Your endocrine system sends and receives chemical messages that control many body functions.

endocrine glands

hormones

thyroid gland

parathyroid glands

pancreas

pituitary glands

adrenal glands

How the Endocrine System Works

The endocrine system includes various organs that work together to regulate body functions.

The endocrine system sends and receives hormones.

How the Endocrine System Works

There are several different endocrine glands.

Endocrine glandsDuctless or tubeless organs or groups of cells that secrete hormones directly into the bloodstream

How the Endocrine System Works

Endocrine glands secret hormones into the blood to influence physical and mental responses.

HormonesChemical substances that help regulate many of your body’s functions

How the Endocrine System Works

Major Glands of the Endocrine System

Thyroid Gland

Parathyroid Glands

Testes

Ovaries

Hypothalamus

Pineal Gland

Pituitary Gland

Thymus

Adrenal Glands

Pancreas

How the Endocrine System Works

The thyroid gland produces thyroxine, which regulates the way cells release energy from nutrients.

Thyroid glandProduces hormones that regulate metabolism, body heat, and bone growth

How the Endocrine System Works

The parathyroid glands are located in the neck near the thyroid gland.

Parathyroid glandsProduce a hormone that regulates the body’s balance of calcium and phosphorus

How the Endocrine System Works

Testes

Ovaries

Hypothalamus

Pineal Gland

Thymus

Adrenal Glands

Male reproductive glands that produce sperm for fertilization

Female reproductive glands that produce the egg cells

Links the endocrine system and the nervous system and stimulates the pituitary gland to secrete hormones

Secretes the hormone melatonin, which is thought to affect the onset of puberty, and regulates sleep cycles

Regulates development of the immune system

Regulate the body’s salt and water balance and control the body’s emergency response

How the Endocrine System Works

The pancreas is an endocrine gland that secretes two hormones—glucagon and insulin—that regulate the level of glucose in the blood.

PancreasA gland that serves both the digestive and the endocrine systems

The Pituitary: The Master Gland

Known as the master gland, the pituitary gland has three sections, or lobes: anterior, intermediate, and posterior.

Pituitary glandRegulates and controls the activities of all other endocrine glands

The Pituitary: The Master Gland

Hormones produced by the pituitary gland play a significant role in determining height.

Anterior Lobe

Somatotropic, or Growth Hormone

Stimulates normal body growth and development

Thyroid-Stimulating Hormone

Adrenocorticotropic Hormone

Follicle-Stimulating Hormone and Luteinizing Hormone

Stimulates the thyroid gland to produce hormones

Stimulates production of hormones in the adrenal glands

Stimulates production of all other sex hormones

The anterior, or front, lobe of the pituitary gland produces these hormones:

Intermediate Lobe

The intermediate, or middle, lobe of the pituitary secretes melanocyte-stimulating hormone, which controls the darkening of the pigments in the skin.

Intermediate Lobe

The posterior, or rear, lobe of the pituitary secretes antidiuretic hormone that

regulates the balance of water in the body, and

produces oxytocin, which stimulates the smooth muscles in the uterus during pregnancy, causing contractions during the birth of a baby.

The Adrenal Glands

The adrenal glands each have two parts: the adrenal cortex and the adrenal medulla.

Adrenal glandsHelp the body deal with stress and respond to emergencies

The Adrenal Glands

The adrenal cortex secretes hormones that

inhibit the amount of sodium excreted in urine and maintain blood volume and blood pressure

aid in the metabolism of fats, proteins, and carbohydrates

influence the body’s response to stress

play a role in both the immune response and sexual function

The Adrenal Glands

The adrenal medulla secretes the hormones epinephrine (also called adrenaline) and norepinephrine.

 

Epinephrine increases heartbeat and respiration, raises blood pressure, and suppresses the digestive process during periods of high emotion.

Maintaining Your Endocrine Health

To keep your endocrine system working at its peak, you need to follow sound health practices.

Your endocrine health is directly related to your overall health.

Maintaining Your Endocrine Health

Get 8 ½ to 9 hours of sleep every night.

Use stress-management techniques.

Eat balanced meals to ensure that you get the nutrients you need.

Tips for Maintaining Your Endocrine Health

Engage in regular physical activity.

Have regular medical checkups.

Maintaining Your Endocrine Health

Hyperthyroidism

Hypothyroidisim

Diabetes mellitus

These Endocrine Disorders May Require Medication

Goiter

Overproduction of adrenal hormones

After You ReadReviewing Facts and Vocabulary

Chemical substances produced in glands that help regulate many body functions

1. What are hormones?

After You ReadReviewing Facts and Vocabulary

2. Name the hormone that stimulates normal growth and development.

Somatotropic hormone

After You ReadReviewing Facts and Vocabulary

3. What gland helps regulate the chemicals that control sleep?

Pineal gland