Thyroid.parathyroid pathology 1 Flashcards Preview

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Flashcards in Thyroid.parathyroid pathology 1 Deck (19):
1

Describe the histology of the thyroid gland 

  • Comprises of follicles 
  • Each follicle surrounded by flat to cuboidal follicular epithelial cells
  • Colloid contains thryoglobulin
  • Scattered amoing the follicles is parafollicular (C-cells) cells  

2

What is thyroglobulin ?

The protein on which T3 and T4 are synthesised 

3

What do C-cells secrete ?

Calcitonin 

4

What are some of the common pathologies affecting the thyroid gland ?

  • Hyperthyroidism/ Thyrotoxicosis
  • Hypothyroidism
  • Goitre
  • Neoplasia

5

What are the antibodies commonly seen in Graves disease causing hyperthryoidism ?

TSH receptor antibodies 

6

Define euthyroid 

Normal function thyroid 

7

What is the most common thyroid disease ?

Non-toxic nulti-nodular goitre 

8

What is non-toxic mutli-nodular goitre ?

  • Nodular enlargement of the thyroid gland
  • Affected individuals can be either euthyroid or hypothyroid 

9

How does non-toxic multi-nodular goitre arise ?

  1. Result from absolute or relative iodine deficiency 
  2. Results in increased TSH secretion 
  3. This induces hyperplasia in an attempt to increase thyroid hormone output 
  4. These increased demands are usually intermittent and the gland therefore undergoes cycles of growth and shrinkage 
  5. End result is nodules of varying size with fibrosis, haemorrhage and focal inflammation seen 

10

What are some of the complications of mutli-nodular goitres ?

  • May produce symptoms suggestive of tumour 
  • Can cause compression of trachea, oesophagus, or recurrent laryngeal nerve 

11

What are some of the histological features seen in graves disease causing hyperthroidism ?

  • Gland is hyperplastic and hyperaemic 
  • Thyroid epithelium is hyperplastic and there is little coloid storage 

12

What antibody is usually present in hashimotos disease causing hypothyroidism 

High-titre antiperoxidase 

13

What are the typical histological features of hashimotos thyroiditis ?

Gland is widely infiltrated by lymphocytes, plasma cells, macrophages

Thyroid follicular cells are enlarged with eosinophilic granular cytoplasm due to accumulation of mitochondria 

14

Define what a goitre is 

Any enlargement of the thyroid gland

15

What are the main types of goitres and how does a goitre occur ?

Diffuse and mutli-nodular goitres 

  • Diffuse = entire goitre becomes enlarged 
  • Multi-nodular = lots of nodules of enlargement 

Occur due to Reduced T3 / T4 production causing a rise in TSH, stimulating gland enlargement

 

16

What are the usual thyroid function results for diffuse goitres ?

T3 / T4 normal but TSH high or upper limit of normal due to increased TSH compensating 

17

Where are the parathyroid glands located ?

You have 4 (2 upper and 2 lower) located posterior to the thyroid gland 

18

What are the 2 main cell types which the parathyroid glands are made up of 

Chief cells and Oxyphil cells 

19

What is the function of chief cells in the parathyroid glands ?

  • Secrete PTH
  • Act on Ca homeostasis (regulates calcium levels)