Muscle Physiology Quiz

What is the basic contractile unit of a muscle fiber?

• Myofibril

• Sarcomere

• Sarcolemma

• Sarcoplasm

Z-lines in a sarcomere represent?

• End of myosin

• Attachment of actin

• Center of sarcomere

• End of sarcolemma

Which band shortens during muscle contraction?

• A band

• I band

• H zone

• Z line

Sliding filament theory involves interaction between?

• Actin & Myosin

• Calcium & ATP

• Myosin & Tropomyosin

• Actin & Troponin

What ion is essential for muscle contraction?

• Sodium

• Potassium

• Calcium

• Magnesium

Tropomyosin in resting state prevents binding of?

• Myosin to actin

• ATP to actin

• Calcium to myosin

• Actin to troponin

ATP is required for which step in muscle contraction?

• Attachment of actin

• Detachment of myosin

• Release of calcium

• Formation of troponin complex

Wallerian degeneration occurs in?

• Distal part of cut axon

• Proximal part

• Cell body

• Neuromuscular junction

Which cell aids regeneration of axons?

• Schwann cell

• Oligodendrocyte

• Astrocyte

• Microglia

Saltatory conduction occurs in?

• Unmyelinated fibers

• Myelinated fibers

• Both

• None