Muscular System Quiz

Which of the following is NOT listed as a major function of the muscular system?

• Maintenance of posture

• Production of body heat

• Storage of minerals

• Movement of the body

The ability of muscle tissue to be stretched beyond its normal resting length and still be able to contract is known as:

• Contractility

• Excitability

• Extensibility

• Elasticity

Which type of muscle tissue is involuntary, unstriated, spindle-shaped, and found in the walls of hollow organs?

• Skeletal Muscle

• Smooth Muscle

• Cardiac Muscle

• Autorhythmic Muscle

Which characteristic is unique to Cardiac Muscle when compared to Skeletal and Smooth muscle in the table?

• Has striations

• Is involuntary

• Has intercalated discs

• Is autorhythmic

Skeletal muscle constitutes approximately what percentage of the body's weight?

• 10%

• 25%

• 30%

• 40%

The basic structural and functional unit of a skeletal muscle, defined as the smallest portion capable of contracting, is the:

• Myofibril

• Fasciculus

• Sarcomere

• Z disk

Which band in the sarcomere is light staining and consists of ONLY ACTIN myofilaments?

• A bands

• H zones

• I bands

• M line

The RESTING MEMBRANE POTENTIAL is characterized by which charge distribution across the cell membrane?

• Positive charge on the inside relative to a negative charge outside.

• Negative charge on the inside relative to a positive charge outside.

• Equal positive and negative charges inside and outside.

• Only POTASSIUM ions moving outside the cell.

During the depolarization phase of an Action Potential, which ion moves into the muscle cell?

• Potassium ions

• Calcium ions

• Sodium ions

• Chloride ions

The cell-to-cell junction between a nerve cell and a muscle fiber is specifically called the:

• Synapse

• Motor end-plate

• Presynaptic terminal

• Neuromuscular junction