Female Reproductive System: Structure & Functions

Female Reproductive System: The process through which organisms generate copies of themselves is known as reproduction. The reproductive system’s primary goal is to keep a species alive. The reproductive system for females performs a number of critical functions for the species’ survival. The ova or oocytes are the egg cells produced by the ovaries that are subsequently transferred to the fallopian tube, then fertilised by a sperm. The fertilised egg is transferred to the uterus.

The fertilised egg can implant into the thicker uterine lining and continue to develop once inside the uterus. The uterine lining is lost as menstrual flow if implantation does not occur. The female reproductive system also produces female sex hormones, which keep the reproductive cycle going. Learn about the female reproductive system functions, primary and auxiliary reproductive organs, oogenesis, fertilisation, pregnancy, and the menstrual cycle by reading the entire article.

Structure of Female Reproductive System

The female reproductive anatomy includes both external and internal structures around the female genitalia. The external female reproductive structures (the genital) has a twofold function: it works as a passage for the sperm to enter the body and also protects the internal genital organs from infectious organisms. Before dwelling on the detailed anatomy and functions of the parts associated with the female reproductive system, let us first look at what reproduction is.

What is Reproduction?

Reproduction is how an organism produces a new offspring or individual of its kind. Sexual reproduction involves the formation and fusion of gametes. Reproductive systems perform in both ways, forming gametes and fusing to form diploid zygotes.

How Do the Female Reproductive System Function?

The female reproductive system is designed to carry out various functions. It helps in producing the female gametes (egg cells) and in the fertilization of these gametes. It consists of primary reproductive organs and external genitalia such as the ovaries, oviduct, fallopian tubes, uterus and vagina. Females are born with immature eggs. During puberty, the eggs mature and ovulate. The ovaries release these eggs.

Diagram of Female Reproductive System

Primary Reproductive Organs

Ovaries are the primary reproductive organs of the female reproductive system as they directly take part in reproduction. They produce gametes and help in the secretion of hormones, which regulates the gamete formation and secondary sexual characters in females.

Ovaries

Structure: The ovaries are the primary reproductive organs present in the female reproductive system. We can find these paired, almond-shaped ovaries on either side of the uterus.

Histology: The ovaries are covered by a simple cuboidal epithelium called the germinal epithelium on the outside. Below the germinal epithelium layer is a dense connective tissue capsule called the tunica albuginea. The ovary is generally divided into an outer cortex and an inner medulla. The cortex is thicker and granular due to many ovarian follicles in various stages of development. Each of the ovarian follicles contains an oocyte, a female germ cell. The medulla is an inner, loose connective tissue. It contains numerous blood vessels, lymphatic vessels and nerve fibres.

Functions

1. The paired ovaries produce the female gamete, the ovum. Every month, one oocyte matures and is ovulated out from the follicle.
2. Ovaries are also engaged in producing sex hormones, which are oestrogen and progesterone.

Additional Information: Polycystic Ovary

It is a type of disorder that causes irregular or prolonged menstrual periods and sometimes leads to increased androgen levels. Ovaries become unable to release eggs regularly and develop small cysts.

Accessory Reproductive Organs

The accessory or secondary reproductive organs are those organs that facilitate the process of fertilization and implantation, support the growth and nourishment of the foetus but do not produce hormones. The oviducts or fallopian tubes, uterus, and vagina are the accessory reproductive organs of the female reproductive system.

Oviducts or Fallopian Tubes

Structure: Oviducts or fallopian tubes are the two tubes where normally fertilization occurs. These are accessory reproductive organs of the female reproductive system. The oviduct stretches out from each ovary to the uterus.

The four parts of fallopian tubes are:

1. The Infundibulum is the funnel-shaped opening near the ovary into which fimbriae are attached.
2. Fimbriae: These are finger-like projections present near the edges of the infundibulum. These help in the collection of the ovum after ovulation.
3. Ampulla:  It is the wider part of the fallopian tube where fertilisation occurs.
4. Isthmus: It is the narrow and last part of the oviduct that joins the ampulla to the uterus.

Functions

1. They provide a site for fertilization.
2. They help in the movement of the egg from the ovaries to the uterus. 
3. They allow the secondary oocyte to complete the cell division and form an ovum. 
4. The zygote is formed by merging of a sperm and an oocyte. Initial development of the zygote upto \(32\)-celled stage takes place in the oviduct.

Uterus (Hystera or Womb)

Structure: The uterus is a hollow muscular organ of the female reproductive system and can be classified into three parts: body, fundus, and cervix. The uterus is also known as the womb and baby maker. The uterus can expand up to \(20\) times during pregnancy. The lowermost part of the uterus is known as the cervix, which is connected to the vagina. The cervix helps in allowing the discharge of menstrual fluid from the body. It keeps away bacteria from entering the uterus. It is almost cylindrical, and it changes at the time of pregnancy. The uterine wall is composed of \(3\) layers:

1. Perimetrium – It is the outermost serous layer.
2. Myometrium – It is the middle layer; interlacing layers mainly composed of smooth muscle.
3. Endometrium – It is the inner layer that allows for implantation of a fertilized egg.

Functions

The main function of the uterus is to nourish the fertilized egg till the birth of the child.

Vagina (Birth Canal)

Structure: Vagina is the female copulatory organ of the female reproductive system. It lies between the cervix to the exterior of the body. It receives the penis during sexual intercourse. It is elastic and muscular with a soft, flexible lining.

Functions

1. The major function of vagina is to carry menstrual fluid out of the body.
2. It provides a passageway for the birth canal at the time of parturition. 

External Genitalia (Vulva)

The vulva consists of the following structures:

1. Mons pubis – These are mounds of fatty tissue overlying the pubic bone. It is covered with pubic hair after puberty.
2. Labia majora – These are outer folds of skin containing fat, sebaceous glands, hairy and homologous to the scrotum of males.
3. Labia minora are inner folds of skin containing sebaceous glands and are non-hairy.
4. Clitoris is present at the junction of labia majora and labia minora. It corresponds to the glans penis in males. It is the centre for sexual excitement.
5. Vestibule is the cleft between the labia minora that comprises the urethral orifice, vaginal orifice, and vestibular glands that produce lubricants during sexual intercourse.
6. Hymen: It is a thin membrane that partially covers the vaginal opening or vaginal orifice.
7. The Bartholin’s glands are two pea-sized glands present near the vaginal opening. These are like the bulbourethral glands in males. These glands release fluid that functions as a lubricant to decrease friction during intercourse and provides a moisturizer for the vulva.

Mammary Glands

The mammary gland is a modified sweat gland and is an accessory gland of the female reproductive system called the breasts of females. These are responsible for the production of milk or lactation. In males, the mammary gland is non-functional or vestigial or rudimentary.

In females, the mammary gland is functional and begins to develop after puberty in response to the release of oestrogen. Mammary glands only produce milk after childbirth. Mammary glands are balanced by the endocrine system and become functional due to the hormonal changes associated with parturition.

Female Reproductive System Functions

The female reproductive system performs the following functions:

1. It produces the female gametes called the eggs or ova.
2. It provides a site for fertilization.
3. It secrets sex hormones like oestrogen and progesterone.
4. It provides a site for the development of the foetus.

Oogenesis

Oogenesis starts in the foetus prior to birth. It is the process by which mature female gametes or ova develop from germ cells by the process of meiosis. There are three stages of oogenesis: (i) multiplication phase (ii) growth phase and (iii) maturation phase

Structure of Mature Ovum

Menstrual Cycle

The cyclic periodic change in the female reproductive system of primate females is called the menstrual cycle. The average interval of the menstrual cycle is \(28\) days. During this period, there are hormonal changes in the female. During the menstrual cycle, a female ovary develops an egg and then the female body prepares for pregnancy. The endocrine system controls the complete process of the menstrual cycle.

The hormones involved in this cycle are Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), oestrogen, and progesterone. The PITUITARY GLAND SECRES the FSH and LH hormones, whereas the ovaries secrete oestrogen and progesterone hormones.

The Phases of the Menstrual Cycle

Menarche

The initiation of menstruation starts at the beginning of puberty. It is called menarche.

Menopause

The permanent stoppage of menstruation at the age of about \(50\) years is called menopause.

Fertilization and Pregnancy

1. Fertilization combines the sperm of the male gamete with the ovum or the female gamete.
2. In humans, internal fertilization takes place.
3. Fertilization in humans takes place in the oviduct or fallopian tube at the ampullary isthmic junction.
4. A Zygote is a cell that is produced during fertilization.

1. Then the zygote undergoes cleavage to form a solid ball of cells called morula.
2. Morula then transforms into a hollow structure called the blastocyst.

1. The blastocyst reaches the uterus and gets attached to the endometrium of the uterus by about 7th day after the fertilization process. This is known as implantation.

1. Human chorionic gonadotropin (hCG) hormone is produced in the blastocyst, whose urine indicates pregnancy.
2. The placenta is a disc-shaped tissue that develops between the uterine wall and the embryo after implantation.
3. The umbilical cord is a tube that connects the foetus to the placenta.
4. Placenta generally helps exchange nutrients, oxygen and waste products between the embryo and the mother.
5. The hormones that are released from the placenta are oestrogen, progesterone, human placental lactogen (hPL), human chorionic gonadotropin (hCG), human chorionic somatomammotropin (ACS).
6. Gestation is the period from fertilization up to the birth of the baby.
7. The average duration of human pregnancy is about nine-month or 38 to 40 weeks.
8. The process of giving birth to a baby starts with mild uterine contractions. This process is called parturition.
9. The hormone oxytocin plays a vital role in uterine contractions.
10. Due to the rhythmic contraction of the uterine muscles, the baby is pushed out from the mother’s body through the vagina. This is the process of formation of a baby.

Related Topics to Study

Summary

The human female reproductive system is a complex system, which consists of ovaries, oviducts, uterus, external genitalia, accessory glands. It helps in the formation of female gametes (ova) and female sex hormones. This system helps in both, fertilisation process as well as childbirth.

FAQs on Reproductive System for Female

Here are the answers to the most commonly asked questions about the female reproductive system:

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