Download Endocrine System

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
Parathyroids
Adrenal Glands
Pineal Body
Reproductive Glands
Hypothalamus
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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 thyroxine and
triiodothyronine.
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 thryoid are
four small glands called the
parathyroids, which, with
the help of calcitonin,
control the calcium level.
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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 Arenal 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 (catecholamines) that increases
blood pressure and heart rate when there is stress. (ex. Epinephrine, or adrenaline)
Adrenal
Glands
• 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…
Male Gonads
• In guys the male gonads, or
testes are located in the
scrotum. They secrete hormones
called androgens, the most
important of which is
testosterone. These hormones tell
a guy's body when it's time to
make the changes associated with
puberty, like penis and height
growth, deepening voice, and
growth in facial and pubic hair.
Working with hormones from the
pituitary gland, testosterone also
• The ovaries are located in her pelvis.
They produce eggs and secrete the
female hormones estrogen and
progesterone. Estrogen is involved when
a girl begins to go through puberty.
During puberty, a girl will experience
breast growth, will begin to accumulate
body fat around the hips and thighs,
and will have a growth spurt. Estrogen
and progesterone are also involved in the
regulation of a girl's menstrual cycle.
These hormones also play a role in
pregnancy.
Female Gonads
What Does the Endocrine System Do?
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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.
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 process is 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.
What
can go
wrong
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Too much or too little of
any hormone can be
harmful to your body.
For example, if the pituitary gland
produces too much 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…
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Adrenal insufficiency. This condition occurs when the
adrenal glands don't produce enough corticosteroids.
The symptoms of adrenal insufficiency may include
weakness, fatigue, abdominal pain, nausea, dehydration,
and skin changes.
Growth hormone problems. Too much growth
hormone in kids and teens who are still growing will
make their bones and other body parts grow excessively.
This rare condition (sometimes called gigantism) is
usually caused by a pituitary tumor and can be treated
by removing the tumor.
Problems…
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Hyperthyroidism. Hyperthyroidism is
a condition in which the levels of
thyroid hormones in the blood are very
high/low.
Precocious puberty. If the
pituitary glands release
hormones that stimulate the
gonads to produce sex
hormones too early, some
kids may begin to go
through puberty at a very
young age.
The End
Made for you by:
• Chelsea Hunter
• Karina Emeric
• Shelby Kesic
• Roberto Ramos
The Endocrine System
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….