What is atresia with respect to ovary in human females?

Answer

### Step-by-Step Solution:

1. **Definition of Atresia**: Atresia refers to the process of degeneration or breakdown of ovarian follicles in the human female reproductive system.

2. **Context of Menstrual Cycle**: The menstrual cycle typically lasts about 28 days. During this cycle, several follicles begin to develop in the ovaries.

3. **Follicle Development**: Throughout the menstrual cycle, particularly in the first half, multiple follicles grow and mature, preparing for potential ovulation.

4. **Timing of Atresia**: Atresia primarily occurs around the 14th day of the menstrual cycle. This is the time when ovulation is expected to happen.

5. **Lack of Fertilization**: If fertilization does not occur after ovulation, the follicles that were developing will begin to degenerate.

6. **Process of Follicular Breakdown**: As the follicles start to degenerate, they lose their defined structure and undergo a transformation into an irregular shape.

7. **Final Structure**: The irregular structure formed from the degenerating follicles is referred to as follicular atresia.

8. **Conclusion**: Atresia is a normal physiological process in the menstrual cycle, indicating the breakdown of non-dominant follicles when fertilization does not take place.