Transcript 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
• 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.
The tiny pituitary has two parts:
the anterior and the posterior lobe.
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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 control the calcium
level.
• 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 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 that
increases blood pressure and heart rate when there is stress.
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.
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.
Female Gonads
• The ovaries are located in
her pelvis. They produce
eggs and secrete the
female hormones
estrogen and
progesterone.
• Estrogen and
progesterone are also
involved in the regulation
of a girl's menstrual cycle.
These hormones also
play a role in pregnancy.
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.
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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.
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When hormone levels reach a certain normal amount, the endocrine system
helps the body to keep that level of hormone in the blood
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An 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.
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….