Question

When a mature egg leaves the ovary, it enters the
(a) Follicle
(b) Endometrium
(c) Interstitial cells
(d) Oviduct

Answer 1

It is a long and thin tube-like structure that is connected to the ovaries through finger-like projections or fimbriae. Each month a mature egg or ova is released by the ovary and guided to the uterus through this. It is also one of the major components of the female reproductive system.

Complete answer:
Each female fetus is born with many follicles in her ovary which contain immature eggs or oocytes. These eggs are released once they reach the maturation stage which also marks the beginning of puberty in girls.
Every month a hormone is released from the pituitary gland known as FSH or follicle-stimulating hormone that encourages these follicles to become mature. In turn, these follicles during maturation produce another important hormone called estrogen. As the amount of estrogen rises in the body, the lining of the uterus thickens to prepare for implantation.
In addition to this, as the egg undergoes maturation the estrogen levels rise in the body and act as a messenger to stimulate the pituitary gland to release LH also known as luteinizing hormone. Every month it is seen that there is a sudden surge in LH. This surge triggers one follicle to produce one mature egg and this process is termed ovulation. When this egg leaves the ovary it enters the fallopian tube which the brush line border helps guide this egg to the uterus. The journey from the fallopian tube to the uterus usually takes five days or more.
If fertilization doesn’t take place then the egg moves through the uterus and disintegrates and hormonal levels get back to normal. The thick lining of the uterus starts to shed and causes bleeding, also known as menstruation.

Additional information:
There are many reasons why a woman may have ovulation problems. Some of them are listed below:
- Blockage in the fallopian tube due to pelvic inflammatory disease.
-Endometriosis: Growth of endometrium or lining of uterus outside the uterine cavity
-Abnormal level of hormones: Abnormal levels of female hormones like progesterone and estrogen lead to irregular menstruation cycles. Ovaries develop various follicles that release a mature egg. This hormonal disorder is commonly known as PCOS or polycystic ovary syndrome.
-Body Mass Index: Both low(person who is underweight) and high(a person who is obese) body mass index lead to irregular ovulation
-Thyroid: Thyroid level other than normal can cause irregular ovulation and this condition is termed amenorrhea.
-Stress: Stress causes the release of a hormone called cortisol which has a direct effect on other hormones mainly progesterone and estrogen.
-Excessive exercise: Due to strenuous exercise there is physiologic stress on the body which causes the hypothalamus to turn down the stimulation of ovaries.

So, the correct answer is option d) Oviduct.

Note:
As it is seen that there is no direct link between the ovaries and oviduct so the egg is transported to the uterus in a peritoneal fluid that is produced by the fimbriae. Additionally, cilia present in the oviduct help guide the mature egg to the uterus.