endocrine pancreas Flashcards
low glucose concentration in blood
hypoglycemia
hungry cell
high glucose concentration in blood
hyperglycemia
cell toxicity
keeps blood glucose from dropping too low
glucagon
produced to keep blood glucose from rising too high
insulin
The two hormones counterbalance each other to stabilize blood glucose
insulin and glucagon
Islets of langerhans are found in the
pancreas
islet of langerhans’s produce 2 hormones:
insulin and glucagon
alpha cells in islet of langerhan’s produce
glucagon
beta cells in islet of langerhan’s produce
insulin
delta cells in islet of langerhan’s produce
somatostatin
hyperglycemia induces production of_____ stimulating_______
insulin
glycogenesis in liver and glucose uptake by cells
hypoglycemia induces production of ______stimulating________
glucagon
gluconeogenesis and glycogenolysis in liver and helps to release glucose to blood
main anabolic hormone of the body.
insulin
mechanism of action of insulin
regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of glucose from the blood into liver, fat and skeletal muscle cells.
Insulin promotes absorption of glucose from blood by which organs
liver
fat
skeletal muscle cells
glucose absorbed in fat, liver and skeletal m. is converted into
glycogen
fats
or both
glycogenesis
converts glucose into glycogen
lipogenesis
converts glucose into fats
t/f the liver can do glycogenesis and lipogenesis
true
glucose production and secretion by the liver is INHBITED by
high concentrations of INSULIN in blood
insulin secretion is primarily stimulated by
high blood glucose level
increased blood glucose will also stimulate what GI hormones and which amino acids?
GIP (glucose-dependent insulinotropic peptide or gastric inhibitory peptide);
GLP-1( glucagon-like peptide-1)
Arginine
somatostatin
leptin
Released when blood glucose decreases
Three main insulin target cells
- Liver cells (hepatocytes)
- Fat cells (adipocytes)
- Skeletal muscle cells
What is specifically stimulated by insulin in skeletal muscle cells and adipocytes and heart to increase glucose uptake?
GLUT4 translocation from intracellular vesicles to membrane
t/f GLUT4 mechanism does not occur in liver cells
true
t/f Insulin acts as a glucose-depositing hormone by decreasing glucose plasma concentration
true
increased Cellular glucose trapping is promoted by
glucokinase activity
increased glycogenesis activity is promoted by
Glycogen synthase (GYS) activity
2 mechanisms are decreased in the liver in response to insulin
Hepatic Glycogenolysis
Hepatic Gluconeogenesis
insulin affects fat metabolism by 2 mechanisms
increasing lipid synthesis = increased activity of mRNA lipogenic enzymes
decreasing lipolysis = decreasing lipase
decreasing the activity of lipase causes
decreased lipolysis
Increasing the activity of mRNA lipogenic enzymes causes
increased lipid synthesis
insulin affects amino acid metabolism by 3 mechanisms
increasing uptake of amino acids into cells
increasing protein synthesis
decreasing protein breakdown
t/f Glucose is the only nutrient that generally can be used by brain, hypoglycemia damages brain cells
true
5 clinical signs of RAPID fall of blood glucose
Sweating
weakness
hunger
increased HR
“inner trembling” due to increase in Catecholamine release
5 CLINICAL SIGNS of SLOW fall of glucose blood levels
Headache
blurred vision
diplopia
coma
convulsions
t/f insulin overdose may present the same clinical signs of rapid or slow fall glucose concentration in blood
true
Glucagon is a peptide hormone that is essential
CATABOLISM
insulin is essential for
ANABOLISM
primary target tissue of glucagon
LIVER
physiologically, the most potent secretory stimulus of glucagon
HYPOGLYCEMIA
T/F Glucagon keeps blood glucose from dropping too low
TRUE
glucose-mobilizing hormone
GLUCAGON
2 main mechanisms of glucagon
increased hepatic glycogenolysis and gluconeogenesis to increase endogenous (hepatic) glucose production and release into blood
INHIBITS any metabolic events caused by INSULIN
glucose-depositing hormone
insulin
t/f After meal, insulin help to direct blood nutrients to tissues. The targets of insulin are liver, muscle, and adipose tissue.
true
t/f In the fasting state, glucagon help to directs the movement of stored nutrients into the blood. The main physiological target of glucagon is Liver
true
The targets of insulin are
liver, muscle, and adipose tissue.
diabetes occurs when
blood glucose is too high
clinical signs of diabetes mellitus
polyuria =- excessive urine production
polydipsia = excessive thirst
dehydration
depression
fatigue
weight loss
Type 1 (insulin-dependent, IDDM) is characterized by
autoimmune disease destroying the INSULIN PRODUCING BETA CELLS
may be triggered by a viral infection
Type 2 (Non-insulin-dependent, NIDDM) is characterized by
adult diabetes
obesity
INSULIN RESISTANCE ABNORMALLY LOW INSULIN IN TISSUE
type 1 diabetes is
INSULIN DEPENDENT
type 2 diabetes is
NON-INSULIN DEPENDENT
HAS A compensatory high β cell mass and function in response to abnormally low tissue sensitivity to insulin,
or an insulin resistance
type 2 diabetes
has a a continuous loss of β cell mass and function but tissue remains normal sensitivity to insulin (no insulin resistance
type 1 diabetes
4 causes of insulin resistance
Obesity/overweight (especially excess visceral adiposity)
Excess glucocorticoids (Cushing’s syndrome or steroid therapy)
Excess growth hormone (acromegaly)
Pregnancy, gestational diabetes
