1. Section 18.1 The Endocrine System Objectives
Describe the general roles of the endocrine system.
Identify the glands of the endocrine system.

2. Health Stats What trends in growth rate does this graph show?
Does your observation of classmates support the trends shown in the graph? Explain.

3. What Is the Endocrine System?
The endocrine system regulates long-term changes in the body such as growth and development.
It also controls many of your body’s daily activities.

4. Hormones
A chemical substance produced by an endocrine gland is known as a hormone.
You can think of a hormone as a chemical messenger.
The endocrine system is kept in balance by the coordinated action of various hormones.

8. The Endocrine System
Thyroid Gland The thyroid gland regulates the body’s overall metabolic rate and controls calcium levels in the bloodstream.
Parathyroid Glands Four tiny parathyroid glands regulate levels of calcium and phosphorus––minerals that are necessary for proper bone and tooth formation and for muscle and nerve activity.
Pancreas The pancreas is a large gland, located behind the stomach, that controls sugar levels in the blood.

9. Hypothalamus The hypothalamus links the nervous system and the endocrine system and controls many of the pituitary gland functions.
The Endocrine System
Pituitary Gland The pituitary gland controls other endocrine glands and regulates growth rate, reproduction, and metabolism.
Thymus Gland Hormones released by the thymus gland help the immune system develop during childhood. By adolescence, this gland has shrunk considerably in size.
Adrenal Glands These glands release several hormones. Adrenaline triggers the body’s response to sudden stress. Other hormones affect salt and water balance in the kidneys and general metabolism.

10. The Endocrine System
Ovaries The female reproductive glands release sex hormones that regulate egg maturation and control changes in a female’s body at puberty.
Testes The male reproductive glands release a sex hormone that regulates sperm production and control changes in a male’s body at puberty.

11. End of Section 18.1 Click on this slide to end this presentation.