During which phase does the site of follicle rupture become a corpus luteum that secretes progesterone to inhibit estrus and, if pregnancy occurs, maintain pregnancy?

During which phase does the site of follicle rupture become a corpus luteum that secretes progesterone to inhibit estrus and, if pregnancy occurs, maintain pregnancy?

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

Answer: (B)

After ovulation, the ruptured follicle transforms into the corpus luteum during metestrus. This new structure begins secreting progesterone, which suppresses further estrus and, if pregnancy occurs, maintains the uterine environment to support the embryo. If there’s no pregnancy, the corpus luteum regresses in diestrus, ending the luteal phase. So the phase that corresponds to the follicle turning into a corpus luteum and starting progesterone production is metestrus.

After ovulation, the ruptured follicle transforms into the corpus luteum during metestrus. This new structure begins secreting progesterone, which suppresses further estrus and, if pregnancy occurs, maintains the uterine environment to support the embryo. If there’s no pregnancy, the corpus luteum regresses in diestrus, ending the luteal phase. So the phase that corresponds to the follicle turning into a corpus luteum and starting progesterone production is metestrus.