Download Endocrine System

Endocrine System
 Called
ductless glands because
they have no ducts connecting
them to specific body parts
 Secrete hormones released
directly into the bloodstream
Endocrinology, the study of the
endocrine glands, is an important
branch of modern medicine.
Endocrinologists are medical
doctors who specialize in
researching and treating disorders
and diseases of the endocrine
system.
Endocrine System, group of
specialized organs and body
tissues that produce, store,
and secrete chemical
substances known as
hormones.
Hormones are chemical
messengers produced by a
tissue or organ and secreted
directly into the bloodstream
affecting specific target cells.
Hormone effects
stimulation or inhibition of
growth
induction or suppression of
apoptosis (programmed cell death)
activation or inhibition of the
immune system
regulation of metabolism
preparation for a new activity
(e.g., fighting, fleeing, mating)
Hormone effects
preparation for a new phase of
life (e.g., puberty, caring for
offspring, menopause)
controlling the reproductive cycle
In many cases, one hormone may
regulate the production and
release of other hormones
How the System Works
 Secreted
directly into the
bloodstream
 Special proteins usually bind to
them to keep them intact
 Only a small fraction of the
hormone circulates in the blood to
affect the target tissue
How the System Works
 Receptors
in the target tissue, bind
with the hormones
 Induction of chemical changes
 Only minute concentrations are
needed to achieve the desired effect
Hormone Regulation

When one hormone stimulates the
production of a second, the second
suppresses the production of the
first.
Example: The follicle stimulating
hormone (FSH) stimulates the
release of estrogens from the ovarian
follicle. A high level of estrogen, in
turn, suppresses the further
production of FSH.
Hormone Regulation

Antagonistic pairs of hormones.
Example: Insulin causes the level
of blood sugar (glucose) to drop
when it has risen. Glucagon
causes it to rise when it has
fallen.
Hormone Regulation

Hormone secretion is increased (or
decreased) by the same substance
whose level is decreased (or
increased) by the hormone.
Example: A rising level of Ca+2 in the
blood suppresses the production of
the parathyroid hormone (PTH). A
low level of Ca+2 stimulates it.

The primary glands that
make up the human
endocrine system are the
hypothalamus, pituitary,
thyroid, parathyroid,
adrenal, pineal body, and
reproductive glands—the
ovary and testis. The
pancreas, an organ often
associated with the
digestive system, is also
considered part of the
endocrine system.
Hypothalamus Gland



Found deep within the brain, directly
controls the pituitary gland
Coordinator of the endocrine system.
May secrete body chemicals that either
stimulate or suppress hormone
secretions from the pituitary gland to
affect the other glands
The primary link between the
endocrine and nervous systems.
Hypothalamus Gland
Pituitary Gland
 Often
described as the master
gland, the pituitary secretes
several hormones that
regulate the function of the
other endocrine glands.
 It is divided into two parts: the
anterior lobe and the posterior
lobe.
Pituitary Gland
ANTERIOR LOBE
HORMONES
Human growth hormone/
somatotropin (HGH)
Gonadotropic hormone
(GH)
Lactogenic hormone/
Prolactin
Thyrotropic hormone
Adrenocorticotrophic
hormone (ACTH)
EFFECT: stimulates
Body skeletal growth and
metabolism
Male and female sex
organs
Milk production
Thyroid glands
Adrenal glands
Pituitary Gland
POSTERIOR LOBE
HORMONES
EFFECT: stimulates
Oxytocin
Contractions of uterus/
milk production
Vasopressin/ Anti-diuretic
hormone (ADH)
Reabsorption of water in
kidneys
Click to open the link
Thyroid Gland
 The
thyroid
gland, located
in the neck,
secretes
hormones in
response to
stimulation by
TSH from the
pituitary gland.
Thyroid Gland
HORMONES
EFFECT
Thyroxine
Stimulates the breakdown
of nutrients to release
energy
Calcitonin
Affects the level of calcium
in the blood and
phosphate in the bone
Parathyroid Glands
 The
parathyroid
glands are four
small glands
located at the
four corners of
the thyroid
gland.
Parathyroid Glands
HORMONE
EFFECT
Parathyroid hormone/
Parathormone (PTH)
Balances the calcium and
phosphorus levels in the
blood
Adrenal Glands
 Located on top of the kidneys
 The outer part, called the adrenal
cortex, produces a variety of
hormones called corticosteroids,
which include cortisol
 The inner part, the adrenal
medulla, produces
catecholamines, such as
epinephrine, also called
adrenaline
Adrenal Gland
HORMONES
EFFECT: stimulates
Epinephrine
Triggers various physiological
changes in the body during
stressful l conditions
Balance salt and water in the
kidneys
Promote increase in blood
glucose
Promote development of sexual
characteristics
Mineralocorticoids
Glucocorticoids
Sex hormones
Pineal Gland/ Body
 Located
in the middle of the brain
 Secretes melatonin, that may help
regulate the wake-sleep cycle
 Research has shown that
disturbances in the secretion of
melatonin are responsible, in part,
for the jet lag associated with longdistance air travel.
Pineal Gland
Pancreas

Although part of
the digestive
system, it is also
considered to be
part of the
endocrine system.
The pancreas is
positioned in the
upper abdomen,
just under the
stomach.
Pancreas: Islets of
Langerhans
HORMONES
EFFECT
Glucagon (Alpha cells)
Allows the liver to convert
glycogen to glucose
Insulin (Beta cells)
Regulates sugar oxidation in
tissues
Enables liver to store sugar
Ovaries
 Located in the pelvis and produce
egg cells
 They also secrete a number of
female sex hormones, including
estrogen and progesterone, which
control development of the
reproductive organs, stimulate
the appearance of female
secondary sex characteristics,
and regulate menstruation and
pregnancy.
Ovaries
Testes
Located in the scrotum, produce sperm
cells and also secrete a number of
male sex hormones, or androgens.
 The androgens, the most important of
which is testosterone, regulate
development of the reproductive
organs, stimulate male secondary sex
characteristics, and stimulate muscle
growth.

Testes
Animation
Click to open the link
Diseases

Diabetes insipidus is caused by a
deficiency of vasopressin, one of the
antidiuretic hormones (ADH) secreted by
the posterior lobe of the pituitary gland.
Patients often experience increased thirst
and urination. Treatment is with drugs,
such as synthetic vasopressin, that help
the body maintain water and electrolyte
balance.
Diseases

Addison's disease is caused by decreased
function of the adrenal cortex. Weakness,
fatigue, abdominal pains, nausea,
dehydration, fever, and
hyperpigmentation (tanning without sun
exposure) are among the many possible
symptoms. Treatment involves providing
the body with replacement corticosteroid
hormones as well as dietary salt.
Diseases

Cushing's syndrome is caused by
excessive secretion of glucocorticoids,
the subgroup of corticosteroid hormones
that includes hydrocortisone, by the
adrenal glands. Symptoms may develop
over many years prior to diagnosis and
may include obesity, physical weakness,
easily bruised skin, acne, hypertension,
and psychological changes. Treatment
may include surgery, radiation therapy,
chemotherapy, or blockage of hormone
production with drugs.
Diseases

Acromegaly and gigantism are caused by
a pituitary tumor that stimulates
production of excessive growth hormone,
causing abnormal growth in particular
parts of the body. Acromegaly is rare and
usually develops over many years in adult
subjects. Gigantism occurs when the
excess of growth hormone begins in
childhood.
Trivia

What organ is both an exocrine & endocrine
gland?
 The pancreas is an exocrine gland because it
releases digestive juices to complete the
breakdown carbohydrates into the small
intestine. The pancreas is also an endocrine
because it has clusters of cell (islets of
Langerhans) that secrete hormones such as
glucagon & insulin directly into the blood
stream
Trivia

Who is the tallest living man?
 Radhouane Charbib at 2 m 35.9
cm (7 ft 8.9 in)

Who is the tallest living woman?
 Sandy Allen at 2.31 m (7 ft 7 in)

Who is the tallest man?
 Robert Pershing Wadlow at 272
cm(8 ft 11 in)
Trivia

What is the tallest tribe?
 The Tutsi
(A.K.A the Watussi)
 Average 1.83 m (6 ft)

What is the shortest tribe?
 Mbutsi tribe
 Average men's height
137 cm (4 ft 6 in)
SITES






http://users.rcn.com/jkimball.ma.ultranet/Biolo
gyPages/H/Hormones.html
http://en.wikipedia.org/wiki/Hormone
http://www.pharmacy-anddrugs.com/Hormones/
http://www.indstate.edu/thcme/mwking/hormo
ne-table.html
http://arbl.cvmbs.colostate.edu/hbooks/pathph
ys/endocrine/moaction/surface.html
http://www.spjc.cc.fl.us/spg/science/lancraft/bs
c1086/content/endocrine.htm
SITES



http://arbl.cvmbs.colostate.edu/hbooks/pathph
ys/endocrine/basics/control.html
http://www.webmd.com/content/tools/1/iguide
_diabetes_type1.htm (ANIMATION)
http://www.diabetes.com/ap010001.html
(ANIMATION)
Hyperlinks






http://encarta.msn.com/encyclopedia_7615742
74/Endocrine.html
http://kidshealth.org/parent/general/body_basic
s/endocrine.html
http://www.innerbody.com/image/endoov.html
http://www.emc.maricopa.edu/faculty/farabee/
BIOBK/BioBookENDOCR.html
http://arbl.cvmbs.colostate.edu/hbooks/pathphy
s/endocrine/
http://www.marylandneurosurgery.com/aniplay
er/index.html
http://www.guinnessworldrecords.com/