Exam 12: A: Physiology of the Muscular System

The A-band in a relaxed sarcomere is composed of only actin.

The study of muscle activity is called myography.

T-tubules are perpendicular to muscle fibers.

T-tubules are formed by an inward extension of the sarcolemma.

Muscles contract more forcefully after they have contracted a few times.

Tetanus will not occur in an individual with an up-to-date tetanus vaccination.

Skeletal muscle has a great ability to stretch.

At rest,troponin covers the active sites on the actin molecules.

Myosin filaments attach to the Z disk.

The H-zone in a relaxed sarcomere is composed of only myosin.

The cell membrane of a muscle fiber is called the sarcoplasmic reticulum.

Myofibrils contain several sarcomeres lined up end to end.

Endurance training usually results in muscle hypertrophy.

A neuromuscular junction is a type of connection called a synapse.

In psychological muscle fatigue,an individual cannot contract his or her muscles.

There are two types of isometric contractions: concentric contractions and eccentric contractions.

Muscle fibers use creatine phosphate to restore their ATP population.

Muscle cells are called fibers because they are long and thin.They can be 40 mm long but only about 10 mm in diameter.

Cramps are painful,involuntary muscle spasms.

During an isotonic contraction,the tension produced by the myosin cross-bridges cannot overcome the load placed on the muscle.