Transcript Endocrine System

D4-3: The Endocrine System
You and Your Endocrine System
 Endocrine System
 A collection of glands and
groups of cells that
secrete hormones that
regulate growth,
development, and
homeostasis.
I. Hormones as Chemical Signals
 Our endocrine system is made up of glands, which are
a group of cells that make special chemicals for the
body.
 The glands secrete hormones, which are substances
that are made in one cell or tissue and that causes a
change in another cell or tissue in a different part of
the body.
 Hormones are able to move very quickly, because of
the bloodstream in our systematic circulation.
I. Hormones as Chemical Signals
 The Adrenal Glands
 These glands release a specific type of hormone called
epinephrine, or adrenaline.
 This chemical increases your heart rate and breathing.
 This response is often called the “fight-or-flight” response.
 When we get frightened, angry, or excited, this response
prepares us to fight the approaching danger or “run for our
lives!!”
I. Hormones as Chemical Signals
II. More Endocrine Glands
 Your endocrine system is made up of several glands and
organs including:
 Pituitary gland
 Thyroid gland
 Parathyroid gland
 Thymus gland
 Adrenal glands
 Pancreas
 Ovaries and Testes
II. More Endocrine Glands
 Pituitary Gland
 Located in your brain
 Stimulates skeletal growth
 Assists in the function of
the thyroid gland
 Regulates the amount of
water in blood
 Stimulates the birth
process in women
II. More Endocrine Glands
 Thyroid Gland
 Important for childhood
 Control the secretion of
growth hormones for normal
body growth
 Controls the growth of the
CNS
 Metabolism
The sum of all the chemical
processes that take place in
an organism.
II. More Endocrine Glands
 Parathyroid Glands
 Regulates Calcium Levels in blood
 Thymus
 Immune System
 Killer T cells grow and mature here
 Assist by destroying or neutralizing substances that invade
the body
II. More Endocrine Glands
 Adrenal Glands
 Produce epinephrine (adrenaline)
 Help the body respond to danger
 Pancreas
 Regulate blood-glucose levels
 Ovaries (in females)-Estrogen
 Produce hormones needed for reproduction
 Testes (in males)-Testosterone
 Produce hormones needed for reproduction
III. Controlling the Endocrine Glands
 These glands have similar feedback mechanisms that the
nervous system has.
 Your pancreas produce two different hormones that
control the level of glucose in the blood.
 Insulin
Lowers blood-glucose levels by telling the liver to convert glucose into
glucagon and store for future use.
 Glucagon
This hormone tells the liver to convert glucagon into glucose and to
release it into the blood. (The opposite affect of Insulin)
III. Controlling the Endocrine Glands
 Let’s take a look at Figure 3 on p.96 to see how
this feedback mechanism works!
IV. Hormone Imbalances
 An endocrine gland can sometimes make too much or
not enough of a hormone, which causes the body to
be unbalanced.
 Diabetes mellitus
 When a person’s body does not produce enough insulin
must take daily injections of insulin to keep his or her bloodglucose level within safe limits.
 If this person does not receive these shots, they can
sometimes slip into a coma and dies of this condition.
IV. Hormone Imbalances
 Pituitary Gland
 Sometimes if a person’s pituitary gland does not produce
enough of a growth hormone, their growth can often be
stunted.
 If this is detected early, growth hormones are prescribed by
doctors and monitor his or her growth.
 If this gland produces too much of the growth hormone, a
child may grow taller than expected.
IV. Hormone Imbalances
DIABETES
PITUITARY GLAND IMBALANCE