Cards (65)

  • What does edema refer to?
    Excess fluid in the body tissues
  • In which fluid compartment does edema mainly occur?
    Extracellular fluid compartment
  • What are the three conditions that cause intracellular edema?
    Hyponatremia, metabolic depression, lack of nutrition
  • What happens when blood flow to a tissue decreases?
    Delivery of oxygen and nutrients is reduced
  • What occurs when blood flow becomes too low for normal metabolism?
    Cell membrane ionic pumps become depressed
  • What happens to sodium ions when ionic pumps are depressed?
    They cannot be pumped out of the cells
  • What is the result of excess intracellular sodium ions?
    Osmosis of water into the cells
  • How much can intracellular volume increase in ischemic tissue?
    Two to three times normal
  • What is a common consequence of increased intracellular volume?
    Preceding death of the tissue
  • In what condition can intracellular edema occur besides ischemia?
    Inflamed tissues
  • What effect does inflammation have on cell membrane permeability?
    Increases cell membrane permeability
  • What are the two general causes of extracellular edema?
    Abnormal fluid leakage and lymphatic failure
  • What is lymphedema?
    Failure of lymphatics to return fluid
  • What is the most common clinical cause of interstitial fluid accumulation?
    Excessive capillary fluid filtration
  • What factors can increase capillary filtration?
    • Increased capillary filtration coefficient
    • Increased capillary hydrostatic pressure
    • Decreased plasma colloid osmotic pressure
  • How is capillary filtration rate mathematically expressed?
    Filtration = K(PcPifπc+(P_c - P_{if} - \pi_c +πif) \pi_{if})
  • What does Kf represent in the capillary filtration equation?
    Capillary filtration coefficient
  • What does Pc represent in the capillary filtration equation?
    Capillary hydrostatic pressure
  • What does Pif represent in the capillary filtration equation?
    Interstitial fluid hydrostatic pressure
  • What does πc represent in the capillary filtration equation?
    Capillary plasma colloid osmotic pressure
  • What does πif represent in the capillary filtration equation?
    Interstitial fluid colloid osmotic pressure
  • What condition results from failure of lymph vessels to return fluid and protein to the blood?
    Lymphedema
  • What happens to plasma proteins that leak into the interstitium when lymphatic function is impaired?
    They cannot be removed effectively
  • How does increased protein concentration in interstitial fluid affect fluid movement?
    It raises colloid osmotic pressure, drawing more fluid out
  • What type of infections can cause severe blockage of lymph flow?
    Infections of the lymph nodes
  • What organism is responsible for lymphatic filariasis?
    Filaria nematodes (Wuchereria bancrofti)
  • How are filaria nematodes transmitted to humans?
    By mosquitoes
  • What severe conditions can result from filarial infections?
    Lymphedema and elephantiasis
  • How many people are affected by lymphatic filariasis worldwide?
    More than 120 million
  • What surgical procedure can lead to lymphedema due to lymph vessel removal?
    Radical mastectomy
  • What happens to lymph vessels after a radical mastectomy?
    A few lymph vessels may regrow
  • How does heart failure lead to generalized extracellular edema?
    It raises venous pressure and decreases kidney excretion
  • What are the main causes of extracellular edema?
    • Increased capillary pressure
    • Decreased plasma proteins
    • Increased capillary permeability
    • Blockage of lymph return
  • What can cause increased capillary pressure?
    Excessive kidney retention of salt and water
  • What is a consequence of heart failure related to edema?
    Increased venous and capillary pressure
  • What happens to pulmonary vascular pressures in left-sided heart failure?
    They rise above normal
  • What can untreated pulmonary edema lead to?
    Death within a few hours
  • What condition can cause edema due to decreased kidney excretion of salt and water?
    Acute glomerulonephritis
  • What is nephrotic syndrome?
    Loss of proteins in urine due to kidney disease
  • What plasma protein concentration indicates serious generalized edema?
    Below 2.5 g/100 ml