The endocrine system

Endocrine glands release __________ into the bloodstream…

4

…Hormones regulate growth, metabolism, sexual development and behavior, and other functions.

The Endocrine System• The Endocrine

System is the body’s “slow” chemical communication system.

• Communication is carried out by hormones

Hormones Neurotransmitters

The Endocrine System:Glands and Hormones

• Hormones – chemical messengers in the bloodstream– Pulsatile release (several times per day in brief

bursts) by endocrine glands– Negative feedback system (levels of hormones

increase until signals are sent to glands to stop secretion of that hormone)

• Endocrine glands:– Pituitary – “master gland,” growth hormone– Thyroid – metabolic rate– Adrenal – salt and carbohydrate metabolism– Pancreas – sugar metabolism– Gonads – sex hormones

Hormones

• Hormones are chemicals synthesized by the endocrine glands that are secreted in the bloodstream. – Hormones affect the brain and many other tissues

of the body.

• For example, epinephrine (adrenaline) increases heart rate, blood pressure, blood sugar, and feelings of excitement during emergency situations.

Endocrine System

• Why is the pituitary gland called the “master gland”?

Review

• Can you remember feeling an extended period of discomfort after some particularly stressful event? How long did those feelings last? Why?