severe renal and hepatic impairment, acute conditions which affect kidney function or cause significant risk of hypoxia or dehydration
Sulfonylurea example
Gliclazide
sulfonylueas MOA
stimulate the pancreatic beta cells, promoting the release of insulin
sulfonylurea max dose
320mg daily
chromaffin cells of the adrenal medulla secrete
noradrenaline and adrenaline
the adrenal medulla is innervated by
splanchnic nerves
Phaeochromocytomas are derived from
chromaffin cells
aldosterone is secreted from
zona glomerulosa
glucocorticoids are secreted from
zona fasiculata
androgens are secreted from
zona reticularis
TFT in hyperthyroidism
TSH low; T4 high, T3 high
hypomagnesaemia can cause hypocalcaemia by
impairing the secretion of PTH and making tissues resistant to its action
sulfonylureas exert their hypoglycaemic effect by
inhibiting ATP sensitive potassium channels on the membrane of pancreatic beta cells -> depolarise beta cells; open VGCC -> exocytosis of vesicles containing insulin
exogenous insulin administration is characterised by
high serum insulin levels with low C-peptide levels
insulin decreases serum potassium through
stimulation of the Na+/K+ ATPase pump
octreotide class
somatostatin analogue
somatostatin functions
inhibition of GH secretion from anterior pituitary; suppression of insulin and glucagon secretion from pancreas
primary polydipsia water deprivation test
urine osmolality high after fluid deprivation and after desmopressin
leptin is secreted by
adipose tissue
leptin acts on
satiety centres in the hypothalamus
ghrelin is produced by
P/D1 cells lining the fungus of the stomach and epsilon cells of the pancreas
Leptin stimulates the release of
MSH and CRH
low levels of leptin stimulates the release
neuropeptide Y (NPY)
PTH regulates serum phosphate levels by
decreasing the expression of phosphate transporters in the renal proximal tubule (decreases expression of sodium-potassium cotransporters) = increases phosphate excretion
Hashimoto's thyroiditis polymorphism associations
HLA-DR3, 4 and 5
Hashimoto thyroiditis pathological features
lymphocytic infiltration of the thyroid gland and the formation of germinal centres
Subacute thyroiditis (De Quervain's) pathological featurs
Disruption of the thyroid follicles with a patchy inflammatory infiltrate with some follicles containing multinucleate giant cells
Riedel's thyroiditis pathological feature
inflammation and sense fibrosis of the thyroid follicles extending to the neck veins, oesophagus and trachea
multi nodular goitres pathological features
Nodular enlargement of the thyroid along with colloid filled cystic and hyper cellular regions
Papillary carcinoma of the thyroid pathology
solid and cystic thyroid mass with papillary formation and empty appearing nuclei
main component of colloid in the thyroid gland
thyroglobulin
thyroglobulin is essential for the storage of
iodine
T3 is formed through the coupling of
MIT and DIT
T4 is formed through the coupling of
two DIT molecules
thyroglobulin contains ... residues which undergo iodination