lecture 4 diabetes Flashcards
what are additional symptoms of diabetes
cells are unable to uptake nutrients from blood - weight lost
fatigue
what kind of disorder is diabetes
a metabolic disorder
what makes diabetes a metabolic disorder
chronic hyperglycaemia and disturbances of carbohydrate, fat and
protein metabolism
defects in insulin secretion and actiom
what does having diabetes mellitus fail to maintain
blood glucose homeostasis
cells cannot absorb glucose from the blood
what is high glucose levels counteracted with
thirst (polydipsia)
urinary volume (polyuria)
what’s a sign of diabetes
production of ketones -> acetone
ketones will be detected in urine
lowers pH in blood
what is another name for type 1 diabetes
Insulin dependent diabetes mellitus (IDDM)
what is another name for type 2 diabetes
non-insulin dependent diabetes mellitus (NIDDM)
who develops gestational diabetes
pregnant women
facts about gestational diabetes?
body does not produce enough insulin to meet demands of pregnancy
resolves after the birth of baby
30% more risk of type 2 after baby
what chains and bonding does insulin have
A and B subunits
disulphide bonds
what cells produce insulin and from where
Beta cells
islets of pancreas
what are the actions of insulin for lipids
increases triglyceride synthesis
increases fatty acid transport into adipose cells
activates lipoprotein lipase in capillary walls
what does insulin do for proteins
increases active transport of amino acids into cells
increases protein synthesis
decreases protein breakdown
what does insulin do for glucose
increase glucose transport to muscles
increase glycogen
decrease glycogenesis
cell types in the islets of pancreas
B cells - insulin
Alpha cells - glucagon
delta cells - somatostatin (inhibits insulin release)
PP cells - produce pancreatic polypeptide
what are the 3 stages of glucose induced insulin secretion
glucose transport and metabolism
electrical
secretatory
what are electrochemical membranes
polarised cell membrane
what are electrochemical membranes maintained by
maintained by pumps that use ATP
How is glucose transported
glucose is transported through GLU2 receptors
glucokinase -> G6P > pyruvate
what happens at the electrical stage
cell membrane is polarised
ATP inhbits the potassium channel maintaining polarisation
membrane depolarises
depolarisation spreads
Ca2+ channel opens and Ca2+ enters
what happens at the secretatory stage
insulin-containing secretory granules fuse with the membrane
insulin is released by exocytosis
when is insulin released
when glucose is high
enables glucose to transport to tissues
when is glucagon released
when glucose is low
what inhibits insulin release
glycogenolysis
gluconeogenesis
what does the liver do for glucose
stores glucose as glycogen
Release when needed
when does insulin inhibit glucagon release
when blood glucose increases
when are GLP-1 and GIP released
after a meal
where are GLIP and GLP-1 released
by the small intestine
what does the release of GLP-1 and GIP do
Stimulates insulin secretion
what stimulates the incretin release
Glucose in small intestine
what are incretins
Hormones released in response to food ingestion
What do incretins do
They modulate the insulin secretory response to ingestion of food
