Reproduction in human beings
- Puberty-it is the period during which adolescents reach sexual maturity and become capable of reproduction
- During early teenage whole new set of changes occurs, appearance of body and proportions change and new features develop.
- As the rate of general body growth slows down reproductive tissues begin to mature.
- If animals are to participate in the process of mating, their state of sexual maturity must be identifiable by other individuals.
|Pubertal changes in males||Pubertal changes in females|
|a) deepening of voice(low pitch)
b) broadening of shoulders
c) appearance of beard & moustaches
d) Growth of axillary & pubic hairs
|a) high pitch voice
b) widening of hips
c) Growth of axillary & pubic hairs
d) Initiation of menstruation
e) Growth of mammary glands.
Male reproductive system
- Testis is a galndular organ made up of fine tubules.
- The formation of germ cells take place in testes, located outside the abdominal cavity in scrotum because sperm formation requires a lower body temperature.
- testis also produces certain hormones, like tetosterone which are responsible for secondary sexual characters in humans.
- These are deep male voice, hair growth in pubic area and under armpits, and facial hair.
2. Seminal Vesicle: Once sperm is produced it is stored in seminal vesicle.
3. Vas Deferens:
- Vas deference is the tube through which semen containing sperm is transferred out.
- The sperms produced are transferred by vas deferens which unites with a tube coming from urinary bladder.
- Urethra forms a common passage for both sperm and urine.
- To make the transportation of sperms easier prostate and seminal vesicles add their seceretions along the path of vas deferens, that makes the sperms to be transported in fluid which provides nutrition.
- Cowper‘s gland – Produces white viscous & alkaline secretion
- Semen = sperm& secretion of accessory glands
Female Reproductive system
- Ovaries are situated on left and right side of the uterus.
- The female germ-cells are produced in ovary, which is also responsible for production of oestrogen.
- On reaching puberty some of the immature eggs present in the ovary of a girl start maturing.
2. Fallopian Tubes:
- Fallopian tubes extends on both sides of the uterus in transverse direction.
- Fallopian tubes have finger like structures which catch the eggs to transfer them to the uterus.
- Uterus is a bag like structure, with an opening in the vagina.
- Uterus opens into the vagina through cervix.
Fertilization In Human Beings
- Sperms enter through the vaginal passage during sexual intercourse and encounters egg in fallopian tube.
- Once eggs reach uterus, a layer of soft tissues develops to support the embryo.
- This layer is called corpus luteum.
- If fertilization takes place, then the embryo develops into a foetus and ultimately to a fully developed child over a period of about 9 months
- The zygote gets implanted into the lining of the uterus and starts dividing.
- The uterus prepares itself every month to receive and nurture the the embryo, the lining thickens and is richly supplied with blood to nourish the growing embryo.
- The embryo gets nutrition from the mother’s blood with the help of a tissue called placenta, a disc embedded in uterine wall.
- The child is born as a result of rhythmic contractions of the muscles of uterus.
- Implantation : Attachment of embryo to the lining of uterus.
- Placenta : A connection between the mother & the foetus
- The foetus meets all its developmental needs such as nutrition, respiration and excretion through the placenta.
- Gestation period :The period between fertilisation & birth
Menstrual Cycle in Females:
- If no fertilization takes place then after about two weeks the dead eggs and corpus luteum gets expelled out of the uterus through vagina.
- This process takes place over a period of about three to four days.
- This clears the way for new batch of eggs to come in the uterus.
- The whole cycle from egg production to the expulsion of eggs takes about four weeks.
- This cycle is known as Menstrual Cycle.
- Apart from humans, some primates like Chimpanzee and Gorilla also show same
- Ovary secretes one of the important hormones estrogen, which is responsible for secondary sexual characters in female, like thin voice and breast enlargement.
Menarche – commencement of menstrual cycle at puberty which marks the beginning of reproductive life of the human female.
Menopause – cessation of menstrual cycle which marks the end of the reproductive life of a human female.
Reproductive Health and Birth Control Methods
- Creation of a mechanical barrier is a method of contraceptive so that the sperm does not reach the egg is called condoms.
- Oral pills change the hormonal balance of the body
- Loops and copper-T is placed in the uterus to prevent pregnancy
- Surgical method can be used to block vas deferens in male and fallopian tube in female.
Previously Asked Questions on Reproduction in Human beings
- How does the male gamete reach the egg present in the ovary?
The pollen tube releases the male gametes in the embryo sac .
- What are gonads?
Gonads are the primary sex organs which produce gametes & secrete sex
- Define syngamy.
The process of fusion of male gamete with the female gamete is known as syngamy.
- At what age human males attain puberty?
At the age of 12-14 years
- At what age human females attain puberty?
At the age of 10-12 years.
- What are the functions of gonads?
i) production of gametes
ii) secretion of sex hormones.
- Why are testes located outside the abdominal cavity ?
Sperm formation requires a temperature lower than that of the normal body temperature.
- Where are ovaries located in human females?
Ovaries are present in the abdominal cavity near the kidneys.
- What is placenta?
A connection between the mother & the foetus.The foetus meets it all its developmental needs such as nutrition, respiration and excretion through the placenta.
- What is menstruation?
If fertilization does not occur the uterine wall slowly breaks & comes out through vagina as blood and mucous.
- What is ovulation?
It is the process of release of a mature ovum from the ovary.