Haemotology

Question 1

List the functions of blood.

Answer 1

Transports
Protects
Regulates (fluid, pH, temp etc)

Question 2

Describe the composition of blood.

Answer 2

Red Blood Cells (erythrocytes)
White Blood Cells (leukocytes) - neutrophils, eosinophils, basophils, lymphocytes and monocytes)
Plasma
Platelets

Question 3

Describe the structure and function of a red blood cell.

Answer 3

Disc shaped cell with a thick rim
Maximised surface area : Volume ratio
No nucleus or organelles
Transports oxygen and carbon dioxide via haemoglobin

Question 4

Describe the production and life cycle of red blood cells.

Answer 4

Tissues that produce blood cells - Yolk sac (in embryo), liver & spleen (until birth), red bone marrow (RBC’s, WBC’s and platelets), lymphoid tissues (WBC production and maturation)
Red blood cell production is stimulated by EPO
Development takes around 3-5 days. They live for around 120 days.
Reticulocyte = Young red blood cell

Question 5

Define anemia and discuss the associated signs and symptoms.

Answer 5

ANEMIA = a condition where there is a deficiency of red cells or haemoglobin in the blood resulting in pallor or weakness.
Effects include shortness of breath, lethargy, light headed, high heart rate, tissue hypoxia, tired and pale.

Question 6

Compare and contrast the causes and effects of: iron deficiency, hemorrhagic, megaloblastic, aplastic and haemolytic anaemia.

Answer 6

Iron deficiency - Diet induced, can’t produce haemoglobin
Hemorrhagic - Excessive blood loss
Megaloblastic - Large, immature red blood cells
Aplastic - Stem cell and bone marrow damage
Haemolytic - Abnormal breakdown of RBC’s bone marrow can’t keep up.

Question 7

MACROCYTIC

Answer 7

Large RBC’s

Question 8

MICROCYTIC

Answer 8

Small RBC’s

Question 9

NORMOCYTIC

Answer 9

Normal sized RBC’s

Question 10

HYPERCHROMIC

Answer 10

High levels of haemoglobin

Question 11

HYPOCHROMIC

Answer 11

Low levels of haemoglobin

Question 12

NORMOCHROMIC

Answer 12

Normal levels of haemoglobin

Question 13

Categories white blood cells based on appearance and function.

Answer 13

GRANULOCYTES

• Neutrophils. 60-70% Phagocytic, release cytokines. Fight against parasites
• Eosinophils. 2-4% Regulates inflammation and allergies
• Basophils.

Question 14

Describe the structure of platelets and their role in haemostasis.

Answer 14

Small fragments of megakaryocyte cytoplasm.
They secrete chemicals such as clotting factors, factors for endothelial repair and vasoconstrictors. Form temporary platelet plugs, dissolve old blood clots and attract leukocytes to sites of infection.

Question 15

Distinguish between and discuss the principles behind, the following tests: Hb conc, haematocrit (PCV), MCV, MCH, MCHC, differential white cell count.

Answer 15

Hb concentration -
Haematocrit (PCV - paced cell volume) - cells when centrefuged
MCV (Mean corpuscular volume) - Average RBC size, haematocrit/number of cells x10
MCH (Mean cell haemoglobin)
MCHC (Mean cell haemoglobin concentration) - MCH/haematocrit
Differential white cell count

Question 16

Distinguish between ABO and Rhesus blood groups.

Answer 16

Blood group A has A antigens and anti-B antibodies.
Blood group B has B antigens and anti-A antibodies
Blood group O has no antigens and anti-A and anti-b antibodies
Blood group AB has A and B antigens and no antibodies
O = universal donor
AB = universal acceptor

Question 17

Explain the importance if matching donor and recipient blood types before administering a blood transfusion.

Answer 17

If a mismatched blood transfusion is given then agglutination will happen blocking the vessel. Haemolysis will also occur, potentially causing the Hb to block the kidney tubules.

Question 18

Describe how the body balances Iron, input and output, time to deplete and replenish stores.

Answer 18

Iron balance is determined by losses and dietary intake. The body can lose iron via blood, urine, or sweat - although these last two don’t appear to be very important.

Question 19

THROMBOSIS

Answer 19

Local coagulation or clotting of the blood in a part of the circulatory system

Question 20

Describe the process of fibrinolysis

Answer 20

fibrinolysis is the maintenance of blood clots or the break down of them via enzymes.

Plasminogen is converted into active plasmin which can break down the fibrin clot to FDP.
Heparin also prevents the formation of thrombin