【正文】 f acetylcholine can be maintained via a hydrolysis reaction catalyzed by the enzyme acetylcholinesterase. This enzyme hydrolyzes acetylcholine into acetic acid and choline. If acetylcholinesterase activity is inhibited, the synaptic concentration of acetylcholine will remain higher than normal. If this inhibition is irreversible, as in the case of exposure to many nerve gases and some pesticides, sweating, bronchial constriction, convulsions, paralysis, and possibly death can occur. Although irreversible inhibition is dangerous, beneficial effects may be derived from transient (reversible) inhibition. Drugs that inhibit acetylcholinesterase in a reversible manner have been shown to improve memory in some people with Alzheimer39。 in response to activation of this nerve supply, smooth muscle contracts (notably in the gut), the frequency of heart beat is slowed, and glands secrete. Acetylcholine is also an important transmitter at many sites in the brain at nervetonerve synapses. To understand how acetylcholine brings about a variety of effects in different cells it is necessary to understand membrane receptors. In postsynaptic membranes (those of the cells on which the nerve fibres terminate) there are many different sorts of receptors and some are receptors for acetylcholine. These are protein molecules that react specifically with acetylcholine in a reversible fashion. It is the plex of receptor bined with acetylcholine which brings about a biophysical reaction, resulting in the response from the receptive cell. Two major types of acetylcholine receptors exist in the membranes of cells. The type in skeletal muscle is known as ‘nicotinic’。 2. 試論述《復(fù)活》對沙皇專制制度的批判 《復(fù)活》通過瑪絲洛娃的悲慘遭遇和聶赫留道夫為她上 訴請愿的過程 ,對沙皇專制制度的反人民本質(zhì)進行了有力而全面的揭露 .它主要包括以下幾方面 : (1)通過對法庭審判過程的描寫 ,真實地反映出沙皇俄國司法制度和暴力鎮(zhèn)壓機構(gòu)的罪惡本質(zhì) ,這包括對法庭上 —— 群法官的揭露 ,對中高級官吏 (副省長 ,典獄長 ,看守長 ,前國務(wù)大臣 ,將軍 ,大法官 )的揭露 ,對監(jiān)獄的可怕和丑惡的揭露 .作者指出 ,許多人遭到逮捕和判刑的原因是他們妨礙了官吏和富人們享有的特權(quán) ,而法律是為了維護對統(tǒng)治階級利益而制定的 . (2)對沙皇專制制度的精神支柱 —— 官辦教會給予了無情的揭露 . (3)《復(fù)活》中的貴族已經(jīng)沒有優(yōu) 秀人物 ,他們都是一些空虛 ,腐朽 ,偽善的寄生蟲 . (4)托爾斯泰的同情完全在農(nóng)民一邊 .在《復(fù)活》中 ,作家真實地描寫了廣大農(nóng)民的悲慘處境 ,并明確表示反對土地私有制 . 請您刪除一下內(nèi)容， O(∩ _∩ )O 謝謝！??！ 2021 年中央電大期末復(fù)習考試小抄大全，電大期末考試必備小抄，電大考試必過小抄Acetylcholine is a neurotransmitter released from nerve endings (terminals) in both the peripheral and the central nervous systems. It is synthesized within the nerve terminal from choline, taken up from the tissue fluid into the nerve ending by a specialized transport mechanism. The enzyme necessary for this synthesis is formed in the nerve cell body and passes down the axon to its end, carried in the axoplasmic flow, the slow movement of intracellular substance (cytoplasm). Acetylcholine is stored in the nerve terminal, sequestered in small vesicles awaiting release. When a nerve action potential reaches and invades the nerve terminal, a shower of acetylcholine vesicles is released into the junction (synapse) between the nerve terminal and the ‘effector’ cell which the nerve activates. This may be another nerve cell or a muscle or gland cell. Thus electrical signals are converted to chemical signals, allowing messages to be passed between nerve cells or between nerve cells and nonnerve cells. This process is termed ‘chemical neurotransmission’ and was first demonstrated, for nerves to the heart, by the German pharmacologist Loewi in 1921. Chemical transmission involving acetylcholine is known as ‘cholinergic’. Acetylcholine acts as a transmitter between motor nerves and the fibres of skeletal muscle at all neuromuscular junctions. At this type of synapse, the nerve terminal is closely apposed to the cell membrane of a muscle fibre at the socalled motor end plate. On release, acetylcholine acts almost instantly, to cause a sequence of chemical and physical events (starting with depolarization of the motor endplate) which cause contraction of the muscle fibre. This is exactly what is required for voluntary muscles in which a rapid response to a mand is required. The action of acetylcholine is terminated rapidly, in around 10 milliseconds。 1669 年后，莫里哀的創(chuàng)作進入最后一個時期，《貴人迷》、《女學者》都嘲笑了貴族世界?！读邌莨怼放c《喬治這時期的主要作品有《可笑的女才子》，把矛頭指向貴族；同時的《丈夫?qū)W堂》、《太太學堂》討論了愛情、婚姻、宗教等問題，維護個性自由，反對封建道德。他學習民間笑劇和意大利即興喜劇的手法，寫了一些作品，漸漸在外省出了名。每題 15 分，共 30 分。在人物的內(nèi)心意識的展現(xiàn)過程中，人物離我們越來越近，而我們仿佛也看到了自己內(nèi)心深處的審判，聽到了自己內(nèi)心深處的吶喊。它所表現(xiàn)的意識深度是有限的，也不象內(nèi) 心獨白那樣毫無保留。無所不知的描寫是有一位無所不知的作家介入描寫人物的精神內(nèi)容和意識活動的過程中，通過運用傳統(tǒng)的敘事和描寫方法對這種意識進行描述。直接內(nèi)心獨白是這樣一種獨白，在描寫這樣的獨白時既無作者介入其中，也無假設(shè)的聽眾，它可以將意識直接展示給讀者，而無需作者作為中介 來向讀者說這說那，也就是說，作者連同他的那 他說 、 他想 之類的引導性詞句和他的那些解釋性論述都從書頁中消失了或近于消失了。因此，面對這一類文本時，解讀者盡可能準確地把握將人物多層次的感覺印象、心理圖象等貫穿起來的意識中心，從中尋繹人物意識流動的線索，是對它們做出細致、準確的解讀的關(guān)鍵。 3. 意識流小說有哪些主要特征 就文體特征而言，由于意識流小說以人物意識活動為結(jié)構(gòu)中心來展示人物持續(xù)流動的感覺和思想，而且通常借助自由聯(lián)想來完成敘事內(nèi)容的轉(zhuǎn)換，因此，它們往往打破傳統(tǒng)小說正常的時空次序，而出現(xiàn)過去、現(xiàn)在乃至未來的大跨度的跳躍。 自然主義的藝術(shù)特點： （一）巨細無遺地描繪現(xiàn)實，排斥虛幻想象，給人一種實錄生活和照相式的印象； （二）注重群體寫照，追求人物氣質(zhì)和心理，逐漸忽 略典型塑造，只追求人物的氣質(zhì)特點和變態(tài)心理； （三）淡化情節(jié)，不去追求戲劇性的曲折變化，主張按照生活的本來面貌去反映現(xiàn)實； （四）將社會現(xiàn)象擬人化，這是物對人的初步異化的描寫，顯得生動形象。詳盡收集、描寫生活材料，客觀冷漠地還原生活，不懼怕流于瑣碎； （二）接受了巴爾扎克描寫一段歷史時期，反映整個社會的成功經(jīng)驗。伽洛蒂》、《智者納旦》、《拉奧孔，或論畫與詩的界限》、《漢堡劇評》 維蘭德：《阿迦通的故事》 2. 自然主義文學有什么特征 自然主義產(chǎn)生于 19 世紀下半葉的法國，在 70－ 80 年代達到盛期。封封這類作品主要有： C D E A. 《米隆老爹》 B. 《蠻大媽》 C. 《羊脂球》 D. 《菲菲小姐》 E. 《項鏈》 2. 下列作家中屬于“湖畔派”詩人有： A C A. 華茲華斯 B. 柯爾瑞治 C. 騷塞 D. 雪 萊 E. 霍夫曼 3. 巴爾扎克的《人間喜劇》分為： A B D A. 《風俗研究》 B. 《哲理研究》 C. 《學術(shù)研究》 D. 《分析研究》 E. 《生活研究》 4. 下列作品屬于莎士比亞四大悲劇的是： A C D E A. 《李爾王》 B. 《羅密歐與朱麗葉》 C. 《麥克白》 D. 《哈姆萊特》