问题 问答题

试述出现脊髓节段性损害的结构以及临床表现。

答案

参考答案:

脊髓灰质中的前角、后角、前连合以及侧角等部位的损害,主要引起节段型(根型)分布的运动或感觉障碍。前角病变:节段型分布的弛缓性瘫痪,如颈5前角损害引起三角肌瘫痪和萎缩,颈8至胸1损害引起手部小肌肉萎缩,腰3损害使股四头肌萎缩无力,腰5损害使踝关节及足趾背屈不能。后角病变:咽痛、温觉纤维进入后角更换神经元而受损,但部分触觉纤维及深感觉纤维则经后索传导而幸免,因而出现一侧节段性分布的痛、温觉障碍,而触觉及深感觉仍保留,称为分离性感觉障碍。脊髓中央灰质病变:病变损伤了前连合,双侧痛温觉纤维受损而触觉及深感觉保留,出现双侧节段性分布的分离性感觉障碍。脊髓侧角病变:发生相应节段的自主神经功能障碍,引起血管运动、发汗、竖毛反应障碍及皮肤指甲的营养改变等,颈8、胸1侧角受累时出现该节段内的自主神经功能障碍,如Horner征等。

单项选择题
单项选择题

Rarely do major diseases have a single cause. They are usually the result of a complex interaction between many factors, including genetic, environmental and lifestyle components. Many media reports, however, can tead us to believe that if we gave up something that we might otherwise enjoy, we could completely escape that particular affliction.

Clearly, this is not the case. Vegetarians die of cancer of the colon (结肠). Teetotallers die of liver complaints, including cirrhosis (硬化). People who never go out in the sun contract skin melanomas (黑素瘤). Always, there are other factors at work than the single element being examined in a scientific study.

Quite often the alleged benefits of a particular nutritional element are the result not so much of the element itself but of the lifestyle and general diet of the people who consume it most. People who eat lots of "healthy" foods, including fiber, carrots, broccoli etc. , also tend to drink less alcohol, take more exercise, avoid too many fatty foods and smoke less. Only when a study can rule out all of these other factors and often we do not know what these factors might be can we say that there is a causal link between two things. That is not to say that things like fiber and broccoli have no beneficial effects at all. But those with sedentary lifestyles cannot expect these foods to make them healthy.

There is, however, one thing which increases the likelihood of dying relatively young, even when all of the other factors have been taken into account. It is one of the biggest killers even among those who lead lifestyles which, by any criteria, are clearly healthy ones. This single, incontrovertible risk factor is that of being poor. Recent report from the Cancer Research Campaign suggested that 12 700 deaths could have been avoided between 1986 and 1990 if inequalities in cancer care did not exist in England and Wales. Comparing cancer survival rates, the study found that England and Wales fared unfavorably with Europe and the US, but the most affluent regions of these two countries exhibited similar figures to the European average.

In an attempt to counter this disparity the government has announced plans for the provision of Health Action Zones which seek to encourage greater cooperation between health and social services, targeting both rural and inner city areas. The emphasis of this new scheme however appears to focus on inadequacies within health education in these areas, rather than attacking the broader issues of social inequality.

According to the first paragraph, what are we likely to read in many media reports()

A. A particular disease is associated with a single cause

B. We should enjoy as many things as possible

C. We can never understand how different factors interact to cause a disease

D. A disease is caused more by genes than by lifestyles