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The
Endocrine
System
Hormones Hormones!!!
Even though the endocrine system
doesn’t seem very important to us, it
really is! It affects almost everything
in our bodies, and participates in
moods, growth and development,
sexual functions, reproductive
processes, tissue function, and
metabolism.
These are the main parts of the
endocrine system…
Hormones & Glands
• The endocrine system is founded on
hormones and glands.
• Hormones transfer info and orders from a
set of cells to another. Each type of
hormone is designed to affect only certain
cells.
• A gland is a bunch of cells that
produce and gives off chemicals. A
gland ‘selects and removes materials from
the blood, processes them, and secretes
the finished chemical product for use
somewhere in the body.’
• For example, exocrine glands like the
sweat glands release secretions in the
skin or inside the mouth.
Endocrine System Parts
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Hypothalamus
Pituitary Gland
Thyroid
Para-thyroids
Adrenal Glands
Pineal Body
Reproductive Glands
Hypothalamus
• In the lower central
part of the brain
• The main link between
the endocrine and the
nervous systems.
• Nerve cells in the
hypothalamus control
the pituitary gland by
producing chemicals
that either stimulate
or suppress hormone
secretions from the
pituitary.
Pituitary Gland
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The gland is no bigger than a pea.
Located at the base of the brain,
and the most important part of
the entire endocrine system.
AKA: The master gland because
it makes hormones that control
other endocrine glands.
The production of hormones and
secretions can be affected by
emotions and seasons change.
Divided into two parts.
The Division
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The tiny pituitary has two parts: the
anterior and the posterior lobe.
The anterior regulates the thyroid,
adrenals, and the reproductive’s
activities. It makes hormones like
growth hormones, prolactin
(breastfeeding), thyrotropin, and
corticotropin.
The posterior releases antiduretic
hormones, which balances the body’s
water level. It also makes oxytocin,
which activates the contractions of the
uterus in a woman in labor.
The pituitary also secretes
endorphins, chemicals that act on the
nervous sytem and reduce painful
feelings. It also gets rid of hormones
that signal the reproductive organs to
make sex hormones. It also controls
ovulation and the menstrual cycle.
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The thyroid is in the front
part of the lower neck,
and is shaped like a
butterfly.
It produces the hormones
known as thyroxin
These control the rate at
which cells burn fuels from
food to produce energy.
Thyroid hormones are
important because they
participate in the growth
and development of kids’
and teens’ bones and the
nervous system.
Attached to the thyroid are
four small glands called the
parathyroid, which, with the
help of calcitonin, control
the calcium level.
Adrenal Glands
• There are two adrenal glands, one on top of each kidney.
• There are two parts, each of which makes hormones and
has a different function.
• The outer part, or the Adrenal Cortex, makes hormones
(corticosteroids) that control the salt and water balance
in the body, responses to stress, metabolism, the
immune system, and sexual development/function.
• The inner part, or the Adrenal Medulla, makes hormones
(catecholamine's) that increase blood pressure and heart
rate when there is stress. (ex. Epinephrine, or adrenaline)
• The pineal gland, or
the pineal body is in
the middle of the
brain. It secretes
melatonin, a
hormone that
regulates when you
sleep at night and
wake up in the
morning.
Reproductive Glands!!!
• The gonads are the main source of sex
hormones. Even though you may think
that gonads are just in guys, you’re
wrong! Girls have them too…
What Does the Endocrine System Do?
• Once a hormone is secreted, it travels from the endocrine gland
that produced it through the bloodstream to the cells designed
to receive its message. These cells are called target cells.
Along the way to the target cells, special proteins bind to some
of the hormones. These proteins act as carriers that control the
amount of hormone that is available for the cells to use.
•
The target cells have receptors that latch onto only specific
hormones, and each hormone has its own receptor, so that each
hormone will communicate only with specific target cells that have
receptors for that hormone. When the hormone reaches its target
cell, it locks onto the cell's specific receptors and these
hormone-receptor combinations transmit chemical instructions
to the inner workings of the cell.
Contd:• When hormone levels reach a certain normal amount,
the endocrine system helps the body to keep that
level of hormone in the blood. For example, if the
thyroid gland has secreted the right amount of thyroid
hormones into the blood, the pituitary gland senses the
normal levels of thyroid hormone in the bloodstream.
Then the pituitary gland adjusts its release of thyrotropin,
the hormone that stimulates the thyroid gland to produce
thyroid hormones.
• Another example of this is using the parathyroid
hormone. Parathyroid hormone increases the level
of calcium in the blood. When the blood calcium
level rises, the parathyroid glands sense the change
and reduce their secretion of parathyroid hormone.
This turnoff process is called a negative feedback
system.
The End
Made for you by:
• Chelsea Hunter
• Karina Emeric
• Shelby Kesic
• Roberto Ramos
• And Mrs Wolfendale!
The Endocrine System
What
can go
wrong
• Too much or too
little of any
hormone can be For example, if the pituitary
harmful to your gland produces too much
body.
growth hormone, a teen may
grow excessively tall. If it
produces too little, a teen may
be unusually short. Doctors can
often treat the problems by
controlling the production of
hormones or replacing certain
hormones with medication.
Some endocrine problems that
affect teens are…
Water Balance/Blood sugar
temp control etc.
• See 239-241-Pearsons and note for self
• Or Teacher Booklet and Worksheets
• ( 2012-use hand out and question sheet)
Review Questions
• TRUE or FALSE?
1. The endocrine system is founded on
hormones and tissues.
2. A gland is a bunch of cells that produce
and gives off chemicals.
3. The Pituitary gland is no bigger than a
bean.
Review Questions (cont.)
What is a gland?
a. Cells that produce and give off gland tissue.
b. Cells that produce and give off chemicals.
c. Transporters of blood to the heart.
What two systems is the hypothalamus linked between?
a.
The nervous and the endocrine
b.
The respiratory and the endocrine
c.
The skeletal and the reproductive
Which part of the endocrine is the most important, and nicknamed the Master Gland?
a.
The thyroid
b.
The testes
c.
The pituitary gland
Review Questions (again)
What gland is important because of the participation in development of kids’ bones and the nervous
system; it’s also shaped like a butterfly.
a.
Pineal Gland
b.
Ovary
c.
Thyroid
The two parts of the adrenal gland are the Adrenal _______ and the Adrenal _______.
What does the pineal gland regulate?
Where are the male gonads located?
a.
In the penis
b.
In the testes
c.
In the scrotum
The ovaries produce ______ and secrete the female hormones _________ and_____________.
• List a few things that could go wrong with
the endocrine system….