Unit 4 New课件.ppt

Unit 4;Word Formation;stria- [strai?] （from Latin: a groove） (plural?striae) a stripe n.? 线痕,? 条纹,? 细沟 levo- (left ) e.g. levodopa dys- (with difficulty) e.g. dyskinesia kinesia- (movement ) e.g. akinesia （运动不能） brady- (slow) e.g. bradykinesia oxid/o (oxidation) 氧化 -ant (substance) …剂 e.g. antioxidant;Questions to consider:; The Basics of Parkinsons Disease What Is Parkinsons Disease? Parkinsons disease, which mostly afflicts older people, results from gradual degeneration of nerve cells in the portion of the midbrain that controls body movements. The first signs are likely to be barely noticeable -- a feeling of weakness or stiffness in one limb, perhaps, or a fine trembling of one hand when it is at rest (activity causes the tremor to disappear). Eventually, the shaking worsens and spreads, muscles tend to stiffen, and balance and coordination deteriorate. ;Depression and other mental or emotional problems are common. Usually the disorder begins between the ages of 50 and 65, striking about 1% of the population in that age group; it is slightly more common in men than in women. Medication can treat its symptoms, and the disorder is not directly life-threatening. ;What Causes Parkinsons Disease? Bodily movements are regulated by a portion of the brain called the basal ganglia, whose cells require a proper balance of two substances called dopamine (多巴胺) and Acetylcholine ( 乙酰胆碱 ), both involved in the transmission of nerve impulses. In Parkinsons, cells that produce dopamine begin to degenerate, throwing off the balance of these two neurotransmitters. ;Researchers believe that genetics sometimes plays a role in the cellular breakdown. In rare instances, Parkinsons disease may be caused by a viral infection or by exposure to environmental toxins such as pesticides, carbon monoxide, or the metal manganese (锰). But in the great majority of Parkinsons cases, the cause