Growth and Development Chapter 8

Adolescence: A Time of Change Lesson 1

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.

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

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.

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

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

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

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.

Human Reproduction Lesson 2

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.

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

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.

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

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.

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.

Heredity and the Life Cycle Lesson 3

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.

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

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.

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

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.

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

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

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.

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+