Common causes of Exam 1 Patho

Hypodipsia

• decrease thirst sensation

Polydispsia

• True thirst: because of water loss (vomiting, diarrhea)

• Excessive thirst: water levels are normal, person is just thirsty

  • CHF, Diabetes Melllitus

• Psychogenic: compulsive water drinking (people with psychiatric disorders)

Diabetes Insipidus

• Decreased ADH secretion: increased urine volume = increased fluid loss

  • Neurogenic (nerves): decreased ADH secretion due to trauma near hypothalamus = decreased ADH production

  • Nephrogenic (kidney): decreased response to ADH in kidneys due to pyelonephritis

• Hypernatremia: Decreased ADH secretion = water is lost in urine (secreted) = increase plasma concentration

SIADH

• Abnormally increased ADH

  • Acute: head trauma, prolonged pain, or fever

  • Chronic: CNS tumors, hydrocephalus, paraneoplastic syndrome (tumor cells secrete molecules similar to ADH), HIV infection

• Hyponatremia: increases in ADH = diluted plasma = less sodium

Congestive Heart Failure

• Increase hydrostatic pressure

Malnutrition

Liver disease

Vomiting & Diarrhea

• Hypovolemia: GI secretions aren’t absorbed

• hypokalemia: decreases BV/BP = activate RAAS = angiotensin II stimulates aldosterone = potassium is secreted

Diarrhea

• Metabolic Acidosis: intestinal & pancreatic juice is rich in bicarbonate and is lost in diarrhea

Vomiting & gastric secretion

• Metabolic Alkalosis: stomach acid is high in HCl and is lost in vomiting and gastric secretion

Insufficient Diet

• Hypocalcemia: inadequate sources of dairy products or leafy greens = dressed calcium. =softening of bones

• hypokalemia: reduced intake of potassium)

Diabetes Mellitus

• Hypovolemia: increased plasma glucose levels will draw water into urine

• hypokalemia:

Diabetic keto Acidosis

• hypokalemia: treatment involves injection of insulin = sodium potassium pumps are activated = more K+ entering the cells = decrease potassium

• Metabolic acidosis: glucose isn’t available in cells, so muscles start using fats and protein. asan energy source = ketone bodies = acidosis

Renal Failure

• hypervolemia: filtration decreases = retaining fluid

• hyperkalemia: decreased renal secretion = K+ accumulates in plasma = out is less

• Metabolic Acidosis: reduced secretion (retention) of H ions & decreased reabsorption of bicarbonate

  • THE cause from the kidney (BIG issue)

Iatrogenic: IV treatment

• hypernatremia: rapid sodium gain

• Hypervolemia: IV infusions administered

• Hypokalemia: a person in a diabetic ketoacidosis is given a large dose of insulin = increases K+ entry into cells

hyperaldosteronism

• Hypervolemia: increases sodium reabsorption and water follows sodium

• hypokalemia: more aldosterone = increase potassium secretion = decrease in plasma K+ levels (Cushing’s syndrome)

  • caused by an adrenal adenoma

hypoaldosteronism

• hyperkalemia: less aldosterone = K+ levels increase (Addison’s disease)

Metabolic acidosis

• hyperkalemia: a lot more H+ than normal in plasma = activation of transporters on membrane = brings H+ into cell and takes out K+ = increase potassium ion in the plasma

Metabolic alkalosis

• hypokalemia: less H+ than normal in plasma = transporters take H+ out of cell and bring K+ in = decrease levels of K+ in plasma

Hypoparathyroidism

• Hypocalcemia: low levels of PTH = cause calcium levels to decrease

  • occurs after surgical removal of thyroid

Hyperparathyroidism

• Hypercalcemia: increased PTH levels = increased calcium levels

Crohn’s Disease

• Hypocalcemia: damaged or distressed cells that absorb = inadequate intestinal absorption

Insulin

• increases Potassium entry into cells along with glucose

• Given to someone with hyperkalemia

Catecholamines (epinephrine & norepinephrine)

• increase potassium entry into cells