Female Reproductive System

Female Reproductive System

Female Reproductive System Anatomy

The female reproductive system is framed to perform different functions. It creates egg cells that are essential for reproduction known as ova. The system is organized to deliver the ova to the region of fertilization. The egg fertilization takes place in the Fallopian tubes along with the sperm. The implanting in the walls of the uterus and initiating the stages of pregnancy is the next step of fertilized eggs. Apart from these function, the reproductive system also creates female sex hormones to maintain the reproductive cycle.
The female reproductive system is composed of a pair of ovaries along with oviducts, vagina, cervix, uterus, and the external genitalia that are located in the pelvic region.  These parts along with a pair of mammary glands that are integrated both functionally and structurally also support the process of ovulation, fertilization, birth and finally the child care.

Ovaries

Ovaries act as the main female sex organs that produce the female gamete and various hormones. These organs are situated one on both the side of the lower abdomen. Each ovary measures about 2 to 4 cm in length which is then connected to the uterus and pelvic wall through ligaments. The ovary is surrounded by a thin covering of epithelium, encloses the ovarian stroma and is divided into two zones – outer cortex and inner medulla.
The cortex consists of various ovarian follicles in different stages of development. The ovarian follicle is called the basic unit of the female reproductive system. Each oviduct is divided into three anatomical regions- ampulla, isthmus, and infundibulum.

Uterus

A uterus is also called as the womb. It is a muscular, inverted pear-shaped organ of the female reproductive system. The walls of the uterus consist of three layers- the inner glandular layer, the middle thick layer, and the outer thin layer. These three layers are maintained by ligaments which are attached to the pelvic wall which then opens into the vagina from a narrow cervix. Cervical canal along with the vagina creates the birth canal. The vagina is a muscular tube which starts at the lower end of the uterus to the outside.

Fallopian Tubes

Fallopian tubes are a pair of muscular tubes and funnel-shaped structures, extend from the right and left of the superior corners of the uterus to the edge of the ovaries. These tubes are enclosed in small projections called fimbriae that swipe over the ovaries to pick up released ova and deliver them to the infundibulum for supplying uterus. Each fallopian tube is covered by cilia that functions by carrying the ovum to the uterus.

Vagina

The vagina is a muscular and elastic tube that connects the cervix to the external body. It functions as the receptacle for the penis in sexual intercourse and delivers sperm to the fallopian tubes and uterus. It also acts as a birth canal by expanding to allow delivery of the fetus during childbirth.

Ovulation 

Ovulation is the process of releasing the eggs from the ovaries. This process takes place as soon as the follicle is fully grown and reaches its size along with the accumulation of liquid in the follicle without a significant rise in pressure. As the follicle swells out, a small oval-shaped area, the stigma or macula pellucida appears sticking outward as a clear cone area and later undergoes localized changes in color, integrity, and translucency. The secretion of estrogen hormones reaches the maximum level before the ovulation. After the surge of luteinizing hormone, ovulation occurs at the site of the stigma. This surge is essential for ovulation.
Ovulation is the process in which the follicle is separated by releasing of follicular fluid along with the ovum surrounded by the corona radiata. The cells of the corona radiata will separate later in the presence of spermatozoa. In ruminants, the oocytes have already lost their corona at the time of ovulation. The very active fimbriae, end of the oviduct picks up the ovum. If fertilized ovum or zygote undergoes cleavage and makes its way to the uterus for implantation. If not fertilized, it degenerates within 24 hours.

Menstrual Cycle

All females, after reaching their puberty produce mature egg cell every month during a process called the menstrual cycle.  During this period, an ovary releases a mature egg. The egg travels to the uterus. If the egg is not fertilized, the uterine lining is shed and a new cycle begins. Overall a menstrual cycle lasts for 28 days. This cycles may either lasts for 21 days or as long as 35 days in some individuals. The entire process of the menstrual cycle is controlled by the endocrine system and the hormones involved are FSH, LH, estrogen, and progesterone. Both FSH and LH hormones are produced by the pituitary gland,  whereas estrogen and progesterone hormones are produced by the ovaries.
Factors including diet, exercise, stress and weight gain or loss affects the menstrual cycle. The cycle may be irregular at times, especially during puberty. Except during pregnancy, menstrual cycles occur every month from the time of puberty up to the age of 45 to 55. After the age of 55 ovaries slows down their production of hormone and release of mature eggs. Gradually, the menstrual cycle stops, and the woman is no longer able to become pregnant.

Fertilization and Pregnancy

Following implantation, the placenta originates from maternal and fetal tissues, producing human chorionic gonadotropin (HCG) that helps in maintaining the level of corpus luteum in the ovary until the placenta begins synthesizing its own progesterone and estrogen hormones.

Estrogen and Progesterone

Estrogen and progesterone hormones are produced by the ovaries that foster the development of reproductive organs by maintaining the proper uterine cycle and by developing female secondary sex characteristics. During menopause, usually between age 45 and 55, the uterine cycle stops, and the ovaries are no longer produce estrogen and progesterone hormones.
Infertility
 In general, infertility can be defined as the failure in couples of not getting pregnant, despite having carefully timed, unprotected sex for one year. It is estimated around 15% of all couples undergo infertility. The reasons behind this infertility in males and females are-

In Females:

  • Blocked oviducts.
  • Endometriosis.

In Males:

  • Low sperm count.
  • Sperm abnormalities.

Reproduction Control

There are various birth control methods and some of them are as mentioned below.

  • Abstinence.
  • Birth control pills
  • Intrauterine device.
  • Male condom.
  • Contraceptive implants.
  • The morning after pills.

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Further Reading


Practise This Question

________  is the region which houses the foetus.