When do corpora lutea develop in the estrous cycle?

When do corpora lutea develop in the estrous cycle?

• A. Proestrus
• B. Estrus
• C. Diestrus
• D. Metestrus

Answer: (D)

The timing of luteal formation after ovulation is being tested here. After ovulation, the follicle that released the oocyte begins to transform into the corpus luteum. This luteinization starts during metestrus, and the corpus luteum reaches full, progesterone-producing function in diestrus. So, the development of the corpora lutea begins in metestrus rather than during proestrus or estrus, when ovulation occurs, or during diestrus, when the corpus luteum is already established and actively secreting progesterone.

The timing of luteal formation after ovulation is being tested here. After ovulation, the follicle that released the oocyte begins to transform into the corpus luteum. This luteinization starts during metestrus, and the corpus luteum reaches full, progesterone-producing function in diestrus. So, the development of the corpora lutea begins in metestrus rather than during proestrus or estrus, when ovulation occurs, or during diestrus, when the corpus luteum is already established and actively secreting progesterone.