大全Passage 39, Q2，4，这次问题比较少，因为一共就4道题！

aaron22

请教各位了，这篇文章是将痛觉的，生物系文章是出了法律类外最讨厌的，也想顺便请教下各位这2类文章怎么应付。

法律类是经常有许多法律知识，美国文化之类的东西（特别是和那些土著的水案），读着读着就蒙了，水案那篇我现在还蒙着呢。。。

生物类的就分情况了，有的因为以前学过点还行，有的知识点没学过，一看整篇的专有名词就傻眼了

请问有没有什么好的办法啊

Passage 39 (39/63)

The sensation of pain cannot accurately be described as “located” at the point of an injury, or, for that matter, in any one place in the nerves or brain. Rather, pain signals—and pain relief—are delivered through a highly complex interacting circuitry.

When a cell is injured, a rush of prostaglandins sensitizes nerve endings at the injury. Prostaglandins are chemicals produced in and released from virtually all mammalian cells when they are injured: these are the only pain signals that do not originate in the nervous system. Aspirin and other similar drugs (such as indomethacin and ibuprofen) keep prostaglandins from being made by interfering with an enzyme known as prostaglandin synthetase, or cyclooxygenase. The drugs’ effectiveness against pain is proportional to their success in blocking this enzyme at the site of injury.

From nerve endings at the injury, pain signals move to nerves feeding into the spinal cord. The long, tubular membranes of nerve cells carry electrical impulses. When electrical impulses get to the spinal cord, a pain-signaling chemical known as substance P is released there. Substance P then excites nearby neurons to send impulses to the brain. Local anesthetics such as novocaine and xylocaine work by blocking the electrical transmission along nerves in a particular area. They inhibit the flow of sodium ions through the membranes, making the nerves electrically quiescent; thus no pain signals are sent to the spinal cord or to the brain.

Recent discoveries in the study of pain have involved the brain itself—the supervising organ that notices pain signals and that sends messages down to the spinal cord to regulate incoming pain traffic. Endorphins—the brain’s own morphine—are a class of small peptides that help to block pain signals within the brain itself. The presence of endorphins may also help to explain differences in response to pain signals, since individuals seem to differ in their ability to produce endorphins. It now appears that a number of techniques for blocking chronic pain—such as acupuncture and electrical stimulation of the central brain stem—involve the release of endorphins in the brain and spinal cord.

2.According to the passage, which of the following is one of the firstthings to occur when cells are injured?

(A) The flow of electrical impulses through nerve cells at the site of the injury is broken.

(B) The production of substance P traveling through nerve cells to the brain increases.

(C) Endorphins begin to speed up the response of nerve cells at the site of the injury.

(D) A flood of prostaglandins sensitizes nerve endings at the site of the injury.

(E) Nerve cells connected to the spinal cord become electrically quiescent.

答案是选对了，但是心里没谱啊

文中怎么读也读不出来prostaglandins是first things，然后就想着rush不是比较快嘛，然后又是在神经末梢又是靠sensitize应该是比较快吧，就这么选了。

请问正确的思路是什么呀？

4 .It can be inferred from the passage that if the prostaglandin synthetase is only partially blocked, which of the following is likely to be true?

(A) Some endorphins will be produced, and some pain signals will be intensified.

(B) Some substance P is likely to be produced, so some pain signals will reach the brain.

(C) Some sodium ionswill be blocked, so some pain signals will not reach the brain.

(D) Some prostaglandins will be produced, but production of substance P will be prevented.

(E) Some peptides in the brain will receive pain signals and begin to regulate incoming pain traffic.

非常白痴的选了C，对答案的时候一看就不对，ions明显是在第3段讲brain itself里，此处扇自己100下，%>_<%

想问的是怎么从prostaglandin synthetase is only partially推出B选项的结论的，看来文章逻辑理解还是不行

aaron22

卖萌都没人回答呀