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Questions and Answers
What percentage of the volume of whole blood does plasma constitute?
What percentage of the volume of whole blood does plasma constitute?
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Which of the following components is NOT part of whole blood?
Which of the following components is NOT part of whole blood?
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How much whole blood does the cardiovascular system of an adult female contain?
How much whole blood does the cardiovascular system of an adult female contain?
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What is the primary role of capillaries in the cardiovascular system?
What is the primary role of capillaries in the cardiovascular system?
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What does the term 'formed elements' in blood refer to?
What does the term 'formed elements' in blood refer to?
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What is the primary function of blood in regulating pH and electrolytes?
What is the primary function of blood in regulating pH and electrolytes?
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Which of the following is NOT a component of whole blood?
Which of the following is NOT a component of whole blood?
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Haematocrit is defined as what?
Haematocrit is defined as what?
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What is the role of platelets in blood?
What is the role of platelets in blood?
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What does an elevated erythrocyte sedimentation rate (ESR) typically indicate?
What does an elevated erythrocyte sedimentation rate (ESR) typically indicate?
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Which characteristic is NOT typically associated with blood?
Which characteristic is NOT typically associated with blood?
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What type of blood cell is primarily responsible for the immune response?
What type of blood cell is primarily responsible for the immune response?
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How does blood contribute to thermoregulation?
How does blood contribute to thermoregulation?
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What percentage of the volume of whole blood do formed elements account for?
What percentage of the volume of whole blood do formed elements account for?
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What is the normal hematocrit (packed cell volume) for adult females?
What is the normal hematocrit (packed cell volume) for adult females?
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Which of the following types of formed elements are produced through hemopoiesis?
Which of the following types of formed elements are produced through hemopoiesis?
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Which stem cells are primarily responsible for the production of formed elements?
Which stem cells are primarily responsible for the production of formed elements?
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What is the primary reason for the difference in hematocrit between males and females?
What is the primary reason for the difference in hematocrit between males and females?
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How many types of formed elements exist in whole blood?
How many types of formed elements exist in whole blood?
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Which hormone primarily stimulates red blood cell production?
Which hormone primarily stimulates red blood cell production?
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What is another term for hemopoiesis?
What is another term for hemopoiesis?
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What primarily reflects differences in blood volume?
What primarily reflects differences in blood volume?
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What percentage of blood plasma is composed of water?
What percentage of blood plasma is composed of water?
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Which of the following components cannot cross capillary walls?
Which of the following components cannot cross capillary walls?
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What is the primary composition of formed elements in blood?
What is the primary composition of formed elements in blood?
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What percentage range does the volume of formed elements in blood typically fall into?
What percentage range does the volume of formed elements in blood typically fall into?
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What do levels of respiratory gases primarily indicate?
What do levels of respiratory gases primarily indicate?
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Which of these is NOT a component of blood plasma?
Which of these is NOT a component of blood plasma?
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Which of the following correctly describes dissolved solutes in plasma?
Which of the following correctly describes dissolved solutes in plasma?
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What is the range of percentages for blood plasma composition?
What is the range of percentages for blood plasma composition?
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What role do formed elements play in the blood?
What role do formed elements play in the blood?
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What is the typical range of hematocrit values for adult males?
What is the typical range of hematocrit values for adult males?
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Which component makes up the majority of whole blood's volume?
Which component makes up the majority of whole blood's volume?
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Which type of white blood cell is involved in the body's immune defense against parasites?
Which type of white blood cell is involved in the body's immune defense against parasites?
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What is one of the main roles of albumins in blood plasma?
What is one of the main roles of albumins in blood plasma?
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What percentage of the whole blood volume do platelets typically occupy?
What percentage of the whole blood volume do platelets typically occupy?
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What is the primary function of fibrinogen?
What is the primary function of fibrinogen?
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Which of the following is NOT a type of cellular element in blood?
Which of the following is NOT a type of cellular element in blood?
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Which nutrient is primarily transported by blood plasma?
Which nutrient is primarily transported by blood plasma?
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Study Notes
Haematology I - Whole Blood
- Haematology I, Whole Blood, presented by Prof TT Nyakudya, Department of Physiology, 2023.
- Blood is the only specialized fluid connective tissue in the body.
- Blood is composed of formed elements suspended in a fluid matrix (plasma).
- Formed elements consist of red blood cells (RBCs), white blood cells (WBCs), and platelets.
- Plasma makes up 55% of whole blood.
- Red blood cells make up 45% of whole blood.
- Platelets and white blood cells combine to form less than 1% of whole blood.
- Hct (hematocrit) measures the percentage of formed elements in blood (RBCs).
- Normal Hct values are 42-52% in men and 36-48% in women.
- Blood volume in adult males is 5-6 Litres and in females 4-5 Litres.
Learning Outcomes & Assessment Criteria
- Understand the general characteristics and functions of blood.
- Describe the composition and volume of whole blood.
- Explain the general functions of blood.
- Define 'hematocrit' and 'erythrocyte sedimentation rate (ESR)'.
- Explain physiological and pathological causes for changes in hematocrit and ESR.
- Explain the inorganic and organic composition of plasma, as well as the functions of the components.
Components and Functions of Blood
- Blood is the only fluid connective tissue in the body.
- Contains formed elements (blood cells) suspended in a fluid matrix (plasma).
- Functions include:
- Transporting dissolved gases, nutrients, hormones, and metabolic wastes.
- Regulating pH and electrolytes
- Reducing fluid losses at injury sites.
- Providing immunity.
- Regulating temperature
Characteristics of Blood
- Physicochemical characteristics
- Color variations
- Blood pH
- Blood temperature
- Contribution to body weight
Components of Blood
- Whole blood
- Plasma
- Fluid portion
- Formed elements
- Erythrocytes (red blood cells)
- Leukocytes (white blood cells)
- Platelets
Fractionation
- Blood sample is centrifuged to separate components based on density
- Cell-free plasma is separated at the top.
- Westergen tube is used for Erythrocyte Sedimentation Rate (ESR) testing.
Blood Plasma: Composition
- Blood plasma is similar in appearance to whey and is transparent, with a faint straw colour.
- Contains over 100 solutes, including:
- Proteins (albumin, globulins, fibrinogen)
- Non-protein nitrogenous substances
- Organic nutrients
- Electrolytes
- Respiratory gases.
- Water accounts for 90% of blood plasma, 8% are proteins and 1-2% is other dissolved substances.
Inorganic Ions in Blood
- Concentration of inorganic ions is usually expressed in mmol/L.
- Key inorganic ions, including sodium (Na+), potassium (K+), calcium (Ca2+), chloride (Cl-), hydrogen carbonate (HCO3-), and phosphate (PO42–).
- Specific concentration ranges are given for each ion.
Other Substances in Plasma
- Oxygen (not very soluble in water)
- Nutrients
- Waste products
- Hormones
- Drugs and alcohol
Acute-Phase Protein (APP)
- Any protein in plasma that increases or decreases by 25% or more due to inflammatory disorders.
- Examples of acute-phase proteins include C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen, and alpha 1-acid glycoprotein.
Acute Phase Protein
- Release of CRP is triggered by infection, trauma, surgery.
- Moderate changes occur after strenuous exercise, heatstroke, and childbirth.
Haematopoiesis
- Monophyletic theory of hematopoiesis.
- Process of blood cell production.
- Organs involved in hematopoiesis (both fetal and postnatal) are specified in the provided reading.
- Key factors influencing blood cell production, along with the stages of erythropoiesis (RBC production), leukopoiesis (WBC production), and thrombopoiesis (platelet production).
Haematopoietic Cytokines
- Erythropoietin (EPO) primarily stimulates production of red blood cells.
- Thrombopoietin (TPO) primarily stimulates production of platelets.
- Colony-stimulating factors (CSFs) and interleukins also contribute to blood cell production.
Platelets
- Platelets (thrombocytes) are cell fragments involved in hemostasis.
- Responsible for clotting
- Recycled by phagocytes, mainly in the spleen.
- Key role in hemostasis, including plugging holes in blood vessels and promoting clot formation to prevent bleeding.
- Mobilized during circulatory crisis
- Help to repair damaged blood vessels.
Platelet Development
- Platelets are produced via thrombopoiesis in bone marrow by megakaryocytes.
- Two methods of release from megakaryocytes:
- Extension of pseudopodia.
- Passage of mature megakaryocytes into circulation and fragmentation in the pulmonary vascular bed.
Hormonal control of platelet production
- Thrombopoietin (TPO)
- Interleukin 6 (IL-6)
- Multi CSF
Erythropoiesis
- Development of red blood cells
- Sequential steps involved in producing red blood cells including
- Hemoglobin accumulation.
- Ejection of the nucleus
- Ribosome synthesis
Hormonal Control of Erythropoiesis
- Erythropoietin release triggered due to reduced oxygen carrying capacity.
Dietary Requirements of Erythropoiesis
- Erythropoiesis requires proteins, lipids, and carbohydrates
- Important minerals include iron, vitamin B12, and folic acid.
- Iron is stored in hemoglobin (Hb), liver, spleen, and bone marrow and stored in complexes like ferritin and hemosiderin.
- Circulating iron is bound to the transport protein, transferrin.
Bone Marrow
- Structure and function of bone marrow
- Marrow is a spongy, vascular tissue.
- Location within bones
- Consisting of blood sinuses (widened vessels) lined with epithelium
- Importance in hematopoiesis (blood production)
Variations in ESR
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Age and gender
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Anemia
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Malignancy
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Pregnancy
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Elevated fibrinogen and albumin
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Connective tissue disorders (SLE)
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Rheumatoid arthritis
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Infections (TB)
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Reduced value of ESR in heart failure, polycythemia, hypofibrinogenemia and cryoglobulinaemia/low plasma protein.
Note: Information provided is based on the available text. Please ensure accuracy with a professional reference if needed.
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Description
Test your knowledge on Haematology I with a focus on whole blood. This quiz covers the composition, characteristics, and functions of blood, including the components like RBCs, WBCs, and plasma. Dive into understanding hematocrit and the assessment of blood volume in adults.
