Blood cell histology and investigations

Question 1

What is haematopoiesis?

Answer 1

The process by which blood cells are made

Question 2

All blood cells arise from what?

Answer 2

Haematopoietic stem cells

Question 3

Describe the potency of haematopoietic stem cells.

Answer 3

Multipotent

Question 4

What is stem cell potency?

Answer 4

The potential of stem cells to differentiate and develop into many different types of specialized cells

Question 5

Name the 5 types of stem cell potency.

Answer 5

Totipotent
Pluripotent
Multipotent
Oligopotent
Unipotent

Question 6

What can totipotent cells differentiate into?

Answer 6

Any cell type, including embryonic and extraembryonic

Question 7

Give an example of a totipotent cell.

Answer 7

The zygote (fertilized egg)

Question 8

What can pluripotent cells differentiate into?

Answer 8

Nearly all cell types but not extraembryonic tissues like the placenta

Question 9

Describe the potency of lymphoid and myeloid stem cells.

Answer 9

Oligopotent

Question 10

Describe the site of haematopoiesis in 0-3 months gestation.

Answer 10

Yolk sac

Question 11

Describe the site of haematopoiesis in 3 months gestation.

Answer 11

Liver and, to a much lesser extent, the spleen

Question 12

Describe the site of haematopoiesis in 4 months gestation.

Answer 12

Bone marrow

Question 13

What are the 2 types of bone marrow?

Answer 13

Red marrow
Yellow marrow

Question 14

Yellow marrow is composed predominantly of what?

Answer 14

Fat cells

Question 15

What happens to red bone marrow as we age?

Answer 15

It’s converted to yellow marrow

Question 16

By the age of 30, red bone marrow is only found in which 5 places?

Answer 16

Cranial bones
Sternum
Ribs
Vertebrae
Pelvis

Question 17

What are the 2 benefits of the biconcave shape of RBCs?

Answer 17

Maximizes the surface-volume ratio and so facilitates the exchange of O2 and CO2

Increases cell flexibility, making it easier for cells to pass through the capillaries

Question 18

What colour do basophils stain? Which compound causes this?

Answer 18

Deep blue – haematoxylin

Question 19

What needs to be added to a blood sample and which colour test tube should be used if you need to look at the cellular components of blood?

Answer 19

An anticoagulant – EDTA, in a purple top tube

Question 20

If serum wants to be looked at, what colour tube should be used?

Answer 20

Gold top tube

Question 21

What is a reticulocyte?

Answer 21

An immature red blood cell

Question 22

How is MCH calculated?

Answer 22

Haemoglobin over RBC count

Question 23

How is MCV calculated?

Answer 23

Haematocrit over RBC count