Pathology of Diabetes Flashcards
where is insulin produced
in beta cells of islets of langerhans in the pancreas
function of insulin
to bind to cell receptors and drive glucose into them to reduce blood glucose
what happens when there is a lack of insulin
glucose uptake by cells is reduced and blood glucose rises.
what is type 1 diabetes
lack of insulin production resulting in high blood glucose
what are the causes of type 1
autoimmune destruction of B cells
gut bacteria as an infant giving predisposition
virus that mimics outside of B cells causing immune attack
what is type 2 diabetes
a combination of reduced tissue sensitivity to insulin and an inability to secrete very high levels of insulin
what cause reduced tissue sensitivity to insulin in type 2
central obesity –> more fatty acids in blood –> decreased insulin receptor sensitivity
how does the body respond to decreased insulin receptor sensitivity
by producing more insulin to get the same amount of glucose into cells (hyperinsulinaemia)
what occurs to turn central obesity into diabetes
the pancreas is unable to produce the higher levels of insulin to overcome the insulin receptor desensitivity
cause of pancreas inability to secrete very high levels of insulin
having many genes abnormal for the ‘high end’ insulin secretion
commonest cause of death in diabetics
MI
how does diabetes cause vascular complications
by accelerating atherosclerosis
how does diabetes accelerate atherosclerosis
high blood glucose –> attaches to LDL –> gets in the way of it attaching to receptor in liver as tightly –> not removed by liver cells –> LDL stays in blood –> hyperlipidaemia –> atherosclerosis
plasma protein accumulation in subendothelial space
collagen makes up basal lamina –> collagen glycosylated –> albumin binds to it –> find it difficult to pass back out of subendothelial space –> accumulation –> narrowed lumen
where is the subendothelial space
between the endothelial cells and basal lamina
