Human Reproductive System
These notes are based on the chapter How do organisms reproduce from class 10 science NCERT book and CBSE syllabus.
- Male reproductive system
- Female reproductive system
- Changes at puberty
- Sexual dimorphism
- Reproductive health
Male Reproductive Sysem: Testis, seminal vesicle and penis are the main organs. Sperms are produced in testis.
Female Reproductive System: Ovaries and uterus are the main organs. Ovaries produce eggs. Fertilisation takes place in fallopian tube. Development of embryo takes place in uterus. Vagina serves as the birth canal.
Male Reproductive System:
The male reproductive system in human beings is composed of following parts:
Testis
There is a pair of testes, which lie in a skin pouch, called scrotum. Scrotum is suspended outside the body, below the abdominal cavity. This helps in maintaining the temperature of testes below the body temperature. This is necessary for optimum sperm production. Testis primarily serves the function of sperm production. Sperms are the male gametes. Apart from that, testis also produces testosterone. Testosterone is also called the male hormone, as it is responsible for developing certain secondary sexual characters in boys.
Vas Deferens
Vas deferens is the tube which carries sperms to the seminal vesicle.
Seminal Vesicle
This is the place where sperms are stored. Secretions from the seminal vesicle and prostate gland add up to make the semen.
Penis
It is a muscular organ which serves the genitor-urinary functions. The urethra works as the common passage for urine as well as for sperms.
Female Reproductive System:
The female reproductive system in human beings is composed of following parts:
Uterus
This is pear-shaped hollow muscular organ. Uterus is the place where the embryo gets implanted and develops into a newborn baby. The wall of the uterus provides safety and nutrition to the growing foetus.
Fallopian Tubes
One fallopian tube comes out from each side at the top of the uterus. The fallopian tubes end in finger-like structures, called flimbriae. Fertilization happens in the fallopian tube.
Ovary
There are two ovaries, one near each fallopian tube. Ovary produces the eggs or the female gametes. All the eggs are produces by the ovary when the female child is still in the womb. One egg matures in each ovulation cycle and is released from the ovary. The egg is caught by the flimbriae and transferred to the fallopian tube.
Vagina
The cervix (mouth of the uterus) opens into the vagina. Vagina is a muscular tube-like organs, which serves as the passage for the sperms and also as the canal during the child birth.
Puberty
Human beings are complex animals and hence there is a distinct phase in their life cycle which marks the onset and attainment of sexual maturity. This period is called puberty. It usually starts at around 10 – 11 years of age in girls and at around 12 – 13 years of age in boys. It usually ends at around 18th year of age in girls and at around 19th year of age in boys. Since the years during puberty end in teens, hence this phase is also called teenage.
Changes in Boys during Puberty
The boys suddenly grow in height dramatically. Voice becomes deep and the Adam's apple becomes prominent. Shoulders become broad and body becomes muscular. Facial hairs begin to grow. Hairs also grow under the armpit and in the pubic region.
Changes in Girls during Puberty
The voice becomes thin. Shoulders and hip become rounded. Breasts get enlarged. Hairs grow under the armpit and in the pubic region.
Sexual Dimorphism
The physical dissimilarities in the male and female of a species which give them different appearances is called sexual dimorphism.
Secondary Sexual Characters
Features which highlight sexual dimorphism are called secondary sexual characters.
Menstruation
Menstruation is a trait which is unique to humans and some primates. During each ovulation cycle, the uterus prepares itself in anticipation of a possible pregnancy. The uterine wall develops an additional lining.
When the egg is not fertilized, it gets disintegrated and so does the additional lining in the uterine wall. The fragments of disintegrated tissues are shed; along with blood. This is observed in the form of bleeding through the vagina which can last from 3 to 7 days.
The whole sequence of events during an ovulation cycle is called menstrual cycle. The bleeding which occurs for few days is called menstruation. The first menstrual flow is called menarche and the last menstrual flow (which happens in the late 40s) is called menopause.
Test Your Knowledge:
- Which hormone is also known as the ‘male hormone’?
Answer: Testosterone - What is the name of the structure which provides nutrition to the developing foetus?
Answer: Placenta
Reproductive Health
Human beings are different than other animals because they have the power of thinking. They have to obey certain moral values and need to behave sensibly in most of the aspects of life. Beginning of puberty does not mean that a person is psychologically ready for the process of reproduction. For a human being, reproduction involves more than just producing an offspring.
As any act of sex has the potential of fertilization, so taking care of contraception becomes important. Moreover, the act of sex also has the potential of creating many sexually transmitted diseases.
Examples of STDs are: gonorrhea, Herpes, syphilis, AIDS, Hepatitis B. AIDS and Hepatitis B are incurable till date. Even the curable STDs are potential dangerous, not only physically but also psychologically.
Reproductive health involves preventing the chances of STDs and preventing unwanted children. Reproductive health means a couple should be able to enjoy the reproductive phase of its life; without taking the burden of gigantic family.