When a skeletal muscle works hard,
A) and pH increase.
B) pH increases and declines.
C) pH declines and increases.
D) pH and increase.
E) pH and decline.

Question

When a skeletal muscle works hard,
A) and pH increase. 
B) pH increases and declines. 
C) pH declines and increases. 
D) pH and increase. 
E) pH and decline.

Quizplus · Accepted Answer

When a skeletal muscle works hard, it undergoes anaerobic respiration, resulting in the production of lactic acid. The accumulation of lactic acid causes the pH of the muscle to decline. Additionally, during hard work, the muscle requires a large amount of ATP for energy, which leads to an increase in the concentration of inorganic phosphate (Pi). This increase in Pi interferes with the muscle's ability to generate force, causing a decline in force production. Therefore, pH declines and force production decreases.

When a Skeletal Muscle Works Hard