Muscle Physiology Quiz

Which type of muscle is involuntary and found in the walls of internal organs?

• Skeletal

• Cardiac

• Smooth

• Voluntary

Which muscle type is responsible for moving the skeleton?

• Cardiac

• Smooth

• Skeletal

• None of the above

Cardiac muscle cells are unique because they are:

• Multinucleated

• Striated

• Non-striated

• Cylindrical

Smooth muscle is characterized by:

• Striations

• Spindle-shaped cells

• Intercalated discs

• Voluntary control

The functional unit of skeletal muscle is called:

• Myofibril

• Sarcomere

• Muscle fiber

• Myosin

Which protein in muscle fibers is responsible for contraction?

• Actin

• Myosin

• Troponin

• Tropomyosin

The action potential in a muscle fiber is initiated by:

• Calcium ions

• Sodium ions

• Potassium ions

• Chloride ions

The sliding filament theory explains muscle contraction by:

• Muscles shortening by sliding actin and myosin past each other

• Muscles contracting without energy

• Myosin pulling on connective tissue

• Actin expanding and pushing myosin away

What happens during direct phosphorylation of ADP?

• ATP is produced by the breakdown of glucose

• Creatine phosphate donates a phosphate to ADP

• Lactic acid is produced

• Oxygen is required

The primary energy source for muscle contraction during the first few seconds of high-intensity exercise is:

• Aerobic respiration

• Anaerobic glycolysis

• Creatine phosphate

• Fatty acids