Why the testes in human beings and mammals are situated outside the abdominal cavity within a pouch called scrotum ?

Options

A. There is not enough space in the pelvic area for the testicless to be housed internally
B. The scrotum helps in maintaining the low temperature of testes , `2.5^(@)C` lower than normal body temperature required for spermatogenesis
C. The scrotum helps in maintaining the high temperature of testis `2.5^(@)C` higher than the normal body temperature required for spermatogenesis
D. Providing more space for the growth of epididymis

Answer

### Step-by-Step Solution:

1. **Understanding the Location of Testes**:
- The testes in human beings and other mammals are located outside the abdominal cavity in a pouch called the scrotum.

2. **Function of Testes**:
- The primary function of the testes is spermatogenesis, which is the process of sperm formation.

3. **Temperature Requirement for Spermatogenesis**:
- Spermatogenesis requires a temperature that is 2-3 degrees Celsius lower than the normal body temperature. This lower temperature is essential for the proper development and maturation of sperm.

4. **Role of the Scrotum**:
- The scrotum provides an external environment that helps maintain this lower temperature necessary for spermatogenesis. By being outside the abdominal cavity, the testes can regulate their temperature more effectively.

5. **Conclusion**:
- Therefore, the main reason the testes are situated in the scrotum is to ensure that they remain at the optimal temperature for sperm production, which is lower than the body’s internal temperature.