Download Filled In Endocrine System Notes

THE ENDOCRINE SYSTEM
(pp. 997 - 1008)
There are two systems that regulate the body. The nervous system relays information to the body using _electrical
impulses________ that travel very _quickly______, but the messages are short-lived. The endocrine system uses
_hormones____, or _chemical_____ messages that travel through the _blood____ to relay information to the body. The
endocrine system is slower-acting, but the action of hormones is _longer lasting________. The _hypothalamus______,
which maintains homeostasis in the body, controls most of the glands of the endocrine system.
I. ENDOCRINE GLAND FUNCTION
A. Hormone Production
Hormones help regulate growth, metabolism, appearance, behavior, growth, reproduction, and fluid balance. Most
hormones are produced by _endocrine______ glands.
Endocrine glands are unique because they are ductless; in other words, hormones are secreted into
_capillaries______ and the _circulatory_______ system transports the hormone to its destination. Its destination is
known as its _target_____. A hormone may have only one target, or it may have several.
B. Control of Hormone Production
Hormone release is regulated by a mechanism known as _negative feedback_____. Information about the effect of the
hormone is “fed back” to the gland. When the desired condition is reached, the gland _is shut off_____
C. Types of Hormones – Hormones can be placed in two groups based on chemical structure:
1. Peptide hormones – Most hormones are composed of _proteins______ and are known as peptide hormones.
2. Steroids – _Lipid____ molecules derived from _cholesterol________. Include the sex hormones - _estrogen and
testosterone_________
II. HORMONES OF THE ENDOCRINE SYSTEM
HORMONE
GLAND
EFFECT
Stimulates _mitosis____; undersecretion results in
Growth Hormone
Pituitary Gland
_dwarfism_______; oversecretion results in
_gigantism____
Regulates __metabolism____; requires _iodine___
Thyroxine
Thyroid
for normal function
_Lowers________ blood _glucose___ concentration
Insulin
Pancreas
by stimulating cells to take up glucose; triggers
storage of glucose as _glycogen______; not
produced in individuals with _Type I Diabetes_____
__Increases______ blood glucose concentration by
Glucagon
Pancreas
breaking down _glycogen_______ stored in liver to
glucose
Known as _”fight or flight”________ hormone

Epinephrine
Adrenal Glands
_Bronchioles___ dilate to increase air flow
for _cellular respiration_____

(_Adrenaline_)
_Glycogen_____ in the liver is broken down
to glucose for _cellular respiration____

_Heart___ rate is increased

Blood flow to the _skeletal__ muscles
increases

Blood flow to the _digestive____ system is
decreased
Triggers development of secondary sex
Testosterone
Testes
characteristics; _meiosis_____ to produce
__haploid____ sperm cells.
Triggers development of secondary sex
Estrogen/
Progesterone
Ovaries
characteristics; __meiosis______ to produce
__haploid_____ egg cells.