Flashcards in Diseases of the Endocrine System (endocrine Pathology) Deck (31):
What is the difference between Endocrine, Paracrine and autocrine/
ENDOCRINE: hormones in blood stream + act systemically.
PARACRINE: hormones act locally
AUTOCRINE: affects cell secreting the hormone.,
Describe the location and location of the pituitary gland?
Location - Brain / Sella Turcica (depression in sphenoid bone), beneath hypothalamus.
Anatomy - 2 parts. Anterior forms 75% of gland. (outpouch of oral cavity)
25% posterior (down growth of hypothalamus)
What are the main (broad) causes of anterior pituitary hypofuntion?
Describe primary pituitary tumours?
Primary Pituitary Tumour:
-most are adenomas and benign,
-Effects are caused secondary to the hormone produced
-can press on optic chiasma
What are the types of anterior pituitary adenoma?
2) Growth hormone secreting
3) ACTH secreting
What are the effects of Prolactinoma (an anterior pituitary adenoma)?
1) Galactorrhoea (excess milk production)
2) Menstrual disturbances
What are the effects of Growth hormone secreting anterior pituitary adenoma?
1) Gigantism in children
2) Acromegaly in adults
What is the affect of ACTH secreting anterior pituitary adenoma?
*ACTH = adrenocorticotropic hormone
1) Cuhing's Syndrome
Describe the anatomy of the thyroid?
2) located at 5th, 6th + 7th vertebra, anterior neck.
3) next to recurrent laryngeal nerve
How does the thryoid develop during embryogenesis?
Develops as 2 parts.
-main part migrates from foregut to anterior neck.
-The ultimobranchial body forms in the branchial arches and fuses with main bit laterally
What are the common sites for ectopic / heterotopic thyroid tissue?
*usually occurs anywhere from foramen cecum (base of tongue) to suprasternal notch.
1) Lingual thyroid - base of tongue.
2) aortic arch
What is a thyroglossal duct cyst?
A peristent track representing the embryological migration path of the thyroid gland in the neck.
What is acute thyroiditis?
Inflammation of the thyroid usually caused by viral, bacterial or fungal infection.
What is palpation thyroiditis?
Occurs secondary to the rupture of thyroid follicles caused by palpation / surgery.
Granuloma cells such as macrophages and also T cells act on the thyroid follicles.
What is Riedel Thyroiditis?
-Riedel Thyroiditis is a rare fibrosing form of chronic thyroiditis.
-Presents with a firm goitre
-can cause dysphagia, hoarseness and stridor as the inflammation presses on the recurrent laryngeal nerver and trachea.
What is Hashimoto's disease?
Hashimoto's disease is a chronic lymphoctytic thyroiditis caused by an autoimmune disease.
Thyroid is attacked by immune system causing hypothyroidism.
There is lymphocytic infiltration of the thyroid parenchyma, often with germinal centreal formation.
-diffuse enlargement of thyroid caused by fibrosis.
-Serum Thyroid antibodies elevated
*many patients become hypothyroid
Give an autoimmune cause of Hypothyroidism?
What condition causes an 80 fold increased risk of thyroid lymphoma?
What is Grave's Disease?
Graves' Disease = Diffuse Hyperplasia of the thyroid
-IgG autoantibodies cause function and growth of thyroid follicular epithelium.
What is a Goitre?
Goitre is enlargement of the whole thyroid gland without hyperthyroidism.
what are the causes of thyroid nodules?
1) Iodine deficiency
2) Follicular adenoma (benign)
3) cysts caused by degenerating thyroid adenomas.
5) carcinoma / lymphoma (malignant)
What are some common benign and malignant thyroid tumours?
-Follicular adenoma (solid mass with fibroid capsule)
-Papillary adenocarcinoma (non-encapsulated inflitrative mass)
What is hyperparathyroidism?
There are 2 types.
1) PRIMARY hyperparathyroidism - excessive secretion from 1 or more glands.
2) SECONDARY hyperparathyroidism - hyperplasia in response of glands with elevated PTH in response to Hypocalcaemia.
3) TERTIARY Hyperparathyroidism - adenoma associated with longstanding 2nd HPT.
What are the clinical features of cushing's syndrome?
1) Excess glucocorticoid
2) obesity, hypertension, diabetes
4) Hirsutism (excess androgens in women)
What are the causes of cushing's syndrome?
- excess glucocorticoid administration
-excess ACTH secretion by adenohophysis
- adrenal cortex neoplasms
-ectopic ACTh secretion
What are the clinical features of Conn's Syndrome?
Conn's syndrome aka primary hyperaldosteronism causing raised aldosterone and low renin.
What is the cause Conn's Syndrome?
Conn's Syndrom is primary hyperaldosteronism.
It is caused by adenoma of te zona glomerulosa. Zona glomerulosa is the outermost layer of the adrenal cortex where aldosterone is secreted from.
What are the clinical features of Addison's Disease?
Addison's Disease is the chronic insuffiency of adrenal cortical hormones causing:
1) weight loss
5) Skin pigmentation
6) chronic dehydration
What are the causes of Addison's Disease?
Destruction of the Adrenal cortex causes chronic insufficiency of adrenal cortical hormones.
What is Phaeochromocytoma?
catecholamine secreting tumour arising from the adrenal medulla.