Question

Describe the changes that occur in ovaries and uterus in human females within the reproductive cycle?

Answer 1

Provided all organs are present, normally constructed, and functioning properly, the essential features of human reproduction are (1) liberation of an ovum, or egg, at a selected time within the reproductive cycle, (2) internal fertilization of the ovum by spermatozoa, or sperm cells, (3) transport of the zygote .

Complete answer:
The duration of the reproductive cycle is split into four phases:
- The phase ,
- The preovulatory phase,
- The ovulatory phase, and
- The postovulatory phase

In the phase , the endometrium of the uterus is shed and therefore the discharge occurs due to the declining levels of hormones, especially progesterone, stimulating the discharge of prostaglandins.
During this phase, some 20 secondary follicles in each ovary begin to enlarge and still do so through the preovulatory phase, the time between menstruation and ovulation, under the influence of FSH. By about day six, one follicle has outgrown the others and becomes the dominant follicle or the Graafian follicle .

Estrogens and inhibins secreted by the follicle decrease the secretion of FSH and therefore the other follicles stop growing. The Graafian follicle continues to enlarge until it's ready for ovulation. It continues to supply estrogen under the influence of LH. At day 14, the follicle ruptures and releases an oocyte. This process is understood as ovulation.

After ovulation, the mature follicle collapses. The postovulatory phase of the feminine reproductive cycle lasts approximately from day 15 to twenty-eight and represents the time between ovulation and therefore the onset of subsequent menses.

Note: The cycle starts with the phase , where menstruation occurs. this is often followed by the follicular phase. During this phase, the first follicles mature into the Graffian follicles and therefore the release of gonadotropins (LH and FSH) also increases. This causes follicular growth and therefore the growing follicles produce oestrogen.