SAT阅读考试模拟题：sensation of pain.

　　SAT阅读考试是整个SAT考试的重中之重，需要我们加强练习。下面澳际小编为大家整理了一篇关于sensation of pain的SAT阅读模拟题，后面附有相关题目和正确答案，希望对大家备考SAT阅读考试有所帮助。

　　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 reli—are delivered through a highly

　　(5) complex interacting circuitry.

　　When a cell is injured, a rush of prostaglandin’s

　　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

　　(10) 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 inter-

　　fering with an enzyme known as prostaglandin synthetase,

　　or cyclooxygenase. The drugs’ fectiveness against pain is

　　(15) proportional to their success in blocking this enzyme at the

　　site of injury.

　　From nerve endings at the injury, pain signais move to

　　nerves feeding into the spinal cord. The long, tubular

　　membranes of nerve cells carry electrical impulses. When

　　(20) 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

　　(25)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

　　(30) 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

　　(35) 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

　　(40) brain stem—involve the release of endorphins in the brain

　　and spinal cord.

　　1. The passage is primarily concerned with

　　(A) analyzing ways that enzymes and other chemicals influence how the body feels pain

　　(B) describing the presence of endorphins in the brain and discussing ways the body blocks pain within the brain itself.

　　(C) describing how pain signals are conveyed in the body and discussing ways in which the pain signals can be blocked

　　(D) demonstrating that pain can be influenced by acupuncture and electrical stimulation of the central brain stem.

　　(E) differentiating the kinds of pain that occur at different points in the body’s nervous system.

　　2. According to the passage, which of the following is one of the first things 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.

　　3. Of the following, which is most likely attributable to the fect of endorphins as described in the passage?

　　(A) After an injection of novocaine, a patient has no feeling in the area where the injection was given.

　　(B) After taking ibuprofen, a person with a headache gets quick reli.

　　(C) After receiving a local anesthetic, an injured person reports reli in the anestherized area.

　　(D) After being given aspirin, a child with a badly scraped elbow feels better.

　　(E) After acupuncture, a patient with chronic back pain reports that the pain is much less severe.

　　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 ions will 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.

　　Correct Answers：CDEB

　　以上便是澳际小编为大家整理的SAT阅读模拟题，希望对大家有所帮助。阅读理解主要考察学生对文章的综合分析和理解能力，大家在备考SAT阅读考试的时候，要要谨慎才行，可以从两个方面入手，长期和短期相结合的备考。