Endocrine System 2: Adrenal and Pancreas Flashcards
where is the thyriod gland located?
anterior to trachela rings 2-3
The right and the left lobes of the thyriod are sepreated by
an isthmus
The follicles of the thyriod are filled with
colloid
thyrogkobulin
TSH
thyroid stimulating
hormone
what produces TSH
anterior pituitary
thryrotrophs (basophil)
TSH controls
- syntheiss
- secrection
of thryroid hormones
syntheiss of thyroid hormones is
exocrine
secretion of thyroid hormones is
endocrine
Exocrrine Synthesis
- uptake
- TGB synthesized
- addition
what is taken up into the cell in the first step of exocrine( synthesis)
amino acids and iodide
What is Thyroglobulin(TGB) synthesized on
RER
How is TGB released?
exocytosis
Thyriod hormones are stored
extracellularly as TGB
Secretion
- endocytosis & digestion of colloid
- colloid fuses with lysosomes
- breakdown of TGB- release of T3 & T4 iodine
- T3 & T4 diffuse into cappilary
What cause the endocytosis of colloid?
due to TSH stimulus
Thyroid gland makes far more
T4
Which is more potent T3 or T4?
T3
3 to 4X more
What transports T3 & T4 in the cappilary
thyroxine-binding protein
what makes thyroxine-binding protein?
the liver
Functions of Thyroid Hormone
- increase metabolic rate
- increase body temp
- increase glucose production
- needed for normal CNS development
C Cells produce
calcitonin
What makes calcitonin?
C Cells
Calcitonin act to
decrease calcium
How does calcitonin decrease calium concentration?
inhibits bone resorption
binds to receptor on osteoclast
Hypercalcemia
high blood calicum
Hyperthryroidism
excess production of TSH
Hyperthryroidism symptoms
- increase metabolic rate
- weight loss
- heat intolerance
Common causes of Hyperthryroidism
- ingestion of T4( used for weight loss)
- loss of feedback control
- over stimulation of adenohypophysis
Graves Disease
autoimmune disorder that produces antibodies to the receptors for TSH
How do the antibodies work in Graves Disease
they bind tothe the receptor and chronically stimulate it
results in too much thyroid hormone
Symptoms of Graves disease
- plus exopthlalmos
- TSH-R in orbital fat
exop- collagen depostion posterior to the eyeball
Treatment for Graves Disease
*surgical removal
radioactive iodine
Hypothyroidism
insufficient production of thyroid hormone
Symptoms of Hypothyroidism
- low metabolic rate
- gain weight
- feel cold
- photophobia
Cause of Hypothyroidism
- decrease iodine intake
- loss of pituitary stimulation
- destruction of thyriod
Treatment for Hypothyroidism
oral thyroid medicaiton
Endmic Goiter is caused by
iodine deficeincy
Most abundent cell
parathyroid
chief cells
Chief cells of parathyroid secrete
parathyroid hormone
What is the function of oxyphil cells?
unknown
Occur in clusters, contain large # of mitochondria, has no secretory vesicles
oxyphil cells
oxyphil cells
- Occur in clusters
- contain large # of mitochondria
- no secretory vesicles
What happens to the parathyroid in older people
get fatty
What cause Chief cells to secrete parathyroid hormone?
low blood Ca levels
PTH regulates
Ca and phosphate balance
PTH on osteoblast
promotes osteoclast activity
PTH and renal tubules
stimulates resorption of Ca
PTH and GI tract
controls rate of Ca uptake by regulating produciton of Vitamin D(kidney)
Vitamin D stimulates
cells on the intestinal mucosa to aborb Ca
What is the carrier protein for Ca in the GI tract?
Calbinin
Hypoparathyroidism
- deficency in secretion of PTH
- blood Ca is low but bone Ca is not released
Ca deficiency results in
spontaneous depolarization of neurons and muscle fibers
results in tetany
Hyperparathyroidism
- high blood Ca
- result in bone loss
- cause Ca depositon oin ateries and kidneys
Centroacinar Cells
- in center of acinus
- start of intercalated ducts
- pale
Islets of Langerhans is ____ part
endocrine
There may more than ________ islets of langehens in the pancreas
1 million
Insuloacinar portal system is found
in the pancreas suppling islets of langerhans
Insuloacinar portal system allows for
direct action of hormones
what are the main islet cells
- alpha
- beta
- gamma
Alpha cells secrete
glucagon
what produces glucagon?
alpha cells
Beta cells secrete
insulin
what secretes insulin
beta cells
Glucagon
increase blood glucose
Insulin
decrease blood glucose
somatostatin
inhibts insulin and glucagon production
What secretes somatostatin
Delta cells
What do the other cells of islet secrete
- vasoactive intestinal peptide
- pancreatic polypeptide
Diabetes Mellitus
- insulin deificiency/ abnormality
- hyperglycmia (increased blood glucose
- glucosuria
Type 1 diabetes
- juvenille
- decrease insulin production
type 2 diabetes
- adult onset
- decrease in # or responsivness of receptors
Where are the adrenal glands located
superior to the kidneys
How are adrenal glands regulated
ACTH
What secretes ACTH
anterior pituitary
corticotrophs which are a type of basophil
In mammals we have _______ endocrin gland with
single; two different embryolocial origin
Steriod hormones are structurally similar to
cholesterol
What are the 3 class of adernal homones
- sex hormones
- glucocorticoids
- minercorticoids
minercorticoids control
- electrolyte and fluid balnace
- regulate Na and K level via Na pumps
what helps to regulate blood pressure via the JGA?
minercorticoids
glucocorticoids
stimulate gluconeogenesis and glycogenolysis
both increase blood glucose
also increase metabolism
What helps to increase the metabolism and breakdown of proteins, carbs, and lipids
glucocorticoids
Sex Hormones
supplement gondal production
very small amount
What is an example of a mineralcorticoids
aldosterone
what is an example of a glucocorticoid
cortisol
what is an example of an sex hormoen produced by the adernal gland
androgen
What is the order from outer to inner the layer of the adrenal
- zona glomerulosa
- zona fasciulata
- zona reticularis
zona glomerulosa is ___ of the cortex
15%
zona glomerulosa secretes
mineralcorticoids
zona fasciulata make up ____ of the cortex
80%
zona fasciulata contians
spongiocytes
zona fasciulata secrete
- gluccocorticoids
- and small amount of androgens
What promotes secretion of cortisol?
stress
Cortisol decreases
immune response
zona reticularis makes up ___ of the cortex
5%
zona reticularis secretes
small amounts of androgens and glucocorticoids
medulla of the the andrenal gets is blood
directly from long cortical artery as well as sinusoids from cortex
What causes aldosterone to be produced
Angiotension 2
Zona fasiculata on other tissues
catabolic effect
The zona fasiculata can supress
the immune system
Zone fasiculata and the liver
promotes uptake/use of fatty acids, amino acids, and CHO
Addisons Disease is
- hypoadrenocortisim
- failure to of adrenal gland to produce hormones
Crushing Disease
- hyperadrenocortisim
- excess cortisol secretion
1’ cause of hyperadrenocorticisim
due to adrenal hyperplasia or functional tumor
excess cortisol secretion
2’ cause of hypoadrenocorticisim
classical
- due to increase in ACTH from anterior pituitary
What is normaly causes addisons?
autoimmune
decrease in cortisol leads to
decrease in blood glucose
What is tx for addisons
given mineral/glucocorticoids
Chromaffin secrete
epinephrine and norepinephrine
Chromaffin are modifed
sympatheitc postganglionic neurons
Catecholemines are secreted in response to
stress
Catecholemines
- increase heart rate
- dialte blood vessels (cardiac and skeltal) and bronchioles
- vasoconstriction of blood suppy to GI, kidney, skin.
Pheochromocytoma
benign tumor of chromaffin cells
Pheochromocytoma cause
increased release of epinephrine and norepinephrine
can Pheochromocytoma kill the person
yes
Pheochromocytoma are _____ familail
25%
Hatfield-McCoy Feud may be due to
rare inhertied disease von Hippel-Landau
von Hippel-Landau can lead to
rage and violent outbursts