QS Study

Estrogens are a group of sex hormones that uphold the growth and continuance of female characteristics in the human body. They play a vital role in the development and growth of female secondary sexual characteristics, such as breasts, pubic and armpit hair, and the regulation of the menstrual cycle and reproductive system.

Functions of the estrogen

Effects on primary and secondary female sex characters. Principle function is to cause cellular proliferation and growth of tissues of the sex organs and other tissues related to reproduction. Estrogen also plays a role in blood clotting, maintaining the strength and thickness of the vaginal wall and the urethral lining, vaginal lubrication and a host of other bodily functions.

Fig: Function of Estrogen

(A) On external genitalia:

  • Causes enlargement of mons pubis, Labia majora, and minora.
  • Greater vestibular glands enlarge and secrete.

(B) On internal genitalia:

(I) On ovary: Facilitates growth of ovarian follicles,

(II) On the uterine tube:

  • Causes proliferation of lining of glandular tissue,
  • Increases the number of ciliated arils and tubular secretion,
  • Increases ciliary beats towards the uterus and motility of tubes.

(III) On the uterus:

  • Increases muscle fibers in number and size and sensitivity to oxytocin,
  • Causes of proliferative phase of the endometrium and increases thickness.
  • Develops the endometrial glands for nutrition of implanted ovum.
  • Increases contractile proteins of muscle become more active and excitable.

(IV) On vagina:

  • Enlargement of the vagina to adult size.
  • Causes proliferation and stratification of vaginal epithelium.

(C) On breast:

  • Increase growth of stromal tissue and ductile system.
  • Increases deposition of fat.
  • Responsible for the pigmentation us the areolas.

(D) On kidney: Causes Na+ and water retention by renal tubules.

(E) On body hair:

  • Causes growth of axillary and pubic hair.
  • Causes less body hair and more scalp hair.

(F) On the skin:

  • Skin becomes soft, smooth, shiny, and more vascular.
  • Causes sebaceous gland to secrete more fluid, thus inhibits the formation of comedones (blackheads) and acne.

(G) On skeleton:

  • Increase osteoblastic activity thus helps in rapid bone growth.
  • Causes uniting of epiphysis with the shaft of long bones.

(H) On protein and fat deposition and on metabolism:

  • Increases synthesis and deposition of body protein.
  • Causes deposition of fat in the buttocks and thigh.
  • Increase whole body metabolic rate slightly.

(I) On CNS:

  • Increase libido,
  • Causes slow progression of Alzheimer’s diseases.

(J) On CVS:

  • Decreases blood cholesterol and increases HDL level.
  • Rapidly produces vasodilation by increasing local production of NO.

(K) In pregnancy:

  • Enlargement at mother’s uterus, breast, and growth at the breast ductile structure.
  • Enlargement of mother’s female external genitalia.
  • Relaxation of the pelvic ligament of the mother.
  • Affects the rate of cell production in the early embryo.