Transcript Endocrine System ppt

Introduction to Health Science
The Endocrine System
General Functions of the
Endocrine System
• Made up of glands that release their
products (hormones) directly into the
bloodstream
• Response of hormones is slower and longerlasting than those of nerve impulses
– Effects may last up to several hours or days
• Hormones help to regulate important
processes throughout the body
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Growth
Development
Maturation
Regulation of chemicals and metabolism
Learning Log-Split ‘em and Hit ‘em
• Where is it located?
• What hormones does it release?
• What are the effects of the hormones
on the body?
– Pituitary Gland
– Thyroid/Parathryoid Gland
– Pancreas
– Adrenal Gland
Pituitary Gland
• Small pea-shaped gland
– Hangs from the underside of the brain
• Often referred to as the “Master
Gland”
– Produces many of the body’s hormones
Hormones Produced by the
Pituitary Gland
• Growth Hormone (GH)
– Produced by the anterior pituitary gland
– Stimulates the production of proteins
and growth in body cells
• Oxytocin
– Stored in posterior pituitary gland
– Stimulates uterine contractions during
childbirth
– Helps to release milk from the milk ducts
of nursing mothers
Thyroid Gland
• Bow-tie shaped gland
• Located in the neck just below the
larynx and around the upper part of
the trachea
– Thyroxine
• Produced by the thyroid which affects
nearly all the cells of the body
• Regulates metabolic rates
– The ability of cells to convert food to energy
through cellular respiration
Parathyroid Gland
• Four glands located next to the thyroid
gland
• Parathormone
– Controls use of calcium
• Bone growth
• Muscle tone
• Nervous activity
Pancreas
• Fish-shaped gland
– Located behind the stomach
• Considered to be an endocrine gland
when it produces hormones
– Also a part of the digestive system when
it produces digestive enzymes
Hormones Produced by the
Pancreas
• Insulin
– Released when the blood sugar (glucose) is high
– Helps the body cells to move glucose into the cells
– Helps the liver and muscle to convert glucose into
glycogen
– Helps to convert excess glucose to fat which is then
stored
• Glucagon
– Released when the blood sugar (glucose) is low
– Helps to break down the glycogen in the liver and the
muscles
– Helps the body cells to expel glucose into blood
– Raises blood glucose levels
Adrenal Glands
• Two triangular-shaped glands that sit
on top of each kidney
Cortisol
• Helps to control the rate of metabolism of
carbohydrates, fats, and proteins
• It is known as the stress hormone and is
released during times of continuous stress
• A negative aspect is that it suppresses the
action of the white blood cells
– Makes a person more susceptible to illness
Adrenaline
• Also known as epinephrine
• Makes up 80% of the secretions from
the adrenal medulla
• Helps regulate the stress
(sympathetic) response or “fight or
flight”
Noradrenaline
• Also known as norepinephrine
• Released from the adrenal medulla, or
the middle section
• Makes up 20% of the secretions from
the adrenal medulla
• Helps to regulate the stress
(sympathetic) response or the “fight
or flight”
The Sympathetic Response
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increased heart rate
increased breathing rate
increased blood flow to the muscles
increased blood pressure
increase in the depth of breathing
increasing oxygen intake
• release of extra glucose for more energy
• sweaty hands and palms
Ovaries
• Found only in women
• Two hormones
– Estrogen
• Produces female characteristics
• Initiates female bodily functions
– Progesterone
• Affects endometrial lining of uterus
Testes
• Only found in men
• Testosterone
– Controls
• Growth of body hair and beard
• Body size
• Deepening of voice
Diseases and Disorders of the
Endocrine System
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Type I Diabetes Mellitus
Type II Diabetes Mellitus
Gigantism
Dwarfism
Hypothyroidism
Hyperthyroidism
Type I Diabetes Mellitus
• Lifelong disease that occurs when
pancreas does not produce enough
insulin to regulate blood sugar
• Without insulin, glucose increases in
the bloodstream instead of going into
the body cells where it can be used for
energy
– Leads to increased hunger
– Mostly incurable
Type II Diabetes Mellitus
• Lifelong disease marked by high levels
of glucose in the blood that occurs
when the body does not respond
correctly to insulin
• In other words, glucose cannot enter
the body cells to be used in energy
production
– They produce enough insulin but the
body doesn’t respond to it
• The most common form of diabetes
– Sometimes curable
Gigantism
• Hypersecretion or overproduction of
the growth hormone during childhood
• Results in a person who grows to a
very large size
• May be caused by a non-cancerous
tumor of the pituitary gland
Dwarfism
• Hyposecretion or underproduction of
the growth hormone during childhood
• Results in a small person of normal
proportions
• May be present at birth or develop as
a result of brain injury, tumor, or other
medical condition
Hypothyroidism
• Hypothyroidism occurs when the
thyroid gland fails to produce enough
thyroid hormone.
– May result in mental retardation and
stunted growth.
– Cretinism (early onset, infants & young
children).
– Myxedema (later onset).
Hyperthyroidism
• Hyperthyroidism occurs when the
thyroid gland produces too much of
the thyroid hormones.
– Symptoms include weight loss, increased
appetite, nervousness, restlessness,
increased sweating and protruding eyes.
– Treatment may include removal of the
thyroid with radiation or surgery and
replacement of thyroid hormones.