Section outline

  • lesson content

    What is the main function of blood?
    ::血液的主要功能是什么?

    Obviously, to transport oxygen to each in your body. Each cell needs that oxygen to survive. But blood does much more than just transport oxygen.
    ::很明显,为了将氧气输送到你的身体。每个细胞都需要氧气来生存。但血液比运输氧气要多得多。

    Functions of Blood
    ::血液功能

    Transport of Oxygen
    ::氧气运输

    The hemoglobin molecule is the major transporter of oxygen in mammals including humans and many other . About 98.5 percent of the oxygen in a sample of arterial blood in a healthy human is bonded with hemoglobin. Only 1.5 percent of the oxygen in blood is not carried by hemoglobin; instead, it is dissolved in the plasma.
    ::血红蛋白分子是哺乳动物(包括人类和许多其他人)中氧气的主要运输者。 健康人体内动脉血液样本中约98.5%的氧气与血红蛋白结合。 血液中只有1.5%的氧气不是由血红蛋白携带的,而是在血浆中溶解的。

    Under normal conditions in humans at rest, the hemoglobin in the red blood cells that are leaving the lungs are about 98 to 99 percent saturated with oxygen, and the blood is referred to as oxygenated. In a healthy adult at rest, deoxygenated blood returning to the lungs is still 75 percent saturated with oxygen. Oxygen saturation of arterial blood at or below 95 percent is considered dangerous to an individual at rest (for instance, during surgery under anesthesia).
    ::在正常的人体休息条件下,离开肺部的红血红细胞中的血红蛋白约98-99%饱和氧气,血液被称为氧气;在健康的成年人休息时,返回肺部的脱氧血液仍然有75%饱和氧气;在休息时(例如在麻醉手术期间),动脉血液的氧饱和度为95%或不到95%,被认为对个人有危险。

    Substances other than oxygen can bind to the hemoglobin; in some cases, this can cause irreversible damage to the body. The gas carbon monoxide , for example, is very dangerous when absorbed into the blood. It bonds irreversibly with hemoglobin, which reduces the volume of oxygen that can be carried in the blood. Carbon monoxide poisoning can very quickly cause suffocation and death. Carbon monoxide is released during combustion (fire). It is released by cigarettes, barbeque grills, combustion of petrol products in cars and trucks, or anything else that can be burned.
    ::氧以外的物质可以与血红蛋白结合;在某些情况下,这可能会对身体造成不可逆转的损害。例如,气体一氧化碳在吸收血液时非常危险。它与血红蛋白不可逆转地联系在一起,因为血红蛋白可以减少血液中携带的氧量。一氧化碳中毒可以很快造成窒息和死亡。一氧化碳在燃烧(燃烧)期间释放出来。它通过香烟、烧烤炉、汽车和卡车燃烧汽油产品或其他可以燃烧的东西释放出来。

    Hemoglobin is allosterically inhibited by CO 2 and H + . This means that if carbon dioxide or protons attach to hemaglobin, it affects the ability of the molecule to remain attached to O 2 . That is how hemaglobin deposits oxygen throughout the body. 
    ::血红蛋白被CO2和H+抑制,这意味着如果将二氧化碳或质子附于 hemaglobin 上,它会影响分子继续附于O2 的能力,这就是 hemaglobin如何将氧沉入全身。

    Transport of Carbon Dioxide
    ::二氧化碳的运输

    When systemic arterial blood flows through capillaries, carbon dioxide diffuses from the tissues into the blood. Since carbon dioxide is 20 times more soluble than oxygen, around 5% of carbon dioxide is dissolved in the blood. The majority of carbon dioxide (85%) is converted to bicarbonate and hydrogen ions , which are then carried in the blood to the lungs where they are converted back to carbon dioxide and released by the lungs. The remaining carbon dioxide (roughly 10%) becomes bound to , especially hemoglobin, and is transported in that manner.
    ::当系统动脉血液通过毛细血管流动时,二氧化碳会从组织中扩散到血液中。由于二氧化碳比氧溶解度高20倍,大约5%的二氧化碳会溶解在血液中。 大部分二氧化碳(85%)被转化成碳酸盐和氢离子,然后通过血液将二氧化碳输送到肺部,再转化成二氧化碳,并由肺部释放。剩下的二氧化碳(大约10%)会被绑在体内,特别是血红蛋白,并以此方式迁移。

    Thermoregulation
    ::温度调节

    In order to function properly, the needs to maintain a constant temperature around 98.6°F (37°C). When the human body is above normal body temperature, it suffers from hyperthermia, and, when it is below normal temperature, it suffers from hypothermia. Blood circulation transports heat through the body, and adjustments to this flow are important parts of thermoregulation. Thermoregulation is the process through which an organism maintains a stable internal body temperature. Increasing blood flow to the surface (e.g. during warm weather or strenuous exercise) causes warmer skin, resulting in greater heat loss. Decreasing surface blood flow conserves heat.
    ::为了正常运转,需要保持98.6°F(37°C)左右的恒定温度。当人体超过正常体温时,体温会高,当体温低于正常体温时,体温会低。血液循环通过身体输送热量,调整这种流动是温度调节的重要部分。温度调节是一个有机体保持稳定的内体温度的过程。不断上升的血液流向表面(如在温暖的天气或艰苦的锻炼期间)会导致更温暖的皮肤,导致更大的热量流失。地表血流减少会保持热量。

    Blood Clotting
    ::输血衣

    Coagulation, or blood clotting, is a complex process by which blood forms solid clots. Coagulation is important in order to stop bleeding and begin repair of damaged . Blood clotting disorders can lead to an increased risk of bleeding or clotting inside a blood vessel. Platelets are important for the proper coagulation of blood.
    ::凝聚或凝凝血是一个复杂的过程,血液形成固体凝块。 凝聚对于停止出血和开始修复受损的疾病非常重要。 血凝块紊乱可能导致血液中出血或凝块的风险增加。 血凝块对于血液的适当凝聚非常重要。

    Clotting is started almost immediately when an injury damages the endothelium of a blood vessel. Platelets clump together, forming a plug at the site of injury. Then, proteins in the plasma called coagulation factors (see the table) respond in a series of chemical reactions that form a tough protein called fibrin. The fibrin strands form a web across the platelet plug, trapping red blood cells before they can leave through the wound site. This mass of platelets, fibrin, and red blood cells forms a clot that hardens into a scab.
    ::当伤害损害血液容器内时,几乎立即开始克隆。 板块聚集在一起, 在受伤地点形成一个塞子。 然后, 血浆中的蛋白质被称为凝固因子( 参见表格) , 反应一系列化学反应, 形成一种叫菲布林的硬蛋白质。 纤维丝在小板塞上形成一个网络, 在红血细胞能够穿过伤口地点前捕捉它们。 血小板、 纤维和红血细胞的这种质量形成凝固的血块。

    Certain nutrients are needed for the proper functioning of the clotting mechanism. Two of these are calcium and vitamin K . Luckily for you, that live in your intestines make enough vitamin K, so you do not need to have extra in your food .
    ::凝固机制的正常运转需要某些营养素。 其中有两个是钙和维生素K。 幸运的是,生活在肠子里的你有足够的维生素K,所以你不需要食物中的额外营养。

    Factor Number Descriptive Name Active Form
    I Fibrinogen Fibrin subunit
    II Prothrombin Serine protease
    III Tissue factor Receptor/cofactor
    V Labile factor Cofactor
    VII Proconvertin Serine protease
    VIII Antihaemophilic factor Cofactor
    IX Christmas factor Serine protease
    X Stuart–Prower factor Serine protease
    XI Plasma thromboplastin antecedent Serine protease
    XII Hageman (contact) factor Serine protease
    XIII Fibrin-stabilizing factor Transglutaminase

      

     

    Summary
    ::摘要

    • About 98.5 percent of the oxygen in a sample of arterial blood in a healthy human is bonded with hemoglobin.
      ::人体健康动脉血液样本中约98.5%的氧气与血红蛋白结合。
    • Carbon dioxide is transported in the blood in three different ways: dissolved in the blood, as a bicarbonate ion, or bound to proteins such as hemaglobin.
      ::二氧化碳以三种不同的方式在血液中迁移:在血液中溶解,作为双碳酸盐离子,或与诸如 hemaglobin等蛋白质捆绑在一起。
    • Coagulation is important in order to stop bleeding and begin repair of damaged blood vessels.
      ::为了停止流血和开始修复受损的血管,凝固很重要。

    Review
    ::回顾

    1. What is considered a dangerously low oxygen saturation level for arterial blood?
      ::对动脉血液而言,什么是被视为危险的低氧饱和度水平?
    2. Why is carbon monoxide so dangerous?
      ::为什么一氧化碳如此危险?
    3. What kind of nutrients are essential for coagulation?
      ::哪种养分对凝固至关重要?
    4. How does hemoglobin release oxygen?
      ::血红蛋白如何释放氧气?