英语听力文摘 English Digest 682 昆虫血为何是绿色或黄色

 

Why Is Insect Blood Green Or Yellow?

You’ve probably heard someone use the phrase “blood red,” but have you ever wondered if all blood really is red? For example, think about the bugs² you’ve seen splatter against your car’s windshield, leaving behind a clear, yellowish, or greenish liquid. That liquid, is hemolymph, or insect blood.

Insect Blood

The blood of an insect functions differently than the blood of a human. In humans, blood gets its red color from hemoglobin, which travels through blood vessels³ carrying oxygen from the lungs to the rest of the body. Insect blood, however, does not carry gasses and has no hemoglobin. Instead, bugs have a system of tubes that transport gasses directly between their cells and the outside air.

In fact, insects don’t even have blood vessels. Instead there is a hollow space inside their external skeleton in which their blood oozes⁴ around. This cavity extends to the antennas⁵, legs, and wing veins⁶. The bug¹’s heart, a long tube that stretches the length of its body, pushes the blood from the rear end of the insect on forward. The bug may also have little hearts at the ends of its extremities⁷ to help move the blood along.

Pigment⁸

Pumping blood is a slow process: it takes about eight minutes for an insect’s blood to circulate completely. Like human blood, bug blood carries nutrients⁹ and hormones¹⁰ to the insect’s cells. The greenish or yellowish color of insect blood comes from the pigments¹¹ of the plants the bug eats.

为什么虫血是绿色或黄色？

你可能听说过有人用“血红”这个短语，但你有没有想过，是否所有的血液都是红色的？例如，想想你看到的虫子溅到你的汽车挡风玻璃上，留下一种清澈、淡黄色或绿色的液体。这种液体是血淋巴或昆虫血。

昆虫血

昆虫的血液与人类的血液功能不同。在人类中，血液的红色来源于血红蛋白，血红蛋白通过血管将氧气从肺部输送到身体其他部位。然而，昆虫血液不携带气体，也没有血红蛋白。相反，昆虫有一个管道系统，可以在它们的细胞和外界空气之间直接输送气体。

事实上，昆虫甚至没有血管。相反，在它们的外部骨骼中有一个中空的空间，血液在其中渗出。这个空腔延伸到天线、腿和翼静脉。这只虫子的心脏是一根长长的管子，它伸展着身体的长度，将昆虫后端的血液向前推。这种虫子的四肢末端也可能有小心脏，以帮助血液流动。

颜料

抽血是一个缓慢的过程：昆虫的血液需要大约八分钟才能完全循环。与人类血液一样，虫子的血液将营养物质和激素输送到昆虫的细胞中。昆虫血液的绿色或黄色来自于昆虫所吃植物的色素。

1 bug   

n.虫子；故障；窃听器；vt.纠缠；装窃听器

参考例句：

• There is a bug in the system.系统出了故障。
• The bird caught a bug on the fly.那鸟在飞行中捉住了一只昆虫。

2 bugs   

adj.疯狂的，发疯的n.窃听器( bug的名词复数 )；病菌；虫子；[计算机]（制作软件程序所产生的意料不到的）错误

参考例句：

• All programs have bugs and need endless refinement. 所有的程序都有漏洞，都需要不断改进。 来自《简明英汉词典》
• The sacks of rice were swarming with bugs. 一袋袋的米里长满了虫子。 来自《简明英汉词典》

3 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

4 oozes   

v.（浓液等）慢慢地冒出，渗出( ooze的第三人称单数 )；使（液体）缓缓流出；（浓液）渗出，慢慢流出

参考例句：

• The spring oozes out of a rock. 泉水从岩石中渗出。 来自《现代汉英综合大词典》
• Blood oozes from a wound. 血从伤口渗出。 来自《现代英汉综合大词典》

5 antennas   

[生] 触角，触须（antenna的复数形式）

参考例句：

• Marconi tied several antennas to kites. 马可尼在风筝上系了几根天线。 来自超越目标英语 第3册
• Radio astronomy today is armed with the largest antennas in the world. 射电天文学拥有世界上最大的天线。

6 veins   

n.纹理；矿脉( vein的名词复数 )；静脉；叶脉；纹理

参考例句：

• The blood flows from the capillaries back into the veins. 血从毛细血管流回静脉。 来自《简明英汉词典》
• I felt a pleasant glow in all my veins from the wine. 喝过酒后我浑身的血都热烘烘的，感到很舒服。 来自《简明英汉词典》

7 extremities   

n.端点( extremity的名词复数 )；尽头；手和足；极窘迫的境地

参考例句：

• She was most noticeable, I thought, in respect of her extremities. 我觉得她那副穷极可怜的样子实在太惹人注目。 来自辞典例句
• Winters may be quite cool at the northwestern extremities. 西北边区的冬天也可能会相当凉。 来自辞典例句

8 pigment   

n.天然色素，干粉颜料

参考例句：

• The Romans used natural pigments on their fabrics and walls.古罗马人在织物和墙壁上使用天然颜料。
• Who thought he might know what the skin pigment phenomenon meant.他自认为可能知道皮肤色素出现这种现象到底是怎么回事。

9 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

10 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

11 pigments   

n.（粉状）颜料( pigment的名词复数 )；天然色素

参考例句：

• The Romans used natural pigments on their fabrics and walls. 古罗马人在织物和墙壁上使用天然颜料。 来自辞典例句
• The original white lead pigments have oxidized and turned black. 最初的白色铅质颜料氧化后变成了黑色。 来自辞典例句