Transport in Human ( 人類的運輸系統 )

Every cell requires food, oxygen & other useful materials for metabolism ( 代謝作用 ). Every cell requires food, oxygen & other useful materials for metabolism ( 代謝作用 ). Food Oxygen Usefulmaterials Metabolism

Metabolism produces toxic waste products which must be removed. Metabolism produces toxic waste products which must be removed. Metabolism Toxic waste products e.g. carbon dioxide

Many cells are far away from the small intestine and the lung. Many cells are far away from the small intestine and the lung. O 2 CO 2 Food A t tt transport system is developed to increase the efficiency of exchange and transport of materials.

Transport System Blood 血液 Blood vessels 血管 Heart 心臟

Blood Cells Blood Platelet White Blood Cell Red Blood Cell

Blood Blood cells ( 血細胞 )(45%) Blood cells ( 血細胞 )(45%) Red blood cells Red blood cells White blood cells White blood cells Blood platelets Blood platelets Plasma ( 血漿 ) (55%) Plasma ( 血漿 ) (55%) 90% water 90% water Dissolved substances: Dissolved substances: Dissolved food substances Dissolved food substances Plasma Proteins Plasma Proteins Wastes Wastes

Red Blood Cells carry oxygen from lungs to all parts of body carry oxygen from lungs to all parts of body

White Blood Cells kill germs ( 病菌 ) kill germs ( 病菌 ) help to defend ( 防衛 ) us against diseases help to defend ( 防衛 ) us against diseases

Blood Platelets are involved in blood clotting ( 凝血作用 ) are involved in blood clotting ( 凝血作用 )

Blood cells are produced by bone marrow ( 骨髓 ).

Blood Vessels Heart Capillaries ( 微血管 ) Vein ( 靜脈 ) Artery ( 動脈 )

carry blood from heartto other parts of the body thick wall with muscles branch into capillaries Arteries

Capillaries the smallest blood vessels reach every part of the body

Capillaries glucose O2O2 CO 2, wastes Tissue cell have very thin walls => substances can diffuse across their walls are the places for exchange of materials between the blood and the cells

Veins Capillaries join up to form veins. carry blood back to heart thinner walls with less muscles ( 瓣膜 ) have valves ( 瓣膜 ) to prevent backflow of blood ( 血液倒流 )

How do valves prevent backflow of blood? Muscle contracts Muscle relaxes Valves closed Valves open Blood is propelled forward Backflow of blood is prevented by valve.

Which one is artery? Which one is vein? Why? Because the wall of artery is thicker than that of vein.

Heart

Structure of a Heart Aorta ( 大動脈 ) Right auricle ( 右心耳 ) Right ventricle ( 右心室 ) Pulmonary artery ( 肺動脈 ) Left auricle ( 左心耳 ) Left ventricle ( 左心室 ) Coronary blood vessels ( 冠狀血管 ) - supply blood to the heart

Auricles Right Left From other parts of body From lungs Veins Pulmonary veins - receive blood from body Heart structure

Ventricles RightLeft To lungs To other parts of body Pulmonary Artery Aorta - pump blood out of the heart Heart structure

Structure of a human heart Pulmonary artery Vein Right auricle Vein Right ventricle Aorta Pulmonary veins Left auricle Valves Left ventricle

Blood Circulation ( 血液循環 ) Blood flow is maintained by pumping action of the Heart.

body Deoxygenated Blood ( 缺氧血 ) Deoxygenated blood ( 缺氧血 ) returns from body to the right auricle. Right auricle contracts and pump blood to the right ventricle. Pulmonary Circulation ( 肺循環 ) Gaseous exchange ( 氣體交換 ) in lungs; blood becomes oxygenated blood ( 含氧血 ) O2O2O2O2 CO 2 Oxygenated Blood ( 含氧血 ) Oxygenated blood flow back to left auricle and then to left ventricle through pulmonary vein. Right ventricle pumps blood to lungs through pulmonary artery.

Systemic Circulation ( 體循環 ) Left ventricle pumps oxygenated blood to all parts of body (except lungs) via aorta. body After flowing through body, the blood becomes deoxygenated. body Deoxygenated Blood ( 缺氧血 ) The blood flows back to the heart. Oxygenated Blood ( 含氧血 )

Double Circulation ( 雙循環 ) Blood flows through the heart twice in one complete circulation Blood flows through the heart twice in one complete circulation Consists of 2 circuits: Consists of 2 circuits: 1. Connection between heart with lungs. 2. Connection between heart with the rest of the body.

Is it possible that blood flows backwards in heart? Why?

Backflow of blood in heart is prevented by valves.

Valves ( 瓣膜 )

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Eating for healthy transport system Takes in too much fat in diet will make us put on weight easily Takes in too much fat in diet will make us put on weight easily Fatty foods also contain a lot of cholesterol Fatty foods also contain a lot of cholesterol Cholesterol is a fatty substance found in the blood. It is used to make cell membranes and some hormones. Cholesterol is a fatty substance found in the blood. It is used to make cell membranes and some hormones.

Eating for healthy transport system Do you remember the chart used in teaching Diet and Health? Do you remember the chart used in teaching Diet and Health? we can also obtain nutritive values of common food from the website of Centre for Food Safety ( 食物安全中心 ) ： arch3.html we can also obtain nutritive values of common food from the website of Centre for Food Safety ( 食物安全中心 ) ： arch3.html arch3.html arch3.html

Too much cholesterol can deposit on the inner walls of blood vessels and harden the walls. Too much cholesterol can deposit on the inner walls of blood vessels and harden the walls.

The vessels cannot expand easily when blood is forced into them. This will result in high blood pressure. The vessels cannot expand easily when blood is forced into them. This will result in high blood pressure.

Eating for healthy transport system Cholesterol deposits may block the coronary arteries that supply oxygen & nutrients to the heart muscle and coronary heart disease results. Cholesterol deposits may block the coronary arteries that supply oxygen & nutrients to the heart muscle and coronary heart disease results. The heart may stop beating due to the lack of oxygen and this may cause death. The heart may stop beating due to the lack of oxygen and this may cause death.

Eating for healthy transport system If there is a blockage or rupture in the brain arteries, stroke may result. This may result in paralysis. If there is a blockage or rupture in the brain arteries, stroke may result. This may result in paralysis. To avoid the trap of cholesterol in the body, it is recommended that we limit our average daily cholesterol intake to less than 300 mg. To avoid the trap of cholesterol in the body, it is recommended that we limit our average daily cholesterol intake to less than 300 mg.