pancreas Flashcards
is the duodenal or splenic lobe of the pancreas thicker?
splenic
what type of hormone is insulin?
protein
where is insulin synthesized?
beta cells of the pancreas
- in the endoplasmic reticulum
what increases insulin productino?
- increased plasma [glucose]
- GI hormones
is insulin water-soluble?
yes
is insulin protein-bound?
no
main actions of insulin:
- anabolic
- metabolism of carbs, fats and proteins
release of insulin via
increased [calcium]i
insulin leads to what
- increased cellular glucose uptake
- increased synthesis of glycogen(liver), triglyceride(adipose), protein (muscle)
what GLUT is used by muscle and adipose tissue?
GLUT 4
what GLUT is used by neurons?
GLUT 3
what GLUT is used by erythrocytes?
GLUT 1
what GLUT is used by intestinal muscosal cells
GLUT2
synthesis of glycogen from glucose occurs where?
liver
synthesis of triglycerides fatty acids occurs where?
adipose tissue
synthesis of protein from amino acids occurs where?
muscle (due to increased AA uptake)
what is the most important factor controlling insulin release?
blood glucose
which produces a greater insulin response, oral glucose or blood glucose?
oral glucose
insulin is governed by a (+/-) feedback mechanism?
positive feedback
what decreases insulin secretion?
catecholamines
-via alpha-adrenergic receptors on beta cells
what input increases insulin release?
cholinergic input
the insulin:____ ratio is important
glucagon
what increases glucagon synthesis?
- catecholamines (e.g. EPI)
- glucocorticoids (e.g. cortisol)
- amino acids
what decreases glucagon synthesis?
- high plasma [glucose], [insulin]
- high plasma [free fatty acids]
what cells produce glucagon?
alpha cells in the pancreas
glucagon has a direct stimulatory effect on what cells?
beta cells
effects of glucagon on the liver
- increased glycogenolysis
- increased gluconeogenesis
- inhibits FFA production from glucose
what is the net result of glucagon?
increased blood glucose
effects of glucagon on adipose tissue?
leads to increased lipolysis
during DM, in what direction is the insulin/glucagon ratio shifted?
liver shifted in the glucagon direction
glucagon and insulin release are stimulated by what nervous system?
parasympathetic NS
glucagon release, and NOT insulin, is stimulated by what nervous system?
sympathetic NS
stressed cats especially display what?
hyperglycemia
how do you test for islet cell function?
- glucose tolerance test
- 3 blood glucose readings
- insulin RIA
what is the translation of diabetes mellitus?
sweet diuresis
what is diabetes mellitus?
absolute of relative deficiency of insulin
what does canine parvovirus cause in the dog?
destruction of beta cells (type I)
what is a major clinical of type of DM?
ketoacidotic
what are the signs of diabetes mellitus?
- polyuria
- polydipsia
- cataracts
- obese w/ recent weight loss
- hepatomegaly
- ketone (acetone) breathe
which type of DM is most common in companion animals?
type I -insulin-dependent
what type of diabetes mellitus is most common in people?
type II - insulin independent
what is the predominant effect of type II DM with low BW?
impaired insulin secretion
what is the predominant effect of type I DM with obesity?
- insulin resistance
- hyperinsulinemia
