小不小

These projections absorb. Absorb what?
::这些预测吸收了这些预测。

Imagine the inside walls of your 23 foot long small intestine covered with these finger-like projections. Why? What's their purpose, and why is the small intestine so long? These projections absorb. Absorb what? Minerals and nutrients from food . And the length of the small intestine allows as much of these important substances to be absorbed as possible.
::想象一下你23英尺长的小肠内墙 被这些手指般的预测所覆盖。 为什么? 它们的目的是什么? 为什么小肠那么长? 这些预测吸收了。吸收了什么?矿物和食物的养分。小肠的长度使得这些重要的物质 尽可能被吸收。

Digestion and Absorption: The Small Intestine
::消化和吸收:小不耐用

The small intestine is a narrow tube about seven meters long in adults. It is the site of most chemical digestion and virtually all absorption . The small intestine is actually much longer than the . It is called “small” because it is smaller in diameter than the large intestine. Like the rest of the GI tract, the small intestine pushes food along with peristalsis . The small intestine is made up of three parts: the duodenum , jejunum , and ileum . Each part has a different function.
::小肠道是一个狭窄的管子,长约7米,是大部分化学消化和几乎全部吸收的场所。小肠道实际上要长得多。小肠道由于直径小于大肠道,所以叫做“小”。小肠道和大肠道的其余部分一样,小肠道将食物推向阴道。小肠道由三个部分组成:二元、jewunum和ileum。每个部分都有不同的功能。

Digestion in the Small Intestine
::《小不适的消化》

The duodenum is the first part of the small intestine. It is only about 25 cm long, but most chemical digestion occurs here. Many are active in the duodenum, and several are listed in  Table . Some of the enzymes are produced by the duodenum. The rest are produced by the pancreas and secreted into the duodenum.
::是小肠肠的第一部分,只有大约25厘米长,但大部分化学消化都在这里进行。许多人在二角膜中活动,有些在表内列出。有些酶是由二角膜生产的,其余的则由胰腺生产,并隐藏在二角膜中。

How does the pancreas “know” when to secrete enzymes into the small intestine? The pancreas is controlled by compounds called . Hormones are chemical messengers in the body. They regulate many body functions including secretion of digestive enzymes. When food enters the stomach , a hormone called gastrin is secreted by the stomach. Gastrin, in turn, stimulates the pancreas to secrete its digestive enzymes.
::胰腺“知道”何时将酶分泌到小肠中?胰腺由叫做 . . . . . 荷尔蒙是体内的化学信使,它们调节许多身体功能,包括消化酶的分泌。当食物进入胃部时,胃部会隐藏一种叫气态的荷尔蒙。反过来,加斯特林会刺激胰腺将其消化酶分泌出来。

The liver produces fluid called bile , which is secreted into the duodenum. Some bile goes to the gall bladder where it is stored and becomes more concentrated. In the duodenum, bile breaks up large globules of lipids into smaller globules that are easier for lipase enzymes to break down chemically.
::肝脏产生液态,叫做Bile,它被隐藏在duodenum中。一些bilil流向储存并更加集中的胆囊。在duodenum中,bilble将大量脂质球分解成小球体,这对脂酶酶化学分裂比较容易。

Bile also reduces the acidity of the chyme entering from the highly acidic stomach. This is important for digestion because digestive enzymes in the duodenum require a neutral environment in order to work. The pancreas also contributes to the neutral environment of the duodenum by secreting bicarbonate, a basic substance that neutralizes acid.
::Bile还降低了从高酸性胃进入的旋律的酸性,这对消化很重要,因为二聚苯乙烯的消化酶需要中性环境才能工作。 胰腺通过隐匿碳酸双碳酸酯(一种能中和酸的基本物质)也促进了二聚苯乙烯的中性环境。

Absorption in the Small Intestine
::吸附在小不适量中的吸附

The jejunum is the second part of the small intestine. It is about 2.5 meters long. This is where most nutrients are absorbed into the .
::Jejunum是小肠的第二部分。 它长约2.5米。 大部分营养素都在这里被吸收到里面 。

As shown in  Figure , the mucous membrane lining the jejunum is covered with microscopic finger-like projections called villi (singular: villus). Each villus, in turn, has thousands of even smaller projections called microvilli (singular: microvillus). The villi contain capillaries, which are tiny . Nutrients are absorbed into these capillaries across the surfaces of the villi and microvilli. Because there are millions of these tiny projections, they greatly increase the surface area for absorption. In fact, villi and microvilli increase the absorptive surface of the small intestine to the size of a tennis court! This allows far greater absorption of nutrients.
::如图所示,Jejunum表面的粘膜膜状粘膜被称为Villi的微小手指类预测(单形:villus)所覆盖,而每个villus则有数千个更小的预测,称为micvilli(单形:micvillus),圆柱状含有细细细的毛细细细的毛细细细细的毛细细细细的毛细细细的毛细小的毛细细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细小的毛细细细小的毛细小的毛细小的毛细细细小的毛细小的毛细细细小的毛小的毛细细小的毛细小的毛细细细细细细细的毛细细细细细细细细的细细细细细细细细细细的细细细细细细细的细的细的细的细的细细细细细细细细细细细的细细细细细细细细细的细细细的细的细的细的细细细细细细细细细细细细的细细细细细细的细的细细细细细细细细细细细细细细细细细细细细细细细细细细细的细的细的细的细细细细细细细的细的细的细的细细的细细细细细的细细细细细的细的细的细的细的细的细的细的细的细的细的细的细细细细的细的细细细细的细的细细细细细细细细细细细细细细细细的细的细的细的细的细的细的细的细的细的细的细的细的细的细的细的细的细的细的细的细的细细细细细细细细的细的细的细的

The ileum is the third part of the small intestine. It is about 3.5 meters long. A few remaining nutrients are absorbed in the ileum. Salts that form from liver bile are also absorbed here. Like the jejunum, the ileum is covered with villi and microvilli that increase the area for absorption.
::肠道是小肠道的第三个部分, 大约3.5米长。 还有一些残留的营养素被吸收到肠道中。 肝脏的盐也是在这里被吸收的。 和Jejunum一样, 肠道被葡萄树和微小树脂覆盖, 增加了吸收面积 。

Summary
::摘要

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• The small intestine is the site of most chemical digestion and virtually all absorption.
  ::小肠是大部分化学消化和几乎全部吸收的场所。
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• When food enters the stomach, a hormone called gastrin is secreted by the stomach. Gastrin, in turn, stimulates the pancreas to secrete its digestive enzymes.
  ::当食物进入胃部时,胃部会隐藏一种叫气喘素的荷尔蒙。 气喘素反过来会刺激胰腺,以隐匿消化酶。
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• The villi contain capillaries; nutrients are absorbed into the capillaries across the surfaces of the villi.
  ::树脂中含有毛皮;营养素被吸收到树脂表面的毛皮中。
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• Because there are millions of villi, they greatly increase the surface area for absorption.
  ::因为有上百万的葡萄酒 它们大大增加了需要吸收的表面积

Review
::回顾

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1. How long is the small intestine in adults?
   ::成年人的小肠子还有多久?
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2. How many parts is the small intestine divided into?
   ::小肠子分为多少部分?
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3. Where does most of the chemical digestion occur?
   ::大多数化学消化现象在哪里发生?
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4. What role does bile play in chemical digestion?
   ::细菌在化学消化中起什么作用?
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5. Where does most of the absorption take place in the small intestine?
   ::大部分吸收在小肠子中在哪里进行?