Endocrine Pathology Flashcards
Hypothalamus
Master gland which produces 9 hormones
Connection between posterior pituitary and hypothalamus
Direct neural connection.
Connection between hypothalamus and anterior pituitary
Portal blood system.
Posterior pituitary hormones
Are made by the hypothalmus and stored in the pituitary. Oxytocin and antidiuretic hormone.
Anterior pituitary hormones
Adrenocorticotropic, follicle stimulating, growth, luteinizing, prolactin, thyrodi stimulating.
Generally, what controls the endocrine system?
Negative and positive feedback loops.
Prolonged hyperstimulation by trophic hormones causes what?
Hyperfunction and physcial enlargement of the peripheral endocrine glands.
Hypofunction of endocrine glands is usually due to what?
Destruction of secretory cells.
Major dieseases of the endocrine system
Hyperfunction, hypofunction, neoplastic and benign tumours.
Ademona
Benign tumours.
Pituitary hyperfunction
Often due to adenomas. Presentation depends on which specific cells are affected.
Types of pituitary hyperfunction
Prolactinoma, somatotropic and corticotropic are relatively common, Gonadotropic and thyrotropic adenomas are relatively rare.
Prolactinoma
Causes cessation of menses, breast enlargement and milk flow and infertility.
Somatotropic adenoma
Causes gigantism, acromegaly, metabolic disturbances and headache.
Gigantism
Excessive growth of long bones before puberty.
Acromegaly
Increased thickness of bones after puberty.
Corticotropic adenoma
Adenoma of the cells which secrete ACTH. Causes Cushing’s disease.
Pituitary hypofunction
Quite rare, but presentation is dependent on cell type.
Diabetes Insipidus
Form of pituitary hypofunction in which antidiuretic hormone is not secreted in sufficient quantity by the posterior pituitary.
Symptoms of diabetes insipidus
Polyuria, polydipsia, and dehydration.
Empty Sella syndrome
The sella turcica is partially or completely filled with cerebrospinal fluid
Thyroid gland
Located in the anterior neck. Has 2 main cell types.
Thyroid follicular cells
Secrete T3 and T4, which regulate metabolism.
Thyroid C cells
Secrete calcitonin, which dow regulate blood calcium.
Hyperthyrodisim
Typically caused by excessive thyroid hormone. Typically autoimmune in nature, but can also be idiopathic nodular hyperplasia or adenomas.
Grave’s Disease
Autoimmune condition in which the body creates antibodies to the TSH receptor on the thyroid.
Symptoms of Grave’s disease
Heat intolerance, swollen neck, sweating, increased heart rate, bulging eyes, cardiac issues, muscle tremors, diarrhea, weight loss and increased appetite.
Nodular goiter
Enlargement of the thyroid caused either by an iodine deficiency or a neoplasm.
Symptoms of nodular goiter
Are related to the compression of adjacent structure. Includes coughing, hoarseness, difficulty breathing and swallowing.
Difference between thyroid adenomas and thyroid cancer
Adenomas are encapsulated by thyroid tissue, wheras cancer usually isn’t
Causes of hypothyroidism
Thyroiditis (Hashimoto’s), thyroidectomy or iodine deficiency.
Hashimoto’s disease
A slow developing autoimmune condition in which the thyroid gland is infiltrated and destroyed by lymphocytes.
Hypothyroidism symptoms in children
Stunted growth, intellectual disability, metabolic disturbances, dry skin and cold intolerance.
Hypothyroid symptoms in adults
Puffy skin, bradycardia, decreased energy, constipation and dry skin.
Thyroid neoplasms
Adenomas are common. Malignant tumours are rare, but can be of any cell type.
Hyperparathyroidism
Increased parathyroid hormone. Can be caused by adenoma, hyperplasia of the gland or carcinoma.
Hyperparathyroidism symptoms
Kidney stones, muscle weakness, heart conduction issues, ocular and skin calcifications.
Parathyroid adenomas
1 parathyroid gland is enlarged.
Parathyroid hyperplasia
All 4 glands are enlarged.
Parathyroid hypoplasia causes
Developmental, autoimmune or due to surgical removal.
Symptoms of parathyroid hypofunction
Hypercalcemia, tetany, irregular heartbeat, nerological symptoms and cardiac arrest.
Types of adrenal cortex disease
Hyperfunction, hypofunction or nonfunctional adrenal tumours.
Types of adrenal hyperfunction
Hyperaldosteronism, hypercortisolism, adrenogenital syndrome.
Hyperaldosteronism (Conn’s syndrome)
Rare condition which causes the hypersecretion of mineralocorticoids such as aldosterone. Causes hypertension due to the retention of sodium and water.
Hypercortisolism (Cushing’s syndrome)
Increased sucretion of glucocorticoids. Can be caused by adrenal hyperplasia or neoplasia, or exogenous steroid administration.
Cushing’s syndrome symptoms
Central trunk obesity, moon face, buffalo hump, stretch marks, red face, glucose intolerance, diabetes, fatigue and mental instability.
Adrenogenital syndrome
Hypersecretion of adrenal sex hormones. Can be congenital or develop in adulthood. Causes females to develop more male-like genitalia.
Addison’s disease
A type of adrenocortical hypofunction. Due to insufficient secretion of corticosteroids and mineralocorticoids from the adrenal gland.
Causes of Addison’s disease
Infection or autimmune dysfunction.
Addison’s disease symptomes
Fatigue, weight loss, nausea, hyperpigmentation, hypotension, syncope and susceptibility to infections.
Tumours of the adrenal medulla
Neuroblastoma or pheochromocytoma.
Neuroblastoma
Malignant tumour of the adrenal medulla found primarily in children. Composed of neuroblasts. Causes a suddenly palpable lump, but is usually curable.
Pheochromocytoma
Tumour of the adrenal medulla. Causes hypertension, light headedness, dizziness and heart lesions due to the overexposure to epinephrine.
Secretory poriton of the pancreas
Islets of Langerhans.
Types of cells in the islets of Langerhans
Alpha, beta and delta.
Alpha cells
Around 20% of the islets of Langerhans, secrete glucagon
Beta cells
Around 70% of the islets of Langerhans, secrete insulin.
Delta cells
Around 10% of the islets of Langerhans, secrete pancreatic polypeptide.
Diabetes mellitus
Insulin deficiency or abnormal response by target tissues to insulin. Can be a primary disease or secondary to some other disease.
Signs and symptoms of diabetes mellitus
Polyuria, polydipsia and poyphagia.
Complications of diabetes mellitus
Prone to bacterial infections, arthosclerosis, coronary heart disease, aortic aneurisms, kidney, eye and nervous system problems.
Insulinomas
Adenoma of the beta cells. Cause syncope, hypolglycemia and sweating.
Gastrinomas
Malignant tumour of the pancrease which cause ulcers.
