L3 nuts and bolts 2 Flashcards
Endocrine
action of hormone on a target organ away from secreting cell
autocrine
action of hormone on secreting cell
paracrine
action of hormone on adjacent cell
neuroendocrine
neural stimulation of endocrine cells to secrete hormones eg - medulla of adrenal gland
structure of endocrine glands
ductless
functional unit has cuboidal secretory cells with centre lumen
secretory cells are supported by myoepithelial cells
not all endocrine functional units have lumen - PTH and pit gland cells have no lumen
What are the cells of the anterior pit gland?
acidophils
basophils
chromophobe
What are pituitary adenomas?
benign tumours from anterior lobe
can be functional or non functional
productive adenomas cause hypopituitarism
space occupying effect of functional or non functional adenomas - headache, vomiting, diplopia, impaired vision
Histology -Features of thyroid gland
thyroid tissue has follicles with varied sized lumens
follicles contain colloids with eosinophilic appearance
follicles are lined by cuboidal cells
very vascular
the endothelial cells lining the capillaries are fenestrated to allow hormone passage into circulation
between follicles there are parafollicular cells or C cells (clear cells).
What do C cells do?
secrete calcitonin
which promotes reduction of calcium concentration in the blood
Pathology of thyroid gland
Goitre - Euthyroid Grave’s Disease - Hyperthyroid Hashimoto’s disease - Hypothyroid Adenoma - Euthyroid Cancer - Euthyroid
Why is it imporant to assess radiology before surgery for multi nodular goitre compressing trachea?
because the patient may arrest after successful thyroidectomy due to tracheomalacia
softening of trachea which collapses and osbtructs the airways
What is Graves disease?
auto antibodies stimulate TSH receptor
diffuse enlargement of thyroid gland goitre due to hyperplasia of thyroid cells
infiltrative opthamology - accumulation of soft tissue and inflammatory cells behind the eye leading to proptosis
Infiltrative dermopathy – thickening and induration of the skin on the anterior shin→ pre-tibial myxoedema
Histology of graves disease
the colloid has soap bubble appearance due to hyperactivity
what thyroid tumours are there
follicular adenoma - benign
carcinoma - 4 main types
papillary 75-85% risk of lymph node metastasis
follicular - increased mets to bone lung and liver
medullary
anaplastic
pathology of PTH gland
adenoma - involves one gland
hyperplasia - involves all 4 glands
BOTH CAUSE HYPERCALCEMIA
