1. What is the endocrine system?
Lesson 23
What is the endocrine system?

2. Conditions inside and outside of your body are always changing.
Some of these changes can be harmful to you.
Your body has two organ systems to help it adjust to these changes.

3. They are the nervous system and the endocrine system.
You have already learned how the nervous system helps us, so let’s learn about the endocrine system.

4. The endocrine system is made up of many glands
The endocrine system is made up of many glands. These glands make chemical messengers called hormones.
Hormones are chemicals that help the body adjust to changes. But that is not all that they do!

5. Hormones also:
-help control chemical reactions in the body
-affect maturity and reproduction
-help regulate physical and mental development

6. You know about many glands, like the salivary glands and sweat glands
You know about many glands, like the salivary glands and sweat glands. Those are NOT endocrine glands!
What, then, are the differences between endocrine and non-endocrine glands???

7. Non-Endocrine Glands:
-also called exocrine glands
-substances made flow through tubes called ducts
-substances leave the ducts directly into where they will be used.

8. For example: the salivary glands:
Saliva is made in the salivary glands, and it goes through tubes directly into the mouth.
The mouth is where the saliva is used.

9. Endocrine Glands:
-make hormones
-do not move through ducts
-do not empty directly into where they will be used.
-they empty into the bloodstream

10. -the blood carries the hormones to the places where they do their work

11. Pituitary Gland
- small round gland at the base of the brain
-makes hormones that regulate
-growth
-production of sex cells
-controls all the other glands, so is called the “master gland”

12. Thyroid Gland
-butterfly shaped; at base of neck
-regulates metabolism
(metabolism is all the chemical reactions that take place in an organism)

13. Parathyroid Gland
-four small glands embedded in the back of the thyroid gland
-regulate the use of the minerals calcium and phosphorus

14. Thymus
-located in the upper chest
-controls the growth of certain white blood cells that help fight infection

15. Adrenal Glands
-two separate glands, located on top of each kidney
-controls muscle reaction in times of stress, especially sudden stress

16. Islets of Langerhans
-scattered throughout the pancreas
-produces insulin, which helps control the amount of sugar in your blood

17. Male Gonads
-called testes
-located in the lower groin
-make sperm
-make male hormones
-controls development of male characteristics
-deepens voice
-facial hair

18. Female Gonads
-called ovaries
-located in the lower abdomen
-almond shaped
-make eggs & female hormones
-control the development of adult female characteristics
-widening of hips
-body hair