MASTER RESEARCH PROPOSAL Example | Topics and Well Written Essays - 1000 words

MASTER - Research Proposal Example The use of business intelligent applications will bring a smooth and easier data storage and retrieval of data hence being able to manage the increasing number of patients in hospitals (Avolio, 2013, pg53). However the difficulty in the application of business intelligent solutions in the health care is mainly because of how the data is collected, procedures used and the knowledge extracted. Moreover, the main aims of using this meth in any firm are to extract information related to customer satisfaction, performance measurement and profit maximization. The recent growth and development in the education systems have led to very high demand for the management, evaluation and accreditation of data management of health care institutions. Many institutions have been forced to adopt and try nonconventional solutions known for massive data management (Dept. of Industry, 1982). The use of new technology in this firm offers great different solutions. They include data warehousing, big data and businesses intelligent. However, this state of art and use of technology is being adapted and installed in many business industries so as to obtain the tailor-made solutions that are needed. The proposed model in that can be used in the health care institution would have a number of procedures that are related to progress of health care services (Cheney, 2011, pg34). This model would analyze the current procedures in decision making in all areas in the health care firm hierarchy and levels of hospital levels. This will help to provide the solutions needed by use the state of the art system in decision making. These key and vital decisions are made with reference to the reference benchmark for these requirements (Wright, 1996, pg42). Objective of this research is to explore the reasons for the lack of use of the new model of business intelligent in the healthcare institution. Some of the specific aims of this research entails establishing the benefits of installing

Review on Mason and Dixon chapter 35 by thomas pynchon Essay

Review on Mason and Dixon chapter 35 by thomas pynchon - Essay Example Reverend Cherrycoke to his twin nephews Pitt and pliney alternatively referred to as the elder, or the Younger throughout the book narrates the tale. The narrative approach dramatically changes from the story to the room where the narrative is being told. It requires a person to be extra careful or else they will be lost in time. The chapter reintroduces Reverend Cherrycoke and introduces the Redzinger family, the gambler Mr. Edgwise as well as the outstanding Armand and his Duck (350). It discusses the history and Christ likening the two to the fate of no man with only the destination of every expedition as the universal factor. Cherrycoke reveals there is a machine, which triggers all history in some part, leaving people in times where they cannot live and remain sane where history disappears. Cherrycoke observations in Christ and history can be thought as a straight denunciation of the Puritan and subsequently, American principle of the theory of Exceptionalism. This theory is of the opinion that America is different from other nations, it has a sacred history and events, and that it is the chosen country. It argues that America’s cities and hidden valleys are of one true god who is always on the American side saving the faithfulness America. America and Americans will suffer to be one, later in ti me in a reunion with their creator as a reward for the sacrifices and hard work for its priceless dedication as well as devotion. To the puritans what is stated to be a fact remains so but to the younger generations in the form of Ethelmer, the Reverend as well as Pynchon this does not hold water (361). The book requires maximum concentration for one to acknowledge the early history and culture. It requires slow and keen reading more so in chapter 35, where the themes require attention to identify, as they are not straightforward. This is critical in the understanding of the

The Madness of John Brown Essay Example for Free

The Madness of John Brown Essay Historians are not the only ones that can elucidate history. History is a extensive puzzle that can be solved by anyone who has an educated diploma on certain subjects. Historians are the main disposition to solve the uncertainty of history with their useful, quality skills of making theories to conjoin loose ends of history, motivation of repeated research, and their undying love to learn new history, but a psychologist can solve history too with their forte. Even though it may seem absurd to believe that this occupation who assesses a mans personality to solve problems; a psychologist can solve an dead mans prospective in life. A letter is a common communication device in the old days and can be read by anyone. A historian would try to find key words in the letter to guesstimate the situation, but a psychologist knowing the mysteries of attitudes and behaviors of people would look at double meanings in passages. Two perceptions are better than one and knowing the true motivation of a persons mind than their careless actions can give an different outlook of a case. Other specialists can help historians find the gist of John Brown rationale of being insane in the terms of slavery and why he killed five men in the open. Although John Brown never underwent a psychological examination about his childhood, he had left a letter with important information of his childhood into a story. Psychoanalytic insight has helped to reveal some of Johns most intense personal conflicts from this letter; his ambivalence toward his fathers strict discipline, the paradox of Browns struggle to internalize and accept his fathers authority in order to become independent himself, and his main concern with property and pets as a means of defining his independence. This ambivalent father-son relationship suggests that Browns intense life-long identification with black slaves might well have sprung from the struggle he experienced with paternal discipline. Helping slaves was ultimately a means of helping himself without consciously recognizing the source of his emotions and convictions. He could have channel the repressed hostility toward his father toward the slaveholders. In conclusion, psychologist has added the tool of psychoanalysis in the study of history. This tool has helped historians to go beyond rational motives in understanding people who have changed society and history in either a good or bad way. History has somewhat gotten more clearer and truthful thanks to psychologists.

Feminist Movement 1960s

Feminist Movement 1960s The Women Movement has been divided into three phases by the feminist experts. Each phase dealt with different issues regarding to females. In the First Wave of Feminism, the movement started from the 18th century which lasted in the beginning of the 20th century. The hurdles of inequality such as property rights and voting rights were the major concerns. Virginia Woolf is the founder of the ideas of this first wave of movement. The first wave completely paid attention to the idea and rights of suffrage. The Second Wave of Womens Movement which is also known as Feminist Movement or the Liberation movement of women in the USA began during the early years of 1960s and lasted throughout the late 1980s. Simone de Beauvoir is allied with the idea of this wave. The second wave of feminism focused on the issues of gender inequality, sexuality, workplace, family and reproductive rights. This wave argued that women have to face the political as well personal tyranny in a society which is male dominant. (Barbara Sinclair, 1983) The womens movement in the 1960s emphasized on attaining freedom in terms of reproductive and sexual. The demands are women specific like centers for rape crisis, birth control options, very reasonably priced child care, emphasis on womens health and other needs of women. This movement resulted in creation of municipal Rape Treatment Center Act, 1974 by which in all city hospitals, rape treatment centers established. This movement also challenged the abortion law in Illinois where abortions were illegal by law by creating an organization named Jane. Other goals of these movements were the equality in terms of economics from 1960 onwards. This movement emphasized on gender equality unlike earlier movements which were aimed for legislation only. Another organization was formed for the rights of women in 1974 name The Coalition of Labor Union Women with the targets like maternity leave, pension benefits deduction and other rights like biased insurance rates and provided access to women who were never before on union level. Women which were already working in Chicago fought hiring and biasness for jobs. The period from 1917 to 1960s had two world wars and an economic boom because of which many women came into Workplace. During the war, women served as labor and then they started working to achieve and maintain the new higher and better living standards which were enjoyed only by middle class families. When women joined the workplace, they soon realized the discriminated behavior towards them in terms of unequal economic and social status. Many movements such as Civil Rights act and student movements were at its peak during the years of 1960s. The women adopted and followed the practices of these movements. They adopted the different methods of awareness raising, demonstrations, protests, and political lobbying to bring in front their own agenda. National Organization for Women (NOW) was established in 1966 which was an official group to represent and fight for the issues and problems of women. This new group of women was not instant success of them but by the end of second years of its creation growing to its members up to the mark of 1035 and was divided by ideological partitions. The founders of NOW began working on the legislation that could improve the living of the women and they also forced the politicians to become aware of the problems of the women. This group worked out six factors which are considered to be essential for womens equality with men which includes the abiding of laws by employers for equal opportunity employment and end the discrimination, equivalent and isolate education as of men. The other factors were maternity leaves, tax deductions and training to poor women while on job. At the same time many other organizations started to establish for the welfare of the women. The two factors on which NOW face d serious problems were Equal Rights Amendment to the US Constitution which makes sure the equivalent rights regardless of gender and the demand of contraception and abortion. United Auto Workers which was supporting NOW with the office space took out its support because the ERA law will prohibit freedom for women. When some of the NOW members called to revoke the abortion amendments, many other members left NOW. NOW was struggling to re-establish itself as a national organization for women for the period of two years. There were other groups formed due to this blow to NOW by female antiwar, civil rights and members who left NOW due to refusal to readdressing the womens concerns. Women during 1960s period were demoralized by unequal treatment. In 1964 at Student Nonviolent Coordination Committee (SNCC) conference a womans resolution was presented, Stokely Carmichael who was Black Nationalism in United States cut off all the debate with the argument that the only place for women in SNCC is prone. NOW aimed on womens rights, the new radical groups emerged with wider themes of womens freedom and spread in Chicago, Toronto, Seattle, Detroit and other places and towns. Although these radical groups structure was not strong as NOW has its national structure. In no time, womens liberation movement was wide spread and can be observed every where. Liberation movement had no officers nor offices, no addresses and no printed agenda to present their point of view. Miss America Pageant presented the image of womanhood during the protest at Atlantic City and New Jersey in 1968. Redstockings which is one of the feminist radical groups published The Bitch Manifesto based in New York City in 1969. In 1969, NOW called the congress to unite women in which was aimed to unite the radical and moderate wings of the womens movement which was almost impossible task. NOW leaders were aimed to have a reform while the radical groups were aimed to revolution. In 1975, the National Agenda of Women the comprehensive program of legal and political reforms- was presented to the president Gerald Ford, all state governors and all the members of the Congress. Subsequently, in 1977 an action plan was presented to the government official in National Womens Conference in Houston to remind them about the feminine constitution which is their responsibility. National Womens Political Caucus and National Organization for Women keep focusing and pressurizing the politicians and legislators and making prominent of womens issues on media. The legal success of the movements were the Affirmative action, Title IX and Women Education Equity Act, The Equal Credit Opportunity Act (1974), the act of Pregnancy Discrimination (1978), the illegalization of marital rape and legalization of no fault divorce in all states. Beside all these victories, the change of social attitudes in favor of female is considered the biggest victory of the womens movement. The year of 1980 is the decline of the second wave of feminine movement. During the early 1980s, it was thought that females have achieved all of their demanded goals. In 1982, the Equal Right Act (ERA) was failed, because only three states did not approve this. The second wave of womens movement was successful except the ERA. (Flora Davis, 1999) Pros and Cons Despite of problems faced by Womens movement due to its leadership and ranks, the movement attained some goals in a very short time. Due to support of the Equal Employment Opportunity Commission in 1965, women in US got jobs in every corner of US and the employees which have decimation histories are required to provide the durations in which they increase the women strength in their companies. Some laws including Divorce laws were relaxed; ensuring that employers can not fire the pregnant women from jobs and some new study programs for women are introduced in universities and colleges. In 1972, Congress passed an amendment in the Higher Education Act which ensured that there must be no discrimination on the bases of gender in educational programs which are getting federal financial helps and also ensured that there must be same space for womens in all male schools. ERA amendments in the US laws including state sodomy laws, existence of single sex bathrooms in public places, legalization of same-sex marriage and relationship and making abortion as a legal right funded by the taxpayer fund. This law required 38 states which were not achieved as expected and amendment fell short of three states support. There was a growing sense that womens movement goals are already achieved. NOW sustained its new role in new millennium by struggling for womens rights including equality in military and federal funding for child care programs and to prevent any violence against womens of US. Despite of its popularity and its membership and funding growth, its activism fragmented and burdened with opposition. In sum, the second wave of womens movement was very successful for the welfare and in status up gradation of women. It has many successes and the only failure is the ERA. In the Third Wave of Feminism started in 1990s and present till today. This movement started in result of the perceived failures of the second wave of Feminism. The Equal Rights amendment is still in question and in progress which was supported by second and third wave movement leaders.

Revolution in Like Water for Chocolate by Laura Esquivel :: Like Water for Chocolate

Revolution in Like Water for Chocolate Revolutions throughout the history of humankind have established change of traditions as the normal occurrence throughout our history. Revolutions in households can also occur when traditions that are contrary to the desires of one, interfere with the values of another. In the book "Like Water for Chocolate," a major revolution develops between mother and daughter, Mama Elena and Tita. Like most revolutions, traditions are the major factor in the revolution that happens between these two; Tradition states that the youngest daughter must not marry, but must take care of the mother until she dies. Nevertheless, when a young man decides to ask for Tita's hand in marriage, Mama Elena flat out refuses to hear any more about the subject. She says to Tita on page 10, "If he intends to ask for your hand, tell him not to bother . . ." Then Tita realizes the hopelessness of her situation and from that moment on she swore "to protest her mother's ruling" (11). The revolution continues to build until finally after many years of torment by her mother, Tita leaves the family ranch. Then after awhile, when Mama Elena becomes paralyzed by bandits, Tita feels compelled to return to the ranch and care for her mother. In returning Tita felt that her return humiliated her mother because how cruelly she had treated her daughter in the past (130). When Tita had made dinner for her mother, Mama Elena brutally rejected her kindness. Tita could not understand why her mother treated her cruelly, "she didn't understand Mama Elena's attitude . . . It was beyond her comprehension that one person, whatever her relationship with another, could reject the kind gesture in such a brutal manner . . ." (130-131). After all that they had gone through, Tita thought at least some things had changed. Of course nothing had changed because Mama Elena saw her daughter as she saw her self many years before. But after her mother's death Tita was enlightened when see discovered her mother's love letters from José, her mother's only true love (137). As Tita read her mothers letters, she discovered the reason behind her mother's personality, both psychologically and emotionally. "José was the love of her life. She hadn't been allowed to marry him because he had Negro blood in his veins .

The Twenties :: essays research papers

Area One-Politics and Government-The Harding Scandals and the Bonus Bill veto   Ã‚  Ã‚  Ã‚  Ã‚  The presidency of Harding was filled with continuous scandal. Many compare the Harding to Grant has both being postwar presidents marked by scandals and corruption. Having appointed several excellent officials, Harding also appointed a number of incompetent and dishonest men to fill important positions, including the Secretary of Interior, Albert B. Fall and Attorney General Harry M. Daugherty.   Ã‚  Ã‚  Ã‚  Ã‚  The Secretary of Interior, Albert B. Fall, in 1921, secured the transfer of several naval oil reserves to his jurisdiction. In 1922, Fall secretly leased reserves at Teapot Dome in Wyoming to Harry F. Sinclair of Monmouth Oil and at Elk Hills in California to Edward Doheny of Pan-American Petroleum. A Senate investigation later revealed that Sinclair had given Fall $305,000 in cash and bonds and a herd of cattle, while Doheny had given him a $100,000 unsecured loans. Sinclair and Doheny were acquitted in 1927 of charges of defrauding the government, but in 1929 Fall was convicted, fined, and imprisoned for bribery.   Ã‚  Ã‚  Ã‚  Ã‚  Another scandal involved Charles R. Forbes, appointed by Harding to head the new Veteran’s Bureau. He seemed energetic and efficient in operating the new hospitals and services for veterans. It was later estimated that he had stolen or squandered about $250 million in Bureau funds.   Ã‚  Ã‚  Ã‚  Ã‚  Scandal also tainted Attorney General Daugherty who, through his intimate friend Jessie Smith, took bribes from bootleggers, income tax evaders, and others in return for protection from prosecution. When the scandal became to come to light, Smith committed suicide in Daugherty’s Washington apartment in May 1923. There was also evidence that Daugherty received money for using his influence in returning the American Metal Company, seized by the government during the war, to its German owners. Area Two-Economics-Prosperity and Innovation   Ã‚  Ã‚  Ã‚  Ã‚  Though overall the economy was strong between 1922 and 1929, certain segments of the economy, especially agriculture, did not share in the nation’s general prosperity. Improved industrial efficiency, which resulted in lower prices for goods, was primarily responsible. Manufacturing output increased about 65%, and productivity, or output per hour increased by about 45%. The numbers of industrial workers actually decreased from 9 million to 8.8 million during the decade. The increased productivity resulted from improved machinery, which in turn came about for several reasons. Industry changed from steam to electric power, allowing the design of more intricate machines and replaced the work of human hands. By 1929, 70% of industrial power came from electricity.

Neurophysiology Study Guide

Neurophysiology Study Guide 1. Define â€Å"equilibrium potential†. Why is the resting potential closer to the potassium equilibrium potential (EK+) than the sodium potential (ENa+)? The equilibrium potential is the point at which the force exerted on an ion by electrostatic and concentration gradient forces are balanced, and there is no net movement of that ion. The resting potential is closer to EK+ than ENa+ because the cell membrane is more permeable to potassium than sodium. 2. How would ENa+ change following an increase in the external concentration of sodium?Would the resting potential be affected significantly? If the external concentration of sodium was increased, the concentration gradient driving the movement of sodium would be increased more sodium would diffuse into the cell and would reduce some of the negative charge on the inner surface of the lipid bilayer. This would serve to decrease (make less negative) the resting potential, but would not affect it signifi cantly since the membrane is much more permeable to K. 3. Does any net Ionic current flow at the resting potential?What are the relationships among â€Å"passive† and â€Å"pump†ionic currents at the resting potential? There is no net ionic current flow at the resting potential. However, since neither Na+ nor K+ is at equilibrium, there is a net flow of each across the membrane. The Na-K pump generates the concentration difference that sustains the resting potential: but it is the passive ionic flow that creates the resting potential. Pump currents balance passive currents (diffusion) at the resting potential. 3. Define â€Å"electrogenic† and â€Å"neutral† pumps.What role does the Na-K pump play in the resting potential? An electrogenic pump creates a potential difference across the membrane – positive and negative charges are not transported across the membrane in equal amounts. Neutral pumps are balanced according to charge – there is no potential difference created. The Na-K pump generates the concentration difference that sustains the resting potential. 5. Describe the sequence of ionic events and their effect upon the resting potential following lockade of the Na-K pump, or following an increase in extracellular potassium or sodium. When the Na-K pump is blocked by an agent such as oubain or digitalis, Na+ and K+ will continue to diffuse passively across the cell membrane down their respective gradients. After a while, intracellular [Na] will increase and intracellular [K] will decrease. The reduced [K] gradient will reduce K efflux through nongated channels; therefore, the resting potential will depolarize. The reduced [Na] gradient will have little effect on the resting potential.If extracellular [K+ ] is increased, the driving force for potassium diffusion out of the cell will decrease, and the resting potential will become less negative (depolarized). If extracellular [Na+ ] is increased, the driving force f or sodium movement into the cell will increase with a resultant slight depolarization, but there will be no significant change in resting potential. Na+ -K+ ATPase pump activity Y [[Na+]in Y [Na+]O/ [Na+]i Y ENa+ Y (EM – ENa+) Y INa+ Y Conduction velocity and Depolarized threshold 6.Explain the interrelationships between ionic and capacitive currents during postsynaptic potentials or during an action potential. Ionic current is the flow of ions through channels into or out of the cell. Capacitive current is the movement of charges, usually positive, up to or away from the cell membrane. During an excitatory postsynaptic potential or an action potential, there is an initial ionic current flow into the cell, followed by a capacitive current out of the cell, which serves to depolarize the membrane potential at a distance. The current loop forms a â€Å"local circuit. † 7.Define â€Å"time constant†. How is it calculated and why is it important for integration of electrical activity at the axon's initial segment? The time constant is the amount of time it takes for EM (membrane potential) to decay to 1/e of its initial strength (37%). It is equal to resistance times capacitance. It is important for integration at the initial segment because it determines whether temporal summation can take place – a long time constant means slow decay which allows summation to occur; a short time constant means fast decay, and therefore no summation. 8. Define â€Å"length constant'.How does it depend upon axon diameter, axial resistance and membrane resistance; what does it suggest about the relative effectiveness of synapses on the soma versus synapses on the dendrites? The length (or space) constant is the distance that a signal can travel before falling to 1/e (37%) of its initial magnitude. It is proportional to the square root of the diameter of the fiber and to membrane resistance, and inversely proportional to axial resistance. The higher the membrane resistance, the farther the signal will go. The larger the length constant, the slower the signal decay.This suggests that synapses on the soma are more likely to undergo spatial summation than dendritic synapses. 9. Define â€Å"graded potentials†. How do these differ from action potentials? A graded potential is one in which the amplitude is directly proportional to the magnitude of the stimulus. It has no refractory period and is a local potential – i. e. it is not actively conducted and spreads only passively. Graded potentials can be either depolarizing or hyperpolarizing and can add. Action potentials cannot add, have refractory periods are all or none, and are propagated actively. 0. Explain the shape of a â€Å"strength duration† curve. Define â€Å"rheobase† and â€Å"chronaxie† The shape of the strength-duration curve shows that initiation of an action potential is dependent on both the amplitude and the duration of a stimulus. Rheobase is the minimum effective stimulus strength. Chronaxie is the duration of the stimulus that is required to just reach threshold when the stimulus amplitude is twice rheobase. 11. Explain in detail how an action potential is generated. What types of channels tend to open as the membrane potential depolarizes?Draw a graph illustrating how sodium and potassium conductances change (with time) during an action potential. When the membrane is depolarized, voltage sensitive Na+ channels open allowing Na+ to enter the cell down its electrochemical gradient This entry of Na+ further depolarizes the cell, resulting in the opening of more Na+ channels: thus allowing more Na+ to enter, and so on. When the influx of Na+ exceeds the efflux of K+ , threshold is exceeded and the response becomes regenerative, leading to the depolarizing or rising phase of the action potential.After a period of time the Na+ channels inactivate and close: blocking further entry of Na+ through these channels. Also after a delay, voltage-sensitive K+ channels open, allowing K+ to leave the cell, traveling down its electrochemical gradient. The inactivation of the Na+ channels coupled with the opening of the K+ channels result in the repolarization of the membrane potential 12. How do the time courses of sodium and potassium conductances differ during a maintained depolarization? A maintained depolarization causes Na+ inactivation (reduces PNa+) and hence increases (depolarizes) the threshold potential.In addition, compared with the Na+ activation process, the K+ activation process (increased PK+ ) is delayed and persists as long as the depolarization is maintained. 13. Define â€Å"sodium inactivation†. How does it explain the â€Å"absolute† and â€Å"relative† refractory periods, or â€Å"accommodation†? How do potassium ions play a role in these processes? What limits a neuron's maximum rate of firing? There are two ‘gates' on the voltage gated sodium channels. As the membrane is depolarized, sodium channels open. When the membrane is fully depolarized, sodium channels become inactivated.Sodium inactivation is high at the peak of the action potential and is maximal about the time that the repolarization phase intersects the zero potential. It is this process and the fact that most potassium channels are open that account for the absolute refractory period. The relative refractory period is the gradual recovery of Na+ channels from the inactivation process. Accommodation is also related to sodium inactivation because a slow depolarization will cause the Na+ channels to go directly from the closed state to the inactivated state. A neuron’s maximum rate of firing is limited by the absolute refractory period. 4. What role does the Na+ -K+ pump play in the action potential? How is the action potential affected by alterations in the concentration of extracellular Na+ or K+ Action potentials arise from the passive movement of ion s down their electrochemical gradients. The Na+-K+ pump creates the electrochemical gradients that sustain the resting potential and generate the action potential. Alterations in the concentration of extracellular K+ will cause fluctuations in the resting potential that will decrease or increase the likelihood of an action potential being generated.Alterations of extracellular Na will increase or decrease the conduction velocity of action potentials as well as the likelihood of an action potential being generated. 15. Explain the mechanism for propagation of an action potential in an unmyelinated nerve or in a myelinated nerve. Why is the latter much faster? What factors affect conduction velocity? Once an action potential has been initiated, the inward Na+ current depolarizes the membrane toward ENa+ . This results in a potential difference between this active region and the adjacent inactive region, which is still near EK+ .Hence, current will flow between the active and adjacent inactive region, depolarizing the inactive region. The resulting increase in intracellular Na+ leads to an outward capacitive current and depolarization of this region of membrane. When the depolarization reaches threshold, an action potential will be initiated in this region of the membrane. In an unmyelinated nerve, this is a continual process moving down the membrane. In a myelinated nerve, this process occurs only at the node of Ranvier. Myelinated nerves have faster conduction velocities because the action potential â€Å"jumps' from node to node, which may be up to 2 mm apart.Conduction velocity is affected by membrane capacitance and by membrane and axoplasm resistances. Myelin increases membrane resistance, thereby constraining incoming positive charge to move down the axon. Myelin reduces membrane capacitance; this reduces the amount of negative charge that must be neutralized to reach threshold. Axoplasm resistance is inversely proportional to axon diameter. Thus, conduct ion velocity increases with fiber diameter,. 16. Describe the process of â€Å"saltatory† conduction. Why is it advantageous? Explain how and why conduction velocity and the length (space) constant are affected by demyelinating iseases. Saltatory conduction is the discontinuous propagation (jumping from one node of Ranvier to the next) of an action potential along a myelinated nerve. Saltatory conduction arises in part from the properties of the myelin sheath, which increases the membrane resistance and decreases the capacitance in the internodal region; the result is an increase in current flow down the core of the axon. In addition the voltage-sensitive Na+ channels responsible for the generation of the action potential are localized only at the nodes.This type of conduction makes possible rapid precise control of muscle contraction. In demyelinating diseases conduction velocity and the length constant are reduced in the unmyelinated areas. The length constant is proportion al to membrane resistance and when the myelin is destroyed, the resistance at that point decreases and therefore the length constant decreases. Because of increase capacitance and negative charge on the inner surface of the membranes, propagation of the signal takes place continuously instead of jumping from node to node; therefore, conduction velocity is decreased. 7. What are the three functions of a sensory receptor? 1) Transduction of the environmental signal Energy Y Change in membrane potential 2) Amplification of the environmental signal 3) Transmission of the environmental signal to the CNS 18. How does a â€Å"receptor potential† or â€Å"generator potential† differ from an action potential? A receptor or generator potential is a graded potential that is proportional to the stimulus. It is not a function of the membrane potential and thus is not regenerative like an action potential.It has no refractory period and, therefore, is additive. It is â€Å"localâ⠂¬  and propagated. Finally, the ion channels producing the receptor/generator potentials are different from those underlying the action potential; they are not voltage gated. 19. Explain how an action potential is initiated in a sensory nerve. What conditions are necessary for repetitive firing? How does the firing frequency depend upon the amplitude of the generator potential? Upon the intensity of the stimulus? A sensory nerve action potential begins with the receipt of an appropriate environmental signal.The stimulus causes a localized increase in the permeability of the nerve terminal to Na+ . The resulting net inward positive ionic current depolarizes the nerve terminal. This current spreads passively along the axon terminal producing a depolarizing outward capacitive current The outward capacitive current, in turn. may induce an action potential in a region of the nerve with a low threshold for generating an action potential- usually at the first node of Ranvier in myelinate d nerves. A maintained stimulus is necessary for repetitive firing.The firing frequency is proportional to the amplitude of the generator potential and the intensity of the stimulus. 19. Define â€Å"sensory adaptation†. Name two classes of receptors. What type of information about the stimulus is derived from each? Give examples. Sensory adaptation is the decline in response that occurs over time when a receptor is subjected to a constant stimulus. There are two types of receptor classifications: slowly adapting (tonic) receptors and rapidly adapting (phasic) receptors. Slowly adapting receptors provide information about the rate of change of a stimulus as well as the magnitude and duration.This type of receptor is seen in touch, pressure, hair cells for hearing and vestibular function, muscle spindle receptors, Golgi tendon organs and in baroreceptors. Rapidly adapting receptors are unable to maintain a sustained depolarization, despite sustained stimulation. They function as rate-detectors providing information about the rate of change of the environmental signal. Rapidly adapting receptors are found in the Pacinian corpuscles and skin hair receptors. 19. Describe in detail the steps involved in the release and degradation of ACh at the neuromuscular junction. What factors regulate how much ACh is released?Chemical synaptic transmission is initiated by a depolarization of the presynaptic element and the subsequent influx of Ca++ ions into the nerve terminal through voltage-dependent Ca++ channels. Ca++ facilitates contact of synaptic vesicles with the terminal membrane, which triggers the synchronous release of several thousands of transmitter molecules into the synaptic cleft. The ACh binds to its receptor on the postsynaptic membrane. After dissociating from the receptor, ACh is degraded by acetylcholinesterase (produced by ) 19. Define â€Å"quantal† release and â€Å"miniature† end-plate potential.How are the two related? Quantal r elease refers to the release of neurotransmitters in discrete packets or vesicles. A single vesicle contains about 5-10,000 ACh molecules, and is capable of depolarizing the membrane about 1mV. The small depolarization caused by the spontaneous release of a few vesicles is called a miniature end plate potential. Spontaneous release of vesicles occurs at a rate of about 1/sec. MEPP's may be important in maintaining the integrity of the muscle fiber. 19. Discuss the â€Å"end-plate† potential (EPP), including its characteristics and underlining mechanisms.Why are its amplitude and duration limited? How does it differ from an action potential? The end-plate potential is the postsynaptic potential produced at motor end plate. The EPP occurs as the result of ACh binding to its receptors on end-plate membrane and opening the chemically gated channels located there. The EPP is a graded potential – the magnitude of the EPP is proportional to the number of channels opened by AC h – and spreads only passively. The EPP acts as a stimulus for the production of an action potential on the muscle membrane contiguous to the end-plate membrane.The amplitude and duration of the EPP may be limited by the amount of neurotransmitter released, or by the number of receptors present, or by the normal activity of AChEase. The EPP differs from an action potential in the same ways that other graded potentials do. 19. How are action potentials initiated at the muscle end plate? What is the ratio of' the number of muscle action potentials to motor neuron action potentials (output: input)? Action potentials are initiated in the region of the muscle end plate when the membrane is depolarized by the electrotonically spreading EPP.The ratio of the number of muscle action potentials to motor neuron action potentials (output: input) is 1:1. 19. What are chemically gated ion channels? Give an example. How do such channels differ from voltage-gated channels? Chemically-gated i on channels are those channels which open only in response to the binding of a chemical neurotransmitter, hormone or other chemicals and not in response to membrane depolarization as voltage-gated channels do. The channel associated with the ACh receptor is a chemically-gated ion channel: 26.Compare and contrast the characteristics of chemical and electrical synaptic transmission. Electrical synaptic transmission is mediated by gap junctions. The gap junctions provide a pathway for cytoplasmic continuity. As a result, a depolarization (or hyperpolarization) produced in the presynaptic terminal produces a change in potential in the postsynaptic terminal. There is minimal synaptic delay and the transmission can spread bidirectionally. Electrical junctions are found in the nervous system, as well as smooth muscle and cardiac muscle.Chemical synaptic transmission occurs between two cell membranes separated by a synaptic cleft. The presynaptic terminal contains a high concentration of mi tochondria and synaptic vesicles and there is a characteristic thickening of the postsynaptic membrane. Since the neurotransmitter must diffuse across the synaptic cleft and bind to its receptor, there is delay of about 0. 5 – 1 msec between the initiation of an action potential in the presynaptic terminal and a potential change in the postsynaptic terminal. Chemical transmission is generally unidirectional.