Muscle fibers that run horizontally across the body.

Oblique (fiber direction)

Muscle fibers that run diagonally to the body’s midline.

Pectoralis (location)

Muscle located in the chest region.

Brachialis (location)

Muscle located in the arm (brachium).

Deltoid (shape)

Triangular-shaped shoulder muscle.

Trapezius (shape)

Large trapezoid-shaped muscle covering the upper back and neck.

Sternocleidomastoid (origin & insertion)

Neck muscle originating on sternum and clavicle, inserting on mastoid process.

Biceps (number of origins)

Muscle with two heads of origin.

Triceps (number of origins)

Muscle with three heads of origin.

Quadriceps (number of origins)

Group of muscles with four heads of origin.

Flexor (action name)

Muscle whose primary action is flexion of a joint.

Extensor (action name)

Muscle whose primary action is extension of a joint.

Levator (action name)

Muscle that raises or elevates a body part.

Adductor (action name)

Muscle that moves a limb toward the body midline.

Supinator (action name)

Muscle that turns the palm anteriorly.

Masseter

Jaw-closing muscle responsible for chewing (mastication).

Skeletal muscle tissue

Long, cylindrical, striated, multinucleate cells under voluntary control; produces body movement and posture.

Cardiac muscle tissue

Short, branched, striated cells with a single central nucleus and intercalated discs; involuntary; found in the heart.

Smooth muscle tissue

Short, spindle-shaped, non-striated cells with a single central nucleus; involuntary; lines viscera and vessels.

Dense regular connective tissue

Tissue of parallel collagen fibers that forms tendons and ligaments; resists pulling in one direction.

Tendon

Cord of dense regular connective tissue that connects muscle to bone.

Neuromuscular junction

Synapse between a motor neuron and a muscle fiber where nerve impulses trigger contraction.