Question

The phase of the menstrual cycle that occurs between the expulsion of the ovum from the ovary and the onset of menses is the _____ phase.

Answer 1

The period between ovum expulsion and menses is the luteal phase, during which the corpus luteum secretes progesterone to maintain the endometrium, ending with its degradation if pregnancy does not occur.

Step-by-step explanation:

The phase of the menstrual cycle that occurs between the expulsion of the ovum from the ovary and the onset of menses is the luteal phase. During the luteal phase, which typically lasts about 14 days in a 28-day menstrual cycle, the empty Graafian follicle is transformed into the corpus luteum.

The corpus luteum, in turn, secretes progesterone which maintains the endometrium, making it suitable for a potential pregnancy. If fertilization does not occur, the corpus luteum degrades, progesterone levels fall, and this triggers the menstrual phase, or menses, during which the endometrium is shed. This event marks the end of the luteal phase and the beginning of a new menstrual cycle.