Question

Assignments, Chapter 39, Introduction to the Reproductive System

Describe and controls the female reproductive system. Explain the clinical nature of female reproductive system

Assignments, Chapter 39, Introduction to the Reproductive System

Answer 1

Female Reproductive System consists of a uterus, a pair of ovaries, a pair of fallopian tubes and a Vulva.

The uterus:-

1)The uterus consists of Body((Corpus) with bulging upper surface, the fundus and Neck called cervix.

2)The uterine cavity is small , triangular in shape with three openings:- two for the fallopian tubes at its upper outer angles and one directed downwards( internal is) which opens into the cervical canal and leads via external os into the vulva.

3)During late pregnancy the uterus enlarges considerably through stretching by the growing foetus and by hormonal action; the final weight being 800- 1000 gms.

4)The body of uterus consists of 3 coats:-

a)Innermost coat is of mucous membrane called Endometrium.

b)Middle thick coat is of smooth muscle called Myometrium which gives strength to uterus.

c)Outermost coat is a serous coat of parietal peritoneum which covers only upper 3/4 the of the uterus.

Endometrium plays an important role in reproduction.It undergoes characteristics changes during the Menstrual Cycle i.e. recurrent monthly discharge of blood from female genital tract.It helps in implantation of fertilized ovum and supplying the nutrients essential for the growth and development.

The Cervix:-

a) It is much less muscular compared to the rest of the uterus and contains more connective tissue.Its mucosa called Endocervix contains columnar mucus secreting epithelium with some ciliated cells.Endocervix is not shed at the time of menstruation.

b)Cervical secretion normally contains 92% water,NaCl and glycoprotein.

Functions:-

a)Allows entry of spermatozoa (sperm) from the vulva into the uterus and to store viable sperms for 1-2 days

b)Allows escape of menstrual wreckage

c)Permits passage of the foetus at term

d)Prevents entry of infectious microorganisms.

The Fallopian Tubes:-

a)Its distal end gets expanded into a funnel like portion called Infundibulum which opens with finger like projections known as Fimbriae.

Functions:-

a)Serve as ducts for ovaries by providing passage by which ova can reach uterus.

b) Fertilization function:-The union of a spermatozoon(sperm) with an ovum(egg) occurs here, normally in the ampulla of the fallopian tube.

The Ovary:-

a)There are two ovaries , one on each side behind and below the fallopian tubes.

b)Primary functions:-

- To produce and discharge ova(eggs)

- To secrete female hormones called ovarian hormones(oestrogen and progesterone mainly)

The Menstrual Cycle:-

Menstrual cycle is recurrent monthly discharge of blood from the female genital canal.It is related to ovulation and the secretion of ovarian hormones( oestrogen and progesterone)which influence the hypothalamo- pituitary activity to bring about cyclical changes in the endometrium during the female reproductive period; between the menarche and menopause The human menstrual cycle is counted from the day on which menstrual bleeding begins.

Menstrual phase:-

a)If the ovum shed at ovulation is not fertilized , menstruation( bleeding from the female genital canal) occurs which on an average lasts for about 3-5 days.During this phase progesterone and oestrogen secretions fall rapidly secondary to degeneration of the corpus luteam.

b)There is bleeding and shedding of the superficial 2/3rd of the endometrium which occurs sequentially in different parts of the endometrium due to spasm of the spiral arteries for several hours leading to the endometrial necrosis.When the vessels relax, shedding of necrotic endometrium , leakage of blood and release of mucus make up the debris lost during menstruation.

c)Menstrual bleeding is predominantly arterial, only 25% of the blood in the flow being venous in origin.Menstrual blood clots promptly in the uterus but is liquified by fibrinolysis in the vagina.This is why the menstrual blood does not contain clots unless the bleeding is excessive.The total blood lost in normal women varies from 10 to 80ml .