The Endocrine System

Mr. Fox Science Class

Endocrine System

• A series of different glands that produce hormones that control many of the body’s daily activities and long term development.

Hormone

• A chemical that can turn on, turn off, speed up, or slow down activities of different organs and tissues.

• While a nerve response is a fast one, it’s very short lived. A hormone response is slower to start, but are longer lived.

The Important Glands

• Look them up in your book. Tell me where, what they produce, how they affect the body, and when they affect the body.

• Hypothalamus • Pituitary (master gland)• Adrenal• Thyroid• Thymus• Ovaries• Testes• Pancreas

Hypothalamus

• Produces hormones that control the pituitary gland.

• Control nerve messages when you need to sleep, when you are hungry and other conditions.

• Helps maintains homeostasis

Pituitary

• Communicates with the Hypothalamus

• Switches on other endocrine glands

• HGH is produced here• Stimulates the thyroid• Controls water in the blood

Thyroid

• Releases hormones that control metabolism.

• Found just under your larynx• Parathyroid glands – regulate

calcium in the blood.

Adrenal Gland

• Produces Adrenaline!• On top of the kidneys like little

hats! • Helps balance water and salt in the

blood. Helps control sugar• Adrenaline triggers the body o

respond to emergency situations.

Thymus

• Middle of the chest, near the heart. • Hormones stimulate the immune

system. • Causes the Immune response to

fight infection

Pancreas

• While part of the digestive system, is also an endocrine gland.

• Produces Insulin and glucagon• Controls the amount of sugar

found in the blood.

Ovaries

• Only found in females. • Release the female sex hormone

estrogen. • Controls the development of the

secondary sex characteristics. • Progesterone and estrogen

together trigger the development of eggs.

Testes

• Found in males only.• Releases the male sex hormone

testosterone. • Controls the development of the

secondary sex characteristics.• It also triggers the production of

sperm.

Feedback Systems

• Negative Feedback System – a system that is turned off by the condition it causes.

• Positive Feedback System – a system that is induced more by the condition it causes.