learningOBJECTIVES At the end of the lesson, you should be able to:- Explain why multi-cellular organisms such as human beings and plants need a transport system.- Describe the parts of the human transport system – heart, vessels, blood.- Describe the parts of the heart - atrium, ventricle. 4 main vessels from and to the heart.- Describe the different components of blood and their functions.- Explain how blood acts as a transport medium.- Explain how diffusion and osmosis are involved in the transport system.- Describe double circulation.
funFACTIt would take about1,200,000 mosquito bitesto completely drain theaverage human of blood.(Discover magazine,August 2007)
whyTRANSPORT?If you stay within 500 m – 1 km of the school,you probably would not mind walking to school…
whyTRANSPORT?Likewise, in unicellular organisms,The cell is in direct contact with the externalenvironment.Diffusion alone is enough to: - transport essential materials such as oxygen and nutrients to the cell - remove waste such as carbon dioxide rapidly
whyTRANSPORT?In multicellular (complex) organisms,Cells are far from the external environment.Diffusion alone is too slow to: - transport essential materials such as food to the various organs - remove waste products efficiently
whyTRANSPORT?Thus, a transport system is developed to move thesesubstances eg. Blood system in humansThis will ensure- a continual supply of nutrients, oxygen and otheruseful materials for metabolism- the removal of toxic waste products produced bymetabolism
circulatorySYSTEMThe human circulatorysystem consists of threeparts: heart• heart (pumps blood bloodaround the body) vessels• blood (liquid which bloodcarries materials)• blood vessels (tubeswhich carry blood aroundthe body)
theHEART left atriumright atrium left ventricle right ventricle
theHEART• pumps blood around the body• all mammals have hearts that aresimilar in structure• human heart is about the size of ourfists• made up of cardiac muscles• comprises 4 chambers 2 upper chambers called atria (left and right) 2 lower chambers called ventricles (left and right)
theHEART• right side of heart pumps blood tolungs only (which are a shortdistance from the heart)• left side of heart pumps bloodaround the body (which are furtheraway from the heart)• hence left ventricle has thickermuscular walls than the rightventricle
theHEART The blood is then De-oxygenated pumped from the This blood passesblood from the body ventricle out of left Oxygenated blood from the rightenters the right atrium heart to the restthe lungs enter from ventricle the out into then and then into the the left atrium and the lungsthe body of right ventricle flow into the left ventricle Right atrium Left atrium Left ventricleRight ventricle
theHEART This blood passes The blood is then from the right pumped from the ventricle then out into left ventricle out of the lungs the heart to the rest of the body De-oxygenated Oxygenated bloodblood from the body from the lungs enterenters the right atrium the left atrium and and then into the flow into the left right ventricle ventricle Right atrium Left atrium Left ventricle Right ventricle
bloodCIRCULATION• In mammals, blood flows through the hearttwice in one complete circuit. This is known asdouble circulation.
bloodCIRCULATION From the heart to the lungs and back to the heart, • In the lungs, the blood collects oxygen and releases carbon dioxide. • Blood that returns to the heart is now rich in oxygen, called oxygenated blood.
bloodCIRCULATION From the heart to the rest of the body and back to the heart, • As blood passes the small intestine, it collects digested food. • The blood supplies all the cells of the body with this digested food together with oxygen picked up in the lungs. • After oxygen is deposited in body tissues, the blood now has little oxygen, called deoxygenated blood.
BLOOD Has two main functions: To carry materials round the body. These materials include nutrients, oxygen, carbon dioxide and other waste substances. To protect us against diseases. BLOODplasma red blood cells white blood cells platelets
bloodCOMPONENTS BLOOD red blood cells white blood cells Plateletsplasma (erythrocytes) (leukocytes) (thrombocytes) PLASMA •Pale yellowish liquid •Contains mainly water (90%) •Contains mainly dissolved substances like nutrients (digested food), hormones, antibodies and waste products (carbon dioxide and urea).
bloodCOMPONENTS BLOOD red blood cells white blood cells Plateletsplasma (erythrocytes) (leukocytes) (thrombocytes) •Contains haemoglobin gives RBC red colour when combined with oxygen; or purplish colour when combined with carbon dioxide combines reversibly with oxygen so RBC can transport oxygen around the body
bloodCOMPONENTS BLOOD red blood cells white blood cells Plateletsplasma (erythrocytes) (leukocytes) (thrombocytes) •Does not contain nuclei More space to contain haemoglobin for oxygen transport
bloodCOMPONENTS BLOOD red blood cells white blood cells Plateletsplasma (erythrocytes) (leukocytes) (thrombocytes) WHITE BLOOD CELLS
bloodCOMPONENTS BLOOD red blood cells white blood cells Plateletsplasma (erythrocytes) (leukocytes) (thrombocytes) WHITE BLOOD CELLS •Much bigger in size than RBC •Fewer in number than RBC •Colourless (no haemoglobin) •Contains a nucleus
bloodCOMPONENTS BLOOD red blood cells white blood cells Plateletsplasma (erythrocytes) (leukocytes) (thrombocytes) WHITE BLOOD CELLS •Two types: Phagocytes Ingests foreign particles by phagocytosis Lymphocytes Produces antibodies that neutralise bacteria and viruses
bloodCOMPONENTS BLOOD red blood cells white blood cells Plateletsplasma (erythrocytes) (leukocytes) (thrombocytes) PLATELETS •Cell fragments (not complete cells) •No nucleus •Involved in the process of blood clotting
circulatorySYSTEMThe human circulatorysystem consists of three heartparts: blood• blood vessels• heart blood• blood vessels
bloodVESSELS• The blood vessels are a network of tubes to carryblood around the body.• Namely the artery, vein & capillary
bloodVESSELS - summary Artery Vein CapillaryStructure Thick, elastic, Thinner, less One-cell thick muscular walls elastic, less endothelium muscular wallsFunctions Transports Transports Transports blood away blood towards nutrients & from the heart the heart waste materials Blood High blood Lowest blood Low blood pressure from pressure pressurePressure heart
bloodDISORDERSCondition/ Description Possible causes TreatmentDiseaseHaemophilia Genetic illnesses that Lack of one of the No cure, controlled affect the ability of clotting factors by regular injection of blood to clot caused by a deficient the deficient clotting gene factorAnaemia Deficiency of red Excessive blood loss, Iron supplement, blood cells or deficient blood cell increased intake of haemoglobin production (such as food rich in iron, due to deficient iron blood transfusion intake)Leukaemia Cancer of the blood Exposure to Chemotherapy, bone or bone marrow radiation, certain marrow transplant characterised by chemicals or viruses, excessive production genetic of usually white blood predisposition cells
heartDISEASESDisease Description Possible causes TreatmentHeart attack Occurs when blood supply to a Blood clot in heart Ensure oxygen intake, part of the heart is interrupted arteries bypass surgery, leading to damage or death of Increased risk factor: medications heart tissue smoking, excessive alcohol consumption, abuse of drugs, high cholesterol, hypertension, diabetes, heart diseasesStroke Rapid loss of brain function due Blood clot, Medications, ensure to interruption of blood supply to haemorrhage (share oxygen intake, surgery all or part of the brain some of the risk factors as heart attack)
bloodTRANSFUSION• Process of transferring blood or blood-basedproducts from one person to the circulatory system ofanother• Life-saving especially to people who sufferexcessive blood loss due to trauma or surgery• Compatibility of blood types: Individual with blood type Can accept blood of type A A, O B B, O AB A, B, AB, O (Universal recipient) O O (Universal donor)