Download The Endocrine System - Valhalla High School

The Endocrine
System
Glands and Hormones
What is your Endocrine system?
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Your endocrine system consists of your
glands and hormones.
Like the nervous system, they work to help
you maintain your homeostasis.
They generally work more slowly, but have
longer lasting effects than the nervous
system.
Endocrine glands
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These glands are different from salivary or sweat
glands.
They do not have ducts! The hormones they
produce are diffused directly into the blood
stream.
Glands that have ducts are called exocrine
glands.
The Pancreas is considered both an endocrine
and exocrine gland. (remember digestion!)
Glands of the Endocrine system
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Hypothalamus (important…but not a gland!)
The Pituitary gland: Has two parts, anterior and
posterior.
Thyroid gland
Parathyroid gland
Adrenal glands
Pineal gland
Pancreas
Gonads: Ovaries and Testes
Location of glands in the body
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Gland Map
Hypothalamus
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Located just anterior of the brain.
Does not secrete hormones into the blood
stream, but acts as an interface between
the nervous and the endocrine system.
Since the hypothalamus does not secrete
any hormones it is not a gland.
It controls the activity of the pituitary
through nerves.
Pituitary Gland
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Called the master gland because it secretes
hormones that stimulate other glands to secrete
their hormones.
The anterior pituitary:
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Prolactin: Stimulates milk production
HGH (Human growth hormone): Initiates growth (Too
much can lead to the condition known as “giantism”.)
TSH (Thyroid Stimulating Hormone): Causes the thyroid
gland to release thyroxin.
ACTH (Adrenocorticotropic Hormone): Stimulates the
adrenal glands to release various hormones.
Anterior Pituitary (cont.)
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This amazing gland also secretes
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FSH (Follicle Stimulating Hormone): Stimulates
production of mature eggs and sperm
LH (Luteinizing Hormone): Stimulates Ovaries
and Testes; Prepares uterus for implantation.
Pituitary gland (cont.)
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Posterior pituitary gland.
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Oxytocin: This is the hormone used to induce
labor in pregnant women. Causes the uterine
contractions during childbirth
Anti-diuretic hormone: Stimulates the
reabsorbtion of water in the kidneys.
Pineal Gland
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The pineal gland secretes
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Melatonin: Melatonin helps regulate our
circadian rhythm, or 24-hour wake-sleep cycle.
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Fun fact! Circadian comes from the latin words:
Circa, which means around or about, and dia,
which means day.
Thyroid gland
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Secretes the hormone thyroxine which
regulates the metabolism of proteins, carbs
and lipids.
Diseases of the thyroid lead to either hyperthyroidism(too much thyroxine), or hypothyroidism(not enough thyroxine).
How do you these conditions would affect a
person?
Parathyroid Gland
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Secretes Parathyroid Hormone (PTH)
which acts upon bones and kidneys. It
helps to regulate calcium levels in the
blood.
It also is associated with the growth of bone
and muscle.
Adrenal glands
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Secretes the hormone:
Adrenalin: which acts upon most of the cells in your
body. It increases heart rate, breathing rate and
increases blood pressure.
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Initates what is commonly referred to as the
“fight or flight” response. It prepares your body
for rapid physical activity.
The adrenal glands have two parts, and secrete other
hormones, but will not concern ourselves with them.
Pancreas
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The pancreas has a section which is called the
“islets of langerhans”.
The “islets” secrete two hormones that help to
regulate blood sugar levels.
Insulin is used to reduce the amount of blood
sugar.
Glucagon is used to increase the amount of blood
sugar.
Glucagon and Insulin work together in a negative
feedback loop.
Gonads
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These are the glands which produce the
sex hormones.
In females, these are the ovaries, and they
secrete the hormones Estrogen and
Progesterone.
In males, these are the testes, and they
secrete the hormone testosterone.
Ovaries
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In women only, these glands secrete
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Estrogen: Causes the breakdown of the uterine
wall, initiating menstruation.
Progesterone: Builds up and maintains the
uterus wall for embedding of fertilized egg.
Associated with secondary sexual
characteristics, e.g. body hair, breast
enlargement, changes in physical body.
Testes
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In men only, these glands secrete:
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Testosterone: Responsible for the development
and function of male sex organs.
Secondary sexual characteristics. e.g. body hair,
muscle development, voice change.
What to do now?
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To help remember the roles of all these
glands and hormones you will make a set
of flash cards.
On one side of the card write the name of
the hormone.
On the other side, write the name of the
gland which secretes the hormone AND
that hormone’s effect on the body.