Endokrin Sistem

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PART I
The Endocrine Glands their Hormones
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The Endocrine Glands their Hormones
Basic principles in hormone actions Many
effects of one hormone are antagonized by another
hormone This helps maintain HOMEOSTASIS
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The Endocrine Glands their Hormones
Pineal Gland
-Main hormone secreted MELATONIN -Role
Melatonin --Mammals Regulate reproductive
activity in response to environmental light
cycles e.g. Some mammals mate in summer
(lot of light), while others mate in
winter (low light).
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The Endocrine Glands their Hormones
Thyroid Gland
-Produces 3 main hormones -Triiodothyronine
(T3) -Thyroxine (T4) Regulate body metabolism
and are important in bone growth and
maturation of the brain -Congenital lack of
thyroid hormones Cretinism. -Calcitonin Acts
by reducing calcium levels
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The Endocrine Glands their Hormones
Parathyroid Gland
-Parathyroid Hormone Raises Blood
Calcium (antagonize Calcitonin) This hormone
acts on bone, kidney and the gut
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The Endocrine Glands their Hormones
Thymus Gland
-Thymosin Stimulates the production of
Lymphocytes -Thymostatin Inhibits the
production of Lymphocytes Thymus Important
for the neonatal production of antibodies Thymus
Gland being at the center of endocrine, neural,
and immune systems
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The Endocrine Glands their Hormones
Heart
-Granular cells in the heart muscle secrete
Atrial Natriuretic Factor (ANF) ..ANF
Regulates blood pressure, blood volume, and
excretion of water, sodium and potassium ..ANF
Also a neuropeptide in the brain
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The Endocrine Glands their Hormones
Gastrointestinal Hormones
-The mucosa of the GI tract secretes a dozen
PEPTIDE hormones 3 most important 1. Secretin
Secreted in the small intestine Stimulates the
secretion of pancreatic bicarbonate and
has other functions on digestion 2. Gastrin
Secreted in the walls of stomach Stimulate
hydrochloric acid secretion stimulate pancreatic
enzyme secretion 3. Cholecystokinin Secreted in
the small intestine Stimulate gall bladder
contraction Stimulate pancreatic enzyme secretion
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The Endocrine Glands their Hormones
Pancreas
Endocrine cells in the pancreas secrete 2 major
types of hormones 1. Insulin Secreted in
response to increase in blood glucose levels
So insulin LOWERS glucose levels by INCREASING
glucose UPTAKE in cells where it is stored as
glycogen. 2. Glucagon Increases blood
glucose levels by stimulating the conversion of
glycogen to glucose in the liver.
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A parte Insulin Diabetes
Insulin Diabetes
Diabetes Hyperglycemia, ie. Elevated
Blood Sugar 2 Types The distinction is based
upon whether the blood sugar problem is caused
by insulin deficiency (Type 1) or insulin
resistance (Type 2) Type 1- Insulin Deficiency
There is not enough insulin produced by the
pancreas so the patient must inject insulin on a
daily basis Type 2 - Insulin Resistance There
is plenty of insulin but the cells of the body
are resistant to its action so, increase in
blood sugar This form is controlled by a strict
diet
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The Endocrine Glands their Hormones
Adrenal Glands
2 parts Medulla Cortex Adrenal Cortex 3
categories of steroid hormones 1.
Mineralocorticoids 2. Glucocorticoids 3. Sex
Steroids Adrenal Medulla 1. Adrenaline 2.
Noradrenaline
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The Endocrine Glands their Hormones
Adrenal Cortex
Influence sexual differentiation and bodily
changes during puberty
Androgen
Estrogen
Stress Hormone, converts stored proteins to
carbohydrate during stress. Antiinflammatory
and Immunosuppressive functions.
If there is a sodium deprivation, Aldosterone is
secreted and acts to increase reabsorption
of sodium ions (NA) in the kidneys salivary
glands, and sweat glands.
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The Endocrine Glands their Hormones
Adrenal Medulla
Adrenaline Released following stress due to
environmental extremes Increases heart rate
and blood glucose levels so, increases the
amount of work the muscles can do
(FLIGHT) Noradrenaline As Adrenaline, act as a
NT in the brain Periphery increase blood
pressure and constrict blood vessels (noradrenal
ine, stress, and heart disease)
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The Endocrine Glands their Hormones
Gonads Testes
The male gonads produces Androgens Primary
androgen TESTOSTERONE Other androgen
Dihydrotestosterone Androstenedione Testos
terone Important for masculinization Control
of sperm production Development of male
sexual characteristics Activation of sexual
and aggressive behaviors
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The Endocrine Glands their Hormones
Gonads Ovaries
2 major classes of hormones ESTROGENS PROGESTINS
Primary ESTROGEN Estradiol others
Estriol Estrone Synthetic estrogens Birth
control pills Estrogens -Development of
sexual characteristics at puberty
-Influence metabolic rate -Influence
sexual and maternal behavior
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The Endocrine Glands their Hormones
Gonads Ovaries
PROGESTIN Progesterone -Stimulates breast and
uterine enlargement at puberty during
menstrual cycle -Maintains pregnancy (inhibits
menstrual cycle during pregnancy) Other hormone
released at the end of pregnancy Relaxin Acts
to prepare the birth canal.
Estrogen and Progesterone act in synergy.
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The Endocrine Glands their Hormones
Placenta
-Hormones secreted by the fertilized egg (Used in
pregnancy tests) Human Chorionic Gonadotropin
(HCG) Act by keeping progesterone high at
the beginning of a pregnancy Human Placental
Lactogen (HPL) Stimulates the mammary glands to
begin to secrete milk
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PART II
The Pituitary Gland its Hormone
Also called the HYPOPHYSIS
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The Pituitary Gland its Hormone
-Attached to the HYPOTHALAMUS -Secretion of the
pituitary hormones is regulated by
hypothalamus -HYPOTHALAMIC-PITUITARY connection
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The Pituitary Gland its Hormone
ANATOMY -3 parts --gt Anterior Lobe -pars
distalis --gt Intermediate Lobe -pars
intermedia --gt Posterior Lobe -pars nervosa
(neural cells) direct extension of the
hypothalamus
ADENOhypophysis
NEUROhypophysis
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The Pituitary Gland its Hormone
PVN
SON
-Neuroscretory Cells -Paraventricular nucleus
(PVN) -Supraoptic nucleus (SON) -Hormones
secreted -OXYTOCIN -VASOPRESSIN
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Neurohypophysis
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The Pituitary Gland its Hormone
PVN
SON
OXYTOCIN VASOPRESSIN -Are really HYPOTHALAMIC
hormones -OXYTOCIN 2 main functions --gt
promotes uterine contractions --gt stimulates
milk ejection from mammary glands during
lactation
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Neurohypophysis
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The Pituitary Gland its Hormone
PVN
SON
-VASOPRESIN --gt Antidiuretic hormone
--gt Raises blood pressure --gt promotes water
reabsorption by kidneys --gt centrally
may promote memory - Binding
proteins for both oxytocin
vasopressin --gt Neurophysins
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Neurohypophysis
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The Pituitary Gland its Hormone
ADENOHYPOPHYSIS (ANTERIOR) Mechanism for
release of hormones True endocrine gland because
release hormone in the bloodstream (hypophysal
portal system)
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Adenohypophysis
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The Pituitary Gland its Hormone
1. Neurosecretory cells of the hypothalamus
release their hormones at the median
eminence 2. Hormones circulate in
bloodstream 3. Carried to the adenohypophysis 4.
Stimulates secretion of other hormones from
the adenophysis 5. These hormones are then
released in the bloodstream to reach
their target cells.
Median eminence
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The Pituitary Gland its Hormone
Adenohypophysis 6 hormones 1. Growth Hormone
(GH) (also called somatotropin)
tropicstimulating effect GH promotes
growth in almost all body cells A lot
of attention for degenerative disease.. -Alzhei
mer -Parkinson -Anti-Aging etc.
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Adenohypophysis
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The Pituitary Gland its Hormone
Adenohypophysis 6 hormones 2.
Adrenocorticotropic Hormone ACTH Role
Stimulates synthesis and release of
glucocorticoid hormones Hypothalamic-pituitary-
adrenal axis 1970s Role of memory .little
problems..
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Adenohypophysis
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The Pituitary Gland its Hormone
Adenohypophysis 6 hormones 3. Thyroid
Stimulating Hormone TSH Role Stimulates the
synthesis and release of thyroxine (T4) and
triiodochyronine (T3) from the thyroid.
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Adenohypophysis
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The Pituitary Gland its Hormone
Adenohypophysis 6 hormones 3 last hormones
.gonadotropic hormones 4. Follicle stimulating
hormone (FSH) Role In both sexes, promotes
the development of reproductive cells (gametes)
and promotes secretion of gonadal
hormones Males stimulates sperm
production Females stimulates growth of
primary follicle of ovary
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Adenohypophysis
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The Pituitary Gland its Hormone
Adenohypophysis 6 hormones 3 last hormones
.gonadotropic hormones 5. Luteinizing hormone
(LH) Role Female Stimulates ovulation
and formation of progesterone- secreting
cells Males Stimulates cells that secrete
androgens (e.g. testosterone)
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Adenohypophysis
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The Pituitary Gland its Hormone
Adenohypophysis 6 hormones 3 last hormones
.gonadotropic hormones 6. Prolactin
(PRL) Role Initiates milk synthesis
in mammary glands Other functions
related to growth parental behavior Interacti
on with serotonin also (important in depression)
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Adenohypophysis
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The Pituitary Gland its Hormone
Non traditional hormone from the adenohypophysis
--gt beta-endorphin Derivative from POMC POMC
synthesized in the pars distalis and pars
intermedia Broken down into ACTH, MSH
beta-endorphins by enzymes
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Adenohypophysis
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The Pituitary Gland its Hormone
Beta-Endorphin Role to play in --gt
Analgesia --gt Learning and Memory --gt
Psychiatric diseases --gt Feeding,
Thermoregulation, --gt Blood pressure --gt
also called the drug of the jogger..
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The Pituitary Gland its Hormone
Pars Intermedia Not present in adult humans
but present in fetal humans and
mammals Synthesize the hormone called Melanocyte
stimulating hormones which acts in amphibian to
change skin color. Our friend Watson Sex
Sunshine MSH..
AXONS
Attaches the hypothalamus to the pituitary. Also
called the Infundibulum
Pars Intermedia
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