Lecture 1 8/22/24

Question 1

What changes do erythrocytes undergo during maturation?

Answer 1

-become progressively smaller
-nucleus becomes progressively condensed

Question 2

What stage of the RBC is released from the bone marrow in the majority of species when in health?

Answer 2

reticulocytes

Question 3

How do mature erythrocytes appear on blood smear?

Answer 3

-red-orange stain
-round and biconcave
-central pallor

Question 4

How do reticulocytes appear on blood smear?

Answer 4

-blue-purple stain
-slightly larger than mature erythrocytes
-more visible central pallor

Question 5

Which state of iron is required for hemoglobin production?

Answer 5

ferrous state (Fe2+)

Question 6

How is bilirubin produced?

Answer 6

breakdown of the porphyrin ring in heme

Question 7

How do enterocytes function in iron metabolism?

Answer 7

absorption and storage of dietary iron

Question 8

How do macrophages function in iron metabolism?

Answer 8

degradation of aged RBCs and recycling and storage of iron

Question 9

How do hepatocytes function in iron metabolism?

Answer 9

storage of iron

Question 10

What is ferritin?

Answer 10

a storage protein for iron that can enter circulation in small amounts

Question 11

Why is measuring ferritin useful?

Answer 11

provides an estimate of the storage iron in an animal’s body

Question 12

What is transferrin?

Answer 12

protein that transports iron in the blood

Question 13

How does inflammation impact iron storage and export?

Answer 13

inflammatory mediator hepcidin degrades the channel that releases iron from the cell into the bloodstream, trapping iron in its storage sites

Question 14

What are the characteristics of iron-restricted erythropoiesis?

Answer 14

-occurs when there are inadequate amounts of iron for normal hemoglobin production
-can lead to anemia

Question 15

What are the two most common causes of iron-restricted erythropoiesis?

Answer 15

-depleted iron stores/absolute iron deficiency
-iron sequestration due to inflammation

Question 16

What is extravascular hemolysis?

Answer 16

removal of RBCs from the blood and degradation of RBCs within macrophages adjacent to the blood vessels

Question 17

What is intravascular hemolysis?

Answer 17

RBCs rupture within the blood vessel, releasing free hemoglobin into the plasma

Question 18

Which form of hemolysis clears the majority of aged RBCs?

Answer 18

extravascular hemolysis

Question 19

What are the two potential causes of increased bilirubin?

Answer 19

-hemolysis
-liver dysfunction

Question 20

What are the two hallmark features of intravascular hemolysis?

Answer 20

-hemoglobinemia
-hemoglobinuria

Question 21

What leads to the red discoloration of urine and plasma in hemoglobinemia and hemoglobinuria?

Answer 21

large amounts of free hemoglobin entering the plasma and urine

Question 22

Which components of the erythrogram are indicators of RBC mass?

Answer 22

-hematocrit/packed cell volume
-RBC count
-hemoglobin concentration

Question 23

What are the characteristics of the indicators of RBC mass as a group?

Answer 23

-typically increase/decrease together
-decrease indicates anemia
-increase indicates erythrocytosis

Question 24

What is indicated by HCT and PCV?

Answer 24

percentage of total blood volume occupied by RBCs

Question 25

What is indicated by RBC count?

Answer 25

number of RBCs in a microliter of whole blood

Question 26

What is indicated by HGB concentration?

Answer 26

grams of hemoglobin in each deciliter of whole blood

Question 27

What is HGB concentration proportional to?

Answer 27

total mass of RBCs in the blood

Question 28

Which components of the erythrogram are considered RBC indices?

Answer 28

-mean cell volume -mean cell hemoglobin concentration -red cell distribution width

Question 29

What information does MCV provide?

Answer 29

average size of the RBCs

Question 30

What information does MCHC provide?

Answer 30

average concentration of hemoglobin in each RBC

Question 31

What information does RDW provide?

Answer 31

variation in RBC size

Question 32

What are the descriptors for MCV?

Answer 32

-normocytic/within ref. interval -microcytic/below ref. -macrocytic/above ref.

Question 33

What are the descriptors for MCHC?

Answer 33

-normochromic/within ref. interval -hypochromic/below ref. -hyperchromic/above ref.

Question 34

What causes increased MCHC to appear on a CBC?

Answer 34

-falsely increased HGB -falsely decreased HCT -MCHC is always artifact and falsely high

Question 35

What is anisocytosis?

Answer 35

variability in cell size

Question 36

What does an increased RDW indicate?

Answer 36

an increased number of smaller and/or larger RBCs

Question 37

What is the importance of the absolute reticulocyte count?

Answer 37

allows for the determination between regenerative and non-regenerative anemia

Question 38

What are the characteristics of the CHr measurement?

Answer 38

-measures amount of hemoglobin present in reticulocytes -used when evaluating for iron deficiency