Question

How and at what stage of menstrual cycle is corpus luteum formed in human females? When does it regress?

Answer 1

• Corpus luteum is formed in an ovary at the site of a follicle, or sac, that has matured and released its ovum, or egg, in the process known as ovulation of menstrual cycle. It is a yellow hormone-secreting body made up of lutein cells ), which develop immediately following ovulation, when yellow pigment and lipids accumulate within the granulosa cells lining the follicle. The size of the corpus luteum is highly variable.
  
• If the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.