Few Important terms:
- The stage of growth and maturity from birth till 2 years of age is Infancy.
- Childhood – Stage of growth from 2 years to 11 years of age is called as Childhood.
- Adolescence – Stage of growth and maturity from 11 years till 18 years is termed as Adolescence.
- In this period body undergo changes leading to reproductive maturity.
- Person undergoing age of adolescence is called Adolescent.
- The period of adolescence varies from person to person.
- Adolescent are also called as Teenagers.
Define Puberty??
- The age at which sex hormones and sex gametes produce and the boy or girl become sexually mature to reproduce is called Puberty.
- Boys attain Puberty at 13-14 years
- Girls attain Puberty at 10-12 years.
- In male child, testes starts to produce Sperm and sex hormone Testosterone.
- In female child, ovary start to produce egg or over and the sex hormone Progesterone
- Puberty ends when adolescent reaches the reproductive maturity.
What are the changes that takes place due to Puberty and Adolescence??
- Increase in height
- Change in body shape
- Change in voice
- Increase activity of the sweat and sebaceous gland.
- Development of the sex organs
- Reaching mental intellectual and emotional maturity.
Increase in Height
- During Puberty stage there is suddenly increase in the height of boys and girls and this is due to the increase in the length of bones of arms and legs along with internal organs.
- Height of the individual depends on Inheritance and Nutrition.
- Inheritance – The height depends on genes inherited from parents. If your mother or father is then there are more chances that you may also be tall.
- Nutrition – Foods rich in Protein and vitamins helps the growth of bones and muscles and other organs to get adequate nourishment for growth.
Change in the body shape:
During Puberty, both boys and girls undergo changes in the body shape.
Boys | Girls |
Shoulders become broader and chest becomes wider. | Hips gain weight and region below wasit pelvic region becomes wider. |
Body muscles of boys grow more prominently than girls. | Breast development also takes place. |
They develop large voice box. voice box can be seen outside in the neck. The protruding part of throat is called Adam’s apple | Voice box is hardly visible from outside due to small size. |
Boys have low pitched deep voice | Girls have high pitched voice |
Increased activity of the Sweat and Sebaceous Gland:
- Sebaceous Gland produce sweat, and oil/ serum.
- During Puberty, there is increased activity of sweat and sebaceous gland so that sweat and oil formation increases
- This leads to the formation of acne and pimples in the face
Development of sex organs:
- Male sex organs development is complete and it starts to produce male gametes called Sperms.
- Female sex organs like ovaries, oviduct and uterus enlarge and start to produce egg or ova
Reaching Mental, Intellectual and Emotional Maturity:
- Adolescence is the time when the brain acquires greatest capacity of learning.
- During this period, they give more importance to friends group.
- Often have mood swings and have emotional outburst
- They are more sensitive and easily lose temper.
- They lose self conscious
- They need for acceptance and understanding increases.
- They are in search of unique social identity.
- They may feel insecure.
- They get attracted to opposite sex.
What should adolescent do at this stage???
- They should learn to cope with stress caused by hormonal changes.
- They should not lose confidence
- They should not develop anxiety over small issues.
- They might take advice from parents and teachers or other guardians who would like them.
Secondary sexual characters
Difference between Primary and Secondary sexual characters
Primary sexual characters | Secondary sexual characters |
Sexual characters that are present from the birth is called as Primary Sexual Characters | Sexual characters that distinguish between the sexually mature males and females are Secondary Sexual Characters |
They are directly involved in reproduction | They are not directly involved in reproduction |
These are not controlled by sexual hormones | These are controlled by sexual hormones |
List the Secondary Sexual characters in Male:
- Hair grow under armpits and genital area between the thighs
- Hair grows and chest face beard Moustache etc.
- Body becomes muscular due to the development of muscles
- Voice depends due to the growth of voice box (Adam’s Apple)
- Chest and shoulders broaden
- Adult males are taller than adult females
- Heavier skull and bone structure
- Testis starts producing sperms and male sex hormone called testosterone
Females
- Hair grow centre armpits and pubic region
- Menstrual cycle/ the monthly cycle starts
- Development of the breast
- Hips broaden and become more curved.
- High pitch voice develops
- Ovary starts to release eggs and female sex hormone Oestrogen and Progesterone formed in the ovary
Define Hormones?
- Hormones are chemical substances that co-ordinate the activities of the living organisms and their growth.
- Hormones act as messengers and so they are called as chemical messengers of the body.
- Hormones are secreted by endocrine glands.
Difference between Endocrine and Exocrine glands??
Exocrine glands | Endocrine glands |
They are duct glands | They are ductless glands |
These glands release their secretion with the help of the duct. | These glands release their secretion directly into the blood stream. |
Ex: Salivary glands secrete Saliva in the mouth. | Ex: Pituitary gland, Adrenal glands etc. |
How Endocrine system function?
- Endocrine glands release hormones directly into the blood stream.
- They are chemical messengers that carry instructions.
- Hormones are transported by blood circulation.
Target site:
- Hormones releases into specific body part such as organ tissue or the cell. This is called as Target Site.
- Target site response to hormones.
Explain the role of hormones in initiating the reproductive functions??
- The onset of puberty is controlled by hormones.
- Testes produces Testosterone. Ovaries produce Progesterone and Oestrogen.
- These hormones under the control of the Luteinising hormone from the pituitary gland.
- Mammory glands secretes hormones that help in the development of the breast.
- Secretion of the sex hormones result in the development of the secondary sexual characters.
Reproductive Phase of life in Humans:
- Women: reproductive phase begin at the puberty ( 10 -12 years) and last till 45 -50 years.
- Men: Reproductive phase begin at the puberty (14-15 years) and last till the end of his life.
Describe Menstrual Cycle??
- Sexual cycle in the female is called as Menstrual Cycle.
- When a girl reaches puberty, Oestrogen hormone make the ovaries to release the ovum into the fallopian tube once in 28 – 30 days.
- The release of the egg or ovum from the ovary is ovulation.
- During the period the inner wall of the uterus become thick and spongy and filled with tiny blood vessels to receive the egg.
- When mature egg is fertilized by the sperm in the fallopian tube the fertilized egg cell begin to divide and form the embryo.
- This embryo gets embedded in the lining of the uterus. This result in pregnancy.
- If the ovum is not fertilized by the sperm, the thick soft inner lining of the uterus along with the blood and death ovum comes out of the vagina in the form of bleeding. This is called mensuration.
- Mensuration occurs 14 days after ovulation and last for 3 to 5 days
- When menstruation is over the inner lining of the uterus starts to build again.
- Menstrual cycle occurs in the women after about 28 to 30 days.
- If the ovum is fertilized menstruation stops and the female gets pregnant.
Define Menarche??
The first Menstrual flow that begins at Puberty in women is called Menarche.
Define Menopause??
The stoppage of the menstrual flow at the age between 45 to 50 years in females is called as Menopause.
Role of the X and Y Chromosomes:
- Chromosomes are there thread like structures that carry information as genes.
- Humans have 23 pairs of chromosome in the nucleus of all the cells.
- Out of 46, 44 are autosomes. They are identical in males and females.
- Remaining two are the sex hormones. They are represented as X and Y.
- When X chromosome containing the sperm fertilizers the egg that has XX chromosome the resulting child is female.
- When Y chromosome containing Sperm fertlises the egg that has XX chromoplast, resulting child is Male.
- So the sex of the child is totally based only on Father’s Sperm.
Role of hormones in the life cycle of the insects and frogs
Define Metamorphosis??
- The transformation of a ladwa into an adult through drastic changes is called a metamorphosis.
- Metamorphosis and insects is controlled by hormones.
- Metamorphosis in frogs is controlled by thyroxine hormones it is secreted by the thyroid gland.
Reproductive Health
- Health of an individual is defined as his or her state of physical social and mental well being.
- And adolescent should follow properly nutrition personal hygiene physical exercise and good habits to be healthy and fit.
State the Nutritional need of adolescent?
- In adolescent stage individuals must take in balanced diet.
- The diet that contains adequate amount of all the essential nutrients like carbohydrates, fats, proteins, minerals, vitamins for normal growth and development of the body.
- Balanced diet help the bones , muscles and other body parts to get adequate nutrition for rapid growth.
Personal Hygiene:
- Personal hygiene is essential to prevent infection and the occurrence of diseases.
- Increase activity of the sweat and the sebaceous gland increases the bad odour in the body. So take bath daily.
- Was your hands before and after meals.
- Change clothes regularly.
- Girls should take special care during menstruation. They should keep track of their Menstrual cycle.
Physical Exercise:
- Physical exercise keeps the body and mind fit and healthy.
- Outdoor games helps them to build strong bones and muscles.
- Say ” No” to drugs:
- Drugs alcohol and tobacco usage leads to the physical and mental illness.
- It increases the risk of lung cancer and heart attack.
- Tobacco chewing leads to oral cancer.
- Conception of alcohol and drugs like cocaine,Heroin damages the nervous system other body parts.
AIDS – ACQUIRED IMMUNO DEFICIENCY SYNDROME
- It is caused by HIV. Human Immuno deficiency virus.
- It weakens the immunity of a human body and make the body prone to other infections.
How AIDS spread ??
- Through transfusion of the blood from HIV infected person to another person.
- Through the use of infected needles for injections.
- AIDA infected mother may spread the disease to her child in the Womb itself.
- Through sexual contact with the HIV infected persons.
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