1. Growth and Development
Chapter 8

2. Adolescence: A Time of Change
Lesson 1

3. Changes During Adolescence
Differences in how younger or older teens may look are caused by adolescence.
Mood swings are a normal part of adolescence.
adolescence The period between childhood and adulthood
Although teens experience these changes, they occur at different times and speeds for everyone.

4. Changes During Adolescence
Hormones are produced in the endocrine system.
endocrine system A body system containing glands that regulate growth and other important activities

5. Changes During Adolescence
These glands make up the endocrine system:
Pituitary
Thyroid
Adrenal
Pancreas
Ovaries / Testes
The pituitary gland produces several hormones that control other glands and organs. It also regulates the body’s growth and development.
The thyroid gland produces a hormone that regulates the speed at which your body turns food into energy. It also helps regulate growth.
The adrenal glands produce adrenaline, a hormone that controls the body’s response to emergencies. They also play a role in digestion and help maintain a balance of salt and water in the body.
The pancreas produces insulin, which controls the ability of body cells to use sugar for energy.
The ovaries and testes produce hormones that control sexual development.

6. Physical Changes
Physical changes that occur during puberty include the growth of body hair and increased sweating, or perspiration.
puberty The time when you start developing the physical characteristics of adults of your gender
Female Changes
Male Changes
Increased level of female hormones
Increased level of male hormones
Acne
Increase in perspiration
Underarm hair
Development of Breasts
Deeper voice
Increase in body fat
Facial hair
Wider hips
Broadened shoulders
Formation of mature eggs
Muscle development
Pubic hair
Beginning of menstrual cycles
Production of sperm cells
Enlargement of external genitals

7. Female Hips wider Menstruation Acne Increase sweating
Increased levels of hormones
Underarm / pubic hair
Development of breasts
Formation of mature eggs
Increase in body fat

8. Male Facial / pubic hair / underarm hair Deepened voice Acne
Increased sweating
Increased hormones
Production of sperm
Shoulders broadened
Muscle development

10. Mental/Emotional Changes
Changes in hormones can affect your feelings as well as your thoughts.
You may experience mood swings.
You might be happy one moment and sad the next. These shifts in emotions are called mood swings and are common in adolescence. Talk about your feelings with others. This will help you manage your feelings in a healthy way.

11. Human Reproduction
Lesson 2

12. Human Reproduction
The male reproductive system is different than the female reproductive system.
reproductive system The body system that makes it possible to create offspring
So far, all the body systems you’ve learned about are the same for females and males. The reproductive system is different.

13. The Female Reproductive System
The two main functions of the female reproductive system are:
Storing egg cells
To reproduce
The egg cell is also called an ovum.
egg cell The female reproductive cell

14. The Female Reproductive System
The process of reproduction begins when the egg cell joins with a male reproductive cell (sperm cell).
The ovaries are the two female reproductive glands that store the egg cells.
The ovaries also release hormones that control growth and play a role in the proper functioning of the reproductive system. During puberty, the ovaries begin to release eggs.

15. The Female Reproductive System
After fertilization, an egg will travel to the uterus, the organ in which the baby will develop.
fertilization The joining of a female egg with a male reproductive cell

16. The Female Reproductive System
Menstruation is often referred to as a “period.”
menstruation Blood, tissue, and the unfertilized egg flow out of the body
If fertilization does not occur, the nutrient-rich lining of the uterus breaks down.
Most girls can expect to begin menstruation anywhere from age 9 through 16.
During menstruation, change sanitary pads or tampons several times a day.
Expect some cramping during menstruation. Talk to your doctor if you have unusual pain or heavy bleeding.

17. The Male Reproductive System
Sperm cells are made inside the testes.
sperm The male reproductive cells
Sperm cells travel through the vas deferens to the urethra where they leave the body.
The testes also produce a hormone that controls the development of the male reproductive system.
The testes begin making sperm cells during puberty.

19. Heredity and the Life Cycle
Lesson 3

20. Heredity
Heredity is the process by which parents pass certain traits to their children.
Hair color and body build are examples of inherited traits.
Children may also inherit talents and abilities. The likelihood of developing certain diseases and health problems is also passed along.

21. Heredity Traits are passed along by chromosomes.
chromosomes Tiny strands of matter that carry the codes for inherited traits
Chromosomes are made up of genes.
Chromosomes are arranged in pairs in your body’s cells. One chromosome comes from your father, the other from your mother.
genes The basic units of heredity

22. Chromosomes and Fertilization
Among each sperm’s 23 chromosomes, one alone determines the gender of the fertilized egg cell.
An egg caries only an X chromosome. Sperm carry either an X or Y chromosome.
If a sperm carries an X chromosome, a female will result. If a sperm carries a Y chromosome, a male will result.
Every type of cell in the human body except one contains 46 chromosomes. That one exception is the reproductive cell. The newly fertilized egg has 46 chromosomes.

25. Data and Observation Inherited Trait Yes No Dimples Earlobe attached
“Widow’s peak”
Left handed
Right handed
Tongue rolling
“Vulcan” sign
Blue eyes
Inherited Trait
Yes No
Brown eyes
Green eyes
Curly hair
Straight hair
Straight thumb
“Hitchhiker’s thumb”
Left hand clasp
Right hand clasp

26. Development Before Birth
The newly fertilized egg travels down the fallopian tube to the uterus.
The egg attaches itself to the wall of the uterus.
The egg begins to be divided millions of times.
The tissues, organs, and body systems are eventually formed.

28. The Developing Baby Time Size Features Development fertilization
microscopic
arms, legs, fingers, toes, eyes, ears
heart is beating; nervous system is forming; cannot survive outside uterus
6 months after fertilization
about 14 inches long; weighs about 2 pounds
hair, eyebrows, fingernails, toenails
can move and kick; sucks thumb; can hear sounds; might survive outside uterus
9 months after fertilization
18–20 inches long; weighs 7–9 pounds
smooth skin, fully developed organs
eyes open and close; fingers can grasp; body organs and systems can now work on their own; ready for birth

29. The Developing Baby
In the uterus, the fetus receives oxygen and nutrients through a tube called the umbilical cord.
fetus What the developing unborn baby is known as from the eighth week until birth

30. The Developing Baby
Throughout pregnancy, an expectant mother needs prenatal care.
prenatal care Special care to ensure that the expectant mother and the baby remain healthy
Pregnancy is a joyful event, but is also means added responsibility. New parents often don’t get a lot of sleep and may experience added stress or other emotional changes.
The mother-to-be must avoid tobacco, alcohol, and other drugs not prescribed by the doctor.
Prenatal care includes eating healthy foods, getting enough rest, and seeing the doctor regularly.

31. The Life Cycle The life cycle is divided into six major stages.
Infancy
Childhood
Adolescence
Early Adulthood
Middle Adulthood
Late Adulthood
Infancy – Age 1
Physically, babies grow fast. Babies also grow mentally/emotionally.
Infants need loving physical car and attention.
Childhood – Ages 1 to 11
During this time, children are busy absorbing information. Encouragement at this stage builds self-esteem.
Adolescence – Ages 12 to 18
This is a time of transition.
Skills such as decision making, goal setting, and good communication help prepare adolescents for adulthood
Early Adulthood – Ages 19 to 30
Many young adults are busy pursuing and education or training for a career..
Some young adults choose to get married and start a family.
Middle Adulthood – Ages 30 to 60
Many at this stage look at ways to contribute to the community.
People at this stage begin planning for the final stage
Late Adulthood – 60+
People at this stage are thinking about retirement,
Those who maintain good health will be able to stay active through this stage.
Age 1
Ages 1–11
Ages 12–18
Ages 19–30
Ages 30–60
Ages 60+