1. D4-3: The Endocrine System

2. You and Your Endocrine System  Endocrine System  A collection of glands and groups of cells that secrete hormones that regulate growth, development, and homeostasis.

3. I. Hormones as Chemical Signals  Our endocrine system is made up of glands, which are a group of cells that make special chemicals for the body.  The glands secrete hormones, which are substances that are made in one cell or tissue and that causes a change in another cell or tissue in a different part of the body.  Hormones are able to move very quickly, because of the bloodstream in our systematic circulation.

4. I. Hormones as Chemical Signals  The Adrenal Glands  These glands release a specific type of hormone called epinephrine, or adrenaline.  This chemical increases your heart rate and breathing.  This response is often called the “fight-or-flight” response.  When we get frightened, angry, or excited, this response prepares us to fight the approaching danger or “run for our lives!!”

5. I. Hormones as Chemical Signals

6. II. More Endocrine Glands  Your endocrine system is made up of several glands and organs including:  Pituitary gland  Thyroid gland  Parathyroid gland  Thymus gland  Adrenal glands  Pancreas  Ovaries and Testes

7. II. More Endocrine Glands  Pituitary Gland  Located in your brain  Stimulates skeletal growth  Assists in the function of the thyroid gland  Regulates the amount of water in blood  Stimulates the birth process in women

8. II. More Endocrine Glands  Thyroid Gland  Important for childhood  Control the secretion of growth hormones for normal body growth  Controls the growth of the CNS  Metabolism The sum of all the chemical processes that take place in an organism.

9. II. More Endocrine Glands  Parathyroid Glands  Regulates Calcium Levels in blood  Thymus  Immune System  Killer T cells grow and mature here  Assist by destroying or neutralizing substances that invade the body

10. II. More Endocrine Glands  Adrenal Glands  Produce epinephrine (adrenaline)  Help the body respond to danger  Pancreas  Regulate blood-glucose levels  Ovaries (in females)-Estrogen  Produce hormones needed for reproduction  Testes (in males)-Testosterone  Produce hormones needed for reproduction

11. III. Controlling the Endocrine Glands  These glands have similar feedback mechanisms that the nervous system has.  Your pancreas produce two different hormones that control the level of glucose in the blood.  Insulin Lowers blood-glucose levels by telling the liver to convert glucose into glucagon and store for future use.  Glucagon This hormone tells the liver to convert glucagon into glucose and to release it into the blood. (The opposite affect of Insulin)

12. III. Controlling the Endocrine Glands  Let’s take a look at Figure 3 on p.96 to see how this feedback mechanism works!

13. IV. Hormone Imbalances  An endocrine gland can sometimes make too much or not enough of a hormone, which causes the body to be unbalanced.  Diabetes mellitus  When a person’s body does not produce enough insulin must take daily injections of insulin to keep his or her blood- glucose level within safe limits.  If this person does not receive these shots, they can sometimes slip into a coma and dies of this condition.

14. IV. Hormone Imbalances  Pituitary Gland  Sometimes if a person’s pituitary gland does not produce enough of a growth hormone, their growth can often be stunted.  If this is detected early, growth hormones are prescribed by doctors and monitor his or her growth.  If this gland produces too much of the growth hormone, a child may grow taller than expected.

15. IV. Hormone Imbalances DIABETESPITUITARY GLAND IMBALANCE