puberty

7th grade-4th partial

Puberty :process of physical changes by which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy. Responding the signals, the gonads produce hormones that stimulate the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sexual organs.

Physical growth—height and weight—accelerates in the first half of puberty and is completed when the child has developed an adult body. The age at which puberty begins varies between 10 and 13 years of age. Puberty age is affected by both genetic factors and by environmental factors :nutritional state and social circumstances.

• The major landmark of puberty for males is the first ejaculation, which occurs on average at age 13. For females, it is menarche, the onset of menstruation, which occurs between ages 12 and 13.

• In the 21st century, the average age at which children reach puberty is lower compared to the 19th century, when it was 15 for girls and 16 for boys. This is possibly due to chemicals in food or a better nutrition.

Testicular size, penis size, fertilityIn boys, testicular enlargement is the first physical manifestation of puberty (gonadarche) Testes in prepubertal boys change little in size from about 1 year of age to the onset of puberty. Size continues to increase throughout puberty.Two primary functions of testes: 1.Produce hormones 2.Produce sperm. During puberty, a male's scrotum will enlarge and begin to hang below the body as opposed to being up tight.

Pubic hair• Pubic hair often appears on a boy shortly after the genitalia begin

to grow. The pubic hairs are usually first visible at the base of the penis

Body and facial hairFollowing the appearance of pubic hair, other areas of skin that respond to androgens may develop androgenic hair. The usual sequence is: underarm (axillary) hair, perianal hair, upper lip hair, sideburn hair, and the beard area. Arm, leg, chest, abdominal, and back hair become heavier more gradually. Facial hair is often present in late adolescence, but may not appear until years after.Significantly chest hair may appear during puberty or also years after. Not all men have chest hair.

Voice change and Adam's apple• Under the influence of androgens, the voice

box, or larynx, grows in both sexes. This growth is far more prominent in boys, causing the male voice to drop and deepen, sometimes abruptly but rarely "over night,". Before puberty, the larynx of boys and girls is about equally small.

Male musculature and body shape• By the end of puberty, adult men have heavier bones and

nearly twice as much skeletal muscle. Some of the bone growth ( shoulder width and jaw) is disproportionately greater, resulting in noticeably different male and female skeletal shapes.

• This muscle develops mainly during the later stages of puberty, and muscle growth can continue even after boys are biologically adult. Often, the fat pads of the male breast tissue and the male nipples will develop during puberty; especially in one breast.

• Body odor and acne• Rising levels of androgens can change the

fatty acid composition of perspiration, resulting in a more "adult" body odor. As in girls, another androgen effect is increased secretion of oil (sebum) from the skin and the resultant variable amounts of acne.

Physical changes in girls

• Breast developmentThe first physical sign of puberty in girls is breast development. Within six to 12 months, the swelling has begun in both sides. • Pubic hairPubic hair is often the second noticeable change in puberty .In about 15% of girls, the earliest pubic hair appears before breast development begins.

Vagina, uterus, ovaries• The mucosal surface of the vagina also

changes in response to increasing levels of estrogen, becoming thicker and duller pink in color .Whitish secretions are a normal effect of estrogen as well. In the two years following thelarche, the uterus, ovaries, and the follicles in the ovaries increase in size.

Menstruation and fertility

The first menstrual bleeding is referred to as menarche.The time between menstrual periods (menses) is not always regular in the first two years after menarche.

Body shape, fat distribution, and body composition

During this period, also in response to rising levels of estrogen, the lower half of the pelvis and hips widen (providing a larger birth canal). Fat tissue increases more than in males, especially in the distribution of breasts, hips, buttocks, thighs, upper arms.

Body odor and acne

• Rising levels of androgens can change the fatty acid composition of perspiration, resulting in a more "adult" body odor. Another androgen effect is increased secretion of oil (sebum) from the skin. This change increases the susceptibility to acne, a skin condition that is characteristic of puberty. Acne varies greatly in its severity.

Nutritional influence

Nutritional factors are the strongest and most obvious environmental factors affecting timing of puberty. Girls are especially sensitive to nutritional regulation because they must contribute all of the nutritional support to a growing fetus.Excess calories (beyond growth and activity requirements) are reflected in the amount of body fat, which signals to the brain the availability of resources for initiation of puberty and fertility.

Physical and mental illness

• Chronic diseases can delay puberty in both boys and girls. Those that involve chronic inflammation or interfere with nutrition have the strongest effect. In the western world.Tuberculosis has been notorious for such an effect in the last century, while in areas of the underdeveloped world, chronic parasite infections are widespread.

• Mental illnesses occur in puberty. The brain undergoes significant development by hormones which can contribute to mood disorders such as major depressive disorder, bipolar disorder, and

schizophrenia. Girls aged between 15 and 19 make up 40% of anorexia nervosa cases.This is an eatingDisorder.

Questionaire• What is androgenic hair? Give examples.• How does facial hair change?• What are the two functions of testes?• What changes do boys experience during puberty?• Where does puberty start in boys and girls?• What are gonads?• What do they do?• Why can puberty begin at different ages?• What is menarche?• What are the physical changes in girls?

evaluation

• Project : 20 pts.• quiz: 10 pts.• Cooking lab: 10 pts• Poster 15• Investigation 15• Exam 30

ANOREXIA• Many people with anorexia nervosa see themselves

as overweight, even when they are clearly underweight. Eating and weight control become obsessions. They weigh themselves repeatedly and eat very small quantities of only certain foods. Some others eat excessively followed by extreme dieting, lots of exercise, self-induced vomiting and laxatives.

BULIMIA• People with bulimia nervosa eat extremely large

amounts of food and can’t control themselves. This binge eating is followed by forced vomiting, excessive use of laxatives or diuretics, fasting, excessive exercise, or a combination of these.

• Unlike anorexia nervosa, people with bulimia nervosa usually maintain a healthy or normal weight, while some are slightly overweight.

Teenage pregnancy

• THis is a worldwide problem seen in almost every country.

• It envolves all the family causing different problems .

• Many methods are being used to prevent this but it still occurs.

• Sufferness is the main issue.

Teenage pregnancy• Teenage births are associated with lower annual income for

the mother. • Teenage mothers are more likely to drop out of school. Only

about one-third of teen mothers obtain a high school diploma.

• Increased rates of alcohol abuse and substance abuse, • lower educational level• Reduced earning potential in teen fathers.

• Babies born to teen age moms have lower birth weight and are more likely to die in their first year of life.

• Children of teenage parents are more likely to have learning problems.

• These children have an increased risk of becoming teenage parents.

contraceptives• These are ways of preventing pregnancies.There are different contraceptives. Some are for

women and others for man.

• Abstinence is a form of contraception.Surgeries to prevent pregnancies are done also

for Men and women :TUBAL LIGATION for women and VASECTOMY for men.

There are different types of pills; some are taken daily while others twice a day.

Not all methods work for everybody.Some can be dangerous for certain people.

poster• Teen age pregnancy Williams Isra • Contraceptive methods Ordoñez Fer Ely • Anorexia Sabas Aaron Angela • Bulimia Diego Raul Carlos• Changes in girls Weddle Luis Moreira Rock• Changes in boys Grajeda Angelica Brian

Rodriguez• Abstinence clubs Jimena Lilian Omar

• 15 pts. Groups of 3• Content: 8 2 pictures : 4 color/contrast : 1 size of

letter: 2• Use a ruler.• Dont emphasize the title too much.

Abstinence clubs These are groups of teenagers formed to

empower each other with the same ideals:• To stay away from things that can keep them

from reaching their long term goals.• Being together makes them develop their

courage, self esteem , knowledge.• They stay away from drugs, alcohol,

pornography ,dropping school ,sex and violence.

• They receive counseling ,information and guidance.

They aren’t very popular since most adolescents practice all those mentioned things.

Their long term goals are : • University degree• Successful carreers and jobs• Well planned families• Good Economical level

HIV - AIDS• HIV stands for the "human immunodeficiency

virus.“ It is a virus that infects human being and leads to problems with their immune system. The immune system is the body's system for fighting disease.

• As HIV infection progresses, there is damage to immune defense cells and the body becomes less able to fight off infection.

• AIDS, "Acquired Immune Deficiency Syndrome" is a group of symptoms and diseases associated with the damage HIV does to the immune system.

• Some people have the virus but never develop AIDS though they contague it to others.

A person can live with HIV for many years without developing AIDS or any symptoms of HIV infection. This is why it is important to be regularly tested for the virus.

Transmission

HIV can be transmitted in three main ways: •Sexual transmission •Transmission through blood •Mother-to-child transmission•Breast feeding

ANTIRETROVIRAL TREATMENT• It is a treatment given to people with HIV.• It enables people living with HIV to enjoy longer,

healthier lives, and as such acts as an incentive for HIV testing.

• Though the treatment is very harsh, causing secondary effects it is very effective.