Human Anatomy Chapter 5 Vocabulary

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

Agonist

Role played by a skeletal muscle to cause a movement

Antagonist

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

Aponeurosis

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

Concentric

A type of contraction that results in shortening of a muscle

Cross Bridges

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

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

Hernia

A balloon-like section of the lining of the abdominal cavity that produces through a hole or weakened section of the muscle

Isometric

A type of contraction that involves no change in muscle length

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 and terminal and a muscle fiber

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

Sarcomeres

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

Synaptic Cleft

The tiny gap that separated the axon terminal and muscle fiber

Contusion

The bruises or bleeding within a muscle that result from impact