Transcript Endocrine System

4
The endocrine system
Endocrine glands
release __________
into the
bloodstream…
…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
Neurotransmitter
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?