Transcript Endocrine System

Endocrine System
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Endocrine Glands
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Endocrine glandssecrete hormones
directly into the
bloodstream
They are ductless
Exocrine Glands
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Secrete substances
through a duct :
Sweat, salivary
Lacrimal, pancreas
Functions of the Endocrine
System
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To secrete
hormones
Hormones are:
Chemical
messengers
that coordinate
and direct target
cells and organs
Hormonal Control
Negative feedback-Drop in hormone
level triggers a chain reaction to increase
secretion, for example:
1.
Blood level of hormone falls
2.
Brain gets message and sends out hormone
to stimulate more hormone
3.
Gland stimulates more hormone
4.
When blood levels of hormone increase, the
brain hormones stop.
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Nervous Control
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In some cases,
sympathetic nervous
system causes direct
release of hormone
from gland (for
example, when stress
causes the adrenal
medulla to secrete
adrenalin
Pituitary Gland
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Tiny structure the size
of a grape
Located at the base of
the brain
Connected to the
hypothalamus
Divided into anterior
and posterior lobes
The “Master Gland”
Anterior Pituitary Gland
Adrenocorticortropic
Hormone
FollicleStimulating
Hormone
Luteinizing
Hormone
Stimulates adrenal
cortex
Stimulates growth
of graafian follicle
and production of
estrogen in
females in the
ovaries and sperm
in males
Stimulates
ovulation in
ovaries and
formation of
corpus luteum
in which
produces
progesterone
in females
Anterior Pituitary Gland
Growth Hormone
Prolactin
Thyroid Stimulating
Hormone
Somatotropin
Responsible for
growth and
development
Develops
breast tissue,
stimulates
Stimulates Thyroxine
One function of the thyroid
hormone is to stimulate
cellular metabolism.
TSH is secreted by the
thyroid gland
production of milk
after child birth
Posterior Pituitary Gland
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Vasopressin
Converts to ADH
(antidiuretic hormone)
in the bloodstream,
acts on kidney to
concentrate urine and
preserve H2O in the
body
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Oxytocin
Released during
childbirth causing
contractions of the
uterus.
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Butterfly-shaped mass
of tissue
On either side of larynx,
over trachea
H-shaped
Main hormone
THYROXINE is
controlled by the
secretion of TSH
Thyroxine controls the
rate of metabolism
CALCITONIN controls
calcium ion concentration
in the body, prevents
hypercalcemia
Thyroid
Gland
Parathyroid Glands
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Parathyroid gland is
located in the neck. Four
glands, each the size of a
grain of rice
Attached to posterior
thyroid
Produce
PARATHORMONE which
helps control blood
calcium level, prevents
hypocalcemia
Thymus
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Endocrine gland and
lymphatic organ
Located behind the
sternum, in the
thoracic cavity above
and in front of the
heart
Begins to disappear at
puberty
Adrenal
Glands
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Located on top of
each kidney
Adrenal cortex
secretes corticoids
(anti-inflammatory
hormones) and sex
hormones
Androgens are male
sex hormones
Adrenalin hormone
form adrenal medulla
powerful cardiac
“fight or flight”
hormone (stress
hormone)
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Ovary in female
located in the pelvic
cavity.
Gonads
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Testes for male
Estrogendevelopment of
female reproductive
organs, secondary
sex characteristics
Progesterone-plays a
part in the menstrual
cycle
Testosterone- male
reproductive organs
and secondary sex
characteristics
Pancreas
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Prostaglandin's- tissue
hormones
Insulin lowers blood sugar
levels
Located behind the
stomach
Endocrine and exocrine
functions
Endocrine portion of the
pancreasI is by ISLETS OF
LANERHANS which
produces insulin
Insulin- promotes utilization
of glucose by the cells
Test Your Grey matter
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Hormones are classified as:
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chemicals
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The endocrine gland that is
located in front of the
trachea is the: Thyroid gland
The chemical substances
that secreted by endocrine
glands are: hormones
The pancreas is located in
the cavity. abdominal
Which endocrine gland is
located in the cranial
cavity?
pituitary
Which endocrine glands are
located above the kidneys?
adrenals
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The parathyroid glands are
located: In the neck
The endocrine portion of the
pancreas is the:
Islets of Langerhans
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What endocrine gland is
normally found in the pelvic
cavity? Ovary
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The endocrine gland
located in the thoracic
cavity is the:
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thymus
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The hormone FSH
stimulates growth of the
graafian follicle to grow in
the: Ovaries
The function of the thyroid
hormones is to:
Stimulate cellular metabolism
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Which endocrine gland
produces a response to
stress: Adrenals
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Body cells that react to a
particular hormone are
called: Target organ cells
When released from
endocrine cells in the
pancreas, insulin acts to:
Lower blood sugar levels
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During what time of day
would the pancreas
normally secrete the most
insulin?
After meals
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Parathyroid hormone
tends to increase the
concentration of :
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Thyroid gland
Calcium in the blood
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Prolactin stimulates
milk secretion after the
delivery of a baby.
Prolactin is produced
by the:
Pituitary gland
TSH is secreted by the
pituitary and acts on
the:
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Which two pituitary
hormones act on the
ovaries and testes?
FSH and LH