Muscular Tissue

Which type of muscle tissue is under direct voluntary control?

• Cardiac muscle

• Smooth muscle

• Skeletal muscle

• None of the above

What is the functional unit of skeletal muscle called?

• Actin

• Sarcomere

• Troponin

• Myofibril

Which statement best describes the regulation of cardiac muscle tissue?

• Non-striated

• It is under voluntary control

• Regulated by the endocrine system
• Regulated by the autonomic nervous system

Which property of muscular tissue refers to its ability to respond to stimuli by generating action potentials?

• Excitability

• Elasticity

• Contractility
• Extensibility

The outermost layer of connective tissue that surrounds the entire skeletal muscle is called:

• Perimysium
• Epimysium

• Myofibril
• Endomysium

Which protein filament in a sarcomere is primarily responsible for generating the force of muscle contraction?

• Myosin

• Tropomyosin

• Troponin

• Actin

The A-band in a sarcomere corresponds to the region where:

• Only myosin filaments are present

• Only actin filaments are present

• Both myosin and actin filaments overlap

• Neither myosin nor actin filaments are present

Which ion is released from the sarcoplasmic reticulum to initiate muscle contraction?

• Calcium (Ca2+)
• Chloride (Cl-)

• Sodium (Na+)
• Potassium (K+)

The power stroke in muscle contraction refers to:

• ATP hydrolysis by myosin heads

• Release of ADP and phosphate by myosin heads

• Sliding of actin filaments past myosin filaments

• Detachment of myosin heads from actin filaments

During muscle contraction, which regulatory protein binds to calcium ions and moves tropomyosin away from the myosin-binding sites on actin?

• Myosin

• Actin

• Tropomyosin

• Troponin