Chapter One: Lesson Three Adolescence-A Time of Change Endocrine System: Endocrine System: body system made up of ductless glands that secrete chemicals called hormones into the blood Hormones: Hormones: chemical substances produced in glands which regulate activities of different body cells and organs Puberty: Puberty: period of growth from physical childhood to physical adulthood

Changes During Puberty  Changes occur at different times for each person  Rapid/uneven physical growth  Usually occurs between the ages of 12 and 18  Maturing mentally  Effects how a teen views themselves  Emotional changes/mood swings due to increase of hormones

Hormones and the Pituitary Gland Hormones stimulate reactions in parts of the body Hormones produce structural changes in the body  Bone development  Maturation of the reproductive organs  Development of secondary sex characteristics Hormones regulate the rate of metabolism ( how fast your body produces and uses energy/food)

Pituitary Gland Pituitary Gland: Pituitary Gland: gland that controls much of the endocrine system.  Pea sized gland located at the base of the brain  Releases hormones that affect the brain, glands, skin, bones, muscles and reproductive organs  Secretes 2 hormones responsible for stimulating the reproductive organs that produce sex cells

Females Estrogen/FSH/LH Control levels of hormones estrogen and progesterone produces by the ovaries (which hold the egg-female sex cell) Controls the maturation of the eggs and stimulates ovulation (release of the egg) Secondary Sex Characteristics Breast development Growth of underarm and pubic hair Widened hips Increase in production of oil and sweat

Males Testosterone/LH Controls the amount of testosterone produced by the testes (hold sperm, male sex cell) Controls sperm production Secondary Sex Characteristics Shoulders to broaden Facial hair Underarm and pubic hair Deepening of the voice Muscular development