Question

The main cause of muscle fatigue
A. Acetic acid
B. Water
C. Lactic acid
D. Hydrochloric acid

Answer 1

Muscles is a soft tissue found in most animals . Muscle cells contain protein filaments of actin and myosin that slide past one another producing a contraction that changes both the length and the shape of the cell.

Complete answer:
1. Aerobic respiration gives more energy but it is a slow process anaerobic respiration like lactic acid fermentation is a fast process but releases less energy.
2. In the case of rapid muscular contraction the muscle performs lactic acid fermentation to provide for rapid energy intake for work. This process releases lactic acid and which causes pain in muscle and muscle fatigue.

Additional Information: Muscles function to produce force and motion . Their primary function is to maintain and change posture and locomotion as well as a moment of internal organs such as the contraction of the heart and the movement of food through the digestive tract via peristalsis.
There are three types of muscle: skeletal muscle, smooth muscle, and cardiac muscle.
Muscle action can be classified as either voluntary or involuntary.
Cardiac and smooth muscles contract without conscious thought and are termed involuntary.
Whereas skeletal muscles are considered voluntary.

So, the correct answer is “Option C Lactic acid”.

Note: Muscle tissues are derived from the mesodermal layer . And are formed by embryonic germ cells in a process known as myogenesis. Muscle fatigue can occur due to various reasons like Addison's disease, age, anaerobic infections, anemia, anxiety, botulism, cerebral palsy, etc.