Please enable JavaScript.
Coggle requires JavaScript to display documents.
Cellular Structure of Islets of Langerhans, Effects of Insulin on Body…
Cellular Structure
of
Islets of Langerhans
Cellular Structure
Each islet contains, an average, 2500 cells which are of 4 types and
arranged as:
Beta (β) cells or B cells
make up 60–70% of the total cells, and
constitute the central core of the islet.
These cells secrete
insulin.
Alpha (α) cells or A cells
form about 20% of the total cells
and constitute the outer rim of the islet.
These cells secrete
glucagon.
Delta (δ) cells or D cells
form about 10% of total cells
and are intermixed.
These are source of
somatostatin.
PP cells or F cells.
These are also peripherally placed
scattered amongst the α cells.
These are source of
pancreatic peptide.
Effects of Insulin on Body Tissues
Liver:
Increases protein synthesis
Increases lipid synthesis
Decreases ketogenesis
Decreases glucose output due to:
Decreased neoglucogenesis
Increased glycogenesis
Increased glycolysis
Muscle:
Increases glucose intake
Increases glycogenesis
Increases amino acid uptake
Increases protein synthesis in ribosomes
Decreases protein catabolism
Decreases release of gluconeogenic amino acid
Increases ketone uptake
Increases K+ uptake
Adipose tissue:
Increases glucose entry
Increases fatty acid synthesis
Increases glycerol phosphate synthesis
Increases triglyceride deposition
Increases activation of lipoprotein lipase
Inhibition of hormone-sensitive lipase
Increases K+ uptake
General: increases growth and development
Diabetes Mellitus
Diabetes means a ‘siphon’ or ‘running through’ and earlier it was used to
describe the polyuria.
Mellitus means sugar.
Therefore, diabetes mellitus is a clinical state which is associated with
flow of sugar in urine.