Download The Endocrine System

The Endocrine System
The body’s “slow” chemical
communication system.
Under “normal” circumstances works in
parallel with the parasympathetic NS
(rest & digest) to sustain our basic
processes.
In a crisis works to support the actions
of the sympathetic NS (fight or flight).
Example...While walking down the street, you see a
giant bear!
the hormone epinephrine (adrenalin)
released into the bloodstream, sustaining
the body’s defensive reaction (“fight or
flight” response)
the endocrine system finishes what your
sympathetic NS started, keeping your
heart pounding and muscles tense, ready
for action
Hormones
Hormones are chemicals synthesized (made) by the various
endocrine glands and secreted (released) in the bloodstream…have
similar structure/function as many neurotransmitters
DIFFERENCES BETWEEN…
Hormones
Neurotransmitters
Speed of transmission
Slow (minutes)
Fast (seconds)
Length of influence
Last longer (wks)
Brief duration
Method of transmission
Bloodstream
Neurons
*they are the same thing, just manufactured and located in different parts of the
body
Neurotransmitters- made in neurons, in the nervous system
Hormones- made by gland, in the body and bloodstream
Pituitary Gland
“master gland”
Attempts to keep all endocrine
responses under tight control
Pituitary gland is under the
control of the
hypothalamus…sends out
hormone signals to the other
endocrine glands
Thyroid & Parathyroid Glands
Regulate metabolic, physical growth and development
and calcium rate.
Adrenal Glands & Pancreas
Adrenal glands regulate “fight or
flight” response & metabolism.
Pancreas regulates level of sugar
(glucose) in the blood.
Gonads
Regulate bodily development (secondary sex
characteristics) and maintain reproductive organs
in adults (produce sperm/eggs).
produces
testosterone
produces
estrogen &
progesterone