Exam 12: A: Physiology of the Muscular System

Muscle cells have one nucleus and one mitochondrion.

Muscle fibers of skeletal muscle contain several nuclei.

Each motor neuron in the motor unit is able to stimulate as many as two dozen muscle fibers.

When smooth muscles have rhythmic contractions called peristalsis,they are able to move food through the digestive tract.

When the sarcomere contracts,the A-bands become smaller.

The term striated involuntary muscle refers to cardiac muscle.

Hemoglobin carries oxygen in red blood cells,and myoglobin stores oxygen in muscle fibers.

The type of contraction exhibited by normal skeletal muscles most of the time is called tetanus.

Muscles with less-than-normal tone are described as in tetanus.

A tetanic contraction is stimulated by a single stimulus.

When the sarcomere contracts,the I-bands become smaller.

The degree of a muscle's strength is influenced by many factors,including its metabolic condition and number of motor units recruited.

The liver has the ability to convert lactic acid back into glucose.

Cardiac fibers form a continuous electrically coupled mass called a syncytium.

There are three high energy bonds in an ATP molecule.

A motor neuron is considered part of the neuromuscular junction.

Excitability and irritability are interchangeable terms in regard to muscle cells.

Oxygen molecules in the sarcoplasm are bound to the troponin molecule.

Skeletal muscles produce a major share of the heat generated by the body.

T-tubules are found in all types of muscle tissue.