Download The Endocrine System

The Endocrine System
-the 2nd in control-
The Endocrine System
Composed of several ductless glands
– Pituitary (anterior & posterior)
– Thyroid
– Adrenal/ Supraranal
– Pineal
– Thymus
– ALONG w/ the Pancreas, Placenta &
Gonads
Endocrine
endo= within & crine=to secrete
Made of glands
• Secrete hormone directly into
bloodstream (ductless glands)
• Specialized epithelial tissue >12.5g
Hormones (hormon = excite)
– Chemical messengers released into the
blood & lymph for transport around the body
– Long lasting effect
– Effect target cells or organs
Hormone Function
• reproduction
• growth & development
• mobilization of body defenses
• cellular metabolism & homeostasis
Mechanisms
of hormone
release
(a) Humoral: in response to changing
levels of ions or nutrients in the blood
(b) Neural: stimulation by nerves
(c) Hormonal: stimulation received from
other hormones
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Hormone Control
Negative Feedback
1. Blood level of
hormone falls
2. Brain gets
message & sends
out hormone to
stimulate gland
3. Gland secretes
hormone
4. When blood level
of hormone
increases, then
brain hormone
stops
Hypothalamus
Releasing
hormones
Nervous
Anterior pituitary
Posterior pituitary
Thyrotropin
Somatotropin
LH
ACTH
Adrenal
Thyroid Cortex Pancreas
T3
Cortisol
aldosterone
Muscles
liver
Tissues
FSH
Ovary
Vasopressin
Prolactin
Adrenal
Medulla
Testis
Insulin,
Estradiol Testosterone
glucagon,
somatostatin
Liver,
muscles
Reproductive
organs
Oxytocin
Epinephrine
Mammary
glands
Pituitary Gland
Anterior Pituitary I
Growth Hormone
• stimulates body to grow &
burn carbohydrates (sugars)
& fat
Dwarfism
hyposecretion
Gigantism
hypersecretion
Anterior Pituitary II
Melanocyte-stimulating Hormone
• increases amount of pigmentation in skin
Prolactin
• stimulates milk production and maintains it
Adrenocorticotropic Hormone
• controls the secretion of hormones from the adrenal cortex
Thyroid Stimulating Hormone
• controls the release of hormones from the thyroid gland
Anterior Pituitary III
Follicle-Stimulating Hormone
• stimulates development of
ova and estrogen production
in ovaries; stimulates sperm
production
Lutenizing Hormone
• stimulates ovulation and
prepares uterus for possible
implantation of fertilized
ovum; stimulates the
production of testosterone
Posterior Pituitary
Oxytocin
• stimulates contraction
of uterus & of the cells
surrounding the
mammary glands
Antidiuretic hormone
• regulates fluid balance
by reabsorbing water in
the kidneys; also helps
to regulate blood
pressure
Thyroid Gland
Thyroxine &
Triiodothyronine
• stimulates metabolism;
promotes protein
synthesis, glucose
uptake and lipid
metabolism; is
regulated by TSH
Calcitonin
• reduces Ca and P
levels in blood;
Thyroid Disorders
Cretinism
Hyposecretion (children)
Graves’
Disease
hypersecretion
Myxedema
Hyposecretion (adults)
Goiter
Adrenal or Suprarenal Glands
(adrenal cortex)- glands on top of kidneys
Aldosterone
• maintains fluid balance by
conserving Na and
excretion of K; cause
water retention and
increased blood pressure
Cortisol
• promotes glucogenesis in
liver; inhibits allergic
response and reduces
inflammation
Androgens and Estrogens
• sex hormones
Adrenal or Suprarenal Glands
(adrenal cortex) disorders
Cushion’s Disease
Androgenital syndrome
Adrenal or Suprarenal Glands
(Adrenal Medulla)
epinephrine & norepinephrine
• copy effects of the sympathetic nervous
system
Pancreas
Glucagon
• stimulates conversion of
glycogen to glucose
Insulin
• stimulates conversion of
glucose to glycogen;
stimulates uptake of
glucose by muscle and
nerve cells
• Diabetes Mellitus
– Hypo/hyper secretion
of insulin
Pineal Gland
Melatonin
• regulates diurnal biorhythms; highest at
night
Thymus Gland
Thymosin
• stimulates the production of T-cells
Gonads
Ovaries - Estrogens
• stimulates development of sex organs
and secondary sex characteristics
Testes -Testosterone
• stimulates development of sex organs
and secondary sex characteristics
Placenta
Human Chorionic Gonadotropin
• stimulates production of
estrogen and progesterone
during pregnancy
Human Placental Lactogen
• prepare breasts for milk
production
Relaxin
• loosens mother's pelvic
ligaments and pubic
symphysis
ENDOCRINE DISORDERS
GIGANTISM:
• Hyperactive pituitary in
preadolescence
• Overgrowth of long bones
Endocrine System…. Professor KS Satyapal
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ENDOCRINE DISORDERS
ACROMEGALY:
• Hyperactive pituitary in
adulthood
• Over development of
bones in face, hands, feet
Endocrine System…. Professor KS Satyapal
20
ENDOCRINE DISORDERS
Dwarfism:
• Hypoactive pituitary in
childhood
Endocrine System…. Professor KS Satyapal
20
ENDOCRINE DISORDERS
GOITER
• Thyroid hyper secretion
• Enlarged thyroid gland
due to iodine
insufficiency
Endocrine System…. Professor KS Satyapal
22
ENDOCRINE DISORDERS
CRETINISM
• Results from thyroid
hormone insufficiency in
infancy
Endocrine System…. Professor KS Satyapal
21
ENDOCRINE DISORDERS
Grave’s
Disease/Exophthalmos
• Hyperactive thyroid
• Bulging eyes
Endocrine System…. Professor KS Satyapal
22
ENDOCRINE DISORDERS
Hypothyroidism
• Hypoactive thyroid
Endocrine System…. Professor KS Satyapal
22
ENDOCRINE DISORDERS
CUSHING’S
SYNDROME
• hypersecretion of adrenal
cortex
• Adipose tissue accumulates
in cheeks & base of neck
Endocrine System…. Professor KS Satyapal
23
ENDOCRINE DISORDERS
Diabetes
• hyposecretion of insulin
• Untreated = hyperglycemia (too much sugar in blood)
• Overtreated = hypoglycemia (too little sugar in blood)
Endocrine System…. Professor KS Satyapal
23