1. Endocrine System

2. Endocrine System
Regulates overall metabolism, homeostasis, growth and reproduction
Glands – are organs that specialize in the secretion of substances needed by an organism
Hormones – are the secretions produced by the endocrine glands
- released into the bloodstream

3. Endocrine Glands
Hypothalamus – part of the CNS, but it produces hormones that influence the pituitary gland
Pituitary Gland – the “master gland”
Located at the base of the brain
Secretes growth hormone which affects growth of bone and cartilage

4. Endocrine Glands (continued)
Thyroid Gland
Located in the neck
Secretes thyroxine which regulates the rate of metabolism in the body
Parathyroid Gland
Embedded in the back of the thyroid
Secretes parathormone which controls metabolism of calcium and phosphate

5. Endocrine Glands (continued)
Adrenal Glands
Located on top of the kidneys
Secrete adrenaline which helps deal with stress and accelerates the heart and breathing rates
Islets of Langerhans – specialized cells
Located in the pancreas
Secrete insulin and glucagon
Insulin lowers blood sugar
Glucagon raises blood sugar

6. Endocrine Glands (continued)
Gonads – sex glands
Male gonads are called testes
Located in the scrotum
Secrete testosterone which regulates male secondary sex characteristics
Female gonads are called ovaries
Located in the pelvic region
Secrete estrogen and progesterone which regulate female secondary sex characteristics

7. Feedback Mechanisms
Negative Feedback – is when an activity alters a condition in the body, and this triggers a series of events that reverses the altered condition
Ex. Body temperature
When body temp. goes up, we sweat
When body temp. goes down, we shiver
Ex. Blood sugar levels
When blood sugar goes up, insulin lowers blood sugar
When blood sugar goes down, glucagon raises blood sugar

8. Feedback Mechanisms (continued)
Positive Feedback – is when a change initiates a response, and that response intensifies the original change
Ex. Contractions of the uterus during childbirth

9. Disorders
Diabetes – is a disease where a person cannot produce insulin
Inability of the body to store sugar as glycogen
Goiter – is enlargement of the thyroid gland caused by iodine deficiency