Erythrocytes• Small, biconcave disc• Have no nucleus• Great quantities of haemoglobin (which contains iron) (Cells become bright red)• Site of production: bone marrow• Life span: 120 days• Site of destruction: liver and spleen (by phagocytes)• Ratio of erythrocytes to leucocytes 1000 : 1 (in normal person)
Leucocytes (White blood cells)• Less numerous than eryhtrocytes.• Have nuclei• Do not have haemoglobin• Larger than erythrocytes and do not have fixed shapes.• Site of production : bone marrow• Site of growth and development: thymus gland or lymph nodes
Cont.Basic types of leucocytes: Granulocytes (have granular cytoplasm and lobed nuclei) • Neutrophils • Eusinophils • Basophils Agranulocytes (clear cytoplasm and no lobed) • Monocytes (largest) • Lymphocytes (smallest)
Quizzes1. The neutrophils are _______ A. Phagocytes B. Leucocytes C. Lymphocytes D. Phosphate2. Which leucocytes that help to control allergic reaction? A. Basophils B. Eosinophils C. Monocytes D. Neutrophils
3. Basophils secrete _________ to prevent blood clotting A. Warfarin B. Fibrinogen C. Heparin D. Walfarine4. Which leucocytes that can move to the body tissues to become phagocytic macrophage? A. Basophils B. Neutrophils C. Eosinophils D. Monocytes
5. Some lymphocytes produce _________ to aid in destruction of __________ A. Antibodies, homogens B. Antibodies, pathogens C. Hormones, pathogens D. Enzymes, pathogens
Platelets• Small, irregularly shaped• F(x) : blood clotting• Life span: 5 -9 days
Plasma• Pale, yellow liquid• Made up of 90% water & 10% dissolved solutes (gases, minerals, hormones, plasma proteins and excretory wastes)• BOOD SERUM : plasma without fibrinogen (clotting factors).
Function of blood in transport• Transport oxygen from the lungs to other parts of the body (form 4)• Transport absorbed food materials from the digestive tract to body tissues (form 4)• Transport waste products (form 4) – Eg: carbon dioxide from body tissues to the lungs – Urea to the kidneys• Transport heat, hormones and water
Transport of heat, hormones & water• Body T can be regulated by blood by distributing heat from heat-producing sites (eg:muscles) to the skin.• Hormones (eg:insulin & glucagon) produced by endocrine glands (pancreas) transported by blood to target organs (liver).• Water is important to provide medium for biochemical reaction.
Function of haemolymph• Circulating blood-like fluid found in invertebrates with open-circulatory systems• Tubular heart pumps the haemolymph into haemocoel.• Haemolymph – bathes the tissues and internal organ directly.• Nutrients and hormones diffuse from haemolypmh into the cells• Waste products diffuse out from the cells into haemolymph.
Structure of human blood vesselsBlood vessels : tubes that transport blood from one part to another. Arteries Capillaries VeinsTransport blood away from Connect arterioles to Transport blood to thethe heart venules heartTransport oxygenated Act as the sites for Transport deoxygenatedblood (except pulmonary exchange of substances blood (except pulmonaryartery) with the cells vein)Thick muscular wall Thinnest wall, one cell Thinner wall thicknessNo valves except semilunar No valves Valves present to preventvalves at the base of the back flow of bloodaorta and pulmonaryarteryBlood flows in pulses under No pulses. Pressure lower No pulses. Blood flowshigh pressure than arteries but higher under lower pressure than than veins arteries.
2. Valves ensure the haemolymph flow in one direction1. When the heart relax, haemolymph re-enters ostia Material exchange occurs here. Haemolymph in haemocoel carry nutrients and waste products
Circulatory system in fish • Single circulatory system. • Deoxygenated blood Sinuses leaves the heart at high pressure and passes through the gills where the gaseous exchange occurs. • Oxygenated blood flows through the organs and blood pressure drops.
Circulatory system in amphibians (eg:frogs)• Double circulatory system: – Pulmonary circulation – Systemic circulation• Have three-chambered heart (2 atria & 1 ventricle)• Mixing of oxygenated and deoxygenated blood in ventricle. The mixed blood enters the systemic circulation.
FAQ SPM1. The diagram below shows a longitudinal section of the human heart. Which of the labeled parts, A, B, C or D, receives blood from the lungs?
2. The diagram shows the circulatory system of a fish. What are the organs P, Q and R? P Q R A Gills Lungs Stomach B Stomach Lungs Gills C Gills Heart Stomach D Stomach Heart Gills
Circulatory system in humans• Double circulatory system (blood passes through the heart twice for each circuit) – Pulmonary circulation – Systemic circulation• Two divisions of heart: – Right side pump deoxygenated blood to the lungs – Left side pump oxygenated blood to the body (except lungs)• Advantage: blood returns to the heart to be pumped again will increase the blood pressure and flow rate, thereby speeding up delivery O2 to the tissues and organs.
Assignment 1.31. Draw and label a longitudinal section of human heart.2. List the functions of the different types of leucocytes.
The necessities of blood clotting• To prevent: – serious blood loss – the entry of microorganisms and foreign particles into the blood• To maintain: – normal blood pressure – circulation of blood in a a closed circulatory system
FAQ SPM1. The conversion of the soluble fibrinogen present in blood plasma into the insoluble fibrin is byA. calcium ionB. thrombinC. thromboplastinsD. vitamin K
FAQ SPM2. Fibrinogen, fibrin, thrombin and prothrombin are necessary for blood clotting. Which of the following is the correct sequence for the involvement of these four substances during blood clotting?A. Prothrombin, thrombin, fibrinogen, fibrinB. Thrombin, prothrombin, fibrin, fibrinogenC. Fibrinogen, fibrin, prothrombin, thrombinD. Fibrin, fibrinogen, thrombin, prothrombin
Impaired blood clotting mechanisms in human The consequences
Assignment 1.41. List the advantages of blood clotting at the site of damaged blood vessels.2. Draw a schematic diagram to illustrate the mechanism of blood clotting.3. What would happen if a blood clot forms a) In the brain b) In the coronary artery