单选题
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 secrete 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 secrete products into the
bloodstream. The term "endocrine" contrasts with "exocrine", which is applied to
glands that secrete their products though ducts to the site of action. Examples
of exocrine glands are the tear glands, the sweat glands, and the pancreas,
which secrete pancreatic juice through a duct into the intestine. Exocrine
glands are also called duct glands, while endocrine glands are called ductless
glands.
单选题
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.
【正确答案】
B
【答案解析】
单选题
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.
【正确答案】
D
【答案解析】
单选题
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
【正确答案】
C
【答案解析】
单选题
The word "liberate" could best be replaced by which of the following?
______
A. Emancipate.
B. Discharge.
C. Surrender.
D. Save.
【正确答案】
B
【答案解析】
单选题
According to the passage another term for exocrine glands is ______.