L03 - Histology of Endocrine System (nuts & bolts) Flashcards
Endocrince glands overall structure
exceptions
cuboidal secretory cells with lumen
myoepithelial cells support secretory cells
but pituitary and parathyroid gland cells have no lumen
Endocrine diseases clinical manifestations?
Hormone over and unerproduction
tumour / mass lesion
—-can be functional or non functional. pressure effecr / over production of hormones
Endocrine diseases clinical manifestations?
Hormone over and unerproduction
tumour / mass lesion
—-can be functional or non functional. pressure effecr / over production of hormones
Pituitary gland divided into?
adenohypophysis / anterior lobe
neurohypophysis / posterior lobe
Cells of the anterior pituitary gland (staining)?
what else can you do to identify specific cells?
acidophils, basophils, chromophobe
acidic/basic/no dye
antibody staining against sp hormone -immunocytochemistry - identifies sp cells if tumour is secreting this
Pituitary adenomas
arise from? effects? symptoms?
anterior lobe
productive adenomas can case hyperpituitarism, pressure effects can cause hypopituitarism
symptoms of pressure - headaches, vom, nausea, diplopis, vision impairment (bitemporal hemianopsia)
Thyroid gland
what secrete what do
what required for synthesis? lack of this causes what? why?
t3 - triiodothyronine
t4 - thryroxine
iodine
lack of causes enlarged thryroid - GOITRE
due to hyperplasia and hypertrophy of cells.
gland enlarges to maximise amount of iodine absorbed
Thyroid gland
structure?
other features, cells. what do they produce
follicles with lumina. eosinophilic or pink appearance.
follicles lined with cuboidal cells
very vascular. endothelial cells lining the capillaries are FENESTRATED - gaps
C CELLS - parafollicular cells. clear cells. between follicles.
C cells found between the follicles. secrete CALCITONIN which reduces Ca in blood
Thyroid gland
pathologies??
Goitre - euthyroid Grave's - hyperthyroid Hashimoto's - hypO Ademona - euthyroid Cancer - euthyroid
Why is it important to assess radiology before thyroidectomy?
patient may arrest due to tracheomalacia
softening of trachea, collapses and obstructs
Grave’s Disease
pathology?
Histology?
autoantibodies stimulate TSH receptors.
enlargement of thyroid gland due to Goitre.
Infiltative opthamopathy - soft tissue and inflam cells behind eye - proptosis
infiltrive dermopathy - induration of skin on the anterior shin - PRE TIBIAL MYXODEMA
histology - COLLOID has SOAP bubble appearance due to hyperactivity
Hashimoto’s Thyroiditis
what is it, how
histology?
most common hypothyroidism cause.
autoimmune disease - immune system destroys throid tissue
progressive depletion of thyroid cells by inflammation and replaced by fibrosis
decr T3&T4, incr in TSH
hist - prominenet lymphocyte infiltrate (blue)
Thyroid tumours
Benign / Carcinogenic - what is each called.
types??
Follicular adenoma - benign tumour of thyroid follicular cells
CARCINOMAs
- papillary
- follicular
- medullary: from C cells. assoc. w MEN2 syndrome
- anaplastic
Parathyroid Glands
what they do, what cell secretes
Secrete PTH
Control Ca levels in blood
decr in Ca –> PTH secr
Chief cells with no lumen - prominent vascularity on histology.
Parathyroid glands
Pathology
adenoma (1 gland)
hyperplasia (all 4 glands)
both cause hypercalcaemia
Adrenal glands
embryological derivatives - structure?
colour? why
Zones? which do what
cortex - mesoderm
meulla - neural crest
colour is orangeyelloe because cells are rich in lipids
appear pale on histology, lipids cleared by chemical processing
Adrenal glands
Zones? which do what
zona glomerulosa - mineralocorticoid, aldosterone (Na absorp)
ROUND CELLS
zona fasciculata - glucocorticoids, cortisol and corticosterone, sex hormones
CLEAR CELLS ARRANGED IN CORDS
zona reticularis - 17 ketosteroids, sex hormones
SMALLER DARKER STAINING CELLS
salt, sugar, sex
Adrenal glands pathology
2 major thing and examples
ADRENOCORTICAL HYPERACTIVITY
- – due to hyperplasia, ademona or cancer (rare)
- – cushing’s syndrome (XS cortisol)
- – conn’s syndrome (XS aldosterone)
- – adrenogenital syndrome (XS adrogens)
ADRENOCORTICAL INSUFFICIENTY
— addinson’s disease
adrenal cortex adenoma
what is it? what can it cause?
non functioning cortical adenoma
functional adenmas can cause cushings or conns syndrome
adrenal medulla
what do they secrete? results in?
histology
what is a tumour of this area called
adren and NA in response to intense emotional reaction. fight or flight
secretion - vasocontriction, increased HR and blood sugar levels
medulla cells are neuroendocrine and darker staining than cortex
Phaechromocytoma
Phaechromocytoma
what is it
why does it happen
what happens as a result
adrenal medulla tumour
0.1-0.3% cause of treatable hypertension
10% tumour
— familial (MEN2), entraadrenal, bilateral, malignant, childhood arisen
due to high levels of catecholamines
precipitous increase in BP, tachycardia, palpitations headache, sweating, tremour and sense of apprehension
incr in BP complications - CCF, IHD, cardiac arrhythmias, CVA
