Unit 5 - Human A&P

Agonist

Role played by a skeletal muscle to cause movement.

Antagonist

Role played by a skeletal muscle acting to slow or stop a movement.

Aponeurosis

A flat, sheetlike fibrous tissue that connects muscle or bone to other tissues.

Concentric

A type of contraction that results in shortening of a muscle.

Eccentric

Contraction accompanied by lengthening of a muscle.

Endomysium

A fine, protective sheath of connective tissue around a skeletal muscle fiber.

Epimysium

The outermost sheath of connective tissue that surrounds a skeletal muscle.

Fascicle

A bundle of muscle fibers.

Isometric

A type of contraction that involves no change in muscle length.

Perimysium

A connective tissue sheath that envelops each primary bundle of muscle fibers.

Peristalsis

A wave of symmetrical squeezing of the digestive tract walls that occurs during digestion to move food along the GI tract.

Sarcolemma

The delicate membrane surrounding each striated muscle fiber.

Acetylcholine

A neurotransmitter chemical that stimulates muscle.

Action Potential

The electric charge produced in nerve or muscle fiber by stimulation; nerve impulse caused by a wave of depolarization along the length of a neuron.

Cross Bridges

Connections between the heads of myosin filaments and receptor sites on the actin filaments.

Motor Neuron

A nerve that stimulates skeletal muscle tissue.

Motor Unit

A single motor neuron and all of the muscle fibers that it stimulates.

Neuromuscular Junction

The link between an axon terminal and a muscle fiber.

Sarcomeres

Units composed of actin and myosin that contract inside the muscle fiber.

Synaptic Cleft

The tiny gap that separates the axon terminal and muscle fiber.

Contusion

The bruises or bleeding within a muscle that result from an impact.

Hernia

A balloon-like section of the lining in the abdominal cavity that protrudes through a hole or weakened section of muscles.