【正文】 events referred to as signal transduction. For a cholinergic neuron to receive another impulse, acetylcholine must be released from the receptor to which it has bound. This will only happen if the concentration of acetylcholine in the synaptic cleft is very low. Low synaptic concentrations of 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’。 第 7 頁 共 8 頁 第 7 頁 共 8 頁 請您刪除一下內(nèi)容， O(∩ _∩ )O 謝謝?。?！ 2021 年中央電大期末復習考試小抄大全，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。（退回公安機關(guān)偵查或自行偵查。 調(diào)查核實其他證據(jù)材料。 聽取被害人意見。 審查起訴的方法步驟： 審查起訴意見書等。 人民檢察院對偵查終結(jié)的案件的處理方式：提起公訴、不起訴和撤銷案件。 搜查的情況應(yīng)當寫成筆錄，由偵查人員和被搜查人員或者他的家屬、鄰居或者其他見證人簽名或蓋章。 搜查時，應(yīng)當有被搜查人或者他的家屬、鄰居或者其他 見證人在場。 任何單位和個人都有義務(wù)按照公安機關(guān)和人民檢察院的要求，交出可以證明犯罪嫌疑人有罪或者無罪的物證、書證、視聽資料。 搜查的程序： 搜查只能由公安機關(guān)，人民檢察院等偵查機關(guān)的偵查人員依法進行，其他任何機關(guān)、團體和個人都無權(quán)對公民人身和住宅進行搜查。 應(yīng)當依法制作詢問筆錄。 偵查人員應(yīng)當告知證人必須如實地提供證據(jù)、證言和有意作偽證或者隱匿罪證要負的法律責任。 郵電在法律規(guī)定的地點進行。 嚴禁刑訊逼供或以威脅、引誘、欺騙以及其他非法方式進行訊問，切實保障犯罪嫌疑人的訴訟權(quán)利。 對特殊的訊問對象適用特殊的程序。持續(xù)的時間最長不得超過 12 小時。 至少由兩名偵查人員進行訊問。 偵查實驗應(yīng)當由偵查人員進行，并應(yīng)當邀請兩名以上見證人在場。逮捕鄉(xiāng)鎮(zhèn)一級人大代表時，應(yīng)報告該人大。 卓 逮捕有檢法決定，公安機關(guān)執(zhí)行。 拘留由公檢決定，公安機關(guān)執(zhí)行。 監(jiān)視居住由公檢法決定，公安機關(guān)執(zhí)行。 取保候?qū)徲晒珯z法決定，公安機關(guān)執(zhí)行。 書記員、翻譯人員、鑒定人回避由法院院長決定（審判階段）。 公安機關(guān)負責人和檢察長回避由同級人民檢察院檢察委員會決定。 ! S, 公訴案件被害人的訴訟代理人有權(quán)在被害人收到不起訴決定書后的 7 日內(nèi)，代第 6 頁 共 8 頁 第 6 頁 共 8 頁 其向人民檢察院提出申訴，也可以經(jīng)被害人授權(quán)代被害人向人民法院提起自訴。 其他： 刑事訴訟法的立法宗旨 是保證刑 法的正確實施，懲罰犯罪，保護人民，保障國家安全和社會公共安全，維護社會主義秩序。 應(yīng)當有具體的訴訟請求，有足夠證據(jù)證明被告人犯罪的事實。 提起自訴必須要有明確的被告人。 檢察院對此案具有公訴權(quán)，案件數(shù)與受訴法院管轄。 公訴案件的法定條件： 犯罪嫌疑人的犯罪事實已經(jīng)查清，證據(jù)確實、充分，這是提起公訴的事實條件。 證據(jù)確實、充分。 采取取保候?qū)彙⒈O(jiān)視居住等方法尚不足以防止社會危險性，而有逮捕必要的。 逮捕的條件： 有證據(jù)證明有犯罪事實。 公訴案件立案的基本條件： 有犯罪事實。 享有政治權(quán)利，人身自由未受到限制。 保證人的條件： 與本案無牽連。 自然人。 卓越人社區(qū) J 條件： 證人的條件： 。 書證的特 點： .符號 .圖畫等記載或者表達了人的一定思想的物品，而且其所記載或表達的思想內(nèi)容能夠為人民認知和理解。 。 .被告人是否有罪，犯有何罪 .應(yīng)否處以刑罰，處以何種