NEETZoologyLocomotion and Movement
A sprinter experiences acute muscle fatigue and stiffness in his legs immediately after a strenuous 400-metre race. Which of the following best describes the physiological and molecular state of his skeletal muscles during this condition?
Options
- AAccumulation of lactic acid due to aerobic breakdown of glycogen, leading to the permanent breakage of cross-b
- BDepletion of calcium ions in the sarcoplasm, which prevents the hydrolysis of ATP required for cross-bridge de
- CAccumulation of lactic acid due to anaerobic breakdown of glycogen, accompanied by a depletion of ATP which hi
- DAccumulation of lactic acid due to anaerobic respiration, which accelerates the binding of new ATP molecules t
Correct answer
C. Accumulation of lactic acid due to anaerobic breakdown of glycogen, accompanied by a depletion of ATP which hi
Step-by-step solution
According to NCERT, repeated and intense activation of skeletal muscles leads to the anaerobic breakdown of glycogen, resulting in the accumulation of lactic acid which causes muscle fatigue. During the cross-bridge cycle, the binding of a new ATP molecule to the myosin head is strictly required to break the cross-bridge and detach it from the actin filament. In a highly fatigued state, the depletion of available ATP hinders this detachment, contributing to muscle stiffness. Option 1 is incorrect because lactic aci