Endocrine System
SIR PHIL!
Endocrine System
• The endocrine system includes the
endocrine glands and their hormones
• The function of the endocrine system is to
secrete hormones into the bloodstream.
• Hormone: A Chemical messenger which
targets a specific group of cells, in order to
cause that group of cells do some activity
or stop doing an activity.
Endocrine System
• Exocrine Glands release their secretions into
ducts, or tubes
– Liver Bile released into the gallbladder, then through a
duct into the small intestine
– Pancreas releases pancreatic juice into the small
intestine via a duct
• Endocrine Glands are called ductless glands
– Release hormones directly into the bloodstream
– Blood transports hormones throughout the body
– Each hormone acts on only a certain kind of tissue called
its target tissue
Endocrine System
• Each hormone acts on a certain kind of
tissue called its target tissue.
Human Endocrine Glands
• Pituitary
• Thyroid
• Parathyroid
• Adrenal
• Pancreas (Islets of
Langerhans)
• Testes and Ovaries
Pituitary
• Pituitary gland is a round organ about the
size of a pea located behind the bridge of the
nose at the base of the brain
• Secretes 9 different hormones, which affect
many different areas of the body, including:
• Growth
• Blood pressure
• Regulation of Pregnancy
• Breast milk production
• Sex organ functions in both men and women
• Thyroid gland function
• Metabolism
• Water regulation in the body (kidneys)
• Temperature regulation
A Few Pituitary Hormones
Hormone Function
Growth Hormone (GH) To increase body size during
childhood and adolescence; to
maintain body size during adulthood
Thyroid Stimulating Hormone To stimulate the thyroid to produce
(TSH) thyroxin
Follicle Stimulating Hormone (FSH) Regulate puberty, development,
and reproductive processes
Luteinizing Hormone (LH) Stimulates the production of
estrogen and testosterone
Growth Hormone
• Oversecretion of Growth Hormone:
– Giantism in childhood and acromegaly in adults
(bones of face, hands and feet enlarge)
• Undersecretion of Growth Hormone:
– Dwarfism in childhood
Thyroid
• Located in the neck
• Releases hormone thyroxin
• Function is to regulate rates of metabolism in the
body
– Essential for normal physical and mental development
• Oversecretion of thyroxin:
– Results in nervousness and weight loss
• Undersecretion of thyroxin:
– Results in cretinism (mental retardation, small size) in
children
Thyroid
• Iodine deficiency in your diet results in
goiter (enlargement of thyroid gland)
Parathyroid
Function is to control metabolism of calcium
– Necessary for normal nerve and muscle function,
blood clotting, healthy bones and teeth
• Located in back of thyroid gland (in neck)
• Hormone released is parathormone
• Undersecretion of parathormone results in
nerve disorders, brittle bones and clotting
problems
Adrenal Glands (Kidney
Hats)
• Located at the top of each kidney
• Hormones released are cortisone and
adrenaline
• Function of cortisone is to regulate
carbohydrate, protein and fat
metabolism
– promotes conversion of fats and proteins to
glucose
• Function of adrenaline is to raise blood
sugar levels and increases heartbeat
and breathing rates
Adrenal
• Undersecretion of adrenaline results in the
inability to deal with stress
Islet of Langerhans
• Located on the pancreas
• Hormones secreted are insulin and glucagon
• Insulin stimulates glucose uptake by cells
• Glucagon promotes conversion of glycogen
(animal-based carbohydrate) to glucose
Blood Sugar Regulation
• Oversecretion of insulin results in low
blood sugar
• Undersecretion of insulin results in high
blood sugar
– This can lead to a condition known as
diabetes
Diabetes-Type 1
• Type 1- Usually found in children and young
adults; the body doesn’t make enough insulin
– Symptoms:
• Frequent urination
• Unusual thirst
• Extreme hunger
• Unusual weight loss
• Extreme fatigue and Irritability
Diabetes- Type 2
• Type 2- Either the body doesn’t produce
enough insulin, or the cells ignore it.
– If you consume too much sugar over a long
period of time, your body has to release large
amounts of insulin. This can result in your
cells building up a tolerance for insulin,
which means they won’t be affected by it.
– Symptoms:
• Any of the type 1 symptoms
• Frequent infections
• Blurred vision
• Cuts/bruises that are slow to heal
• Tingling/numbness in the hands/feet
• Recurring skin, gum, or bladder infections
Assignment!
• Draw a table comparing the differences
between the Nervous & Endocrine System.
At least three differences should be listed.
