1. Endocrine System Chapter 3 Section 3

2. Endocrine System Consists of gland that secrete substance, hormones, into the bloodstream. Hormones stimulate growth and many reactions, such as change in activity levels and moods.

3. Pituitary Gland Master Gland Lies below and is stimulated by the hypothalamus (size of a pea) Secretes different hormones at affect different aspects of behavior Growth hormone – growth of muscles, bones, and glands Prolactin – stimulates milk production in nursing women Oxytocin – stimulates labor in pregnant women

4. Thyroid Gland Produces thyroxin – affects the body’s metabolism Too little thyroxin – hypothyroidism- overweight Too much thyroxin – hyperthyroidism- weightloss, excitability, inability to sleep

5. Adrenal Gland Located above the kidneys Cortical steroids – increase resistance to stress and promote muscle development. Cause to liver to release stored sugar, making energy for emergencies. Adrenaline/nonadrenaline- help arouse the body, enabling a person to cope with a stressful situation. Also can intensify emotions.

6. Testes and Ovaries Testosterone Both sexes have this hormone and is a kind of steroid Aids in the growth of muscle and bone Primary sex characteristics directly involved in reproduction Secondary sex characteristics not involved in reproduction, but distinguish males from females (beard growth) Estrogen and progesterone Found on both sexes Estrogen fosters the development of primary and secondary sex characteristics (breast enlargement) Changes in levels have been linked to PMS Higher estrogen seem to be connected with optimal 1cognitive functioning Progesterone has multiple functions Prepares body for pregnancy