What tissue and hormonal phase occurs during the last 14 days of a normal 28-day menstrual cycle?

During the last 14 days of a normal 28-day menstrual cycle, the correct phase is the secretory luteal phase. This phase follows ovulation and is characterized by the presence of the corpus luteum, which forms from the remnants of the Graafian follicle after it releases the ovum.

In this phase, the corpus luteum secretes both progesterone and some estrogen, which are critical for preparing the endometrial lining for potential implantation of a fertilized egg. The primary function of progesterone during this time is to induce changes in the endometrium that transform it into a secretory type, facilitating the nourishment of an embryo should fertilization occur.

This secretory phase is vital for establishing an environment conducive to implantation, with increased blood supply and nutrient-rich secretions. If implantation doesn’t occur, the corpus luteum eventually degenerates, leading to a decline in these hormones and the subsequent shedding of the endometrial lining during menstruation.

In contrast, the other choices represent different phases or hormonal influences that do not accurately describe the last 14 days of the cycle. For instance, the proliferative follicular phase is influenced by estrogen and occurs prior to ovulation, while the secretory phase is