Download Lesson 5 Endocrine System

Brain, Body, & Behavior:
LESSON 5: THE ENDOCRINE SYSTEM
Endocrine System:
 ENDOCRINE SYSTEM:
 The system of the body
made up of glands and
hormones.
 It is made up of the
following glands and their
hormones:
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Pituitary Gland.
Thyroid Gland.
Parathyroid Glands.
Adrenal Glands.
Pancreas.
Gonads:

Ovaries/Testicles.
Also :
Thymus
Pineal Gland
Hormones:
Different hormones are secreted by
different glands.
 Hormones are stored inside the
GLANDS:
 Units of the body that control the
release of hormones.
 They hold and release hormones
into the bloodstream.
 Activities regulated by hormones include:
 Reproduction.
 Growth patterns.
 Body’s fluid and salt balances.
 Occasionally, the endocrine system may
malfunction:
 Ex: diabetes, gigantism, dwarfism,
etc…
 ENDOCRINOLOGIST:
 Doctor who treats diseases of the
Endocrine System.

Hormones:

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Hormone means “to activate” or
“to urge.”
HORMONES:
 Chemicals released by glands
into the bloodstream that
control body processes such as
emotional responses, growth
and sexuality.
They pass through the body into the
blood stream to deliver instructions to
various organs, etc…
Each hormone influences only certain
organs or tissues.
The more the hormone; the more the
activity in the body.
They turn on other parts of the body.
Virtually every system in the body is
affected by hormones.
• Hypothalamus:
HYPOTHALAMUS:
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Part of the lower brain that
controls the release of hormones
when it turns on the pituitary
(master) gland.
IT IS NOT A GLAND ITSELF
BECAUSE IT DOES NOT RELEASE
HORMONES!
It means “below the thalamus.”
It is the size of a large pea.
The hormones regulated by this area of
the brain govern body temperature,
thirst, hunger, sleep, circadian rhythm,
moods, sex drive, etc...
It is involved in many necessary
processes of the body including
behavioral, autonomic, and endocrine
functions.
The hypothalamus' primary function is
homeostasis, which is to maintain the
body's status quo system.
Pituitary Gland:
 PITUITARY GLAND:

Master gland that releases
human growth hormone and
also tells the other glands to
release their hormones.
 Very important for sexual

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


functions.
Triggers menstruation in women.
It is located in the brain attached
to the hypothalamus.
It is bean shaped.
It activates other glands and
controls growth hormone.
Scientists once thought mucus
came from the pituitary gland:

Pituita was a slang word for
“mucus.”
Pituitary Gland:
 ROLE OF THE PITUITARY
GLAND:


To send messages that will
start other glands going.
To determine how tall or how
short someone will be.
 The pituitary gland makes
HUMAN GROWTH
HORMONE:

The hormone that regulates
the growth process.
 It intermittently makes growth
hormone:

Accounts for growth spurts
or early/late bloomers.
Fun Facts:
 Tallest Person in History:



Robert Wadlow from
the U.S.
He stood 8 feet 11.1
inches tall.
He died at age 22 in
1940.
Fun Facts:
 Shortest Person in
History:



Gul Mohammed from
India.
He stood 1 foot 10.5
inches short.
He died in at age 39
in1997.
Pituitary Gland:
 They probably died young
because of medical conditions
associated with the pituitary
gland.
 Most defects in pituitary gland
can be treated with medicine
today.
 Environment and nutrition can
negatively affect pituitary gland:


Poor nutrition lowers
amount of growth hormone
produced.
Poor nutrition levels in third
world countries have on average a
shorter population than
wealthy nations.
Thyroid Gland:
 THYROID GLAND:
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This gland looks like a bow
tie located inside the neck.
Thyroid means “shield shaped.”
It is the gland that controls
and regulates metabolism by
releasing thyroxine.
METABOLISM:



The speed of bodily
processes.
The speed at which the body
operates.
The speed at which the body
uses up energy.
 It produces THYROXINE:

Thyroid hormone that
regulates metabolism.
Hyperthyroidism:
 HYPERTHYROIDISM:
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Hyper means “over.”
Overactive thyroid disease.
When the thyroid produces too
much thyroid hormone.
 Symptoms:

Weight loss, restlessness,
overactive, anxiety,
nervousness, sweating,
increased heart rate, etc…
 It is fatal if untreated.
 Treatment:
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A liquid form of radioactive
iodine.
Iodine slows production of
thyroid hormone in the body.
Anti-thyroid medication pills.
Surgery.
Hypothyroidism:
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HYPOTHYROIDISM:
 Hypo means “under.”
 Underactive thyroid disease.
Symptoms:
 Drowsiness, fatigue, slight
weight gain, intolerance to
cold, lethargy, slowed physical
and mental functions, slow
heart rate, sadness,
depression, sluggish, etc…
Slow thyroid gland from birth could
cause mental retardation.
Occasionally treatment for
hyperthyroidism works too well
causing hypothyroidism.
Hypothyroidism can result form a
lack of iodine in the diet:
 Rare due iodized salt.
Treatment:
 Daily consumption of thyroid
hormone for life.
Parathyroid Gland:
 PARATHYROID GLANDS:


These are 4 rice sized
glands located on the
thyroid gland.
They produce a hormone
called parathyroid
hormone (PTH)
(parathormone) that
controls the level of
calcium in the blood.
Adrenal Glands:
 ADRENAL GLANDS:
 The glands that cause
excitement in order to
prepare the body for
an emergency by
releasing adrenaline or
for some important
activity.
 They are located on
the left and right sides of
the body slightly above
the belly button directly
above the kidneys.
Adrenal Glands:

In response to stress, they create
ADRENALINE:
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EPINEPHRINE.
A chemical that prepares the body
for an emergency activity by tensing
muscles, increasing breathing rate,
blood pressure, heart rate, and
energy level (high energy level caused
by an increase in blood sugar).
It produces a sudden and
remarkable burst of energy.
 Often hands will tremble, the mouth
will get dry, the hands, armpits and feet
will sweat, and the blood will even clot
faster in case of an injury.
 The adrenal glands send
adrenaline into the bloodstream
to prepare the body for an
emergency or a stressful
situation:
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Accident, taking test, getting
married, public speaking.
Pancreas:
 PANCREAS:
 It is located behind the stomach.
 Produces enzymes essential for the
digestion of food.
 Enable the body to break down the
food people eat which is turned into
energy.
 Regulates the body’s use of
GLUCOSE (blood sugar):

An energy source for the body.
 Levels change in the body but
remains within set limits.
 The gland that secretes the
hormone insulin.
 INSULIN:
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Enables body to regulate amount
of glucose in bloodstream.
It is produced when the level of
sugar in the body increases.
Diabetes:
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DIABETES:
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The word means “to draw off liquid.”
Disease in which the body is unable
to regulate the body’s level of
glucose.
Levels of blood sugar remain very
high.
Symptoms:

Increased thirst, increased
urination, weight loss, fatigue,
nausea, vomiting, blurred vision,
etc…
Complications:
Untreated, diabetes can negatively
affect the body due to exposure of the
organs and tissues to high blood sugar
levels, causing blindness, kidney
failure, amputations, etc…
 HYPOGLYCEMIA:
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Low blood sugar level.
Diabetes:
 Type 1 diabetes:
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Insulin dependent
Severe Symptoms
Fatal unless the body’s
missing insulin is replaced.
People with this form of diabetes
must test their blood sugar
levels daily and administer
insulin if needed.
 Cause:

The pancreas does not
produce insulin needed to
regulate blood sugar levels:
 Treatment:
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Injections of animal or
genetically engineered insulin:
Cannot take insulin orally because
the digestion system breaks down
insulin.
Type 2 Diabetes:
 Type 2 Diabetes:
 Non-insulin dependent.
 Mild symptoms.
 Cause:
 The pancreas does not
produce insulin needed to
regulate blood sugar levels.
 Treatment:
 Losing weight, maintaining
healthy diet and exercising
regularly reduce the body’s
resistance to insulin.
 Affects more than 100
million people worldwide.
Gonads: (Ovaries and Testicles)

GONADS:
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Sex glands.
They make the sperm and the eggs
used for reproduction.
OVARIES:
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The two internal female
reproductive glands that produces
eggs.
Produces mostly ESTROGEN:
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Also produces ANDROGEN:
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Female sex hormone.
Male sex hormone.
TESTICLES:
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The two external male reproductive
glands that produces sperm to
fertilize female eggs.
Produces mostly ANDROGEN:
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Male sex hormone.
Also produces ESTROGEN:
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Male sex hormone.
Gonads: (Ovaries and Testicles)
Q: What is the difference between
androgen and testosterone?
A: Testosterone is the most well
known form of androgen.
Testosterone in men is secreted
from the testicles and is
responsible for male growth and
development. Deficiencies of this
hormone lead to muscle weakness
and erectile dysfunction in men .
This condition can often be
treated today by a doctor with
testosterone replacement therapy.
Gonads: (Ovaries and Testicles)
Gonads:
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Men and women both have
androgen and estrogen in their
bodies; men have more androgen
and women have more estrogen.
These sex hormones are what make
women appear feminine and men
appear masculine.
Women with too much androgen
may grow body hair (beard).
Men with too much estrogen may
grow breasts.
Androgen starts the sex drive for
both men and women:
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The hormones start the process but
then it is taken over by the Cerebral
Cortex:
Sex is believed to be a learned behavior,
not an instinct.
 The Cerebral Cortex adds to sex:
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Love, respect, warmth, fear, anxiety,
heartbreak, pain, etc…
Pineal Gland:
 PINEAL GLAND:
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A gland located in back of
the brain stem which
releases melatonin.
A.k.a. “pineal body.”
It regulates circadian rhythms
in the body.
In the dark it releases the
MELATONIN: the
hormone released by the
pineal gland which helps
one fall asleep.
Its function is not fully
understood.
It is thought to be an
evolutionary leftover from the
endocrine system of animals.
Thymus:
 THYMUS:
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The gland located just behind
the breast bone between the
lungs which releases
thymosin and plays a role in
setting up the body’s immune
system.
It is the largest during childhood
and it shrinks after puberty and is
replaced by fat.
It plays a part in setting up the
body’s immune system.
It is only active until puberty.
THYMOSIN: the hormone
released by the thymus that
stimulates the development
of disease fighting T cells, a
type of white blood cell that
protects the body from
viruses and infections.