Blood Histology

Question 1

What are the components of blood?

Answer 1

1. ) Erythrocytes (or red blood cells)
   - typically make up about 44% of a blood sample
   - %RBC volume = hematocrit

2.) Buffy coat composed of leukocytes (or
white blood cells) and cell fragments called
platelets forms less than 1% of a blood sample

3.) Plasma Fluid component, minus the
formed elements generally makes up about
55% of blood

Question 2

What are the components of Plasma?

Answer 2

Complex mixture of water, proteins, and other solutes.

When the proteins are moved from
plasma, the remaining fluid is termed serum.

Water makes up about 92% of plasma’s total volume.

water facilitates the transport of materials in the plasm

Question 3

What are plasma proteins?

Answer 3

The next most abundant materials in plasma
are the
plasma proteins.

6 and 8 grams of protein in a volume of 100
milliliters of blood (referred to as g/dl)

The plasma proteins include:

Albumins

Globulins

Fibrinogen

Regulatory proteins–
primarily enzymes &
hormones

Question 4

What is Elliptocytosis?

Answer 4

Elliptocytosis
is an autosomal dominant disorder
characterized by the presence of oval
-
shaped RBCs. It is
caused by defective self
-
association of spectrin subunits,
defective binding of spectrin to ankyrin, protein 4.1
defects, and abnormal glycophorin

Question 5

What is Spherocytosis?

Answer 5

Spherocytosis
is also an autosomal dominant condition
involving a deficiency in spectrin. The common clinical
features of elliptocytosis and spherocytosis are anemia,
jaundice, and splenomegaly (enlargement of the spleen).
Splenectomy is usually curative, because the spleen is
the primary site responsible for the destruction of
elliptocytes and spherocytes.

Question 6

What is sickle cell anemia?

Answer 6

Sickle cell anemia
results from a point mutation in which
glutamic acid is replaced by valine at the sixth position in the β-globin chain.

Defective hemoglobin (Hb S) tetramers aggregate and
polymerize in deoxygenated RBCs, changing the biconcave
disk shape into a rigid and less deformable sickle-shaped cell.

Hb S leads to severe chronic hemolytic anemia and obstruction
of postcapillary venules

Question 7

What are Thalassemia syndromes?

Answer 7

Thalassemia syndromes are heritable
anemias characterized by defective
synthesis of either the α or β chains of
the normal hemoglobin tetramer (α2β2).

Question 8

Hydrops fetalis

Answer 8

• most severe α form
• Usually
  results in intrauterine fetal death

Question 9

ß-Thalassemia major

Answer 9

most severe ß form,
results in severe transplant dependent
anemia.

Question 10

Polycythemia

Answer 10

condition of having too many
erythrocytes in the blood

Question 11

What type of anemias are there?

Answer 11

Congenital hemolytic–
accelerated destruction. Abnormal
protein increases fragility of plasma membrane

Pernicious–
chronic illness caused by impaired absorption of
vitamin B
- 12 because of a lack of intrinsic factor (IF) in
gastric secretions.

Iron deficiency –
most common but rarely due to diet. Most
common causes: excessive menstrual bleeding, ulcers &
colon cancer

Aplastic-
Significantly decreased formation of RBCs & hemoglobin,
defective red bone marrow

Question 12

What type of Polycythemias are there?

Answer 12

Erythrocytosis – increase in erythrocytes due to increase in
erythropoietin (EPO)

Polycythemia vera – RBC growth in
the red marrow is not regulated. RBC
precursors continue to grow/mature
even in the absence of EPO

Question 13

Erythroblastosis fetalis

Answer 13

Antibody-induced
hemolytic disease in
the newborn (HDN)
that is caused by
blood group incompatibility between
mother (Rh-) and fetus (Rh+)

This incompatibility occurs when the
fetus inherits RBC antigenic
determinants that are foreign to the
mother.

ABO and Rh blood group antigens are
of particular interest.