A generation does not go on without reproduction because reproduction produces the progeny that carries the generation forward. It is not a miracle when a woman gives birth to a child, it is science and there is a system in the human body that controls it. The system is known as the Reproductive System, but it is not the same in both the sexes. Let’s find out how these systems works.
What is a Reproductive System?
The Reproductive System consists of sex organs which are involved in the process of reproduction. The system consists of two types of organs; male reproductive organs in males and female reproductive organs in females. Their functions and structures differ but they complement each other to produce the next generation.
What are the male reproductive organs?
The male Reproductive System has different organs with varied roles. They are:
Scrotum: It is a sac-like organ which has two pouches each of which has testes in it. The scrotum is made of skin and smooth muscle. It maintains the distance between the testes and the rest of the body. When the testes become warm, the scrotum relaxes and keeps the testes away from the body. On the other hand, when the temperature drops, the scrotum contracts and brings the testes closer to the body.
Testes: It is the male reproductive organ that is responsible for the production of the reproductive cells, namely sperm and testosterone. The internal part of testes is divided into several compartments known as lobules; each of which has a section known as seminiferous tubule where the sperms are produced.
Epididymis: It is the storage area of sperm in the testes. It is a long thin tubule which has been coiled and rested in the posterior edge of the testes. It stores the sperm and they stay there till it reaches its maturity.
Spermatic cords and ductus deferens: Spermatic cord is a cord like structure in the scrotum that connects testes to the abdomen. It consists of nerves, blood and lymphatic vessels and a muscular tube known as ductus deferens, thus helping the testes to function. Also known as vas deferens, ductus deferens is a tube-like structure that stores the matured sperms and transports it to the ejaculatory duct.
Ejaculatory duct: It is the structure that connects the ductus deferens to the urethra. At the time of ejaculation, this duct opens and expels the sperm along with a liquid secreted by the seminal vesicles into the urethra.
Seminal Vesicles: These are a pair of glands located posterior to the urinary bladder and anterior to the rectum. It stores the liquid portion of semen which contains sperm, and it contains proteins and mucus. It is also an alkaline liquid, thus helping the sperm to survive in acidic environment of female reproductive organ. The fructose content of the liquid helps the sperm cells to survive for long.
Urethra: It is a muscular tube through which the sperm from the ejaculatory duct and the urine passes out of the body. It also passes through the prostate gland. Prostate: It is a gland bordering the lower end of the urinary bladder and surrounds the urethra. It secretes a milky fluid which contains enzymes, proteins and other chemicals. This fluid makes up the semen.
Cowper’s gland: It is a pea-sized gland located below the prostate. It secretes an alkaline fluid which lubricates the urethra and clears the acid content caused by the leftover urine, and also prepares the urethra before ejaculation.
Penis: It is the external reproductive male organ whose main purpose it to deliver the semen into the female reproductive organ.
Semen: It is the fluid secreted by the male reproductive organ. It contains the male reproductive cells called sperms. It is alkaline and it contains around 100 million sperms per millilitre.
How does the male Reproductive System function?
The male Reproductive System functions so as to produce sperm through the following process:
Spermatogenesis: It is a process of producing sperm, which takes place in the testes and epididymis of adult males after puberty. It starts with the production of hormones - luteinizing hormone (LH) and follicle stimulating hormone (FSH). While LH triggers the production of testosterone, FSH triggers its maturation. The matured testosterone then stimulates the development of spermatocyte from the reproductive cell, spermatogonium. The spermatocytes then go through cell divisions forming spermatid cells. The spermatid cells then undergo the process of spermiogenesis where it develops a head and a flagellum protruding from the head. Now the cell is a completely formed sperm.
What are the female reproductive organs?
The female reproductive organs differ from the male ones and they are:
Ovaries: Ovaries are a pair of glands located on both the sides of uterus. It produces the female sex hormones, estrogen and progesterone, and the female sex cells, ova (also known as eggs). The ova are produced during the early stage of a women’s life but it gets matured only by puberty. One matured ovum gets released every month and travels through the fallopian tube before it enters the uterus.
Fallopian tubes: These are a pair of muscular tubes that run from the ovaries to the uterus. The tubes form into a funnel-shaped structure known as infundibulum towards its end. Infundibulum is covered by tissues which are a bunch of finger-like projections known as fimbriae. These fimbrae collect ova from the ovaries and pass it on to the infundibulum to get it transported to the uterus.
Uterus: Uterus is a hollow, muscular organ which is also known as the womb. It is the organ inside which a foetus develops at the time of pregnancy. The inner lining of a uterus has a mucous membrane known as the endometrium which protects the embryo at its early stage. The uterus also has visceral muscles which contract to push the foetus through the birth canal (vagina) at the time of birth.
Vagina: It is an elastic muscular tube connected to the uterus and extends to the outside of the body. At the time of sexual intercourse, it is in the receiving end of the sperm from the penis and finally passes the sperm to the fallopian tube. The vagina is also the birth canal that stretches at the time of delivery letting the foetus to move out.
Vulva: It is a collection of external female sex organs. It has the mon pubis which is a layer of fat between the skin and the pubic bones. The lower portion of mon pubis splits into two halves known as labia majora. Both mon pubis and labia majora are covered with pubic hairs, but the lower end of labia majora has a hairless fold of skin known as labia minora. Towards the higher end of the labia majora is a tissue known as clitoris which contains nerves that senses sexual pleasure.
Breast and Mammary glands: Breasts are the specialised organs for women which contain mammary glands that produce breast milk for the infants. There are two breasts on the left and right side of the chest with a pigmented structure called nipple at the centre of each breast that serves the purpose of releasing milk. There are 15 to 20 clusters of mammary glands that get activated at the time of pregnancy thus producing milk till it is no longer needed for the infant after its birth.
How does the female Reproductive System function?
The female Reproductive System functions through the following processes:
The Reproductive cycle: It is the entire process from producing an ovum till the time it gets fertilised- and pregnancy begins. The entire cycle takes place for an average of 28 days, but it may be 24 days for some or extended up to 34 days. The cycle resets if the ovum implanted in the uterine wall is unfertilised.
Oogenesis and Ovulation: Oogenesis is the process of production of ovum and ovulation is the process in which the ovum matures. An ovum reaches maturity by the 14th day of the reproductive cycle and many oocytes are matured each month but only one is released in every reproductive cycle.
Menstruation: It is the process in which the cells in the endometrium die due to the lack of blood which is caused by the constriction of the arteries of uterus. This constriction happens when the matured ovum is not fertilised and fails to implant into the endometrium. The process starts mostly on the 28th day of the reproductive cycle and continues till the first few days of the new reproductive cycle.
Pregnancy: It is the period which starts from the moment the mature ovum gets fertilised with a sperm cell and forms an embryo. The fertilised embryo gets itself implanted on endometrium and starts to develop into a foetus. Various organs develop during this period which lasts for nearly 38 weeks until its birth.
Lactation: It is the process of production of breast milk under the control of the hormone, prolactin and oxytocin. As the infant sucks the nipple, prolactin and oxytocin are secreted as a response and thus stimulates the production of milk. Breast feeding lasts till the weaning continues.
What is fertilisation?
Fertilisation is the process in which the sperms enter the fallopian tube through the vagina and uterus, and penetrate inside the matured ovum thus combining with the ovum to form a zygote. The zygote undergoes a rapid cell division for two weeks which is known as the germinal period of development. It then forms an embryo which later gets implanted on the uterine wall and develops as the pregnancy begins.
What are the Reproductive System disorders?
There are a number of major Reproductive System disorders some of them are:
Uterine Cancer: It is a disease in which cancer cells start to grow in the uterus of a woman. There are three types of uterine cancer, namely cervical cancer (cancer growth in the cervix, the lower portion of uterus closest to vagina), the most common adenocarcinoma (cancer grows in the endometrium) and sarcomas (cancer cells grow in the outer wall of the uterus, myometrium)
Dysmenorrhea: It is the painful menstruation which gives rise to abdomen, back and legs pain, also causing abdominal cramps, headache and fatigue. It is caused by either strong contraction of the uterine muscles or due to infection in the uterus.
Infertility: Infertility in men is the production of very few sperms or low quality sperms while infertility in women is the inability to ovulate, conceive or carry an infant to full term.
Testicular cancer: It is the growth of cancer cells in the testicles.