endocrine system chemical control: similar to nervous control, coordinate body processes by...
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Endocrine System
• Chemical Control: similar to nervous control, coordinate body processes by transmitting messages from one part of the body to another
• Achieved through hormonal action
Endocrine System
Function: to maintain homeostasisEndocrine glands: synthesize and secrete hormones (ductless)Hormones ≡ chemicals secreted in one area of body which affect responses in other areas. The circulatory system aids in the distribution of
these hormones Delivered to target tissue which recognize specific
hormones by receptor cells Hormones have specific shape that fit the
receptors
Regulation
How we maintain homeostasis nervous system
nerve signals control body functions (faster & short-lasting)
endocrine systemhormoneschemical signals control body functions
(slower & longer-lasting)
Hormones
Why are hormones needed? chemical messages from one body part to cells
in other areas of body communication needed
to coordinate whole body maintaining homeostasis
growth hormones
Endocrine System
Endocrine system releases hormones glands which secrete (release)
chemical signals into bloodchemicals cause changes
in other areas of body growth hormones sex hormones response hormones metabolism hormones and more….
Responding to hormones
Lock and key system hormone fits receptor on “target” cell
targetcell
non-targetcells
secretingcell
can’treadsignal
can’treadsignal
Control of the Endocrine system
The hypothalamus integrates endocrine and nervous functionNervous tissue; part of the mid-brain
Maintaining homeostasis
high
low
hormone 1
lowersbody condition
hormone 2
gland
specific body condition
raisesbody condition
gland
Feedback
Negative Feedback
Response to changed body condition if body is high or low from normal level a signal
tells body to make changes that will bring body back to normal level
once body is back to normal level, signal is turned off
high
hormone 1
lowersbody conditiongland
specific body condition
liver
pancreas
liver
Regulation of Blood Sugar
blood sugar level(90mg/100ml)
insulin
body cells takeup sugar from blood
liver storessugar
reducesappetite
glucagon
pancreas
liver releasessugar
triggershunger
high
low
Feedback
Diabetes: insulin deficiency-results in an elevated blood sugar level (glucose)
Regulation by chemical messengers
axon
endocrine gland
receptor proteins
target cell
Neurotransmitters are released by neuronsHormones are released by endocrine glands
receptor proteins
hormone carried by blood
neurotransmitter
Body Regulation
hormones hormones
Nervous system & Endocrine system work together hypothalamus
“master nerve control center”
receives information from nerves around body about internal conditions
Body Regulation
hormones hormones
Nervous system & Endocrine system work together hypothalamus ‘talks’ with
pituitary gland “master gland”releases many hormones
sexual development, growth, milk production, pain relief
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