Tiêu đề BODY FLUIDS & CIRCULATION.pdf ✅

 Digital www.allendigital.in [ 105 ] 1. Introduction : • You have learnt that all living cells have to be provided with nutrients, O2 and other essential substances. Also, the waste or harmful substances produced, have to be removed continuously for healthy functioning of tissues. • It is therefore, essential to have efficient mechanisms for the movement of these substances to the cells and from the cells. • Different groups of animals have evolved different methods for this transport. • Simple organisms like sponges and coelenterates circulate water from their surroundings through their body cavities to facilitate the cells to exchange these substances. • More complex organisms use special fluids within their bodies to transport such materials. • Blood is the most commonly used body fluid by most of the higher organisms including humans for this purpose. • Another body fluid, lymph, also helps in the transport of certain substances. • Lymph helps in the transport of certain substances like fat. • In this chapter, you will learn about the composition and properties of blood and lymph (tissue fluid) and the mechanism of circulation of blood. • The study of blood vascular system is called Angiology. • Father of Angiology is William Harvey. • The study of heart is called Cardiology 2. Blood : • Fluid connective tissue / special connective tissue • Mesodermal in origin • Blood is a false connective tissue because - (a) Cells of blood have no power of division. (b) Matrix is devoid of fibres. (c) Matrix of blood is not secreted by blood cells. • Study of Blood — Haematology • Process of blood formation Haemopoiesis (in bone marrow). Colour — Red pH — 7.4 (Slightly alkaline) Weight — 7 to 8% of body weight Volume — 5 - 6 litres in male and 4 - 5 litres in female. • Anticoagulant present in human blood – Heparin Body Fluids and Circulation 03

Body Fluids and Circulation  Digital www.allendigital.in [ 107 ] RBCs in Different Conditions of Solutions : • Change in the shape of RBC is called as Poikilocytosis. • If RBC is kept in hypertonic solution it will shrink (crenation). • In hypotonic solution it will burst. • 0.8 - 1% NaCl solution is isotonic for RBC. (0.9% of NaCl) • Glucose 5.0% (w/v) solution is isotonic for RBC. Structural Details of RBC : • Mature mammalian RBCs are devoid of nucleus (Enucleated). • Plasma membrane of RBC is called Donnan's membrane. • ER (Endoplasmic reticulum), GC (Golgi complex), Ribosomes & Mitochondria are absent in mature mammalian RBC. • Network of structural protein called stomatin is present which forms a spongy cytoskeleton. • Carbonic anhydrase (One of the fastest enzyme) - Zinc containing enzyme which helps in transportation of CO2. Haemoglobin (Hb) : • RBCs have a red coloured, iron containing complex protein called haemoglobin, hence the colour and name of these cells. • Red coloured respiratory pigment which helps in transportation of O2 & CO2. (function) • A healthy individual has 12-16 gms of haemoglobin in every 100 ml of blood. Formation of RBC (Erythropoiesis) : • Organs which produce RBCs are called Erythropoietic organs. • Hormone which stimulate Erythropoiesis is called Erythropoietin, synthesized by Kidney. • 1st RBC is produced by yolk sac. • During embryonic life RBC are produced by Liver, Spleen, Placenta, Thymus gland. • In adult stage RBCs are produced by RBM (Red Bone marrow). Life Span of RBC : • Human adult — 120 days • New Born Baby — 100 days • 1% RBC are destroy daily but in same number new RBC enter into the blood. • Destruction of RBC occurs in spleen. (Graveyard of RBC) • Spleen also stores extra blood corpuscles so it is also called Blood Bank of Body. 2 components Haem - 5% (Iron and Porphyrin) Globin- 95% (Protein part) Iron present in the form of Fe+2 (ferrous ions) Each molecule of globin protein is composed of 4 polypeptide chains :- • 2 polypeptide chain having 141 amino acids. (compulsory) • 2 2 or 2 polypeptide chains having 146 amino acids. HbA - Adult haemoglobin HbF - Foetal haemoglobin Haemoglobin(Hb) HbA → 2 + 2 HbF → 2 + 2
NEET : Biology [ 108 ] www.allendigital.in  Digital 1. Which of the following is most abundant in blood? (1) RBC (2) WBC (3) Platelets (4) All are equal 2. Mammalian mature RBC does not contain :- (1) Membrane bounded cell organelles (2) Carbonic anhydrase (3) Haemoglobin (4) Enzyme of glycolyte pathway 3. Organisms which circulate water from their surrounding through their body cavities to facilitate the cells to exchange the substances are (1) Porifera (2) Sponges (3) Both (1) and (2) (4) Insects 4. Father of Angiology is :- (1) Hippocrates (2) William Harvey (3) Aristotle (4) Linnaeus 5. Human blood consists of (1) Fluid matrix (2) Plasma (3) Formed elements (4) All the above 6. Match the following columns. Column-I Column-II A Fibrinogen 1 Clotting or coagulation of blood B Globulin 2 Defence mechanism of Body C Albumin 3 Osmotic balance (1) A—3, B—2, C—1 (2) A—3, B—1, C—2 (3) A—2, B—1, C—3 (4) A—1, B—2, C—3 7. Formed elements present in the human blood are :- I. Erythrocytes II. Leucocytes III. Platelets IV. Plasma V. Lymph Choose the correct option. (1) I, II and III (2) II, III and IV (3) III, IV and V (4) I, II, III, IV and V 8. Formed element constitutes what percentage of the blood? (1) 55% of blood (2) 45% of blood (3) 35% of blood (4) 25% of blood 9. In humans, RBCs are formed in :- (1) Red bone marrow (2) Heart (3) Lungs (4) Yellow bone marrow 10. Properties of human RBCs are :- I. Devoid of nucleus II. Formed in bone marrow III. Possess healing properties IV. Biconcave in shape V. Help in blood clotting. Choose the option with correct properties. (1) I, II and III (2) I, II and IV (3) III, IV and V (4) III, II and IV 11. Sponges and coelenterates circulate which fluid in their body cavities :- (1) Blood (2) Lymph (3) Tissue fluid (4) Water BEGINNER’S BOX-1 PLASMA AND RBC