Life Science 4.3

The Endocrine System

1. Explain why the endocrine system is important to the body.

2. Identify five glands of the endocrine system, and describe what their hormones do.

3. Describe how feedback mechanisms stop and start hormone release.

4. Name two hormone imbalances.

Objectives:

Endocrine system Collection of glands and

groups of cells that secrete hormones.

Gland group of cells that make

special chemical messengers, called hormones, for your body.

Hormone Chemical messenger

made in one cell or tissue that causes a change in another cell or tissue in another part of the body.

Hormones as Chemical Messengers

Adrenal GlandsEpinephrine – also known as adrenaline, is

released in “fight or flight” response.Prepares you to fight or run from danger.

Thyroid gland Controls the secretion of growth hormones for

normal body growth.Thymus gland

Produces killer T cells that help destroy or neutralize cells or substances that invade your body.

Metabolism Sum of all the chemical processes that take place

in an organism.

More Endocrine Glands

Endocrine glands control feedback mechanisms in the body.

Occasionally, an endocrine gland makes too much or not enough of a hormone. For example, sometimes a child’s pituitary gland

doesn’t make enough growth hormone. As a result, the child’s growth is stunted.

Controlling the Endocrine Glands

Hormone Imbalances