Histology of the endocrine system Flashcards Preview

203: The endocrine system > Histology of the endocrine system > Flashcards

Flashcards in Histology of the endocrine system Deck (22)
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1

T4

Thyroxine

Thyroid hormone, requires iodine for synthesis

2

T3

Triiodothyronine

Thyroid hormone
- Requires iodine for synthesis

3

Iodine deficiency

Iodine is required for the synthesis of T3 and T4.
- Can be found in see salt.

Lack of iodine causes goitre, the enlargement of the thyroid.
- Allows more absorption of iodine.

4

Acidophils

Cells of the anterior pituitary that stain with acidic dyes.
- Appears pink

5

Basophils

Cells of the anterior pituitary stained with basic dye.
- Appears blue/purple

6

Chromophobes

Cells of the anterior pituitary that has no staining features.
- Appears greyish

7

Immunohistochemistry and anterior pituitary

Method of identifying what cell secretes specific hormones.

Antibodies are created to bind to specific hormones.
- Causing them to bind to cells secreting those hormones.

8

Cellular structure of endocrine glands

Contains cuboidal epithelial cells supported by myoepithelium
- Myoepithelium contains smooth muscle that contracts to secrete hormones.

Contains a lumen which hormones are secreted into.
- Except the pituitary and parathyroid gland.

9

Pituitary adenomas
- Description
- Manifestion

Benign neoplasm, mainly of the anterior pituitary cells.

Accounts for 10% of intracranial neoplasm.

If non-functional
- Causes pressure effects---> hypopituitarism

Function
- Secretes hormones---> Hyperpituitarism

Space occupying
- Headaches
- Vomiting
- Diplopia + visual defects
- Nausea

10

Thyroid gland histology

Composed of follicles
- C cells in-between

Abundant fenestrated endothelial cells in blood vessels.
- Allows the secretion of hormones into the blood.

11

C cells

Para-follicular cells of the thyroid.
- Secrete calcitonin into the blood.

Calcitonin decreases calcium levels in the blood.

12

Multi-nodular goitre
- Description
- Effects
- Treatments

Hyperplasia and hypertrophy of the thyroid cells.
- Presents as euthyroid.

Can compress airway.

Treated via removal in thyroidectomy.
- Removal can cause tracheomalacia as it weakens the airway
- Can cause airway to collapse---> cardiac arrest.
- Removal involves special care for CN X.

13

Grave's disease
- Presentation
- Pathology

Hyperthyroidism
- Can present with diffuse enlargement of the thyroid---> Goitre.

Other manifestations
- Infiltrative ophthalmology---> proptosis
- Infiltrative dermopathy---> pre-tibial myxoedema.

Pathology
- Increased vascularity
- Soap bubble colloid due to hyperactivity.

14

Hashimoto's thyroiditis
- Cause
- Biochemical presentation
- Patholgy

Autoimmune condition that destroys thyroid cells and leads to fibrosis

Causes of hypothyroidism when iodine is readily available.

Will show increased TSH levels.
- Decreased T4/T3 levels.

Pathology
- Lymphocytic infiltrate.
- Thyroid atrophy.

15

Follicular adenoma

Type of benign thyroid neoplasm.

16

Papillary thyroid cancer
- Description
- Metastasis

Carcinoma of the thyroid
- Accounts for most of the carcinomas
- 75-85%

Has a high risk of lymphatic metastasis.

17

Follicular thyroid cancer
- Description
- Metastasis

Carcinoma of the thyroid
- Accounts for 10-20% of thyroid carcinomas

High risk of metastasis to
- Bone
- Lung
- Liver

18

Medullar thyroid cancer
- Description
- Origin

Carcinoma of the thyroid.
- C cell origin
- Accounts for 5% of thyroid carcinomas
- Associated with MEN syndrome (20%)

19

Anaplastic thyroid cancer

Carcinoma of the thyroid
- Mainly found in elderly patients
- <5% of all thyroid carcinomas.

20

MEN 2
- Cancers associated

Multiple endocrine neoplasia type 2

Associated with
- Phaochromocytoma [adrenal medulla]
- Medullary carcinoma of the thyroid
- Pituitary adenoma

21

Parathyroid adenoma

Benign neoplasm of the parathyroid

Affects one gland

Causes hypercalcemia

22

Parathyroid hyperplasia

Affects all four glands

Causes hypercalcemia