Question

During the menstrual phase of the uterine (menstrual) cycle

A. A new ovarian follicular phase is beginning

B. The corpus luteum degenerates

C. Estrogen and progesterone levels reach their lowest concentration

D. All of these answers

E. Vasoconstriction of the uterine vessels occurs in response to release of a uterine prostaglandin

Answer 1

Answer - D. All of these answers

• The menustral / bleeding phase begins just after the secretory / luteal phase.
• At this phase the LH production will be greatly reduced.
• Endometrium degeneration and break down is observed during this phase.
• On reduing the LH hormone, corpus luteum degeneration takes place
• Hence the progestrone levels will be greatly reduced.
• endometrial secretions, blood and unfertilised ova is observed in the bleeding.
• They also have fibrinolysin, which prevent the clotting of blood.
• It lasts of about 4- 7 days.
• estrogen level will be also lower. their increase occur with start of follicular phase.
• Just after the menustral phase, The FSH secretion occurs leading to next phase- ovarian follicular phase.
• prostagladins are related to the estrogen and progestrone hormones.
• during menustral phase, PGE2 is released, which cause the vasoconstruction of the uterine vessels and can make the myometrial smooth muscles to contract.
• So all options are correct.