Physiology of the endocrine pancreas Flashcards
Which of the following cells produce insulin?
A. alpha cells
B. beta cells
C. D cells
D. F cells
B
Which of the glucose transporters is present in skeletal and cardiac muscle, and adipose tissue and facilitates insulin-mediated glucose uptake?
A. GLUT 1
B. GLUT 2
C. GLUT 3
D. GLUT 4
D
Primary target of insulin
A. Glucokinase B. Acetyl-CoA carboxylase C. Uncoupling proteins D. Fatty acid synthase E. GLUT-4
E
What is the most important stimulus for insulin release?
a. glucose
b. glucagon
c. adrenergic stimulation
d. cholinergic stimulation
A
With inactivating mutation to GLUT-2 transporter
a. patient loses consciousness and seizure
b. pancreas do not produce insulin when glucose increases after meals
c. glucose is not transported to muscles and adipose
d. fructose is not transported
B
What happens after pancreatectomy?
a. hypoglycemia
b. decreased FFA
c. decreased acetoacetate
d. metabolic alkalosis
D
Insulin affects the metabolism of which substances?
a. carbohydrates
b. carbohydrates and fats
c. carbohydrates and proteins
d. carbohydrates, fats and proteins
D
Which of the following is true about insulin?
a. The active hormone is composed of 4 peptides
b. The secretory granules contain insulin and c-peptide in 2:1 ratio
c. insulin is released into the duct of Wirsung to reach the liver
d. The order of synthesis of the polypeptide chain is n-terminal signal peptide- b-chain- c-peptide- a chain
D
Insulin receptors belong to which family of receptors?
a) Tyrosine kinase receptor
b) Steroid receptor
c) Cytokine receptor
d) G protein-coupled receptor
e) LDL receptor
A
First action of secreted insulin:
a) Activate lipoprotein lipase
b) Inhibit glucagon secretion
c) Stimulate hepatic glycolysis
d) Mobilize GLUT4 into myocellular membrane
e) Inhibit appetite
b
Type 1 diabetes (juvenile-onset) suspected by parents on their child because of change in appearance or behavior.
a) Sudden increase in muscle mass
b) Darkening skin
c) Increased thirst and frequency of urination
d) Puffiness around face
e) Early pubertal growth spurt
c
Which is found in the pancreatic islets?
a) Insulin-secreting alpha cells
b) Glucagon-secreting beta cells
c) Gastrin-secreting delta cells
d) Pancreatic polypeptide-secreting F cells
d
Which of the following steps occur in the process of insulin secretion?
a) Opening of potassium channels
b) Closure of calcium channels
c) Exocytosis of secretory granules
d) AOTA
c
Increase insulin:
a) Decrease in plasma glucose
b) Decrease in amino acid
c) Decrease in ketone bodies
d) AOTA
d
The following stimulate insulin secretion except
A. decrease in blood glucose
B. GI hormones
C. acetylcholine
D. Glucagon
A
Hormone which decreases plasma glucose
a. insulin
b. glucagon
c. cortisol
d. epinephrine
a
Biological effects of glucagon
a. stimulate gluconeogenesis
b. stimulate glycogenesis
c. stimulate glucose uptake
d. stimulate protein synthesis
a
Which cells secrete insulin?
Beta cells
Which cells secrete glucagon?
Alpha cells
Which cells secrete somatostatin?
Delta cells
Which pancreatic structures consists of the endocrine pancreas?
Islets of Langerhans
Insulin is composed of 51 amino acids arranged in two polypeptide chains. T/F
T
Insulin: catecholamine, peptide, steroid, iodothyronine?
Peptide
Two inactive precursors of insulin
Preproinsulin and proinsulin
Insulinase, the enzyme that degrades insulin, is found in which organs?
Liver and kidney
The most important glucose-sensing cell in the body
Beta cells
A particularly important amino acid stimulus for insulin synthesis and secretion
Arg
Epinephrine (stimulates/inhibits) secretion of insulin
Inhibits
The effects of insulin on glucose metabolism are most prominent of which tissues?
Liver, muscle and adipose
Insulin decreases the production of glucose by inhibiting gluconeogenesis and the breakdown of glycogen in which organ?
Liver