P9 - Erythrocytes Part 4

Question 1

pathogenesis of extravascular hemolytic anemias

Answer 1

• macrophages engulf and lyse RBC

- macrophages degrade Hgb to form bilirubin -> icterus and bilirubinuria

Question 2

pathogenesis of intravascular hemolytic anemias

Answer 2

• erythrocytes lyse within blood

- Hgb present in plasma -> hemoglobinuria

Question 3

pathogenesis of hemolytic icterus (extracellular hemolysis)

Answer 3

• macrophages engulf and lyse RBC
• macrophages degrade Hgb to form bilirubin -> binds to albumin -> transported to liver -> hyperbilirubinemia
• BU enters hepatocyte and conjugated -> excreted in bile or regurgitated to plasma -> hyperbilirubinemia
• conjugated BU passes through glomerulus and is excreted -> bilirubinuria

Question 4

pathogenesis of hemoglobinemia and hemoglobinuria due to intravascular hemolysis

Answer 4

• erythrocytes lyse within blood -> Hgb in plasma -> Hgb dimers bind to Hpt -> removed
• too much Hgb passes through glomeruli -> incomplete tubular resorption -> hemoglobinuria

Question 5

hemolytic disorders and conditions (4)

Answer 5

• immune hemolytic disorders
• hemolysis induced by bacterial or viral infections
• erythrocytic metabolic defects
• erythrocyte fragmentation in blood creating schizocytes, keratocytes, or acanthocytes

Question 6

Heinz body (intra and extravascular) HMP shunt pathogenesis to cause hemolytic disorders

Answer 6

• produce reducing compounds
• oxidant overwhelms pathway -> Hgb denatured -> Heinz bodies -> hemolysis
• methemoglobinemia

Question 7

eccentrocytic (intra and extravascular) HMP shunt pathogenesis to cause hemolytic disorders

Answer 7

• produce reducing compounds
• oxidant overwhelms pathway -> RBC membranes damaged -> eccentrocytes -> hemolysis
• methemoglobinemia

Question 8

hypophosphatemic (intra and extravascular) glycolysis pathogenesis to cause hemolytic disorders

Answer 8

marked hypophosphatemia -> decrease ATP -> hemolysis

Question 9

L-sorbose intoxication pathogenesis to cause hemolytic disorders

Answer 9

• glycolysis (produce ATP and ingest L-sorbose)

- L-sorbose-PO4 inhibits hexokinase -> decrease ATP production -> hemolysis

Question 10

spherocytes are seen in extravascular or intravascular hemolysis

Answer 10

• extravascular

Question 11

hemolysis induced by bacterial or viral infections (2)

Answer 11

• mycoplasma

- anaplasma

Question 12

major functions of RBC biochemical pathways (4)

Answer 12

• produce NADPH & GSH
• produce ATP
• produce NADH
• produce 2,3-DPG

Question 13

hypophosphatemic disorders in cattle due to

Answer 13

• postparturient hypophosphatemia -> postparturient hemoglobinemia

Question 14

hypophosphatemic disorders in dogs due to

Answer 14

• hyperinsulinemia -> PO4 enters cells -> hypophosphatemia -> intravascular hemolysis

Question 15

hypophosphatemic disorders in dogs and cats due to

Answer 15

• hyperalimentation (following anorexia) -> hypophosphatemia

Question 16

L-sorbose intoxication does not affects

Answer 16

• dogs with low K RBC

- high K RBC

Question 17

erythrocyte fragmentation in blood creating (3)

Answer 17

• schizocytes
• keratocytes
• acanthocytes

Question 18

heparin-induced hemolytic anemia in horses pathogenesis

Answer 18

• erythrocyte agglutination -> agglutinated RBCs trapped in spleen -> RBCs die -> develop mild hyperbilirubinemia