Endocrine System Pathology Flashcards
______ is caused by deficient ADH production by the neurohypophysis
Diabetes Insidpidus
What is the consequence of decreased ADH?
- Excess water excretion
- Serum Na+ and osmolarity increase
What are some potential causes of diabetes insipidus? (3)
- Head trauma
- Tumors
- Inflammation of the hypothalamus/pituitary
What are the two types of diabetes insipidus?
- Insufficient ADH → Central DI (CDI)
- ADH insensitivity → Nephrogenic DI (NDI)
What are the symptoms of CDI? (3)
- Frequent urination
- Extreme thirst
- Life-threatening dehydration
What are the treatments for mild and severe CDI?
- Mild - drink more water
- Severe - vasopressin
What is SIADH?
Syndrome of Inappropriate ADH secretion
What is the most common cause of SIADH?
ADH-secreting tumors (ex: small-cell lung carcinoma)
What is the consequence of excess ADH secretion?
- Excessive water resorption
- Dilutes blood → hyponatremia
How does SIADH present clinically?
- Hyponatremia
- Cerebral edema
- Neurologic dysfunction (like water intoxication)
Urine excretion can be increased to ___ mL/min when large quantities of hypotonic fluids are ingested.
16 mL/min
What are the symptoms of water intoxication? (3)
- Swelling of CNS neurons
- Convulsions
- Coma (deadly)
What is Sheehan syndrome? Cause?
- Ischemic necrosis to the pituitary during/after pregnancy
- Anterior pituitary undergoes hypertrophy during pregnancy without new vasculature
What are the symptoms of Sheehan syndrome? (5)
- Amenorrhea
- Infertility
- Lactation failure
- Hypothyroidism
- Pallor due to loss of melanocyte stimulation
Where are steroid and peptide hormones produced?
- Steroid - adrenal cortex
- Peptide (catecholamines) - adrenal medulla
Release of catecholamines are induced by _____
nerve signals
What disease is known as the progressive destruction of the adrenal cortex?
Addison disease
What are the different causes of Addison disease and how do they affect the gross appearance of the adrenal glands? (4)
- Autoimmune - shrunken
- Infection - inflammatory
- AIDS - inflammatory
- Cancer - enlarged with tumor
What are the symptoms of Addison’s disease? (5)
- Progressive weakness and easy fatigue
- GI disturbances
- Skin hyperpigmentation due to increase in POMC
- Volume depletion/hypotension
- Hypoglycemia and lack of gluconeogenesis
Cushing syndrome results from _____
- chronic exposure to high blood glucocorticoid levels
- Most commonly due to excess ACTH secretion by the adenohypophysis
Iatrogenic Cushing syndrome results from ____
- Medical administration of glucocorticoids to treat non-endocrine disorders
- Immune suppression for autoimmune/transplant patients
Endogenous Cushings can be _____ or _____.
- ACTH dependent
- ACTH independent
Is an adrenocortical tumor ACTH dependent or independent?
- ACTH independent
- Produces ACTH or ACTH-like peptide
What is the cause of Cushing’s disease?
- ACTH-secreting pituitary adenoma
- Leads to high cortisol levels
How do high cortisol levels affect other hormones?
- Suppress CRH secretion (hypothalamus)
- Suppress ACTH secretion (pituitary)
- Inhibits GH, TSH, and gonadotropin
- Decreases insulin production and gluconeogenesis
What are the symptoms of Cushing’s?
- Hypertension
- Centralized weight gain
- Atrophy of fast-twitch muscle fibers → proximal limb weakness
Cushing’s promotes catabolism of collagen and bone production which leads to?
- Fragile skin with poor wound healing
- Striae on the skin
- Osteoporosis
What is a pheochromocytoma?
- Benign tumor of chromaffin cells in the adrenal medulla
- Results in norepinephrine secretion
What are the symptoms of a pheochromocytoma? (6)
- Tachycardia
- Cold hands/feet
- Feeling hot (cannot dissipate)
- Throbbing headache (secondary to severe HTN)
- Nausea and vomiting
- Visual disturbances
Goiters result from ____
- Impaired synthesis of thyroid hormones
- Usually due to iodine insufficiency
Size of a goiter is directly related to _____
amount of hormone deficiency
What foods can impair thyroid hormone synthesis and lead to development of a goiter?
- Cabbage
- Cauliflower
- Cassava root (tapioca)
- Thiocyanate inhibits iodine transport
Thyroiditis refers to any inflammation of the thyroid. What are the 3 most common types?
- Hashimoto
- Granulomatous
- Subacute lymphocytic
______ is an autoimmune disorder that results in autoantibodies against thyroglobulin and thyroid peroxidase.
Hashimoto thyroiditis
What are the general symptoms of hypothyroidism? (7)
- Depression-like symptoms (fatigue, apathy, mental sluggishness, etc.)
- Slower metabolism (weight gain)
- Cold intolerance
- Decreased sympathetic nerve activity → constipation, decreased sweating
- Decreased blood flow → skin becomes cool and pale
- Reduced cardiac output → SOB, decreased exercised capacity
- Accumulation of ECM substances into the skin → nonpitting edema, enlargement of the tongue, deepening of voice
_______ is an autoimmune disorder of the thyroid, where autoantibodies cause stimulation of the thyroid.
Graves disease
How does Graves disease present clinically? (5)
- Hyperthyroidism (diffuse hypertrophy); may result in goiter
- Heart hypertrophy/ischemia
- Exophthalmos
- Localized infiltrative dermopathy on the shins (less common)
- Generalized lymphoid hyperplasia
What is osteomalacia?
- Failure to mineralize calcium from bone
- Results from vitamin D deficiency
- Hypocalcemia
How does osteomalacia present clinically?
- Soft bones prone to breaks (similar to osteoporosis)
- In children, rickets
How is osteomalacia treated?
Vitamin D supplementation; mostly with milk
What is the difference between primary and secondary hyperparathyroidism? Which is most common (***)
- Primary - increased PTH production, typically by a solitary parathyroid adenoma
- ***Secondary - result of chronic renal failure
