L03 - Histology of Endocrine System (nuts & bolts)

Question 1

Endocrince glands overall structure

exceptions

Answer 1

cuboidal secretory cells with lumen

myoepithelial cells support secretory cells

but pituitary and parathyroid gland cells have no lumen

Question 2

Endocrine diseases clinical manifestations?

Answer 2

Hormone over and unerproduction

tumour / mass lesion
—-can be functional or non functional. pressure effecr / over production of hormones

Question 3

Endocrine diseases clinical manifestations?

Answer 3

Hormone over and unerproduction

tumour / mass lesion
—-can be functional or non functional. pressure effecr / over production of hormones

Question 4

Pituitary gland divided into?

Answer 4

adenohypophysis / anterior lobe

neurohypophysis / posterior lobe

Question 5

Cells of the anterior pituitary gland (staining)?

what else can you do to identify specific cells?

Answer 5

acidophils, basophils, chromophobe

acidic/basic/no dye

antibody staining against sp hormone -immunocytochemistry - identifies sp cells if tumour is secreting this

Question 6

Pituitary adenomas

arise from? effects? symptoms?

Answer 6

anterior lobe

productive adenomas can case hyperpituitarism, pressure effects can cause hypopituitarism

symptoms of pressure - headaches, vom, nausea, diplopis, vision impairment (bitemporal hemianopsia)

Question 7

Thyroid gland

what secrete what do

what required for synthesis? lack of this causes what? why?

Answer 7

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

Question 8

Thyroid gland

structure?

other features, cells. what do they produce

Answer 8

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

Question 9

Thyroid gland

pathologies??

Answer 9

Goitre - euthyroid
Grave's - hyperthyroid
Hashimoto's - hypO
Ademona - euthyroid
Cancer - euthyroid

Question 10

Why is it important to assess radiology before thyroidectomy?

Answer 10

patient may arrest due to tracheomalacia

softening of trachea, collapses and obstructs

Question 11

Grave’s Disease

pathology?

Histology?

Answer 11

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

Question 12

Hashimoto’s Thyroiditis

what is it, how

histology?

Answer 12

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)

Question 13

Thyroid tumours

Benign / Carcinogenic - what is each called.

types??

Answer 13

Follicular adenoma - benign tumour of thyroid follicular cells

CARCINOMAs

• • papillary
• • follicular
• • medullary: from C cells. assoc. w MEN2 syndrome
• • anaplastic

Question 14

Parathyroid Glands

what they do, what cell secretes

Answer 14

Secrete PTH
Control Ca levels in blood
decr in Ca –> PTH secr

Chief cells with no lumen - prominent vascularity on histology.

Question 15

Parathyroid glands

Pathology

Answer 15

adenoma (1 gland)
hyperplasia (all 4 glands)

both cause hypercalcaemia

Question 16

Adrenal glands

embryological derivatives - structure?

colour? why

Zones? which do what

Answer 16

cortex - mesoderm

meulla - neural crest

colour is orangeyelloe because cells are rich in lipids

appear pale on histology, lipids cleared by chemical processing

Question 17

Adrenal glands

Zones? which do what

Answer 17

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

Question 18

Adrenal glands pathology

2 major thing and examples

Answer 18

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

Question 19

adrenal cortex adenoma

what is it? what can it cause?

Answer 19

non functioning cortical adenoma

functional adenmas can cause cushings or conns syndrome

Question 20

adrenal medulla

what do they secrete? results in?

histology

what is a tumour of this area called

Answer 20

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

Question 21

Phaechromocytoma

what is it

why does it happen

what happens as a result

Answer 21

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