Question

Which of the following muscles gets fatigued very soon?

• A. Skeletal muscle
• B. Smooth muscle
• C. Cardiac muscle
• D. All of the above

Answer 1

The correct option is A Skeletal muscle

• Muscle fatigue refers to a decrease in muscle force generated over time.
• Skeletal muscles are used to move the bones in the body and may get fatigued because of overexertion.
• Overexertion such as intensive exercise results in depletion of oxygen levels in the muscles. So, the muscles shift temporarily to anaerobic metabolism to generate energy. This is done by the formation of lactic acid and energy. Accumulation of lactic acid in muscles leads to muscle fatigue.
• The cardiac muscles are resistant to fatigue as they contain large numbers of mitochondria (powerhouses of the cell), enabling continuous aerobic respiration and ATP production required for mechanical muscle contraction. The rate of contraction and relaxation in smooth muscles is very slow which consumes less ATP. Thus, smooth muscles also do not experience fatigue.
  

So, the correct answer is option A.