Whole Blood, Haematology (physiology)

Question 1

What are the functions of blood? (5)

Answer 1

-Reduce fluid loss at injury sites.
-Immunity
-Thermoregulation
-Regulation of pH and electrolytes.
-dissolved in hormones, gases, nutrients and metabolic wastes.

Question 2

Characteristics of blood (5)

Answer 2

Physicochemical characteristics
Colour variations
Blood pH
Blood temperature
Contribution to body weight.

Question 3

How do we determine haematocrit?

Answer 3

Haematocrit= Height of RBC’s/ Total height

Question 4

What do we call the blood cells that are not in plasma?

Answer 4

Formed elements

Question 5

What is haematocrit?

Answer 5

It is the PERCENTAGE of total blood volume that is occupied by packed RBC’s.

Question 6

What is packed cell volume?

Answer 6

It is the amount/VOLUME of the total blood volume that is occupied by packed RBC’s.

Question 7

What is the clinical significance of determining PCV/Hct? (3)

Answer 7

It helps with diagnosis and treatment of anaemia and polycythaemia.
-Determine the hydration status
-Decision of blood transfusion

Question 8

What does the value of haemoglobin reflect in the blood?

Answer 8

It reflect the oxygen carrying capacity of RBC’s.

Question 9

What are the causes of elevated haematocrit? (6)

Answer 9

-Polycythaemia vera
-Dehydration
-Heart disease
-Lung disease
-Kidney cancer
-Genetic disease

Question 10

What causes lowered haematocrit? (8)

Answer 10

-Sickle cell anaemia
-Thalassemia
-Cancer
-Kidney failure
-Autoimmune diseases
-Bone marrow disorders
-Nutrient deficiencies
-Chronic bleeding

Question 11

Given Hct and plasma volume, how can we calculate blood volume?

Answer 11

BV= PV/1-Hct

Question 12

What is erythrocyte sedimentation rate (ESR)?

Answer 12

It is the rate at which cells sediment (settle down).

Question 13

How do we determine the ESR? (4)

Answer 13

-Add an anticoagulant (e.g heparin) to the fresh blood sample.
-Sample must be in a narrow vertical tube (westergen tube)
-Read the rate of sedimentation after an hour.
-Height of the cell-free, clear column of plasma at the upper level of the tube=ESR.

Question 14

What is the value of the ESR that declares a pathology?

Answer 14

> 100mm/hr

Question 15

What are the factors that affect ESR? (6)

Answer 15

-Blood viscosity
-Specific gravity of RBC
-Increase in the size of RBC
-RBC count
-Increased fibrinogen
-Rouleaux formation

Question 16

What are the causes of elevated ESR? (8)

Answer 16

-Age & gender
-Anaemia
-Malignancy
-Pregnancy
-Connective tissue disorders
-Rheumatoid arthritis
-Infections
-Elevated fibrinogen and albumin

Question 17

What are the causes of lowered ESR? (4)

Answer 17

-Heart failure
-Polycythaemia
-Hypofibrinogenemia
-Cryoglobulinaemia/low plasma proteins

Question 18

Clinical significance of:
1.RBC count
2. Hemoglobin
3. RBC indices
4. Mean corpuscular hemoglobin
5. WBC count
6. Immature neutrophils
7. Monocytes
8. Basophils

Answer 18

1. Decreased in anaemia, increased in dehydration and polycythemia.
   2.Decreased anaemia, haemorrhage and haemolysis reactions. Increased in dehydration, heart and lung disease.
2. Help with diagnosis and classification of anaemia.
3. Helps with differentiation of types of anaemia in severly anaemic patients.
4. Increased in leukaemia.
5. Increased in bacterial infections.
6. Increased in viral infections.
   8.Increased in allergic disorders.