Download Endocrine System

Endocrine System
Mrs. Paparella
Updated: April 23, 2012
Endocrine System
• Glands produce and
secrete chemical
messengers called
hormones that travel
in the bloodstream.
• The thyroid gets
instructions from the
pituitary to secrete
hormones which
determine the pace of
chemical activity in the
body (the more
hormone in the
bloodstream, the faster
the chemical activity;
the less hormone, the
slower the activity)
• Hyperthyroidism or thyrotoxicosis results from excess
quantities of thyroid hormone in the body. This excess of
hormones may be caused by tumors of the thyroid or
rarely of the pituitary or ovaries, inflammation of the
thyroid, or ingestion of excessive amounts of thyroid
hormone or iodine.
•Those with
increased thyroid
hormone levels
experience heat
intolerance,
increased energy,
difficulty sleeping,
diarrhea and
anxiety.
Graves Disease
• an autoimmune disorder of the thyroid
which causes over-production of
thyroid hormones. Hallmarks of the
condition are bulging eyes
(exophthalmos), heat intolerance,
increased energy, difficulty sleeping,
diarrhea and anxiety.
Parathyroid
• The parathyroid glands are
located at the front and base
of the neck around the thyroid
gland and produce
pararthyroid hormone.
Parathyroid hormone
regulates calcium,
phosphorus, and magnesium
balance within the blood and
bone by maintaining a
balance between the mineral
levels in the blood and the
bone.
Adrenal Glands
Adrenal Glands
• Triangular-shaped glands located on
top of the kidneys. They produce
hormones such as estrogen,
progesterone, steroids, cortisol, and
cortisone, and chemicals such as
adrenalin (epinephrine),
norepinephrine, and dopamine.
Pancreas: Insulin and Glucagon
Role of Insulin
• Islets of Langerhans contain beta cells and are located within the
pancreas. Beta cells produce insulin which is needed to metabolize
glucose within the body.
• When your blood glucose levels are higher(after eating a meal with
carbohydrates) the pancreas will secrete insulin to help remove the
glucose from the bloodstream and transport it into the cells of the
body.
• Once the blood glucose level goes down, a negative feedback
mechanism signals for insulin to stop being secreted.
Role of Glucagon
• Glucagon is a polypeptide made of 29 amino acids. It has the
opposite effect of insulin: It raises the blood glucose levels.
• Glucagon stimulates breakdown of glycogen stored in the liver.
When blood glucose levels are high, large amounts of glucose are
taken up by the liver and stored in form of glycogen.
• Later, when blood glucose levels begin to fall, glucagon is secreted
by the pancreas and acts on hepatocytes (liver cells) to activate the
enzymes that depolymerize (break apart) glycogen and release
glucose back into the blood stream so it can go where it is needed
in the body’s cells for mitochondrial cellular respiration to make
ATP.
• High blood levels of amino acids (after eating a protein –rich meal),
cause glucagon to convert excess amino acids to glucose.
Ovaries
• The ovaries have two functions:
they produce eggs (also called
ova) and female hormones.
The size of each ovary is about
1.5 inches long.
• Alternate name: female
gonads
• The ovaries are the main
source of female hormones
(estrogen and progesterone).
These hormones control the
development of female body
characteristics, such as the
breasts, body shape, and body
hair. The ovaries also regulate
the menstrual cycle and
pregnancy.
.
Polycystic Syndrome can result from
imbalance of hormones; most
functional cysts are harmless and go
away w/o treatment. There are many
different types of cysts.
• Estrogen is a female sex
hormone that stimulate the
appearance of secondary
female sex characteristics in
girls at puberty.
• Estrogen controls the growth of
the lining of the uterus during
the first part of the menstrual
cycle and cause breast
development in pregnancy.
• Progesterone thickens the
endometrial lining and when
pregnancy occurs, supports
the nourishing environment for
the embryo to maintain the
pregnancy. (placenta actually
makes the progesterone during
pregnancy.)
Testes
•
The testes are two
egg-shaped male
reproductive organs
located in the scrotum.
They produce sperm
and the male hormone,
testosterone.
• Alternative Names:
-Testicles
-Gonads - male
Functions of testosterone
• plays a role in determining the gender of developing
fetuses.
• development of a deeper voice, muscle mass, facial hair
growth and male genital development at puberty.
• contributes to an active sexual drive in both men and
women.
• increases the metabolic functions in men, which
contribute to faster healing and lower total body fat.
• Needed for sperm to mature and contributes to the
overall quality of the sperm.
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