4.4 Endocrine diabetes Flashcards
what are other names for hyperthyroidism?
1) graves disease
2) toxic goiter
3) thyrotoxicosis
causes of hyperthyroidism? which one is most common?
1) tumor = over-secretion of T4 and T3
2) autoimmune response
describe the autimmune causation for hyperthyroidism. How is this tested?
**Called LATS= Long Acting Thyroid Stimulator; hypertrophy gioter
antibody is formed against TSH receptor. SO when antibody binds to receptor, the receptor treats it like TSH so you’ll see lots of T3/T4 produced. BUT LOW LEVELS OF TSH!!!
**test with an assay, - feedback with T3/T4 causes low TSH, but T3/T4 still being produced due to antibody interaction
general effects of hyperthyroidism
opposite of hypo
- early eruption and shedding of primary teeth
- early epiphyseal plate closure
- osteoporosis
- weight loss
- increased:
- –metabolic rate
- –heat production
- –protein synthesis
- –potentiation of GH and somatomedin –effects on tissue growth
- –nutrient utilization
- –oxygen consumption
- –synaptic activity
define exophthalamos
BUG EYES
an autoimmune response to 1/3 of cases of hyperthyroidism. It is an immune attack of soft tissue in the orbit associated with high levels of T3T4
–can even happen with hypo
location of pancreas
abdominal cavity, behind stomach, near duodenum
describe the 2 portions of the pancreas
1) exocrine = 98%
- -secretes bicarbonate solution (ducts) and digestive enzymes (acinar cells) into duedenum
2) endocrine = 2%
- -secrete hormones from clusters of cells, scattered throughout pancreas= pancreatic islets or islats of langerhans
pancreatic islets or islets of Langerhans
part of 2% endocrine portion of pancreas
acinar cells in what part of pancreas?
in 98% exocrine portion
insulin comes from?
endocrine beta cells in pancreas
what are the 4 types of cells in islets of Langerhans (endocrine pancreas)? what do they secrete? amount?
1) alpha cells 20%
- secrete glucagon
2) beta cells 75%
- secrete insulin
3) delta cells 4%
- somatostatin
4) phi cells 1%
- pancreatic polypeptide
what is the importance of the 4 islets of Langerhans cells being close together?
they proabably regulate each other or have sort of effect on eatch
what two cell types of islets of Langerhan regulate glucose levels?
alpha with glucagon secretion and beta with insulin secretion
pancreatic hormone is what type of hormone?
paptide; 29 AA long
main function of glucagon? stimulates
- increase blood glucose levels
* stimulats glycogenolysis, gluconeogenesis, ketogenesis ALL TO KEEPPROTEIN SPARING
what is the main thing that simtulates glucagon secretion?
low plasma glucose
automatically think what when you hear protein hormone?
- membrane receptors
- 2nd messenger
- -maybe couple to a G-protein
glucagon mechanisms of action
binds to membrane receptors and acts via caMP
-glocagon’s glycogenolysis research is the discovery of cAMP
how was cAMP discovered?
thru the research of the relationship between glucogenolysis and glucagon
how do you regulate glucagon secretion?
1) primarily on plasma glucose concentration
- -low glucose = stimulate alpha cells
- -high glucose= inhibits alpha cells
2) low blood glucose > nervous system via both branches of autonomics to stimulate alpha cells
3) low blood glucose stimulates the adrenal gland to release epi and nor which in turn stimulates alpha cells to release glucagon
low or high glucose effect on alpha cells
- -low glucose = stimulate alpha cells
- -high glucose= inhibited alpha cells
idiopathic hypoglycemia is correlated with?
abnormal secretion of glucagon
- may involve lack of alpha cells
- uncommon and not much known
insulin is what type of hormone?
peptide with two chains connected by two disulfide bridges
general effects of insulin
-lowers blood glucose levels
=promotes nutrient storage
-HORMONE of ABuNDANCE
main job of insulin?
lower plasma glucose levels by storing it in cells
insulin carbohydrate metabolism?
1) hepatic cells: inhibits glycogenolysis and glucose release
2) extrahepatic cells: stimulates glucose transport; facilitated diffusion of glucose
what cells do NOT require insulin for glucose uptake?
1) intestine
2) kidney
3) liver
4) nervous system
5) SOME skeletal muscles
do cells that do NOT require insulin for glucose uptake still have insulin receptors?
Yes! insulin can still help in the uptake of glucose, but it is not dependent on it
insulin in fat metabolism?
indirect effect
-insulin increase glucose uptake by liver and adipose cells which then STORE fat and decrease fat utilization
hepatocytes (liver) stores glucose as
glycogen or fat
insulin in protein metabolism?
indirect effect
-insulin increases the action of GH’s AA uptake and protein synthesis
why would insulin inhibit glycogenolysis?
bc it is a storage hormone; you don’t want to take stuff out when trying to store it
regulation of insulin secretion is primarily bu?
plasma glucose concentration
- high plasma glucose = increase B cell activity
- low glucose= decreased beta cell activity
what AA increase the effect of glucose on beta cells?
arginine and lysine
when in excess, what does GH, glucagon and glucocorticoids do?
cause diabteogenic
-this can lead to hyperglycemia with increase of beta cells activity and secretion of insulin
describe diabetes mellitus type 1?
caused by?
- juvenile onset (early)
- insulin deficiency
- caused by
1) virus or unknown environmental agent directly attacks beta cells
2) autoimmune response to beta cells
what is the most common cause of diabetes mellitus type 1?
autoimmune response to beta cells
–an attack of beta cells causing a deficiency in insulin
describe diabetes mellitus type 2?
causes?
-maturity onset; after 40
-primarily decrease tissue sensitivity to insulin
caused by: (combined cause)
1) decrease # of receptors
2) decrease sensitivity of receptor
big main difference between type 1 and type 2?
1= deficient in insulin 2= decreased sensitivity to insulin in tissues, but insulin is present
can type 2 become type 1?
yes. after a period of time they lose ability to secrete insulin
what is “B cell burnout”
when beta cells of pancreas are no longer about to secrete insulin due to high levels of glucose for a long period of time
***type 2 becomse type 1
treatment for type 2?
exercise and weight loss
- increase # and sensitivity of insulin receptors
- increase noninsulin-dependent glucose uptake by muscle cells
what does obesity and weight gain do to the number and sensitivity of insulin receptors?
decreases it
what are the 3 primary effects of diabetes?
1) decrease GLUCOSE uptake, utilization and storage
2) increased FAT mobilization and utilization
3) increased PROTEIN metabolism and decreased protein synthesis
what are seconadry effects of diabetes?
1) hyperglycemia = polyuria
2) hyperlipidemia and ketosis= atherosclerosis and metabolic acidosis causing HYPERVENTILATION, CNS depression and diabetic coma
3) poor wound healing due to unavailibility of AA bc AA is being used as energy; caused periodontal disease and bone loss
define polyuria
lots of urine output that is high in sugar (dehydrating tissues)
causes of hypERinsulinemia?
- pancreatic adenoma (rare)
* insulin overdose (usually)
main reason to have TOO MUCH insulin?
exogenous overdose
adenoma means?
benign tumor formed from galndular structures in epithleium causeing over-secretion of beta cells … TOO MUCH insulin
primary effect of hyperinsulinemia?
increased glucose uptake by most cells
secondary effect of hyperinsulinemia?
insulin shock!
-due to increase stimulus to sym NS, dizzy/weak/hungry/high HR causing lowered brain function and loss of consciousness
diabetic coma symptoms? treatment?
- *NEED insulin, electrolytes and bicarbonate due to high glucose, dehydration and acidosis**
- acetone frutiy smell
- hyperventilation
- dry not sewaty skin
- unconscieousness
insulin shock symptoms? treatment?
- NEED SUGAR, epi and glucagon administered due to high insulin and to simulate liver glycogenolysis*
- no acetone frutiy smell
- SWEATY skin
- unconscious
what is the same symptom for insulin shock and diabetic coma?
unconsciousness after a few hours
what is normal fasting blood glucose? compared to diabetic and hyperinsulinemia?
70-
diabetic= higher
hyprinsulinemia= lower
glucose tolerance test?
compare results for diabetic, normal, and islet tumor
give sugar and havepatient pee; see how long it takes glucose levels to rise and become normal
- *normal= glucose won’t rise as high and returns to baseline easy
- **diabetic= glucose level rises HIGHER and returns to baseline SLOWLY
- **islet tumor= glucose levels do not rise high and returns to baseline quickly
how can you test for diabetes diagnosis?
1) urinary sugar
2) fasting blood glucose
3) glucose tolerance test
4) insulin sensitivity test
insulin sensitivity test
determines if eleveated blood glucose is due to insulin deficiency
phi cells or secretion of pancreatic polypeptide is stimulated by?
CCK; not well understood; cause gall bladder contractions
