“Calm Your Hormones!”
The Endocrine System
The Endocrine System
A system of “ductless” glands that secrete
hormones directly into the bloodstream
Chemical “messengers”
Distributed throughout body
Only affect certain “target” cells
If they have the corresponding receptor molecules
The Endocrine System
Pineal
The
pituitary
gland
called the
“MASTER
GLAND”
because
its
hormones
influence
other
endocrine
glands
hypothalmus
*pituitary*
parathyroid
thyroid
thymus
adrenal
*pancreas*
*ovary*
*testes*
Negative Feedback
Blood Sugar Maintenance
More Blood Sugar Maintenance
Nervous vs. Endocrine
• Fast
• short duration
• Message is an
electrochemical
(impulse)
• Impulses travel
directly to effector
• A bit slower
• longer lasting
• Message is a
chemical (hormone)
• Hormones circulate
throughout body
Nervous AND Endocrine
Both
• Regulate (maintain homeostasis)
• Involve stimulus-response relationships
• Use specially shaped chemicals
(neurotransmitters or hormones) to
transmit their message.