阅读练习

Without regular supplies of some hormones our capacity to behave would be seriously impaired; without others we would soon die. Tiny amounts of some hormones can modify moods and actions, our inclination to eat or drink, our aggressiveness or submissiveness, and our reproductive and parental behavior. And hormones do more than influence adult behavior; early in life they help to determine the development of bodily form and may even determine an individual’s behavioral capacities. Later in life the changing outputs of some endocrine glands and the body’s changing sensitivity to some hormones are essential aspects of the phenomena of aging.

Communication within the body and the consequent integration of behavior were considered the exclusive province of the nervous system up to the beginning of the present century. The emergence of endocrinology as a separate discipline can probably be traced to the experiments of Bayliss and Starling on the hormone secretion. This substance is secreted from cells in the intestinal walls when food enters the stomach; it travels through the bloodstream and stimulates the pancreas to liberate pancreatic juice, which aids in digestion. By showing that special cells secret chemical agents that are conveyed by the bloodstream and regulate distant target organs or tissues. Bayliss and starling demonstrated that chemical integration could occur without participation of the nervous system.

The term “hormone” was first used with reference to secretion. Starling derived the term from the Greek hormone, meaning “to excite or set in motion. The term “endocrine” was introduced shortly thereafter “Endocrine” is used to refer to glands that secret products into the bloodstream. The term “endocrine” contrasts with “exocrine”, which is applied to glands that secret their products though ducts to the site of action. Examples of exocrine glands are the tear glands, the sweat glands, and the pancreas, which secrets pancreatic juice through a duct into the intestine. Exocrine glands are also called duct glands, while endocrine glands are called ductless.

1.What is the author’s main purpose in the passage?
A.To explain the specific functions of various hormones.
B.To provide general information about hormones.
C.To explain how the term “hormone” evolved.
D.To report on experiments in endocrinology.

2.The passage supports which of the following conclusions?
A.The human body requires large amounts of most hormones.
B.Synthetic hormones can replace a person’s natural supply of hormones if necessary.
C.The quantity of hormones produced and their effects on the body are related to a person’s age.
D.The short child of tall parents very likely had a hormone deficiency early in life.

3.It can be inferred from the passage that before the Bayliss and Starling experiments, most people believed that chemical integration occurred only___.
A.during sleep.
B.in the endocrine glands.
C.under control of the nervous system.
D.during strenuous exercise.

4.The word “liberate” could best be replaced by which of the following?
A.Emancipate
B.Discharge
C.Surrender
D.Save

5.According to the passage another term for exocrine glands is___.
A.duct glands
B.endocrine glands
C.ductless glands
D.intestinal glands.

答案和词汇讲解

答案：BDCBA

词汇讲解

1. capacity 能力,容量,容积

In prospect of increase in demand, we should operate at full capacity.
预计需求会有很大增长, 我们应该开足马力生产。

The drama drew a capacity audience; you should have gone to see it.
这出戏吸引了满场观众；你真该去看的。

2. impair 损害

On a communications link, noise or unwanted signals that impair the receipt or correct interpretation of speech or data.
在通信链路上出现的噪音或无用的信号，它损害语音、数据的接收或正确的解释。

His illness has impaired his efficiency.
生病降低了他的效率。

3. aggressiveness 进取精神,侵犯,侵略

Surely, while most intellectuals cannot bear the aggressiveness of Bill, they admire his generosity.
大多数的知识分子不能忍受盖茨的凶悍，但欣赏他的慷慨。

4. submissiveness 柔顺, 服从

The condition or quality of being passive; inactivity, quiescence, or submissiveness.
被动性被动的状态或性质；不主动、沉默或顺从

5. pancreatic 胰(腺)的

The starch-digesting amylase produced by the pancreas and present in pancreatic juice.
胰淀粉酶胰产生的淀粉酶，存在于胰液中