$$ \text { What is the role of cervix in the human female reproductive system? } $$
(i) The fundus is the broad, curved, dome-shaped upper area that receives the Fallopian tubes.
(ii) The body is the main part of the uterus, that starts directly below the level of the Fallopian tubes and continues downward until the uterine walls and cavity begin to narrow.
(iii) The isthmus is the lower, narrow neck region.
(iv) The cervix is the lowest part that extends downward from the isthmus until it opens into the vagina.
Why are menstrual cycles absent during pregnancy?
The menstrual flow results due to breakdown of endometrial lining of the uterus and its blood vessels which forms liquid that comes out through vagina. Menstruation only occurs if the released ovum is not fertillised.
During pregnancy, all events of the menstrual cycle stop and the corpus luteum secretes large amounts of progesterone which is essential for the maintenance of the endometrium. These changes lead to no menstruation, during pregnancy.
Female reproductive organs and associated functions are given below in column I and II. Fill the blank blanks.
| Column I | Column II |
|---|---|
| Ovaries | Ovulation |
| Oviduct | $A$ |
| $B$ | Pregnancy |
| Vagina | Birth |
| Column I | Column II |
|---|---|
| Ovaries | Ovulation |
| Oviduct | Fertilisation |
| Uterus | Pregnancy |
| Vagina | Birth |
The female reproductive system consists of a pair of ovaries, a pair of Fallopian tubes (oviducts), uterus, vagina, external genitalia and mammary glands.
The ovaries have both an exocrine function (production of ova) and an endocrine function (secretion) of female sex hormones.
The oviduct (Fallopian tube) conveys the egg from the ovary to the uterus, and also provides the appropriate environment for its fertilisation. The uterus (womb) is a large, inverted, pear-shaped, elastic sac specialised for the development of the embryo.
The vagina is adapted for receiving the penis during copulation, allowing menstrual flow and serving as the birth canal during parturition
From where the parturition signals arise-mother or foetus? Mention the main hormone involved in parturition.
Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully developed foetus and the placenta which induce mild uterine contractions called foetal ejection reflex.
The hormone involved in parturition is oxytocin that acts on the uterine muscle and causes stronger uterine contractions. This leads to the expulsion of the baby out of the uterus through the birth canal.
What is the significance of epididymis in male fertility?
The epididymis helps the sperm in attaining maturity, acquiring increased motility and fertilising capacity. It also stores sperms for a short period before entering the vasa deferens. The epididymis shows peristatic and segmenting contractions at intervals to push the sperm away from the testis.