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Published byEvan Gerard Evans Modified over 8 years ago
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THE MAMMALIAN CIRCULATORY SYSTEM SBI3C
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Main Parts of the System Heart (the pump) Vessels (tubes) Blood (transport fluid)
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An Efficient System Blood travels within vessels at all times Efficient transport of materials to and from cells of body 3 circulatory pathways - systemic pathway (to & from body’s organs) - pulmonary pathway (to & from lungs) - cardiac pathway (to & from heart muscle)
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General Functions Transport - oxygen to body cells - carbon dioxide to lungs - nutrients to body cells (sugars, amino acids, vitamins, etc) - hormones (e.g. insulin) - wastes to kidneys (urea) Defense against foreign invaders (e.g. bacteria, viruses) Repair to blood vessels (clotting) Body temperature regulation Maintenance of water levels in body
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The Blood The red, opaque whole blood of mammals consists of 4 components – Red blood cells White blood cells Platelets Plasma
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Blood Parts Whole blood can be separated into 3 layers by centrifugation (spinning it at high speeds)
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Red Blood Cells also called RBC’s or erythrocytes Biconcave shape Lack a nucleus Iron-containing, red protein, hemoglobin Carry the majority of oxygen as oxyhemoglobin to cells from lungs Carry the majority of carbon dioxide as bicarbonate ions (HCO 3 - ) from cells to lungs
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White Blood Cells Also called WBC’s or leucocytes WBC’s defend body against bacteria & viruses Macrophages, produced in bone marrow, destroy by phagocytosis Lymphocytes, produced in lymph tissue (glands, tonsils, adenoids), destroy by producing antibodies and toxic chemicals
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Platelets Also called thrombocytes Gather at site of damaged blood cells React with plasma factors to form a temporary clot (thrombus) to stop leakage of blood from vessel
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Plasma A clear, straw-coloured liquid 91% water 55% of blood Transports - some O 2 and CO 2 - nutrients and wastes - hormones - clotting factors - blood cells and platelets - water balance chemicals - heat to keep body warm & cool
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The Blood Vessels Blood vessels create a continuous pathway to and from heart 3 main types of blood vessels - arteries - veins - capillaries All arteries carry blood away from heart All veins carry blood towards the heart Capillaries connect arteries to veins
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Comparing Circulatory Pathways Mammalian system uses a double pump (heart) and keeps oxygenated blood separate from deoxygenated blood
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Arteries Large, muscular thick-walled vessels with a small inner diameter Carry mainly oxygenated blood under high pressure from heart to body* *Exception – pulmonary arteries deliver deO 2 blood from heart to lungs Disorder – aneurysm
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Veins Large, thin-walled vessels with a large inner diameter Contain one-way valves Carry mainly deoxygenated blood under low pressure from body to heart* Skeletal muscle contractions return blood to heart *Exception – pulmonary veins return O 2 blood from lungs to heart Disorder – varicose veins
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Major Arteries & Veins Associated with heart, lungs and abdominal cavity renal artery renal vein
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Capillaries Microscopic, one-cell thick vessels Inner diameter less than 7 m Carry blood cells under low pressure in single file for O 2 -CO 2 exchange and nutrient-waste exchange Plasma and WBC’s able to squeeze out of capillaries at organs
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The End
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