网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
Inhibitory receptors
参考答案
更多 “Inhibitory receptors” 相关考题
考题
The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, __1__ this is largely because, __2__ animals, we stand upright. This means that our noses are __3__ to perceiving those smells which float through the air, __4__ the majority of smells which stick to surfaces. In fact, __5__, we are extremely sensitive to smells, __6__ we do not generally realize it. Our noses are capable of __7__ human smells even when these are __8__ to far below one part in one million.Strangely, some people find that they can smell one type of flower but not another, __9__ others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate __10__ smell receptors in the nose. These receptors are the cells which sense smells and send __11__ to the brain. However, it has been found that even people insensitive to a certain smell __12__ can suddenly become sensitive to it when __13__ to it often enough.The explanation for insensitivity to smell seems to be that brain finds it __14__ to keep all smell receptors working all the time but can __15__ new receptors if necessary. This may __16__ explain why we are not usually sensitive to our own smells we simply do not need to be. We are not __17__ of the usual smell of our own house but we __18__ new smells when we visit someone else’s. The brain finds it best to keep smell receptors __19__ for unfamiliar and emergency signals __20__ the smell of smoke, which might indicate the danger of fire.1________________[A] although[B] as[C] but[D] while
考题
Primer on Smell
In addition to bringing out1 the flavor of food, what does the sense of smell do for us ?
Smell “gives us information about place, about where we are,” says Randall Reed, a Johns Hopkins University professor whose specialty is the sense of smell. ___1___ “Whether we realize it or not, we collect a lot of information about who is around us based on smell,” says Reed.
Even at a distance, odors can warn us of2 trouble — spoiled food, leaking gas, or fire. “It’s a great alert,” offers Donald Leopold, a doctor at Johns Hopkins. For example, if something in the oven is burning, everyone in the house knows it.
With just a simple scent, smell can also evoke very intense emotion. Let’s say, for example, that the smell is purple petunias. ___2___ Now let’s imagine that your mother died when you were three, and she used to have a flower garden. You wouldn’t need to identify the smell or to have conscious memories of your mother or her garden. You would feel sad as soon as you smelled that spicy odor.
Compared with3 animals, how well do people detect smelts ?
That depends on what you mean by “how well”. We are low on receptor cells ： current estimates say that humans have roughly five million smell-receptor cells, about as many as a mouse. ___3___
Reed says that, across species, there is a relatively good correlation between the number of receptor cells and how strong the sense of smell is. “You can hardly find the olfactory bulb in a human brain —— it’s a pea-sized object. In a mouse, it’s a little bigger. It’s bean-sized in a rat, about the size of your little finger in a rabbit, and the size of your thumb in a bloodhound.”
Does that mean that our sense of smell is not very acute ?
Not exactly. While we may not have the olfactory range of other creatures, the receptors we do have are as sensitive as those of any animal. ___4___ A trained “nose”, such as that of a professional in the perfume business, can name and distinguish about 10,000 odors. Reed says that a perfume expert can sniff a modem scent that has a hundred different odorants in it, go into the lab, and list the ingredients. “In a modest amount of time, he comes back with what to you or me would smell like a perfect imitation of that perfume. It’s amazing.”
What happens to4 our sense of smell as we age ?
Many people continue to have good olfactory function as they get older. ___5___ Leopold says that smell is generally highest in childhood, stays the same from the teens through the 50s, and drops starting at about 60 for women and 65 for men. “The average 80-year-old is only able to smell things half as well as the average 20-year-old,” says Leopold.
词汇：
scent /sent/ n. 气味，香味
petunia /p 'tju:ni / n. 喇叭花
olfactory / l'f kt( )ri/ adj. 嗔觉的，味道的
sniff /snif/ v. 嗅，闻，用力吸
注释：
1. bring out：使……显出，使……变得明显
2. warn of：发出关于……的警告。warn sb. of sth.：警告某人某事
3. compare with：与……相比
4. happen to：发生于，发生在
练习：
A These flowers have a rich spiciness that no other petunia has.
B Odors, or smells, can warn us about trouble.
C That’s not the rule, however.
D And smell tells us about people.
E We can also think, and we make conscious (and successful) efforts to tell the difference between one smell and another.
F A rat has some 10 million, a rabbit 20 million, and a bloodhound 100 million.
考题
The brain finds it best to keep smell receptors（ ）for unfamiliar and emergency signals such as the smell of smoke,which might indicate the danger of fire.A.available
B.reliable
C.identifiable
D.suitable
考题
This may be because some people do not have the genes necessary to generate particular smell receptors in the nose.These receptors are the cells which sense smells and send（ ）to the brain.A.signs
B.stimuli
C.messages
D.impulses
考题
Mind wandering has long been thought of as the enemy of concentration,but that's not always true-the right kind of daydreaming can actually help you focus.Read on to discover how to take control of your wandering mind,and other simple ways to stay sharp when deadlines are looming.41.Research by Nilli Lavie at University College London has found that adding deliberate distractions-a jazzy border on a page or a bit of background noise-actually reduces distractibility.Her"load theory"proposes this works because attention is a limited resource,so ifyou fill all the attentional"slots"in your mind,it leaves no room for other distractions.42.The prospect of a treat can keep people focused,but only when it is well-timed,studies show.Offering people small rewards throughout a boring task didn't stop them from losing focus,but the promise of a larger reward that they would receive at the end of the task kept them alert.This approach probably works best with an accomplice to keep you from caving early,says Michael Esterman,at the Boston Attention and Learning Laboratory,who did the research 43.Stopping every now and again to give your mind a chance to wander can invigorate focus,says psychologist Paul Seli of Harvard University."If you say to yourself,now I'm going to think about something unrelated,maybe problem-solve something else that is on your mind,and then come back to your task,That can definitely be beneficial,"he says.44.You might think that an adrenaline boost would focus the mind,but stress actually stimulates the release of hormones,including noradrenaline（去甲肾上腺索）,which bind to receptors in the cognitive control circuits.This in turn makes it harder for them to keep tabs on mind wandering.45.A lack of sleep hammers mental performance in general,and reduces our ability to resist both internal and external distractions.And there's an added bonus-sleep is also important for memory consolidation.In fact,recent research suggests that if you have an hour spare before an exam,a nap could be a more effective use of your time than spending it revising.42选？A.Bribe yourself
B.Daydream during breaks
C.Get some breaks
D.De-stress
E.Give your mind more to do
F.Have a big meal
G.Test yourself regularly
考题
共用题干
Teaching and Learning Medicine AwardTwo scientists who have won praise for research into the growth of cancer cells could be candidates for the Nobel Prize in medicine when the 2008 winners are presented on Monday,kicking off six days of Nobel announcements.Australian-born U.S.citizen Elizabeth Blackburn and American Carol Greider have already won a Series of medical______(51)for their enzyme（酶）research and experts say they could be among the front-runners for a Nobel.Only seven women have______(52)the medicine prize since the first Nobel Prizes were______(53) out in 1901.The last female winner was U.S.researcher Linda Buck in 2004,who______(54)the prize with Richard Axel.Among the pair's possible______(55)are Frenchman Pierre Chambon and Americans Ronald Evans and Elwood Jensen,who______(56)up the field of studying proteins called nuclear hormone receptors（核激素受体）.As usual,the award committee is giving no______(57)about who is in the running before presenting its decision in a news conference at Stockholm's Karolinska Institute.Alfred Nobel,the Swede who______(58)dynamite（炸药）,established the prizes in his will in the ______(59)of medicine,physics,chemistry,literature and peace.The economics prize is technically not a Nobel but a 1968 creation of Sweden's central bank.Nobel left few instructions on how to______(60)winners,but medicine winners are typically______(61)for a specific breakthrough rather than a body of research.Hans Jornvall , secretary of the medicine prize committee , said the 10 million kronor（瑞典克朗）prize encourages______(62)research but he did not think winning it was the primary goal for scientists."Individual researchers probably don't______(63)at themselves as potential Nobel Prize winners when they,re______(64)work,"Jornvall told the Associated Press-They get their kicks from their research and their interest in how life______(65)."60._________A:find B:select C:locate D:search
考题
What physical characteristic does a retinal scan biometric device measure?视网膜扫描设备检测哪些人体物理特性？（）A、The pattern of light receptors at the back of the eye眼底光受体组织的图案B、The pattern of blood vessels at the back of the eye眼底血管的图案C、The amount of light reaching the retina视网膜受光量
考题
单选题What physical characteristic does a retinal scan biometric device measure?视网膜扫描设备检测哪些人体物理特性？（）A
The pattern of light receptors at the back of the eye眼底光受体组织的图案B
The pattern of blood vessels at the back of the eye眼底血管的图案C
The amount of light reaching the retina视网膜受光量
热门标签
最新试卷