Human Reproduction Test - 18

Menstrual flow occurs due to the lack of progesterone.  Progesterone is secreted by corpus luteum and is essential for the maintenance of endometrium, This endometrium is responsible for implantation of the fertilized ovum, i.e. Pregnancy. FSH Stimulates gonad activity and also called as gonadotrophins. Oxytocin Stimulates contraction in uterus during childbirth.  Vasopressin Stimulate resorption of water and electrolytes by the distal tubules, also called as Antidiuretic Hormone (ADH).

Oxytocin stimulates powerful contractions that help to thin and open (dilate) the cervix, move the baby down and out of the birth canal, push out the placenta, and limit bleeding at the site of the placenta. During labor and birth, the pressure of the baby against your cervix, and then against tissues in the pelvic floor, stimulates oxytocin and contractions. So does a breastfeeding newborn.

It is this portion of the blastocyst which adheres to the endometrium and initiates implantation. Rapid trophoblast proliferation occurs and cells penetrate between endometrial cells. Human chorionic gonadotropin (hCG) starts to be secreted by the trophoblast cells around the time they start their endometrial invasion.

Follicles that form an antrum during maturation are called antral follicle or Graafian follicle. During the development of the follicle, a glycoprotein polymer capsule called the zona pellucida which is acellular, forms around the oocyte, separating it from the surrounding Granulosa cells.

This layer remains with the oocytes after ovulation and contains enzymes that catalyze with sperm to allow penetration.

Spermiation is the process by which mature Spermatids are released from Sertoli cells into the seminiferous tubule lumen prior to their passage to the epididymis.

400 sperms Spermatozoa will be produced from 100 primary spermatocytes and 100 ova will be produced from primary oocytes.

Menarche is the beginning of menstruation at puberty in primates / human females at about 13 years of age. Menopause is the stoppage of menstruation and menstrual cycle at the age of 45-55.

The corpus luteum is colored as a result of concentrating carotenoids (including lutein) from the diet and secretes a moderate amount of estrogen that inhibits further release of gonadotropin-releasing hormone (GnRH) and thus secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).