11 - blood

Question 1

What are the three components of blood that can be seen when you centrifuge a blood sample with anticoagulant?

Answer 1

Plasma (55%), red blood cells (45%) and the buffy coat which is composed of white blood cells and platelets

Question 2

What is contained in the blood plasma?

Answer 2

Water, electrolytes and plasma proteins

Question 3

What are the three formed elements of blood and what is there main role?

Answer 3

Red blood cells - transport of oxygen and carbon dioxide
White blood cells - immunity
Platelets - control of bleeding and blood clotting cascade

Question 4

What is the scientific name for the development of red blood cells?

Answer 4

Haemopoiesis

Question 5

What hormone stimulates haemopoiesis?

Answer 5

Erythropoietin

Question 6

Which type of stem cell develops into red blood cells, megakaryocytes, monocytes and granular leukocytes?

Answer 6

Myeloid stem cell

Question 7

Which type of stem cell develops into T and B lymphocytes?

Answer 7

Lymphoid stem cells

Question 8

From what cell are platelets formed from?

Answer 8

Megakaryocytes

Question 9

Where are blood cells produced?

Answer 9

red bone marrow in spongy bone

Question 10

Describe the structure of an erythrocyte

Answer 10

• biconcave disc
• 7.8um diameter
• no nucleus
• contains haemoglobin and enzymes

Question 11

What does a eosinophil look like when stained with Wright’s stain?

Answer 11

• purple double lobed nucleus

- a strongly stained pink cytoplasm

Question 12

What does a basophil look like when stained with wright’s stain?

Answer 12

• dark purple nucleus and cytoplasm

verty concentrated purple area that takes up most of cell

Question 13

What does a neutrophil look like when stained with wright’s stain?

Answer 13

• light purple/pink cytoplasm

- dark purple, multi-lobed nucleus

Question 14

What does a monocyte look like when stained with wright’s stain?

Answer 14

• light purple cytoplasm

- irregular purple nucleus

Question 15

What does a lymphocyte look like when stained with wright’s stain?

Answer 15

• large purple nucleus that covers the majority of the cell

- small area of light purple cytoplasm

Question 16

Describe the structure of haemoglobin

Answer 16

A globular protein made of two beta haemoglobin and two alpha haemoglobin chains, which each contain a haem residue

Question 17

How does sickle cell anemia occur?

Answer 17

• mutation causes a glutamic acid in the beta haemoglobin chain to become a valine.
• causes haemoglobin chains to stick together when deoxygenated which deforms the erythrocytes.
• causes the erythrocytes to get stuck in capillaries which starves tissues of oxygen.

Question 18

What causes thalassemia?

Answer 18

A reduced rate of synthesis of alpha and beta globin chains results in the formation of small and weakly staining erythrocytes. These erythrocytes are destroyed which leads to anaemia.

Question 19

What are the features of type A blood?

Answer 19

• A antigen presentation on red blood cells

- Anti-B antibody in the plasma

Question 20

What are the features of type B blood?

Answer 20

• B antigen presentation on red blood cells

- Anti-A antibody in the plasma

Question 21

What are the features of type AB blood?

Answer 21

• A and B antigen presentation on red blood cells

- Neither A or B antibodies are present in the plasma

Question 22

What are the features of type O blood?

Answer 22

• neither A or B antigens are present in the red blood cells

- plasma contains both anti-A and anti-B antibodies

Question 23

What are three possible complications of blood transfusions?

Answer 23

• wrong blood type given (ABO incompatibility)
• iron overload that causes iron deposits on organs (in repeated transfusions)
• infection