Muscle Physiology | MCQs

Explanation

Muscle tissues are responsible for movement through contraction and relaxation.

They enable functions like heartbeat, digestion, and voluntary movements.

Explanation

• Protein fibers like actin and myosin take part in muscle: Contraction
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• Muscles are composed of two major protein filaments:
• a thick filament composed of the protein myosin and a thin filament composed of the protein actin.
• Muscle contraction occurs when these filaments slide over one another in a series of repetitive events.
  

Explanation

After muscle contraction, calcium is pumped back into the sarcoplasmic reticulum for muscle recovery.

Explanation

The muscles that never fatigue are the heart muscle (cardiac muscle)

Cardiac muscle has more mitochondria than skeletal muscle (up to 35% compared to 1-2%), Which makes it resistant to fatigue.

Mitochondria are essential for generating ATP, the cell's energy source.

Other muscles, such as skeletal muscles, can experience fatigue and failure under strenuous conditions.

Explanation

• The muscle part of the heart is called:  Myocardium
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• The cardiac muscle (or myocardium) makes up the thick middle layer of the heart.
• It is one of three types of muscle in the body, along with skeletal and smooth muscle.
  
  

Explanation

Once the myosin-binding sites are exposed, and if sufficient ATP is present, myosin binds to actin to begin cross-bridge cycling.