Download The Endocrine System

The Endocrine System
the body’s network of glands
Stephanie B
Kim T
The Main Functions
• To maintain homeostasis
• Promote permanent structural
change
– Instrumental in:
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Regulating mood
Growth and development
Tissue function
Metabolism
Sexual function and reproductive
processes.
Endocrine System
Glands
• Groups of tissue that produce and secrete a
produce
– Endocrine
• Discharge their goods near the organ they control or
into the body’s blood system
– Exocrine
• Release products onto some body surface through a
tube or duct
Target Organs
• Each type of hormone affects only
specific tissue cells or organs
• Messages can be delivered to every
cell in the body
– One gland transmits instructions on
how to use glucose
• Messages can directly regulate only
one or two body functions
– One gland sends a message to the
kidneys that determines how much
water is removed from the body to
make urine
Hormones (set in motion)
• Chemicals produced in one part of the body
that affect the activity of a specific group of
cells and tissues within a target organ
• Most are composed of amino acids
• Hormone regulation
– Input from the nervous system
– Chemicals in the blood
– Environment
– Negative Feedback Loop
Hypothalamus
(the master of the master)
• Not a gland
• Region of the brain
containing many control
centers for body functions
and emotions
• Regulates the activity of the
pituitary by producing a
specialized set of
chemicals—releasing
hormones
Pituitary Gland (master gland)
• Controls and coordinates the
secretion of other endocrine glands
• Anterior
– 4 trophic hormones—they control
the activity of other endocrine
glands
– 2 growth hormones
• Posterior
– Serves as a storage chamber that
holds antidiuretic hormones (ADH)
and oxytocin (OT)
• Thyroid-stimulating hormone regulates secretion of hormones produced
by the thyroid gland
• Adrenocorticotropic hormone —controls the production of hormones by
the adrenal cortex, the outer layer of the adrenal gland
• Follicle-stimulating hormone—gonadotrophins (gonad growers) regulate
gonads, or sexual organs
• Luteinizing hormone—gonadotrophins—when an egg cell has reached
maturity, LH triggers its release from the ovary—in males, FSH works in
concert with LH to regulate production of sperm, male reproductive cells,
and testosterone
• Prolactin—causes milk production after the
birth of a baby
• Growth hormone (GH)—general metabolic
hormone, affects the way cells work
throughout the body
– Stimulates body cells to grow and divide,
helps new cells take up and use nutrients
Posterior
• ADH and OT are chemicals made by
nerve cells in the hypothalamus
– Drain into the posterior part of the gland
– Enter the bloodstream when signaled by
the nervous system
• ADH helps maintain water in the body
– Reduces the amount of water that the
kidneys excrete
• The primary target organs of oxytocin
are the uterus and breasts
Thyroid Gland
• TSH’s target organ
• Thyroxine and Triiodothyronine
– Regulate the rate at which glucose is used
by cells to make energy
– Need iodine to produce these two
hormones
• Calcitonin—control the amount of
calcium and phosphate in the blood
– If there is an excess of calcium in the
blood, the anterior pituitary releases
calcitonin
Parathyroid Gland
• Parathyroid hormone (PTH)—
works with calcitonim to regulate
calcium levels in the blood, the
effect of one opposes the effect
of the other
– PTH, activated when calcium levels
in the blood drop
• increases blood calcium
– Target organs are bones, kidneys,
and the small intestine
Adrenal Gland
• Medulla (central portion)—when the body is under
stress, nerve fibers stimulate the adrenal medullas,
causing them to pump their hormones into the
bloodstream
– Epinephrine (adrenaline) and Norepinephrine (noradrenaline)
• increase the heart rate, strengthen the heartbeat, elevate blood
pressure, speed up breathing, and slow digestive processes
• Changes get more oxygen and glucose into the blood and raise
thinking to higher level of alertness
• Cortex (outer)—produces aldosterone,
cortisol, sex hormones
– Aldosterone—helps regulate the amount of water
and minerals, or electrolytes, in the body
• Direct the kidneys either to remove or leave the minerals
– Cortisol—keeps blood glucose levels constant,
targets every cell in the body
• Slows swelling after an injury
• Helps reduce discomfort by inhibiting the release of pain-causing
secretions, prostaglandins
Reproductive Glands (Gonads)
• Estrogen and Progesterone
• Estrogen—stimulates the maturation of
reproductive organs and development of
secondary sex characteristics
• Help maintain pregnancy and prepare breast
to produce milk, working with progesterone
prepares the uterus to receive a fertilized egg
• Testosterone
– Bring about the development of secondary sex
characteristics
– Maturation of the reproductive system
– Development of the male sex drive
Pancreas
• Exocrine part of the pancreas
makes digestive juices that flow
through a duct to the upper end
of the small intestine
• Endocrine part is made up of
thousands of small patches of
cells (islets of Langerhands)
scattered through the pancreas
– maintain stable levels of glucose in
blood
• Alpha—produce the hormone
called glucagon (primary secreted
during the night)
– Low levels of glucose triggers the
release of glucagon from alpha cells
– This hormone stimulates the liver to
change glycogen into glucose, thus
raising blood levels of this lifesustaining sugar
• Beta—make another hormone,
insulin-lowers the blood levels of
glucose (day)
– Insulin is released after a meal
when glucose is abundant in the
body
Pineal Gland
• Stimulated by the environment (light)
• Secretes melatonin
– Targets cells in the brain that help regulate sleep
behavior
Thymus
• Secretes hormones known collectively as
thymosins
• Thymosins help change lymphocytes (white
blood cells) into T cells
– T cells are programmed to attack any foreign
substance in the body
Mixed Glands
• Pancreas - digestive system
– Secretes pancreatic juices into the small intestine
• Ovaries and testes - reproductive system
– Produce gametes or the male and female
reproductive cells
• Thymus - lymphatic system
– Helps white blood cells to develop in order to fight
germs
Diabetes mellitus
aka Diabetes
Diabetes can be divided into 3
different types….
• Type 1 Diabetes
• Type 2 Diabetes
• Gestational Diabetes
Each type’s symptoms are similar
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extreme thirst and/or hunger
excessive urination
unusual weight loss
fatigue
blurred vision
skin complications
Type 1 Diabetes
(Juvenile Diabetes)
• ETIOLOGIES/RISK FACTORS
– exact cause is unknown
– could be: genetics or autoimmune disorder
• TREATMENTS:
– regular insulin injections
– monitoring blood sugar levels
– maintaining a diabetic diet
– pancreas or kidney transplant
– (experimental) islet cell transplant
Type 2 Diabetes
• ETIOLOGIES/RISK FACTORS:
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- body does not produce enough insulin
- cells ignore insulin
- being overweight or obese
- genetics
- history of Gestational Diabetes
- high blood pressure
- age
- older adults over the age of 65 are more at risk
- inactivity
- prediabetes
Type 2 Diabetes ( cont.)
• TREATMENTS:
– regular insulin injections
– monitoring blood sugar levels
– maintaining a diabetic diet
– pancreas or kidney transplant
– (experimental) islet cell transplant
Gestational Diabetes
• temporary• ETIOLOGIES/RISK FACTORS
• - hormones produced by placenta have possible
blocking affect on insulin
• - pancreas not able to produce additional insulin
• - family history of diabetes
• - obesity
• - given birth previously to an overweight child, a
stillbirth, or a child with a birth defect
• - age
Gestational Diabetes (cont.)
• TREATMENTS:
– balanced diet
– regular exercise
– monitoring blood sugar and fetal growth
– insulin injections
International Research
• AUSTRALIA
– research has provided new evidence that
prevention or delaying Type 1 Diabetes is possible
– intranasal delivery of an insulin solution
• UNITED KINGDOM
– testing islet cell transplantations
– using stem cell research to search for treatments
for Diabetes
Acromegaly
• which the anterior pituitary overproduces
growth hormone, resulting in abnormal
enlargement of the extremities
– nose, jaw, fingers, and toes
• in children, the disorder produces gigantism
Acromegaly
• Tumor causes the anterior pituitary to ignore
growth hormones
• Inhibiting hormone GHIH, a regulating
hormone secreted by the hypothalamus that
stops the pituitary from producing GH
Symptoms
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Headache
Visual field loss or double vision
Excessive sweating
Hoarseness
Milk secretion from breast
Sleep apnea
Carpal tunnel syndrome
Joint pain and limitation of motion
Muscle weakness
Numbness or tingling of skin
• Examination-large “doughy” hands,
large feet, large face, enlarged jaw,
tongue problems, big forehead,
darkened skin in armpits, widely
spaced teeth, oily, tough skin, skin
pigmentation changes, excessive
hair growth in females, high blood
pressure, goiter (enlarged thyroid),
kyphosis or loss of disc spaces of the
spine, osteoporosis, osteoarthritis
• Laboratory findings-growth
hormone level is high
• Imaging-MRI shows pituitary tumor
Treatment
• Pituitary microsurgery to remove tumor
• Pituitary radiation if surgery fails
• Gamma knife radiation treatment (a special type
of focused radiation)
– Medication to help reduce the secretion of GH
– Bromocriptine (helps decrease growth hormone in
some patients)
– Octreotide (partially shrinks pituitary tumor)
• Without treatment individual will most like die
early because of the disorder’s effects on the
heart, lungs, and brain
Cushing’s Syndrome
• Disorder caused by an overproduction of steroids
(mostly cortisol) by the adrenal cortex, resulting
in obesity and muscular weakness
• Caused by a tumor in either the pituitary gland or
in one of the adrenal glands
• The anterior pituitary secretes
adrenocorticotrophic hormone (ACTH), which
stimulates the adrenal cortex to release cortisol
Symptoms
Treatment
• Surgical removal of either the
pituitary tumor or the adrenal
tumor
• Radiotherapy with yttrium
implants
– Medical-reduce ACTH with
bromocriptine after surgery
• If the entire adrenal gland is
removed, the patient will have
to take steroid medication for
the rest of his life