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1 Chapter 13 Transport in Humans Summary Bk2 Ch13 Transport in Humans/1 Table 1: The human circulatory system (Section 13.1) Importance Components of circulatory system Transport of oxygen, carbon dioxide, nutrients and waste products from one part of the body to another Blood - a transport medium Heart - a pump for pumping blood from one place to another Blood vessels - a system of tubes for transporting blood to different parts of the body Table 2: The composition of blood (Section 13.2; Figs and 13.3) Composition Plasma proteins (e.g. antibodies) Food substances (e.g. glucose, amino acids, fats and minerals) Plasma Hormones Dissolved gases (e.g. carbon dioxide) Excretory products (e.g. urea) Red blood cells Blood cells White blood cells Blood platelets 1

2 Bk2 Ch13 Transport in Humans/2 Table 3: The comparison of blood cells (Section 13.2) Shape Nucleus Red blood cells (Fig. 13.6) Biconcave discs Provide a large surface area for oxygen diffuse in and out of the cells rapidly Absent White blood cells Irregular shape (Fig. 13.7) Phagocyte: lobed nucleus Lymphocyts: oval nucleus Blood platelets (Fig. 13.9) Tiny fragments of specialized cells in the bone marrow Absent Size Small Large Very small Number /mm /mm /mm 3 Colour Red No colour No colour Site of production Function Bone marrow Cytoplasm contains haemoglobin which is responsible to carry oxygen between the lungs and body cells Bone marrow, lymph nodes and spleen Phagocytes: engulf and digest bacteria Lymphocytes: produce antibodies that can attack particular types of pathogen Bone marrow Blood clotting Table 4: The importance of blood (Section 13.3) Transport Body defence Respiratory gases Oxygen is carried from the lungs to body tissue by red blood cells Carbon dioxide is carried from body tissues to the lungs mainly by plasma Food substances Glucose, amino acids, vitamins and minerals are transported from the small intestine to various parts of the body Hormones Excretory wastes Heat White blood cells Blood platelets Secreted by hormonal glands and carried to the target organs Urea is carried to kidneys for excretion Produced in tissue and distributed all around the body Protect human against various diseases Initiate the formation of blood clot over wound and stop bleeding 2

3 Bk2 Ch13 Transport in Humans/3 Table 5: Transport of oxygen in the blood (Section 13.3; Fig ) Transport of oxygen Reaction In the lungs Oxygen concentration is high Oxygen diffuses into red blood cells and combines with haemoglobin to form oxyhaemoglobin Oxygen is transported to other parts of the body In the tissues Oxygen concentration is low Oxyhaemoglobin breaks down into haemoglobin and oxygen Oxygen is used by body cells The uptake and release of oxygen by haemoglobin is a reversible reaction Table 6: Transport of carbon dioxide in the blood (Section 13.3; Fig ) Transport of carbon dioxide Reaction In the tissues Carbon dioxide concentration is high Carbon dioxide diffuses into the blood and enters red blood cells and reacts with water to form hydrogencarbonate ions Hydrogencarbonate ions then diffuse out of the red blood cells into the plasma for transport In the lungs Carbon dioxide concentration is low Hydrogencarbonate ions from plasma enter the red blood cells and split into carbon dioxide and water Carbon dioxide diffuses from the blood plasma to the lungs for removal The formation of hydrogencarbonate ions in the blood is a reversible reaction Table 7: The relationship between blood vessels (Section 13.4; Fig ) Arteries carry blood from the heart and branch into smaller arterioles Relationship Arterioles branch into a network of fine capillaries Capillaries join together eventually into venules Venules then join into veins which direct blood to the heart 3

4 Table 8: The characteristic features of arteries and veins (Section 13.4; Fig ) Blood content Blood pressure Artery High level of oxygen and low level of carbon dioxide (except pulmonary artery) High blood pressure due to the pumping action of the heart Vein High level of carbon dioxide and low level of oxygen (except pulmonary vein) Low blood pressure due to the blood has flowed through the capillaries before reaching the vein Wall Thick and elastic Thin and less elastic Lumen Small Large Valve Force of movement Function Absent The contraction and relaxation of muscle layer together with the pumping action of the heart force the blood forward Carries oxygenated blood from the heart to various organs Present (Prevent the blood from flowing backward) In the presence of valves, the skeletal muscles contract to squeeze the vein and force the blood forward Carries deoxygenated blood from various organs back to the heart Bk2 Ch13 Transport in Humans/4 Table 9: The general internal features of heart (Section 13.5; Fig ) General structure Atria Ventricles Valves Four chambers The upper two chambers are atria The lower two chambers are ventricles Septum separates the left and right sides of the heart Receive blood from the lungs and different parts of the body Pump blood to the lungs and other parts of the body Present in some blood vessels to ensure the blood flow through the heart in only one direction 4

5 Bk2 Ch13 Transport in Humans/5 Table 10: The characteristic features of atria and ventricles (Section 13.5; Fig ) Blood received Blood vessels involved Atria Ventricles Left Right Left Right Oxygenated blood from the lungs Pulmonary veins Deoxygenated blood from the body tissues Superior vena cava carries blood from the upper parts of the body (the head and the arms) Inferior vena cava carries blood from the lower parts of the body (e.g. the legs) Oxygenated blood from left atrium Left ventricle pumps oxygenated blood to all arteries of the body via the aorta Deoxygenated blood from right atrium Right ventricle pumps deoxygenated blood to the lungs via the pulmonary arteries Table 11: The characteristic features of valves (Section 13.5) Location Characteristic feature Function Tricuspid valve Present between the right atrium and the right ventricle Made up of three flaps 1. Prevents the backflow of blood into the atria when the ventricles contract Bicuspid valve Present between the left atrium and the left ventricle Made up of two flaps 2. The valves are attached by heart strings to the muscular wall of the ventricles to prevent the valves from being turned into the atria when the contraction of ventricles Semilunar valves Located at the aorta and the pulmonary arteries Pocket shaped-valves Prevent the blood in the arteries from flowing back into the ventricles when the ventricles relax 5

6 Bk2 Ch13 Transport in Humans/6 Table 12: The stages of pumping action of the heart (Section 13.5; Figs and 13.29) Action Function Time used Contraction of atria Atria contract, blood flows from the atria into the ventricles The valves in the venae cavae and pulmonary veins are forced shut by the high blood pressure of the atria Prevents the flow of blood into the venae cavae and pulmonary veins About 0.1 second Contraction of ventricles Ventricles contract, blood flows into the pulmonary arteries and aorta The tricuspid and bicuspid valves are forced shut by the high blood pressure developed in the ventricles Prevents the backflow of blood into the atria About 0.3 second The atria and ventricles relax, there is a drop in blood pressure in the atria and ventricles About 0.4 second Relaxation of atria and ventricles The right and left atria are filled with blood from the venae cavae and pulmonary veins, respectively The drop in blood pressure in the ventricles causes the semilunar valves to close Prevents the backflow of blood into the ventricles from the pulmonary arteries and aorta 6

7 Bk2 Ch13 Transport in Humans/7 Table 13: Human blood circulatory system (double circulation) (Section 13.6; Fig ) Process Pulmonary arteries are the only type of artery that contains deoxygenated blood Pulmonary veins are the only type of vein that contains oxygenated blood Pulmonary circulation Systemic circulation (Fig ) Deoxygenated blood passed from venae cavae to the right atrium and then right ventricle the blood pumps through the pulmonary arteries to the lungs the blood runs through the capillaries over the surface of the air sacs and gives up carbon dioxide and takes up oxygen the oxygenated blood is then collected by the pulmonary veins and returned to the left atrium and then to the left ventricle Contraction of the left ventricle pumps oxygenated blood out of the heart through the aorta and arteries to all parts of the body Exchange of materials takes place in the capillaries of tissues or organs Oxygen and nutrients diffuse from blood to tissue cells and carbon dioxide and other wastes diffuse in the opposite direction The blood becomes deoxygenated and is carried by veins and drained into the right atrium through the venae cavae Table 14: The advantages of having a double circulation (Section 13.6) Advantage Oxygenated blood from the lungs is returned to the heart before pumping around the body, which can ensure a constantly high blood pressure for rapid transport of oxygen and nutrients to and removal of wastes from body cells Oxygenated blood and deoxygenated blood are separated by the septum in the heart, which can prevent mixing of the two types of blood and the blood supply to the body cells has a high oxygen content 7

8 Bk2 Ch13 Transport in Humans/8 Table 15: The exchange of materials between blood and body cells (Section 13.6; Fig )) Process Capillaries are the main sites for exchange of materials Body cells take up oxygen and nutrient from the surrounding tissue fluid for respiration and other activities Exchange of material Waste products diffuse out of the cells into tissue fluid and then diffuse into the capillaries White blood cells can move out from the blood through the capillary wall to the tissue fluid for patrolling and killing bacteria in the body cells or tissue fluid Table 16: The adaptive features of capillaries for exchange of materials (Sections 13.4 and 13.6) Structure Adaptation One layer of cell (one-cell thick) Allows substances to diffuse rapidly Small diameter or lumen of the capillary network Numerous branches of capillaries Allows blood flow very slowly and have sufficient time for exchange of substances between the blood and tissue fluid Provide a large surface area for diffusion of substances Table 17: Formation, movement, compositions and functions of tissue fluid (Extension Study) (Section 13.7; Fig ) The capillary wall is very thin, usually one-cell thick The pressure of blood in capillaries is higher than that of tissue fluid Formation and movement of tissue fluid Composition Function Some plasma in the blood is forced out at the arterial end of a capillary network into the spaces among tissue cells and this tissue fluid is constantly formed When the blood reaches the venous end of the capillary network, its pressure may have dropped below the pressure of the tissue fluid The water potential of the tissue fluid is higher than that of the blood because it does not contain plasma proteins Tissue fluid will eventually moves back into the capillaries at the venous end Contains glucose, amino acids and minerals (like plasma) No plasma proteins and red blood cells present as they are too large to pass through the capillary walls Acts as an essential bridge for exchange of materials between the blood and tissue cells Provides a stable environment for normal functioning of tissue cells 8

9 Table 18: The composition and characteristic features of lymphatic system (Extension Study) (Section 13.7; Fig ) Bk2 Ch13 Transport in Humans/9 Lymph vessels Lymph Lymph node Characteristic feature Thin-walled, blind-ended tubes of lymph capillaries joined to form larger vessels and eventually joined into a large vein near the neck region Present of valves Tissue fluid drained into the lymph vessels is called lymph The composition is similar to plasma except no plasma protein and red blood cells At certain points along the lymph vessels are swellings of lymph nodes Transport of lymph Action/ Movement All tissue fluid collected by the lymphatic system is finally returned to the circulatory system Prevent the back flow of lymph 1.There is no pumping mechanism in the lymphatic system 2.Skeletal muscles surrounding the lymph vessels force the lymph along when they contract 3.The valves in the vessels can present the backflow of the lymph Important sites for body defence by producing and storing white blood cells to kill invading germs Table 19: The functions of lymphatic system (Extension Study) (Section 13.7) Collects and carries excess tissue fluids from the space of body tissues back to the blood stream Function Transports the absorbed fat from lacteals of the small intestine through the lymphatic system and eventually to the blood stream Consists of lymph nodes which filter out germs from the lymph before it returns to blood stream 9

10 Bk2 Ch13 Transport in Humans/10 Glossary Vocabulary 詞彙 Page Description 解釋 blood 血液 186 the circulating body fluid which delivers food and oxygen to all parts of the body and carries away wastes from body parts blood cell 血細胞 186 a collective term for the cells contained in blood, such as red blood cell or white blood cell circulatory system 循環系統 186 the body system consisting of the heart, blood vessels and blood that circulates blood throughout the body; delivers nutrients and other essential materials to cells, and removes waste products plasma 血漿 186 the liquid portion of blood, without blood cells, used in the transport of nutrients blood platelet 血小板 187, 191 a small, non-nucleated cell fragment, responsible for the clotting of blood at wounds red blood cell 紅血球 187 also called erythrocyte, a disc-like cell in blood, biconcave in shape, with no nucleus when mature, containing haemoglobin for carrying oxygen white blood cell 白血球 187 also called leukocyte, blood cell with nuclei but not haemoglobin, responsible for body defense mechanism antibody 抗體 70, 188 hormone 激素 188, 258, 277 a protein produced by lymphocyte (a kind of white blood cell) when foreign substance (an antigen) gets into the body. It reacts specifically to the antigen a chemical produced in small amount by an endocrine gland, carried by the blood and exert its function in target organ; helps to regulate the proper functioning of the body 循環全身的體液, 把食物和氧帶到身體的所有部位, 並把廢物從身體部分帶走 一個集合用詞, 指任何血液所含的細胞, 如紅血球或白血球 由心臟 血管和血液組成的身體系統, 負責把血液循環輸送至全身, 把營養素和其他有用物質帶到細胞, 以及運走廢物 血液的液體部分, 用以運送養分 細小且無細胞核的細胞碎塊, 與傷口的凝血作用有關 血液內圓盤形的細胞, 兩邊凹陷, 細胞成熟時沒有細胞核 ; 含有血紅蛋白, 以運送氧 血細胞的一種, 有細胞核, 不含血紅蛋白, 負責參與身體防禦的機制 外來物質 ( 抗原 ) 進入身體時, 淋巴細胞 ( 一種白血球 ) 所製造的蛋白質 ; 抗體會對抗原起特定反應 由內分泌腺少量製造的化學物質, 由血液所帶動, 到達目標器官以發揮其作用, 有助調節體內正常的運作 10

11 Bk2 Ch13 Transport in Humans/11 Vocabulary 詞彙 Page Description 解釋 urea 尿素 71, 188 a soluble nitrogen-containing compound excreted by some animals, from deamination of protein in liver bone marrow 骨髓 189 the soft tissue in the shaft of a long bone, being the site for blood cell formation haemoglobin 血紅蛋白 70, 158, 189 the red, iron-containing pigment in red blood cells; combines with oxygen and transports it to the tissues spleen 脾臟 189 an organ just beneath the stomach of vertebrate, having the function of making and storing lymphocytes and destroying red blood cells engulf 吞沒 190 to swallow up a substance by overflowing and enclosing leukaemia 白血病 190 a type of cancer, characterized by the abnormal rapid growth of one particular kind of white blood cells, that disrupt the normal functioning of other blood cells lymph node 淋巴結 190, 218 small structure situated along the lymphatic vessels; act as filters to prevent the spread of unwanted substances to the blood from the lymph lymphocyte 淋巴細胞 190 a kind of white blood cell which produces antibodies pathogen 病原體 190 disease-causing microorganism or substance phagocyte 吞噬細胞 190 a kind of white blood cell which engulfs the particles or pathogens from its surroundings by opening a food vacuole around them (phagocytosis) and then digests them blood clotting 凝血作用 79, 191 oxyhaemoglobin 氧合血紅蛋白 the process of closing of an open wound to prevent entry of germs and loss of blood from the body 192 a compound formed from the binding of oxygen molecule to haemoglobin 可溶的含氮化合物, 由一些動物的肝臟進行蛋白質的脫氨作用而產生, 然後再從體內排走 長骨骨幹內的柔軟組織, 是血液細胞形成的位置 紅血球裡含鐵質的紅色色素 ; 負責氧氣結合並將氧氣運送到組織 在脊椎動物胃以下的器官, 其功能包括製造與儲藏淋巴細胞, 及破壞紅血球 把目標物質包圍然後將其吞下或掩沒 癌症的一種, 某種白血球異常迅速地生長, 導致其他血細胞不能正常地運作 位處淋巴管的細小構造, 作用是過濾淋巴, 以防止身體不需要的物質從淋巴進入血液 一種製造抗生素的白血球 會導致疾病的微生物或任何其他物質 白血球的一種, 延伸出食物泡, 透過吞噬作用, 把四周的粒子或病原體吞沒, 然後消化 把暴露的傷口封閉的過程, 以防止病菌進入體內, 及防止血液持續流失 氧與血紅蛋白結合而形成的化合物 11

12 Bk2 Ch13 Transport in Humans/12 Vocabulary 詞彙 Page Description 解釋 blood vessel 血管 195 tubular structure, through which blood is circulated around the body capillary 微血管 195, 199 the smallest type of blood vessel that carries blood from artery to vein, only one-cell think, and is the site where food substances pass from blood to tissue fluid for use by body tissues vein 靜脈 195 a vessel which carries blood towards the heart artery 動脈 195 a blood vessel which carries blood away from the heart; typically has thick and elastic wall arteriole 小動脈 196 small arteries that branch from arteries and connect to capillaries constrict 收縮 196 to make smaller or narrower by binding or squeezing dilate 舒張 196 to widen in size due to the relaxation of muscles 血液流經循環至全身的管狀構造 由單層細胞構成的微細的血管, 將血液從動脈運送至靜脈, 食物粒子經管壁從血液運送到組織液, 以供身體組織使用 將血液帶至心臟的血管 從心臟帶走血液的血管 ; 一般具厚彈性管壁 窄小的動脈分支, 連接到微血管 因受到束縛或擠壓而縮小或收窄 因肌肉鬆弛而變闊 pulmonary artery 肺動脈 196 a blood vessel that carries deoxygenated blood from the heart to the lungs valve 瓣膜 196 structure within the veins and heart to ensure that blood flows in one direction only venule 小靜脈 196 the smallest branch of a vein that carries blood away from the capillaries pulmonary vein 肺靜脈 197 vessel that carries oxygenated blood from the lungs to the left atrium of the heart skeletal muscle 骨骼肌 197, 300 muscles connected with bones; capable of rapid contraction and controlled by impulses from the nervous system arteriosclerosis 動脈硬化 201 a class of diseases characterized by thickening, hardening and loss of elasticity of the artery wall and narrowing of its lumen, leading to an impairment of the blood circulating process pericardium 圍心膜 201 the membrane enveloping the heart of vertebrates 把缺氧血從心臟帶到肺的血管 心臟與靜脈內的構造, 確保血液只沿一個方向流動 靜脈最細小的分支, 負責把血液帶離微血管 把含氧血從肺帶到左心房的血管 與骨連接的肌肉, 能迅速收縮, 其活動由神經系統的神經脈衝所控制 指一系列的疾病, 特徵包括動脈管壁增厚 變硬及失去彈性, 動脈管腔縮小, 導致血液循環的運作受損 包圍脊椎動物心臟的膜 12

13 Bk2 Ch13 Transport in Humans/13 Vocabulary 詞彙 Page Description 解釋 stroke 中風 201 a sudden loss of brain function caused by a blockage or rupture of blood vessel leading to the brain, characterized by loss of muscular control, loss of sensation or consciousness, dizziness, slurred speech or other symptoms that vary with the extent and severity of the damage to the brain varicose vein 靜脈曲張 201 the swollen veins near the skin surface, caused by the failure of the valves in the veins to work properly and cannot stop the blood flowing backwards, often seen on the legs cardiac muscle 心肌 202 a type of branched, slightly striated muscular tissue found only in the wall of heart; its contraction brings about the pumping action of the heart coronary artery 冠狀動脈 202 artery that supplies nutrient- and oxygen-rich blood to the heart tissues atrium 心房 203, 204 ventricle 心室 203, 204 the upper chamber of the heart, receiving blood from the veins the lower chamber of heart which pumps blood into arteries aorta 大動脈 204 the main artery of the body through which oxygenated blood leaves the heart bicuspid valve 二尖瓣 204 the two-flaps valve between the left atrium and left ventricle of heart; opens in the direction of the ventricle and prevents back flow of blood chorda tendinea (plu. chordae tendineae) 腱索 204 fibrous cord joining between the ventricle and the lower edges of the bicuspid or tricuspid valve inferior vena cava 下腔靜脈 204 main vein of the body into which all the other veins feed from tissues in the abdomen and leg regions 通往腦部的血管堵塞或破裂, 導致腦部突然喪失本身功能的情況 ; 中風者會喪失控制肌肉的能力, 甚至失去感覺或知覺, 亦可能感到暈眩, 出現口齒不清或其他的症狀, 病情的輕重視乎腦頭受損的幅度與嚴重程度而定 由於皮膚表面的靜脈中的瓣膜無法正常運作, 血液倒流受阻而導致靜脈腫脹的現象, 常於腿部出現 僅在心臟壁找到的肌肉組織, 有纖幼條紋, 表面佈滿血管分支, 心肌的收縮造成心臟的泵壓活動 將含豐富氧和營養素的血液帶給心肌組織的動脈 心臟上方的空腔, 接收來自靜脈的血液 心臟下方的空腔, 將血液泵送到動脈 體內的主要動脈, 含氧血經此離開心臟 心臟中左心房與左心室之間的瓣膜, 由兩塊薄膜組成, 開往心室, 有助防止血液倒流 連接心室與二尖瓣或三尖瓣底端的纖維質腱 身體的主要靜脈, 所有其他從腹部或足部組織而來的靜脈均會引入下腔靜脈中 13

14 Bk2 Ch13 Transport in Humans/14 Vocabulary 詞彙 Page Description 解釋 superior vena cava 上腔靜脈 204 blood vessel that carries blood from the upper parts of the body (the head and the arms) to the heart tricuspid valve 三尖瓣 204 the valve located between the right atrium and right ventricle of the mammalian heart; for preventing the flowing of blood back from the right ventricle to the right atrium vena cava 腔靜脈 204 the main vein of the body through which deoxygenated blood enters the heart semilunar valve 半月瓣 205 pocket-shaped valves situated at the entrance to the aorta and pulmonary artery in the heart diastole 心舒期 206 a stage in the cardiac cycle, refers to the relaxation of the heart muscles, the four heart chambers are filling with blood 把血液從上身 ( 頭和手臂 ) 帶到心臟的血管 哺乳動物的心臟中, 右心房和右心室之間的瓣膜, 其功用是防止血液從右心室倒流進入右心房 體內的主要靜脈, 缺氧血經此進入心臟 呈袋狀的瓣膜, 位處大動脈與肺動脈在心臟的入口 心搏週期中, 心肌鬆弛的階段, 期間四個心腔會充滿血液 systole 心縮期 206 the phase of contraction in the cardiac cycle, during which the valves between atria and ventricles are closed, and the valves under the aorta and pulmonary artery are open, blood is pumped out of the heart cardiac cycle 心搏週期 207 the sequence of events taking place in the heart during one heartbeat; each cardiac cycle lasts about 0.8 second coronary vein 冠狀靜脈 208 vein that drains deoxygenated blood away from the muscular tissue of the heart septum (pl. septa) 中隔 209 a wall between two cavities, here refers to the muscular wall between the left and right heart cavity double circulation 雙循環 210 the pulmonary circulation and systemic circulation in organism with the development of lung; the blood will flow through the heart twice for every circulation round the body pulmonary circulation 肺循環 210 the circulation of blood to and from the lungs 心臟收縮的期間, 期間心房與心室之間的瓣膜閉合, 位於大動脈與肺動脈底部的瓣膜則開啟, 血液透過心臟的收縮泵走 心臟在一次心搏中所發生的一連串情況 ; 每次心搏週期持續約 0.8 秒 把缺氧血從心肌組織帶走的靜脈 兩個空腔之間的隔壁, 在此是指左與右心腔之間的肌肉壁 生物隨肺的發展而形成的肺循環與體循環 ; 血液運行全身一次, 會流經心臟兩次 進出肺部的血液循環 14

15 Bk2 Ch13 Transport in Humans/15 Vocabulary 詞彙 Page Description 解釋 systemic circulation 體循環 210 the circulation of blood throughout the body, excluding the lungs tissue fluid 組織液 212 fluid which is forced through capillary walls into the intercellular spaces lymph 淋巴 83, 130, 216 fluids drained by lymph vessels from intercellular spaces lymph vessel 淋巴管 216 thin-walled (one-celled thick) tube carrying lymph lymphatic system 淋巴系統 216 a system of vessels that transports lymph from the tissues to the circulatory system edema 水腫 218 swelling of body parts due to an excessive accumulation of tissue fluid in tissue spaces or body cavities lymph node 淋巴結 190, 218 small structure situated along the lymphatic vessels; act as filters to prevent the spread of unwanted substances to the blood from the lymph elephantiasis 象皮病 224 a chronic disease caused by infection with a roundworm in which the larvae block lymphatic drainage and produce edema; the lower areas of the body can become enormously swollen as a result heart attack 心臟衰竭 70, 224 occurs due to the blockage of the coronary arteries, leading to a severe reduce or stopping of blood supply to the heart muscle; if the condition lasts for over a few minutes, heart muscle cells may suffer permanent damage or die, which may leads to disability or death 除肺部外環繞身體的血液循環 經微血管壁擠出到胞間隙的液體 從胞間隙流入淋巴管的液體 運送淋巴的薄壁 ( 單細胞厚 ) 的管道 將淋巴液從各組織運送至循環系統的系統, 由管道構成 因體腔內或組織之間, 組織液過度積聚而引致腫脹的情況 位處淋巴管的細小構造, 作用是過濾淋巴, 以防止身體不需要的物質從淋巴進入血液 一種慢性病, 由受線蟲感染引起 ; 線蟲幼蟲堵塞淋巴管, 因而導致水腫, 該部分的皮膚及皮下組織脹大和硬化 ; 病情通常在身體下半部如足部和外生殖器中出現 因冠狀動脈閉塞, 導致流往心臟細胞的血液供應突然中止或變得不足, 如此狀況維持超過數分鐘, 心臟細胞會受損, 甚至死去, 引致人體部分位置癱瘓, 嚴重的更會致命 15