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Endocrine System -Training Handout
Karen L. Lancour
National Rules Committee Chairman – Life Science
The endocrine system is a chemical control system. It functions in conjunction with the nervous system to
control the internal environment (homeostasis).
Nervous System vs. Endocrine System – both systems enable cells to communicate with other by using
chemical messengers.
Nervous System Endocrine System
Chemical Messenger neurotransmitters hormones
Location of message synapses target cells
Effects rapid & short-lasting slower & longer lasting
Controls muscles & glands activities of cells
o
Type of Glands
• Endocrine Glands – discharge
secretions through a duct to a targeted
tissue such as digestive glands
• Endocrine Glands – release secretions
directly into the blood stream so they
are ductless.
o The secretions are chemical
messengers or hormones
o Each hormone has a specific
target tissue which may
increase or decrease its activity
such as insulin
o They are not secreted at a
constant rate – the rate will
vary with the needs of the
body
Endocrine Glands
• The endocrine system is in charge of
processes that happen slowly, such as the
growth of cells.
• The glands and hormones of the endocrine system influence almost every cell and organ in the body
