七班三组成员 蔡明静 陈亮 丁光耀 丁菱芷 顾运乐 韩露 蒋尚武 李海燕

李涛 刘宁 罗满 梅浩浩 阮娇 陶正 寿涛 胡文杰

Blood and immunity

人体的防线

Blood is composed of cells ， or formed elements ,suspended in a clear ,straw-colored fluid

called plasma .The cells include erythrocytes ,leukocytes, and platelets or

thrombocytes (clotting cells） , and constitute about

45 per cent of the total blood volume

血是血细胞或有形成分组成，它们悬浮在叫血浆的透明的 , 淡黄色液体中。血细胞包括红细胞、白细胞和血小板 ( 凝血细胞 ) ，这些血细胞构成血液总量的 45% 。

The remaining 55 per cent of blood is plasma. 90% of is water. The remaining 10% contains

nutrients ,electrolytes (dissolved salts), gases, albumin(a protein),clotting factors , antibodies,

wastes, enzymes, and hormones. The ph of the plasma is steady at about 7.4.

剩下的 55% 的血液是血浆， 90% 的血浆是水。剩下的 10% 是营养物质 , 电解质 ( 溶解盐 ) 、气体、白蛋白 ( 一种蛋白质 ), 凝血因子 , 抗体、废弃物、酶、激素。血浆的酸碱度稳定在 7.4 左右。

血液（ blood ） 血细胞（ 45% ）：

红细胞 血小板

血浆（ 55% ）

Oxygen from the lungs and nutrients from the digestive tract are absorbed into blood for

transport to the tissues

从肺吸入的氧和从消化道吸收的营养物质随血液运送到组织。

At the same time ,carbon dioxide and other waste products of cellular metabolism are

absorbed form the tissues for transport to the organs of elimination . The blood also

transports hormones from endocrine glands to their target organs

与此同时 , 二氧化碳和其他来源于组织细胞的代谢废物被运送到具有消除功能的器官，血液还将内分泌腺分泌的激素运送到靶器官

Erythrocytes. The major functions of erythrocytes are to carry oxygen from the lungs to the

tissues ,and to carry carbon dioxide from the tissues to the lungs. This oxygen is bound to

hemoglobin,which consists of an iron-containing pigment called heme and a protein part called

globin . 红细胞 红细胞的主要功能将氧气从肺运输到组

织以及将二氧化碳从组织运输到肺的功能 ，携带氧的血红蛋白由一种叫亚铁血红素的含铁色素和一种叫球蛋白的蛋白质组成

hemoglobin has a high affinity for oxygen ,enabling erythrocytes to carry large

amounts of oxygen through the blood. Hemoglobin gives erythrocytes their red color.

血红蛋白具有很高的氧亲合力 , 使红细胞在血液里能携带大量的氧气。血红蛋白使红细胞呈现红色。

The erythrocyte concentration of about 5 million per cubic millimeter of blood makes them by far

the most numerous of the blood cells .

血液中红细胞浓度为每立方毫米 500 万个，这使他们成为到目前为止最多的血细胞。

the hemoglobin that they carry averages 15 g per 100 ml of blood. Erythrocytes originate in the

bone marrow ,and their production is stimulated by a hormone called erythropoietin . which is

secreted by the kidney ..

100 毫升血液中平均含 15 克血红蛋白。红细胞起源于骨髓红细胞 , 他们的产生是受一种叫做促红细胞生成素的激素调控的，这种激素是由肾分泌的。

骨髓幼红细胞超微结构模式图

Leukocytes are mainly responsible for protecting the body from bacteria and other potential harmful foreign substances. leukocytes show very prominent nuclei when stained. They total about 5,000 to 10,000 per cubic millimeter, bu t their number may increase during infection. There are five different types of leukocytes：three types of granulocytes (eosinophil, basophil, and neu-trophil)and two types of agranulocytes （monocytes and lymohocyte).

白细胞主要负责保护机体免受细菌和其他潜在的有害的外来物质的伤害。白细胞染色后核非常突出。每立方毫米约 5000 至 10000 个，但感染期间数目有可能会增加。有五种不同类型的白细胞：粒细胞 三种（嗜酸性粒细胞，嗜碱性粒细胞，中性粒细胞），无颗粒细胞两种（单核细胞和淋巴细胞）。

Granulocytes are characterized by the presence of visible particle (granules)in their cytoplasm and by their multi-lobed nuclei. Because of their oddly shaped nuclei, granulocytes are sometimes called polymorphonuclear leukocytes (pmn). The three types of granulocytes are named for the types of dye they take up in laboratory tests.

粒细胞的特点是在细胞质中可见粒子（颗粒）的存在和他们的多裂核。 由于其细胞核形状奇特，粒细胞有时也被称为多形核白细胞（ PMN）。粒细胞的三种类型是以在实验室做染料实验的类型命名的。

嗜酸性粒细胞 嗜碱性粒细胞

Unlike granulocytes, agranulocytes do not contain granules in their cytoplasm ,nor do they have multi-lobed nuclei. Agranulocytes are charcaterized by the presence of a single large nucleus. The two types of agranulocytes are monocytes and lymphocytes.

与粒细胞不同，无颗粒细胞不含有细胞颗粒，也无多叶核。 无颗粒细胞特征是有一个的大型核。无颗粒细胞包括单核细胞和淋巴细胞两种类型

单核细胞 淋巴细胞

Like neutrophils, monocytes are phagocytic cells. In fact,many monocytes travel to the tissures and become larger phagocytic cells called macrophages. Lymphocytes ,on the other hand, mature in the lymph nodes and circulate in both the blood and lymphatic systems. They play an important role in the immune response.

像中性粒细胞一样，单核细胞也是吞噬细胞。事实上，许多单核细胞游走到组织成为大的吞噬细胞，称为巨噬细胞。另一方面，淋巴细胞在淋巴结中成熟，在血液系统和淋巴系统循环。他们在免疫反应中发挥重要作用。

Leukocytes protect us against foreign substances. Some engulf foreign material by the process of phagocytosis; others function as part of the immune system.

白细胞保护我们免受外来物质的侵害，有些通过吞噬作用吞噬外来物质，其他的功能作为免疫系统的一部分。

Platelets. The blood platelets, also called thrombocytes, are actually cell fragments （碎

片） rather than complete cell.

　血小板。血液中的血小板，也被称为凝血细胞，实际是细胞碎片

而不是完整的细胞。

血小板的发生

血小板从巨核细胞脱落

The main function of plateiets is to initiate blood clotting at sites of vascular injury, preventing

blood loss. When a vessel is injured, platelets

stick together to form a plug at the site of injury.

血小板主要功能是在血管损伤中启动血液凝固（系统），防止失血。当血管受伤时，血小板粘在一起，在受伤的部位形成一个栓子

Plasma is the liquid part of the blood and consist of water, dissolved proteins, sugar

salts, hormones, and other substances. The four major plasma proteins are albumin,

globulin, fibrinogen, and prothrombin

血浆是血液中的液体部分，包括水，溶解蛋白质，糖盐，激素和其他物质。四大血浆蛋白是白蛋白，球蛋白，纤维蛋白原及凝血酶原。

The globulin contains antibodies, which, as part of the body’s immune system, destroy

foreign substances called antigens. Immunoglobulins are a specific type of gamma

globulins, a kind of the three globulins in plasma (alpha, beta, and gamma), which are

capable of acting as antibodies. 球蛋白中的抗体是机体免疫系统一部分，它能够消灭外来抗原。免疫球蛋白是三种血浆球蛋白 (α、 β和 γ) 中一种特殊的 γ 球蛋白 , 它的作用与抗体类似。

The immune system provides the body's special defense response against foreign organisms.This system includes the lymphoid organs (lymph nodes,and thymus gland)and their products (lymphocytes and antibodies) and macrophages (phagocytes that are found in the blood,liver,brain,lymph nodes,spleen,and other organs).

免疫系统发挥对抗外来生物的特殊机体防御反应，它包括淋巴器官（淋巴结，胸腺）和它们的产物（淋巴细胞和抗体）以及巨噬细胞（来自于血液，肝，脑，淋巴结，脾脏和其它器官吞噬细胞）。

When bacteria enter the body,phagocytes such as neutrophils migrate to the site of infection and ingest the bacteria.They release proteins that attract other immune cells and cause local heat and inflammation.Macrophages from local tissue and from the bloodstream move to clear away the dead cells and debris as the infection subsides.

当细菌进入人体，吞噬细胞，例如中性粒细胞，迁移到感染部位摄取细菌。它们释放蛋白质，吸引其他免疫细胞，造成局部发热和炎症。来自局部组织和血流中的巨噬细胞清除死亡的细胞及其碎片，至此感染消退。

When bacteria or viruses enter the body in sufficient numbers to overcome these

phagocytic cells at the site of local infection ., the next line of defense consists of lymphocytes.There are two types of

lymphocytes that circulate in the lymphatic system and the blood

在局部感染部位当足够数量的细菌或病毒进入机体战胜吞噬细胞的吞噬作用，则会启动下一道由淋巴细胞组成的防线，包括淋巴循环和血液循环中的两种淋巴细胞

One type, the T cells (T lymphocytes), mature in the thymus gland.They are capable of

attacking a foreign cell directly, producing cell-mediated immunity.The other is the B cells (B

lymphocytes), which mature in lymphoid tissue.When they meet a foreign antigen, they

multiply rapidly and produce antibodies that inactivate the antigen.

第一种淋巴细胞， 在胸腺成熟 是能够直接攻击非己细胞的 T 细胞（ T 淋巴细胞），它能够产生细胞介导的免疫 . 另一种是 B 细胞（ B 淋巴细胞），在淋巴组织中成熟。当它们接触到外来抗原时，它们迅速增殖并产生抗体，灭活抗原。

If an antigen encounters a T cell, the T cell can multiply rapidly . These activated T cells engulf and digest the antigen , such as a cancer cell, virus ,fungus , or bacterium .T cells also react to foreign tissues , such as skin grafts and transplanted organs.

当 T 细胞与抗原接触时， T 细胞能迅速增殖。能激活 T 细胞吞噬和吸收抗原的物质有癌细胞，病毒，真菌或细菌， T 细胞同样会对非己组织产生反应，如皮肤移植和器官移植。

Interferons inhibit the ability of viruses to infect uninfected cells and stimulate macrophages to ingest bacteria .Interleukins activate T cells and are cytotoxic for some tumor cells .

干扰素抑制病毒感染正常细胞的能力，并刺激巨噬细胞摄取细菌。白细胞介素激活 T 细胞并且对一些肿瘤细胞具有细胞毒性。

There is another specific class of T cells , called helper cells or T4 cells ,which can stimulate antibody production . Others regulate the amount of antibodies produced ,acting as suppressor cells that inhibit the activity of B cell lymphocytes.

另一种特殊类型的 T细胞称为辅助细胞或T4 细胞，它可以刺激抗体的产生。其它的T 细胞调控产生抗体，作为抑制细胞抑制B淋巴细胞的活性。

单词复习 Erythrocyte Leukocyte Platelet Plasma Granulocyte Basophil Eosinophil Neutrophil Monocyte Lymphocyte

红细胞 白细胞 血小板 血浆 粒细胞嗜碱性粒细胞嗜酸性粒细胞嗜中性粒细胞 单核细胞 淋巴细胞

Agranulocyte Phagocytic cells Megakaryocyte Heparin Albumin Globin fibrin Affinity Phagocytosis Hemostasis interact

无颗粒细胞吞噬细胞巨核细胞肝素 白蛋白珠蛋白纤维蛋白 亲和性吞噬作用 止血相互作用

Thank you