Chapter 4: Evaluation of Erythrocytes

Question 1

Which veterinary species’ erythrocytes have the most central pallor?

Answer 1

dogs

Question 2

Name two of the benefits of an erythrocyte being a biconcave disc.

Answer 2

1) high area:volume ratio

2) deformable

Question 3

What are the three main erythrocyte functions?

Answer 3

1) transport of oxygen to tissues
2) transport of carbon dioxide to lungs
3) buffering of H+

Question 4

Which three things does the transport of oxygen and oxygen carrying-capacity depend on?

Answer 4

1) blood hemoglobin content
2) partial pressure of dissolved oxygen (PO2) in blood
3) affinity of hemoglobin for oxygen

Question 5

Which typically has greater oxygen affinity, fetal or maternal hemoglobin? What species is the exception?

Answer 5

fetal > maternal

cat

Question 6

Describe on the molecular level how carbon dioxide is transported via erythrocytes. What is the name of this reaction?

Answer 6

• CO2 converted to carbonic acid (H2CO3) –> ionizes to H+ and bicarb –> bicarb diffuses down concentration gradient and Cl- moves in to maintain electrical neutrality
• carbonic anhydrase rxn

Question 7

Which of the following is most involved with carrying erythrocyte antigens and serving as a receptor or transport protein?

a) phospholipid bilayer
b) glycolipids
c) glycoproteins
d) membrane skeleton

Answer 7

c) glycoprotein

Question 8

Which of the following is the primary determining factor of membrane shape?

a) phospholipid bilayer
b) glycolipids
c) glycoproteins
d) membrane skeleton

Answer 8

d) membrane skeleton

Question 9

Name three inherited membrane defects that results in shorter erythrocyte half-life.

Answer 9

1) Band 3 deficiency in cattle. Causes marked spherocytosis with marked membrane instability and anemia.
2) Protein 4.1 deficiency or mutant B-spectrin in dogs. Causes hereditary elliptocytosis w/no anemia, but reticulocytosis.
3) Hereditary stomatocytosis.