Thursday, March 26, 2020

More About The 1968 Tet Offensive Essays - Vietnam War,

More About The 1968 Tet Offensive For several thousand years, Vietnamese Lunar New Year has been a traditional celebration that brings the Vietnamese a sense of happiness, hope and peace. However, in recent years, It also bring back a bitter memory full of tears. It reminds them the 1968 bloodshed, a bloodiest military campaign of the Vietnam War the North Communists launched against the South. The "general offensive and general uprising" of the north marked the sharp turn of the Vietnam War. Today there have been a great number of writings about this event. However, it seems that many key facts in the Communist campaign are still misinterpreted or neglected. In the mid-80, living in Saigon after being released from the Communist "re-education camp," I read a book published in the early 1980's in America about the story of the 1968 Tet Offensive. It said that the North Vietnamese Army supreme command had imitated one of the greatest heroes of Vietnam, King Quang Trung, who won the most spectacular victory over the Chinese aggressors in the 1789 counter-attack - in planning the 1968 operations. The book quoted King Quang Trung's tactic of surprise. He let the troops celebrate the 1789 Tet Festival one day ahead so that he could launch the attacks on the first three days of the lunar new year while the Chinese troops were still feasting and not ready to organize their defense. Those who claimed the similarity between the two campaigns certainly did not know the whole truth, but jumped into conclusion with wild imagination after learning that the North Vietnamese attacking units also celebrated Tet "one day ahead" before the attacks. In fact, the Tet Offensive broke out on the Tet's Eve - in the early morning of January 30, 1968 at many cities of Central Vietnam, such as Da Nang and Qui Nhon, as well as cities in the central coastal and highland areas, that lied within the Communist 5th Military Region.. The other cities to the south that included Saigon, were attacked 24 hours later at the small hours of January 31. Thus the offensive lost its element of total surprise that every tactician has to respect. But It surprised me that some in the American media were still unaware of such tragic story. The story started some 5 months previously. On August 8, 1967, the North Vietnam government approved a lunar calendar specifically compiled for the 7th time zone that covers all Vietnam, replacing the traditional lunar calendar that had been in use in Asia for hundreds of years. That old calendar was calculated for the 8th time zone that Beijing falls right in the middle. It was accepted in general by a few nations such as China, Vietnam, Taiwan, Hong Kong and somewhat in Japan and Korea, mostly for traditional celebrations and religious purposes. South Vietnam used this calendar. With common cultural origin, these countries needed not have their own calendar, particularly it has not been used for scientific and administrative activities. The North Vietnam new lunar calendar differs from the common calendar about some dates, such as the leap months of certain year (1984 and 1987) and the Tet's Eve of the three Lunar New Years: Mau Than (1968), Ky Dau (1969) and At Suu (1985). South Vietnam celebrated the first day of the Mau Than lunar year on January 30, 1968, while North Vietnam celebrated it on Jan 29, 1968. It was obviously that the North Vietnamese leaders had ordered the offensives to be launched on the night of the first day of Tet to take the objectives by total surprise. By some reason, the North Vietnamese Army Supreme Command was not aware of the fact that there were different dates for Tet between North and South Vietnam. Therefore, most NVA units in the Communist 5th Military Region - closer to North Vietnam - probably used North Vietnamese calendar, and conducted their attacks in the night between Jan 29 and 30, while their comrades farther to the south attacked in the night from Jan 30 to 31. Many in the intelligence branch of the South Vietnamese Armed Forces were well aware of the reason why the Communist forces launched their attacks at two different dates. Information from sources among NVA prisoners of war and ralliers about the new calendar of North Vietnam should have been neglected by the American side. The information was also available in broadcast from Hanoi Radio. In military operations, nothing is more important than surprise. So the Communist forces lost their advantage of surprise on more than half of the objectives. Had the Vietnamese Communists conducted their coordinated attacks at the same H-hour, South Vietnam would have

Friday, March 6, 2020

Terms of Arithmetic and Math in Spanish

Terms of Arithmetic and Math in Spanish You can talk about math in Spanish by learning a few basic terms. Many of the words are ones you already may know from other contexts. Spanish Terms of Arithmetic Here are the words for the simple mathematical functions and how theyre used with numbers: Addition (Suma):  Dos ms tres son cinco. (Two plus three is five.) Note that in other contexts, ms is usually an adverb. Subtraction (Resta):  Cinco menos cuatro son uno. (Five minus four is one.) Multiplication (Multiplicacià ³n):  Tres por cuatro son doce. (Three times four is twelve.) In other contexts, por is a common preposition. Division (Divisià ³n):  Doce dividido entre cuatro son tres. (Twelve divided by four is three.) Doce dividido por cuatro son tres. (Twelve divided by four is three.) Entre is another common preposition. Note that all of these sentences use the verb son, which is plural, in contrast with the singular verb is of English. It is also possible to use es or  the phrase es igual a (is equal to). Other Mathematical Terms Here are some less common mathematical terms: el cuadrado de - the square ofel cubo de - the cube ofecuacià ³n - equationelevado a la enà ©sima potencia - raised to the nth powerfuncià ³n - functionnà ºmero imaginario - imaginary numberpromedio - average, meanquebrado, fraccià ³n - fractionraà ­z cuadrada - square rootraà ­z cà ºbica - cube root Sample Sentences Solo un idiota que no sabe que dos ms dos son  cuatro le creerà ­a. (Only an idiot who doesnt know that two plus two equals four would believe him.) Una fraccià ³n es un nà ºmero  que se obtiene de dividir un entero en partes iguales. (A fraction is a number that is obtained by dividing a whole number into equal parts.) Pi se obtiene al dividir la circunferencia de un cà ­rculo del dimetro. (Pi is obtained by dividing the circumference of a circle by the diameter.) El triple de un nà ºmero menos el doble del mismo nà ºmero son ese nà ºmero. (Three times a number minus two times that number is that number.) Una funcià ³n es como una mquina: tiene una entrada y una salida. (A function is like a machine: It has an input and an output.) Una ecuacià ³n es una igualdad matemtica entre dos expresiones matemticas. (An equation is an equality between two mathematical expressions.) La ciudad est dividida en dos partes iguales. (The city is divided into two equal parts.)  ¿Cul es el resultado de dividir 20 por 0.5? (What is the quotient of 20 divided by 0.5?) El cuadrado de un nà ºmero menos el doble del mismo nà ºmero son 48.  ¿Cul es ese nà ºmero? (The square root of a number minus double the same number is 48. What is that number?) El promedio de edad de los estudiantes es de 25 aà ±os. (The average age of the students is 25.) La divisià ³n entre cero es una indeterminacià ³n. Asà ­Ã‚  la expresià ³n 1/0 carece de sentio. (Division by zero yields an indeterminable number. Thus the expression 1/0 doesnt make sense.) Los nà ºmeros imaginarios pueden describirse como el producto de un nà ºmero real por la unidad imaginaria i, en donde i denota la raà ­z cuadrada de -1. (Imaginary numbers can be described as the product of a real number by the imaginary unit i, where  i denotes the square root of -1.)

Wednesday, February 19, 2020

Motives and Incentives in the Performance of Employees Dissertation

Motives and Incentives in the Performance of Employees - Dissertation Example One of the most important aspects of a business in production is the motivation of the workforce. Manual labour is not comparable to the work produced by machines, and therefore the amount of work done is not the same. Thus, the most effective way to increase company performance and ensure productive, effective employees is to take steps to motivate the staff. One of the usual managerial approaches to this goal is through the use of financial rewards, however research suggests that there may be other more suitable strategies. In fact, Kohn (1993) suggests that if the motivational frame is focused only on material rewards, the levels of production might actually decrease.  Pugh and Hickson (1989) investigated this area through the â€Å"Hawthorne Experiment†. The conclusion of their study was that if the managers do not take into account the employees’ personal necessities and desires, they will be likely to maximize payment but minimize effort. Therefore, it is a cruc ial issue among business at present to learn how to offer non-material rewards as motivation. Hoegl and Gemuenden (2001) support this by stating that teamwork can be defined as a social structure comprised of over three people in context or organization. Therefore, as members of this structure work together as a single unit and look to achieve the same objective, techniques which improve the inter-relationship will improve group output. Additionally, the power of agglomerate and relation of status, composition, leadership, size, principles.... The global crisis has made it increasingly vital for organizations to take measures to ensure the life of their businesses, overcoming both internal and external operation factors to achieve revenue growth and corporate performance. It is widely agreed that effective management of one of the most important factors for organizations to stay profitable in a highly competitive global economy. These factors of production are the three M’s: materials, machine and manpower. It is the last of these, the human resource of a company, which poses the biggest challenge. A motivated employee is a valuable asset that brings tremendous worth to an organization. 1.2 The Objectives of the Research This research will try to resolve the problem of employee motivation and incentives programs by determining the factors that would give them motivation in their work, which in turn will result into satisfactory performance that would make possible the organization’s success. It will also try to look into the style and strategies of Al-Amal Hospital in Jeddah, the company in focus, in dealing with their workforce and how their workforce stay motivated and happy with their job. 1.3 Research Problems It is the purpose of this paper to identify the motivational strategies and incentives that would improve employee behaviour in the workplace. The focus of this study will be an evaluation of the practices of hospitals in Saudi Arabia, particularly Al-Amal Hospital in Jeddah. This will include an evaluation of the employee motivation and incentive strategies available to Al-Jamal Hospital, how they were applied in the organization and the effectiveness of these approaches. 1.4 Limitations of the Study As the data collected for random sampling will be from a single

Tuesday, February 4, 2020

Riyadh City Council, Essay Example | Topics and Well Written Essays - 1750 words

Riyadh City Council, - Essay Example For instance, they have experienced problems with improving the methods for keeping up with rapid changes such as civilizational shifts or new lifestyles among community members (Al-Nuaim 2001). To consider services for health, safety, and security, housing plans, and preservation of the environment and historical sites has become a challenge for Riyadh’s local administrators. Moreover, most often, the public’s opinion on the policies implemented by the City Council as well as on the implementation of projects and activities, and the performance of the governing body, has created difficulties for mayors and the rest of the administration in developing their community (Al Riyadh 2004). Because of these, the Riyadh City Council has aimed to boost their performance by focusing on the capability of their workforce, enhancing their projects by being consistent with the community’s needs, and providing their administration with the necessary procedural and managerial s pecialisations. One weak point that the local city councils in Riyadh has demonstrated is that they are not very capable of integrating various departments for planning and implementation, hence, reducing their likelihood for accomplishing main goals. The Royal Decree No. 5 in Riyadh has mandated the division of municipalities and villages along with the regulations and functions that go with them. Although municipalities have been given administrative and financial autonomy with which authorities and obligations are extended, regional decentralization has not been fully achieved through the administrations’ actual performance. Moreover, mayors and deputy directors lack the proper guidance and follow-up measures in securing the coordination of administrative practices and activities, and maintaining a good level of performance and usage of performance management approaches. The current study, thus, aims to answer the question: What are the strengths and weaknesses of the perf ormance management system of Riyadh City Council? In relation, it aims to address the following objective: 1. Identify the strengths and weaknesses with regards to the performance management system in the Riyadh City Council. 2. Provide recommendations on the areas that need further improvement in the performance management system of the Riyadh City Council. Review of Related Literature Introduction The local and municipal government of Riyadh has aimed to improve and develop their local community by reaching out to the public as well as understanding and finding solutions to various problems. This ability occurs by allowing the local administration to interact with the community which brings about the effective involvement of citizens in relevant activities, thereby increasing the likelihood for national participation in the development process. In order to allow such circumstances to occur, there is a need to look into how the Riyadh City Council sets their standards for performan ce management as well as the actions that they take to generate favorable outcomes. Performance Management: An Overview The important need for implementing an effective and well-organized performance management system has significantly increased over the years. This has occurred due to the fact that performance management can not only enhance performance but the quality of a company as well (Lawson, Stratton, and Hatch 2003). Without the necessary regarding the implementation of systems for performance management, organizations can experience inefficiency and decreased productivity, thus the need to further look into the components of successful performance management. The concept of performance management can be applied on the performance of either the organization as a whole or the individual

Monday, January 27, 2020

On-chip Static RAM

On-chip Static RAM For code and/or information stockpiling on-chip static RAM can be utilized. The SRAM might conceivably access as 8 bit, 16 bit and 32 bit. It gives the 8 KB of static RAM for the LPC2109 and 16 KB for the LPC2119 and LPC2129. 3.1.6 10-bit ADC The LPC 2109/2119/2129 every having a solitary 10 bit progressive rough guess ADC with four multiplexed channels. ADC Elements Introduce in LPC2129 The diminished intrude on overhead had committed result register for each simple data. Once the transformation is finished each simple information can create an intrude. When arranged for computerized information yield works the ADC cushions are 5v tolerant. 3.1.7 UARTs There are two UARTs in each LPC2109/2119/2129. The UART1 likewise gives a full modem control handshake interface. Notwithstanding the standard transmit and get information lines. UART Elements Display IN LPC2129 UARTs in LPC2109/2119/2129 present a fragmentary baud rate generator for both UARTs contrasted with past LPC2000 microcontrollers. These microcontrollers are empowered to accomplish standard baud rate like 115200Bd with over two megahertz recurrences. Auto RTS/CTS stream control is completely executed in equipment. Fractional baud rate generator permits standard baud rate, for example, 115200 Bd to accomplish with any gem recurrence. Auto-bauding 3.1.8 PULSE WIDTH MODULATION Just the beat width tweak is stuck out on the LPC2129 in spite of the fact that the pulse width, balance is in light of the standard clock square and acquires every one of its elements. The clock is intended to tally cycles of the fringe clock and perform different activities and produce hinders alternatively when indicated clock qualities happened, taking into account seven match registers. The capacity of the beat width balance is in view of coordinated register occasions. The beat width, balance can be utilized for more applications as it has the capacity to independently control rising and falling edge area. To give the single edge controlled pulse width, balance yield two match registers can be utilized. The pulse width, balance cycle rate can be controlled by Match Register (MR0) by again setting the number upon match and the other match register controls the beat regulation edge position. Since the redundancy rate is the same for all yield of heartbeat width balance. An extra single edge controlled yield, require stand out match enroll every in heartbeat width adjustment. At the point when the MR0 match happens, various single edge controlled pulse width, balance yields will have rising edge toward the start of every pulse width adjustment cycle. With both edges controlled the match registers can be utilized to give beat width adjustment yield. Particular match registers control the rising and falling edge of yield, with twofold edge controlled yields of pulse width modulation. 3.1.8.1 Elements of pulse width modulation Seven match registers apportion up to six single edges controlled or three twofold edge controlled pulse width tweak yields or a blend of both sorts. The match registers permit persistent operation with discretionary intrude on era on the match With discretionary intrude on era stop clock to match. Reset clock, on match with discretionary intrudes on era. The pulse width and period may be of number of clock numbers. At the same redundancy rate all yields of heartbeat width adjustments will happen. 3.1.9 FRAMEWORK CONTROL 3.1.9.1 Crystal oscillator The crystal is bolstered by the oscillator in the scope of 1 megahertz to 30 megahertz. fosc is known as the frequency oscillator and ARM processor clock frequency is alluded as CCLK with the end goal of rate comparisons. Unless the stage bolted circle is running and joined fosc and CCLK have the same qualities. 3.1.9.2 PHASE LOCKED LOOP The loop permits a data check recurrence in the scope of 10 megahertz to 25 megahertz. With a present crystal control oscillator (CCO) the info recurrence is reproduced up into the scope of 10 megahertz to 60 megahertz. While the loop is giving the wanted yield recurrence, the present control oscillator works in the scope of 156 megahertz to 320 megahertz. So there is an extra driver tuned in to keep the momentum control oscillator inside of its recurrence range. To deliver the yield clock, the yield driver may be set to separation by 2, 4, 8 or 16. It is guaranteed that the stage bolted circle yield has 50 percent obligation cycle; subsequent to the base yield driver quality is 2. The system must develop and actuate stage bolted circle, sit tight for the circle to bolt and after that as a clock source join in the stage bolted circle. 100s is the settling time of the stage bolted circle. 3.2 CAN The controller area network (CAN) is a consecutive message convention with abnormal state of security which effectively backings conveyed constant control. The application area ranges from high velocity systems to the minimal effort multiplex wiring. Utilizing CAN by a method for bit rates up to 1Mbits/s, in car gadgets; motor control unit, sensors and so forth are associated. To finish similarity among at all two CAN executions is the intension of this particular. Similarity has distinctive perspectives with respect to for instance, electrical short and the clarification of information to be exchanged. CAN is disengaged into diverse layers to land at configuration straightforwardness. The item layer The exchange layer The physical layer The article layer and the exchange layer include the whole administrations and purposes of the information connection layer characterized in the OSI model. The extension (territory) of the item layer incorporates Finding information or messages which are to be transmitted. Deciding which messages got by exchange layer is to be utilized really. An interface is given to the application layer related equipment. In characterizing the item taking care of there is much opportunity. The exchange layers fundamental extension is exchange convention, i.e. encircling control, performing an intervention, checking lapse, blunder flagging and repression of shortcoming. It is resolved whether the transport is open to beginning a late transmission or whether a capacity is simply beginning by method for the exchange layer. As a piece of exchange layer different, universally handy component of the bit timing are considered. There is no opportunity for alteration in the exchange layer. The real move between the changed hubs with concession to every single electrical property is the scope of the physical layer. The physical layer must be same for all hubs inside of one system. Be that as it may, there is much opportunity in selecting physical layer. FUNDAMENTAL IDEAS OF CAN There are the accompanying properties of CAN- Priority of messages Latency times insurance Flexibility setup Time synchronization with multicast gathering. System wide consistency of information. Signalling and lapse recognition. When the transport is sitting once more, there is programmed retransmission of debased messages. 3.2.1 MESSAGE EXCHANGE 3.2.1.1 Edge Sorts There are four unique sorts of edges all through which message exchange is controlled- DATA Outline conveys information as of transmitter to the recipient. REMOTE casing is transmitted completely through transport unit to request transmission of the information outline with the same identifier. A blunder Edge is transmitted by some component continuing to recognize a transport lapse. An Overburden Casing is utilized to offer a further postpone between the former and succeeding information or remote casings. Information outlines alongside Remote casings are expelled from going before edges by casing crevice. 3.2.1.2 Information Outline There are seven distinctive bit handle in information edge: begin of casing, mediation field, control field information field, CRC field, ACK field and end of the edge. The information field of can be of length zero. Begin Of Casing It comprises of single overwhelming bits. It denotes the initiation of information casings alongside remote edges. At the point when the transport is sitting out of gear then the main station is permitted to begin transmission, by beginning of the edge of the station. Beginning transmission to start with, all the station needs to synchronize to the main edge. Mediation FIELD This field comprises of the IDENTIFIER and RTR bit. IDENTIFIER The length of the identifier is 11 bits. These bits are transmitted in the request from ID-10 to ID-0. ID-0 is the minimum noteworthy bit and the seven most huge bit (ID-10 –ID-4) must not be all latent. RTR bit- remote Transmission Solicitation Bit The RTR bits must be overridden in information casings and it must be latent inside of remote edge. Control Field This field comprises of six bits. It held the two bits for future development and incorporates information length code. This information length code is cable cars mitted inside of the control field and is 4 bits wide. Information Field The information field holds the information to be exchanged contained by an informational outline. It contains 0 to 8 bytes, with each byte containing 8bits which move MSB first. CRC FIELD It contains CRC SEQUECE and additionally CRC DELIMITER. CRC Succession the edge check arrangement is duplicated from cyclic repetition code as it is best suitable for the edges by a method for bit innumerable then 127 bits (BCH code). CRC Delimiter-the CRC delimiter which comprises of single latent bit takes after the CRC arrangement. ACK Field The ACK field contains the ACK opening and the ACK delimiter as it is two bits in length. Two latent bits are sent by the transmitting station in ACK field. At the point when a substantial message is gotten from the beneficiary effectively, this report to the transmitter by sending a prevailing bit amid the ACK opening that sending it the ACK. ACK opening All stations in the wake of getting the coordinating CRC request, send ACK to the ACK space super copyist the latent bit of the transmitter by a prevailing bit. ACK Delimiter As we probably are aware the ACK space is limited by two latent bits that is CRC delimiter and ACK delimiter. Along these lines, ACK store meter must be a latent bit. End of Casing In end of casing a banner arrangement is comprised of seven latent bits, where together information edge and remote edge are delimited. 3.2.1.3 Remote Edge As the station goes about as a collector, for certain information it can start the transmission of the separate information by sending remote edge by its source mode. There are six diverse bit handle in remote edge: Begin of casing, discretion field, control field, CRC field, ACK field and end of casing. 3.2.1.4 Blunder Outline The mistake casing contains two dissimilar to fields where the first field is superposition of slip banners include from distinctive areas. The second field is the blunder delimiter. Mistake Banner The mistake banners are of two sorts 1. A dynamic lapse banner 2. A latent slip banner There are six back to back prevailing bits in dynamic slip banner. There are six back to back latent bits unless it is over composed of prevailing bits from different hubs in uninvolved mistake banners. With conduction of a dynamic mistake banner blunder dynamic station can recognize a slip state signal. The law of bit stuffing is connected to all fields structure begin of casing to CRC delimiter or wipe out the altered structure ACK field or end of edge recorded, when the banners structure abuses. Therefore, all the remaining stations distinguish a blunder and on their part begin transmission of a lapse banner. The general length is fluctuated from list of six, and most extreme of twelve bits. By this the transmission of aloof slip hail, a lapse inactive station recognizes a mistake condition attempted to flag. At the point when 6 equivalent bits have been identified, the inactive mistake banner is finished.

Sunday, January 19, 2020

Clashes of Race Essay

Abstract The purpose of this paper is to explore racism and discrimination within America. It was also a goal to show the relationships between racial clashes throughout history, and what the purpose behind the clashes was. By showing these clashes society gets a better understand of what triggers these action within society. Running Header: CLASHES OF RACE: UNDERSTANDING THE PURPOSE In the rather complex world in which society dwells on, society lacks appreciation for the simplicity of the universe. one act or idea can spawn certain events that affect the course of history. To understand history, it is essential for society to look at the causes behind the significance of an event. racial discrimination has spawned social clashes between ethnicities for generations, and it continues to do so. to understand the significance of these events, it is important to analyze the source of these racial clashes throughout history. analyzing the sources of these events provides, if any, patterns of human nature in response to mistreatment due to racial profiling. it is also essential to analyze the basic principles of discrimination within the twenty-first century and what society faces in present day. Before analyzing racial discrimination in the twenty-first century, the importance of understanding the different types of racism is needed. There are two types of discrimination that society faces present day, direct discrimination and indirect discrimination. direct discrimination by definition, is when an individual or group is singled out directly by society or an individual based on there race. indirect discrimination is when an individual is singled out surreptitiously by an individual or group. this is more prevalent within present day culture, compared to direct discrimination. The reason being that racism in the twenty-first century is less acceptable among society. the result of racism is that it is less acceptable within modern day society is racism taking on a more enigmatic face. Running Header: CLASHES OF RACE: UNDERSTANDING THE PURPOSE social clashes that resulted from direct discrimination have been apart of america for decades. prime examples of direct discrimination are famously the wars and massacres enacted on early native americans. The reasons for these attacks on native americans were due to new settlers in america wanting to acquire resources from the natives themselves. The colonist’s believed that the natives way of life was inferior to their own, due to the savageness of their own human nature. This is a prime example of micro-aggression in early american culture. Such events such as the â€Å"trail of tears† and many other attacks on the native american’s way of life was justified due to the idea of manifest destiny, which is a belief that the territory was a divine gift to the american colonist. This resulted in constant conflict between american society and native americans in the twenty-first century. it is important to understand how micro-aggression works and operates in the twenty-first century. With modern society changing into a more diversified culture in the United States, it is important to understand how indirect discrimination works in modern society. Society by nature tends to group themselves within certain micro-cultures, it is important to understand this important dynamic due to its purpose within society. this dynamic by nature forces ethnicities to side with a certain set of social norms and values. (West,2004) examples of how this affects modern day society would best be described by conflict with interracial marriages and racial generalization. Ethnic grouping has been apart of america since the beginning of american society. the colonist settled in america based on their religions and values, in which the colonist Running Header: CLASHES OF RACE: UNDERSTANDING THE PURPOSE had previously in britain. more modern examples of ethnic grouping would be groups, such as the black panther party, naacp are examples of more modern cases of ethnic grouping. (Jablonski,2012) the common feature of today’s society, also well known as mass media, has a huge impact on racial conflictions with the populace of today’s society. One psychological principle says that if an image or idea is shown repetitively that the image or idea will leave an imprint on the mind, later on making the mind recognize the image or ideology as† normalcy†. (Yosso,2002) the mainstream media controls the public agenda, as well as the emotions reflected within society. the mass media needs to recognize the effect in which it has on society, the purpose of the media should be to promote the truth of a matter accurately. This would help balance out racial out lashes between ethnic neighborhood, as well as riots and other ethnic protest. (Vann,2006) in recent times of society, racism in north america has went through a major transformation, especially after the post-civil rights era where the democrats believed in equality for all types of ethnicities that specifically did not get along throughout the history of racism in society(Wamsted,D,2012). This shows the progression of diversity within America. however, even with change in equality the south still shows a higher percentage of direct discrimination as well as indirect discrimination in modern day society than the north. Some examples of the result of discrimination can best be depicted is social out lashes of an ethnic communities. this can be shown through protest, as well as more Running Header: CLASHES OF RACE: UNDERSTANDING THE PURPOSE serious demonstrations such as riots. the causes of these demonstrations can be a number of reasons, but one pattern that is shown throughout history is that most social out lashes resulted due to mistreatment among their race. an example of this would be the los angeles riots of 1992. The riots resulted from six officers found not guilty that were accused of beating a black male, rodney king. the riots lasted for six days, and resulted in thousands of injuries and fifty-three deaths. (Watts,2011) however, not every protest result in death and injury. through the civil rights era many protesters believed in the nonviolent approach of martin luther king jr. most protesters believed in sit-ins, boycotts, and other forms of nonviolent forms of protest. however, the effects of racism and discrimination has not stopped america from diversifying, but rather fueled individualism among minorities within america. A study shows that more minorities are striving for higher education within america. derek bok reported in 2000 in his book The Shape of the River that eighty-six percent of black students who enrolled in twenty-eight selective universities across the nation were apart of the middle-class or upper-middle class. This shows not only an increase in african american on college campus, but also the percentage of success among blacks with a stable financial backing. This trend is important to understand due to the progression of diversity within america. It is prevalent that not only income have increased among african americans, but also the number of blacks going to college compared to college statistics of the 1990s and 1980s. (Harring-Smith,2012) to understand the importance of an action, is in essence the greatest ideology or knowledge to grasp. for every action within society has an effect on history. The Running Header: CLASHES OF RACE: UNDERSTANDING THE PURPOSE importance of diversity within society continues to show progression. however, racism will always have its place within society. Society has to continue to evolve as well as continue to educate the youth in society to limit the grasp that racism has on america, whether the discrimination is indirect or direct. â€Å"we’ve got to face the fact that some people say you fight fire best with fire, but we say you put fire out best with water. we say you don’t fight racism with racism. we’re gonna fight racism with solidarity. †-Fred Hampton Running Header: CLASHES OF RACE: UNDERSTANDING THE PURPOSE References: Haring-Smith, T. (2012). Broadening Our Definition of Diversity. Liberal Education, 98(2), 6. Jablonski, N. (2012). The struggle to overcome racism. New Scientist, 215(2880), 26. Vann, A. (2006, June 29). Sometimes the allegation of â€Å"reverse racism† is camouflage for maintaining the â€Å"status quo†. New York Amsterdam News. p. 13. Wamsted, D. J. (2012). Opening Doors for Diversity. Electric Perspectives, 37(3), 26. Watts. (2011). Columbia Electronic Encyclopedia, 6th Edition, 1. West, E. (2004). Expanding the Racial Frontier. Historian, 66(3), 552. doi:10. 1111/j. 1540-6563. 2004. 00088. x Yosso, T. J. (2002). Critical Race Media Literacy: Challenging Deficit Discourse about Chicanas/os. Journal Of Popular Film & Television, 30(1), 52.

Friday, January 10, 2020

Exercise 7 Respiratory System Mechanics

EXERCISE 7 Respiratory System Mechanics O B J E C T I V E S 1. To explain how the respiratory and circulatory systems work together to enable gas exchange among the lungs, blood, and body tissues 2. To define respiration, ventilation, alveoli, diaphragm, inspiration, expiration, and partial pressure 3. To explain the differences between tidal volume, inspiratory reserve volume, expiratory reserve volume, vital capacity, residual volume, total lung capacity, forced vital capacity, forced expiratory volume, and minute respiratory volume 4. To list various factors that affect respiration 5. To explain how surfactant works in the lungs to promote respiration 6. To explain what happens in pneumothorax 7. To explain how hyperventilation, rebreathing, and breathholding affect respiratory volumes T he physiological functions of respiration and circulation are essential to life. If problems develop in other physiological systems, we can still survive for some time without addressing them. But if a persistent problem develops within the respiratory or circulatory systems, death can ensue within minutes. The primary role of the respiratory system is to distribute oxygen to, and remove carbon dioxide from, the cells of the body. The respiratory system works hand in hand with the circulatory system to achieve this. The term respiration includes breathing—the movement of air in and out of the lungs, also known as ventilation—as well as the transport (via blood) of oxygen and carbon dioxide between the lungs and body tissues. The heart pumps deoxygenated blood to pulmonary capillaries, where gas exchange occurs between blood and alveoli (air sacs in the lungs), oxygenating the blood. The heart then pumps the oxygenated blood to body tissues, where oxygen is used for cell metabolism. At the same time, carbon dioxide (a waste product of metabolism) from body tissues diffuses into the blood. The deoxygenated blood then returns to the heart, completing the circuit. Ventilation is the result of muscle contraction. The diaphragm—a domeshaped muscle that divides the thoracic and abdominal cavities—contracts, making the thoracic cavity larger. This reduces the pressure within the thoracic cavity, allowing atmospheric gas to enter the lungs (a process called inspiration). When the diaphragm relaxes, the pressure within the thoracic cavity increases, forcing air out of the lungs (a process called expiration). Inspiration is considered an â€Å"active† process because muscle contraction requires the use of ATP, whereas expiration is usually considered a â€Å"passive† process. When a person is running, however, the external intercostal muscles contract and make the thoracic cavity even larger than with diaphragm contraction alone, and expiration is the result of the internal intercostal muscles contracting. In this case, both inspiration and expiration are considered â€Å"active† processes, since muscle contraction is needed for both. Intercostal muscle contraction works in conjunction with diaphragm muscle contraction. 87 88 Exercise 7 (a) Atmospheric pressure Parietal pleura Thoracic wall Visceral pleura Pleural cavity Transpulmonary pressure 760 mm Hg 756 mm Hg 4 mm Hg 756 760 Intrapleural pressure 756 mm Hg ( 4 mm Hg) Lung Diaphragm Intrapulmonary pressure 760 mm Hg (0 mm Hg) (b) F I G U R E 7 . 1 Respiratory volumes. a) Opening screen of the Respiratory Volumes experiment. (b) Intrapulmonary and intrapleural relationships Respiratory System Mechanics 89 Respiratory Volumes Ventilation is measured as the frequency of breathing multiplied by the volume of each breath, called the tidal volume. Ventilation is needed to maintain oxygen in arterial blood and carbon dioxide in venous blood at their normal levels—that is, at their normal partial pressures. [The term partial pressure refers to the proportion of pressure that a single gas exerts within a mixture. For example, in the atmosphere at sea level, the pressure is 760 mm Hg. Oxygen makes up about 20% of the total atmosphere and therefore has a partial pressure (PO2 ) of 760 mm Hg 20%, close to 160 mm Hg. ] Oxygen diffuses down its partial pressure gradient to flow from the alveoli of the lungs into the blood, where the oxygen attaches to hemoglobin (meanwhile, carbon dioxide diffuses from the blood to the alveoli). The oxygenated blood is then transported to body tissues, where oxygen again diffuses down its partial pressure gradient to leave the blood and enter the tissues. Carbon dioxide (produced by the metabolic reactions of the tissues) diffuses down its partial pressure gradient to flow from the tissues into the blood for transport back to the lungs. Once in the lungs, the carbon dioxide follows its partial pressure gradient to leave the blood and enter the air in the alveoli for export from the body. Normal tidal volume in humans is about 500 milliliters. If one were to breathe in a volume of air equal to the tidal volume and then continue to breathe in as much air as possible, that amount of air (above and beyond the tidal volume) would equal about 3100 milliliters. This amount of air is called the inspiratory reserve volume. If one were to breathe out as much air as possible beyond the normal tidal volume, that amount of air (above and beyond the tidal volume) would equal about 1200 milliliters. This amount of air is called the expiratory reserve volume. Tidal volume, inspiratory reserve volume, and expiratory reserve volume together constitute the vital capacity, about 4800 milliliters. It is important to note that the histological structure of the respiratory tree (where air is found in the lungs) will not allow all air to be breathed out of the lungs. The air remaining in the lungs after a complete exhalation is called the residual volume, normally about 1200 milliliters. Therefore, the total lung capacity (the vital capacity volume plus the residual volume) is approximately 6000 milliliters. All of these volumes (except residual volume) can be easily measured using a spirometer. Basically, a spirometer is composed of an inverted bell in a water tank. A breathing tube is connected to the bell’s interior. On the exterior of the inverted bell is attached a pen device that records respiratory volumes on paper. When one exhales into the breathing tube, the bell goes up and down with exhalation. Everything is calibrated so that respiratory volumes can be read directly from the paper record. The paper moves at a pre-set speed past the recording pen so that volumes per unit time can be easily calculated. In addition to measuring the respiratory volumes introduced so far, the spirometer can also be used to perform pulmonary function tests. One such test is the forced vital capacity (FVC), or the amount of air that can be expelled completely and as rapidly as possible after taking in the deepest possible breath. Another test is the forced expiratory volume (FEV1), which is the percentage of vital capacity that is exhaled during a 1-sec period of the FVC test. This value is generally 75% to 85% of the vital capacity. In the following experiments you will be simulating spirometry and measuring each of these respiratory volumes using a pair of mechanical lungs. Follow the instructions in the Getting Started section at the front of this lab manual to start up PhysioEx. From the drop-down menu, select Exercise 7: Respiratory System Mechanics and click GO. Before you perform the activities watch the Water-Filled Spirometer video to see the experiment performed with a human subject. Then click Respiratory Volumes. You will see the opening screen for the â€Å"Respiratory Volumes† experiment (Figure 7. 1). At the left is a large vessel (simulating the thoracic cavity) containing an air flow tube. This tube looks like an upside-down â€Å"Y. † At the ends of the â€Å"Y† are two spherical containers, simulating the lungs, into which air will flow. On top of the vessel are controls for adjusting the radius of the tube feeding the â€Å"lungs. This tube simulates the trachea and other air passageways into the lungs. Beneath the â€Å"lungs† is a black platform simulating the diaphragm. The â€Å"diaphragm† will move down, simulating contraction and increasing the volume of the â€Å"thoracic cavity† to bring air into the â€Å"lungs†; it will then move up, simulating relaxation and decreasin g the volume of the â€Å"thoracic cavity† to expel air out. At the bottom of the vessel are three buttons: a Start button, an ERV (expiratory reserve volume) button, and an FVC (forced vital capacity) button. Clicking Start will start the simulated lungs breathing at normal tidal volume; clicking ERV will simulate forced exhalation utilizing the contraction of the internal intercostal muscles and abdominal wall muscles; and clicking FVC will cause the lungs to expel the most air possible after taking the deepest possible inhalation. At the top right is an oscilloscope monitor, which will graphically display the respiratory volumes. Note that the Yaxis displays liters instead of milliliters. The X-axis displays elapsed time, with the length of the full monitor displaying 60 seconds. Below the monitor is a series of data displays. A data recording box runs along the bottom length of the screen. Clicking Record Data after an experimental run will record your data for that run on the screen. A C T I V I T Y 1 Trial Run Let’s conduct a trial run to get familiarized with the equipment. 1. Click the Start button (notice that it immediately turns into a Stop button). Watch the trace on the oscilloscope monitor, which currently displays normal tidal volume. Watch the simulated diaphragm rise and fall, and notice the â€Å"lungs† growing larger during inhalation and smaller during exhalation. The Flow display on top of the vessel tells you the amount of air (in liters) being moved in and out of the lungs with each breath. 2. When the trace reaches the right side of the oscilloscope monitor, click the Stop button and then click Record Data. Your data will appear in the data recording box along the bottom of the screen. This line of data tells you a wealth of information about respiratory mechanics. Reading the data from left to right, the first data field should be that of the Radius of the air flow tube (5. 00 mm). The next data field, Flow, displays the total flow volume for this experimental run. T. V. stands for â€Å"Tidal Volume†; E. R. V. for â€Å"Expiratory 90 Exercise 7 Reserve Volume†; I. R. V. for â€Å"Inspiratory Reserve Volume†; R. V. for â€Å"Residual Volume†; V. C. for â€Å"Vital Capacity†; FEV1 for â€Å"Forced Expiratory Volume†; T. L. C. for â€Å"Total Lung Capacity†; and finally, Pump Rate for the number of breaths per minute. 3. You may print your data at any time by clicking Tools at the top of the screen and then Print Data. You may also print the trace on the oscilloscope monitor by clicking Tools and then Print Graph. 4. Highlight the line of data you just recorded by clicking it and then click Delete Line. . Click Clear Tracings at the bottom right of the oscilloscope monitor. You are now ready to begin the first experiment.  ¦ A C T I V I T Y 2 6. Click Clear Tracings before proceeding to the next activity. Do not delete your recorded data—you will need it for the next activity.  ¦ A C T I V I T Y 3 Effect of Restricted Air Flow on Respiratory Volumes 1. Adjust the radius of the air flow tube to 4. 00 mm by clicking the ( ) button next to the radius display. Repeat steps 2–5 from the previous activity, making sure to click Record Data. How does this set of data compare to the data you recorded for Activity 2? The breathing isn't as strong ________________________________________________ the flow and tidal volume have decreased ________________________________________________ Is the respiratory system functioning better or worse than it did in the previous activity? Explain why. functioning worse, it isn't moving as much air or expanding ________________________________________________ the lungs as far because of the decreased space for intake ________________________________________________ and output of air 2. Click Clear Tracings. 3. Reduce the radius of the air flow tube by another 0. 0 mm to 3. 50 mm. 4. Repeat steps 2–6 from Activity 2. 5. Reduce the radius of the air flow tube by another 0. 50 mm to 3. 00 mm. 6. Repeat steps 2–6 from Activity 2. What was the effect of reducing the radius of the air flow tube on respiratory volumes? furthur decrease of flow and tidal volume ________________________________________________ ________________________________________________ What does the air flow tube simulate in the human body? trachea ________________________________________________ ________________________________________________ Measuring Normal Respiratory Volumes 1. Make sure that the radius of the air flow tube is at 5. 00 mm. To adjust the radius, click the ( ) or ( ) buttons next to the radius display. 2. Click the Start button. Watch the oscilloscope monitor. When the trace reaches the 10-second mark on the monitor, click the ERV button to obtain the expiratory reserve volume. 3. When the trace reaches the 30-second mark on the monitor, click the FVC to obtain the forced vital capacity. 4. Once the trace reaches the end of the screen, click the Stop button, then click Record Data. . Remember, you may print your trace or your recorded data by clicking Tools at the top of the screen and selecting either Print Graph or Print Data. From your recorded data, you can calculate the minute respiratory volume: the amount of air that passes in and out of the lungs in 1 minute. The formula for calculating minute respiratory volume is: Minute respiratory volume tidal volume bpm (breaths per minute) Calculate and en ter the minute respiratory volume: _7,500________ Judging from the trace you generated, inspiration took place over how many seconds? __2 seconds_____________ Expiration took place over how many seconds? What could be some possible causes of reduction in air flow to the lungs? obstruction, inflammation from illness or allergic ________________________________________________ reaction ________________________________________________ ________________________________________________ 7. Click Tools > Print Data to print your data. _____2 seconds____________ Does the duration of inspiration or expiration vary during yes ERV or FVC? _____ Respiratory System Mechanics 91 FIGURE 7. 2 Opening screen of the Factors Affecting Respiration experiment. Express your FEV1 data as a percentage of vital capacity by filling out the following chart. (That is, take the FEV1 value and divide it into the vital capacity value for each line of data. ) Factors Affecting Respiration Many factors affect respiration. Compliance, or the ability of the chest wall or lung to distend, is one. If the chest wall or lungs cannot distend, respiratory ability will be compromised. Surfactant, a lipid material secreted into the alveolar fluid, is another. Surfactant acts to decrease the surface tension of water in the fluid that lines the walls of the alveoli. Without surfactant, the surface tension of water would cause alveoli to collapse after each breath. A third factor affecting respiration is any injury to the thoracic wall that results in the wall being punctured. Such a puncture would effectively raise the intrathoracic pressure to that of atmospheric pressure, preventing diaphragm contraction from decreasing intrathoracic pressure and, consequently, preventing air from being drawn into the lungs. Recall that airflow is achieved by the generation of a pressure difference between atmospheric pressure on the outside of the thoracic cavity and intrathoracic pressure on the inside. ) We will be investigating the effect of surfactant in the next activity. Click Experiment at the top of the screen and then select Factors Affecting Respiration. The opening screen will look like Figure 7. 2. Notice the changes to the FEV1 as % of Vital Capacity Radius FEV1 Vital Capacity FEV1 (%) 5. 00 4. 00 3. 50 3. 00 3541 1422 822 436 4791 1962 1150 621 1. 35% 1. 37% 1. 39% 1. 42%  ¦ 92 Exercise 7 quipment above the air flow tube. Clicking the Surfactant button will add a pre-set amount of surfactant to the â€Å"lungs. † Clicking Flush will clear the lungs of surfactant. Also notice that valves have been added to the sides of each simulated lung. Opening the valves will allow atmospheric pressure into the vessel (the â€Å"thoracic cavity†). Finally, notice the changes to the display windows below the oscilloscope screen. Flow Left and Pressure Left refer to the flow of air and pressure in the left â€Å"lung†; Flow Right and Pressure Right refer to the flow of air and pressure in the right â€Å"lung. Total Flow is the sum of Flow Left and Flow Right. A C T I V I T Y 4 3. Click Flush to remove the surfactant from the previous activity. 4. Be sure that the air flow radius is set at 5. 00 mm, and that P ump Rate is set at 15 strokes/minute. 5. Click on Start and allow the trace to sweep the length of the oscilloscope monitor. Notice the pressure displays, and how they alternate between positive and negative values. 6. Click Record Data. Again, this is your baseline data. 7. Now click the valve for the left lung, which currently reads â€Å"Valve closed. † 8. . Click Start and allow the trace to sweep the length of the Click Record Data. oscilloscope monitor. Effect of Surfactant on Respiratory Volumes 1. The data recording box at the bottom of the screen should be clear of data. If not, click Clear Table. 2. The radius of the air flow tube should be set at 5. 00 mm, and the Pump Rate should be set at 15 strokes/minute. 3. Click Start and allow the trace to sweep across the full length of the oscilloscope monitor. Then click Record Data. This will serve as the baseline, or control, for your experimental runs. You may wish to click Tools and then Print Graph for a printout of your trace. 4. Click Surfactant twice to add surfactant to the system. Repeat step 3. When surfactant is added, what happens to the tidal volume? It increases the amount of air being inhaled ________________________________________________ As a result of the tidal volume change, what happens to the flow into each lung and total air flow? ________________________________________________ they all increase Why does this happen? urfactant decreases teh surface tension of water in the ________________________________________________ fluid that lines the walls of the alveoli ________________________________________________ Remember, you may click Tools and then either Print Data or Print Graphs to print your results.  ¦ A C T I V I T Y 5 What happened to the left lung when you clicked on the valve button? Why? The lung deflated due to the change in the intrapleural ________________________________________________ pressure ________________________________________________ ________________________________________________ What has happened to the â€Å"Total Flow† rate? t reduced ________________________________________________ by half 0 What is the pressure in the left lung? ___________________ no Has the pressure in the right lung been affected? _________ If there was nothing separating the left lung from the right lung, what would have happened when you opened the valve for the left lung? Why? Both lungs would have collapsed due to pressure ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ Now click the valve for the left lung again, closing it. What happens? Why? nothing , there is excess air remaining in the lung ________________________________________________ ________________________________________________ Click Reset (next to the Flush button at the top of the air flow tube). What happened? the lung reinflated ________________________________________________ Describe the relationship required between intrathoracic pressure and atmospheric pressure in order to draw air into the lungs. intrathroacic pressure must be greater or lower than ________________________________________________ atmospheric pressure to draw air in and out of the lungs _______________________________________________ Effect of Thoracic Cavity Puncture Recall that if the wall of the thoracic cavity is punctured, the intrathoracic pressure will equalize with atmospheric pressure so that the lung cannot be inflated. This condition is known as pneumothorax, which we will investigate in this next activity. 1. Do not delete your data from the previous act ivity. 2. If there are any tracings on the oscilloscope monitor, click Clear Tracings. Respiratory System Mechanics 93 FIGURE 7. 3 Opening screen of the Variations in Breathing experiment. Design your own experiment for testing the effect of opening the valve of the right lung. Was there any difference from the effect of opening the valve of the left lung? no ________________________________________________ Remember, you may click Tools and then either Print Data or Print Graphs to print your results.  ¦ Variations in Breathing Normally, alveolar ventilation keeps pace with the needs of body tissues. The adequacy of alveolar ventilation is measured in terms of the partial pressure of carbon dioxide (PCO2). Carbon dioxide is the major component for regulating breathing rate. Ventilation (the frequency of breathing multiplied by the tidal volume) maintains the normal partial pressures of oxygen and carbon dioxide both in the lungs and blood. Perfusion, the pulmonary blood flow, is matched to ventilation. The breathing patterns of an individual are tightly regulated by the breathing centers of the brain so that the respiratory and circulatory systems can work together effectively. In the next activity you will examine the effects of rapid breathing, rebreathing, and breathholding on the levels of carbon dioxide in the blood. Rapid breathing increases breathing rate and alveolar ventilation becomes excessive for tissue needs. It results in a decrease in the ratio of carbon dioxide production to alveolar ventilation. Basically, alveolar ventilation becomes too great for the amount of carbon dioxide being produced. In rebreathing, air is taken in that was just expired, so the PCO2 (the partial pressure of carbon dioxide) in the alveolus (and subsequently in the blood) is elevated. In breathholding, there is no ventilation and no gas exchange between the alveolus and the blood. Click Experiment at the top of the screen and select Variations in Breathing. You will see the next screen, shown in Figure 7. 3. This screen is very similar to the ones you have been working on. Notice the buttons for Rapid Breathing, Rebreathing, Breath Holding, and Normal Breathing—clicking each of these buttons will induce the given pattern of breathing. Also note the displays for PCO2, Maximum PCO2, Minimum PCO2, and Pump Rate. 94 Exercise 7 A C T I V I T Y 6 How does the rebreathing trace compare to your baseline trace? (Look carefully—differences may be subtle. ) ________________________________________________ Why? _______________________________________________ ________________________________________________ Click Clear Tracings to clear the oscilloscope monitor.  ¦ A C T I V I T Y 8 Rapid Breathing 1. The oscilloscope monitor and the data recording box should both be empty and clear. If not, click Clear Tracings or Clear Table. 2. The air flow tube radius s hould be set to 5. 00. If not, click the ( ) or ( ) buttons next to the radius display to adjust it. 3. Click Start and conduct a baseline run. Remember to click Record Data at the end of the run. Leave the baseline trace on the oscilloscope monitor. 4. Click Start again, but this time click the Rapid Breathing button when the trace reaches the 10-second mark on the oscilloscope monitor. Observe the PCO2 levels in the display windows. 5. Allow the trace to finish, then click Record Data. What happens to the PCO2 level during rapid breathing? it decreased ________________________________________________ Why? co2 was removed more than during normal breathing ________________________________________________ ________________________________________________ Remember, you may click Tools and then either Print Data or Print Graphs to print your results. Click Clear Tracings before continuing to the next activity.  ¦ A C T I V I T Y 7 Breath Holding 1. Click on Start and conduct a baseline run. Remember to click Record Data at the end of the run. Leave the baseline trace on the oscilloscope monitor. 2. Click Start again, but this time click the Breath Holding button when the trace reaches the 10-second mark on the oscilloscope monitor. Observe the PCO2 levels in the display windows. 3. At the 20-second mark, click Normal Breathing and let the trace finish. 4. Click Record Data. What happens to the PCO2 level during breath holding? t rose ________________________________________________ Why? co2 exchange could not take place ________________________________________________ ________________________________________________ Rebreathing Repeat Activity 6, except this time click the Rebreathing button instead of the Rapid Breathing button. What happens to the PCO2 level during rebreathing? it increase ____________________________________ ____________ ________________________________________________ Why? there was more co2 in the inhaled air ________________________________________________ ________________________________________________ What change was seen when you returned to â€Å"Normal Breathing†? the rate and depth of breathing increased ________________________________________________ ______________________________________________  ¦ Remember, you may print your data or graphs by clicking Tools at the top of the screen and then selecting either Print Data or Print Graph.  ¦ A C T I V I T Y 9 Comparative Spirometry In Activity 1, normal respiratory volumes and capacities are measured. In this activity, you will explore what happens to these values when pathophysiology develops or during episodes of aerobic exercise. Using a water-filled spirometer and knowledge of respiratory mechanics, changes to these values in each condition can be predicted, documented, and explained. Did the total flow change? just a little ________________________________________________ Why? increase pump rate ________________________________________________ ________________________________________________ Respiratory System Mechanics 95 FIGURE 7. 4 Opening screen of the Comparative Spirometry experiment. Normal Breathing 1. Click the Experiment menu, and then click Comparative Spirometry. The opening screen will appear in a few seconds (see Figure 7. 4). 2. For the patient’s type of breathing, select the Normal option from the drop-down menu in the Patient Type box. These values will serve as a basis of comparison in the diseased conditions. 3. Select the patient’s breathing pattern as Unforced Breathing from the Breathing Pattern Option box. 4. After these selections are made, click the Start button and watch as the drum starts turning and the spirogram develops on the paper rolling off the drum across the screen, left to right. 5. When half the screen is filled with unforced tidal volumes and the trace has paused, select the Forced Vital Capacity button in the Breathing Pattern Options box. . Click the Start button and trace will continue with the FVC maneuver. The trace ends as the paper rolls to the right edge of the screen. 7. Now click on the individual measure buttons that appear in the data table above each data column to measure the lung volume and lung capacity data. Note that when a measure button is selected, t wo things happen simultaneously: (1) a bracket appears on the spirogram to indicate where that measurement originates on the spirogram and (2) the value in milliliters appears in the data table. Also note that when the FEV1 measure button is selected, the final column labeled FEV1/FVC will be automatically calculated and appear in the data table. The calculation is (FEV1/FVC) 100%, and the result will appear as a percentage in the data table. What do you think is the clinical importance of the FVC and FEV1 values? ________________________________________________ Why do you think the ratio of these two values is important to the clinician when diagnosing respiratory diseases? _______ demonstrates how the lungs are functioning ________________________________________________ FEV1 /FVC 100% 80% ______________________ 96 Exercise 7 Emphysema Breathing In a person with emphysema, there is a significant loss of intrinsic elastic recoil in the lung tissue. This loss of elastic recoil occurs as the disease destroys the walls of the alveoli. Airway resistance is also increased as the lung tissue in general becomes more flimsy and exerts less mechanical tethering on the surrounding airways. Thus the lung becomes overly compliant and expands easily. Conversely, a great effort is required to exhale as the lungs can no longer passively recoil and deflate. A noticeable and exhausting muscular effort is required for each exhalation. Thus a person with emphysema exhales slowly. . Using this information, predict what lung values will change in the spirogram when the patient with emphysema breathing is selected. Assume that significant disease has developed, and thus a loss of elastic recoil has occurred in this patient’s lungs. 2. Select Emphysema from the drop-down menu in the Patient Type box. 3. Select the patient ’s breathing pattern as Unforced Breathing from the Breathing Pattern box. 4. After these selections are made and the existing spirogram screen clears, click the Start button and watch as the drum starts turning and a new spirogram develops on the paper rolling off the drum. . Repeat steps 5–7 of the Normal Breathing section in this activity. 6. Now consider the accuracy of your predictions (what changed versus what you expected to change). Compared to the values for normal breathing: reduced Is the FVC reduced or increased? ______________________ reduced Is the FEV1 reduced or increased? _____________________ fev1 Which of these two changed more? ____________________ Explain the physiological reasons for the lung volumes and capacities that changed in the spirogram for this condition. _______________________________________________ ________________________________________________ ________________________________________________ 1. Using this information, predict what lung values will change in the spirogram when the patient who is having an acute asthma attack is selected. Assume that significantly decreased airway radius and increased airway resistance have developed in this patient’s lungs. 2. Select Asthmatic from the drop-down menu in the Patient Type box. 3. Select the patient’s breathing pattern as Unforced Breathing from the Breathing Pattern box. . After these selections are made and the existing spirogram screen clears, click the Start button and watch as the drum starts turning and a new spirogram develops as the paper rolls off the drum. 5. Repeat steps 5–7 of the Normal Breathing section in this activity. 6. Now consider the accuracy of your predictions (what changed versus what you expected to change). Compared to the values for normal breathing: reduced Is the FVC reduced or increased? _____________________ reduced Is the FEV1 reduced or increased? _____________________ fev1 Which of these two changed more? ___ ________________ Explain the physiological reasons for the lung volumes and capacities that changed in the spirogram for this condition. ________________________________________________ ________________________________________________ How is this condition similar to having emphysema? How is the fvc is less reduce than emphysema and it different? ______________________________________ the fev1 is more reduced, the fcv/fev1 % is also reduced ________________________________________________ Emphysema and asthma are called obstructive lung diseases as they limit expiratory flow and volume. How would a spirogram look for someone with a restrictive lung disease, such as pulmonary fibrosis? decreased fev1/fev ________________________________________________ What volumes and capacities would change in this case, and would these values be increased or decreased? normal or above normal volume ________________________________________________ ________________________________________________ In an acute asthma attack, the compliance of the lung is decreased, not increased as it was for emphysema, and air flows freely through the bronchioles. Therefore, will the FEV1/ FVC percentage be less than normal, equal to normal, or higher higher than normal? ______________________________________ Acute Asthma Attack Breathing During an acute asthma attack, bronchiole smooth muscle will spasm and thus the airways become constricted (that is, they have a reduced diameter). They also become clogged with thick mucous secretions. These two facts lead to significantly increased airway resistance. Underlying these symptoms is an airway inflammatory response brought on by triggers such as allergens (e. g. , dust and pollen), extreme temperature changes, and even exercise. Similar to emphysema, the airways collapse and pinch closed before a forced expiration is completed. Thus the volumes and peak flow rates are significantly reduced during an asthma attack. However, the elastic recoil is not diminished in an acute asthma attack. Respiratory System Mechanics 97 Acute Asthma Attack Breathing with Inhaler Medication Applied When an acute asthma attack occurs, many people seek relief from the symptoms by using an inhaler. This device atomizes the medication and allows for direct application onto the afflicted airways. Usually the medication includes a smooth muscle relaxant (e. . , a beta-2 agonist or an acetylcholine antagonist) that relieves the bronchospasms and induces bronchiole dilation. The medication may also contain an antiinflammatory agent such as a corticosteroid that suppresses the inflammatory response. Airway resistance is reduced by the use of the inhaler. 1. Using this information, predict what lung values will change in the spirogram whe n the patient who is having an acute asthma attack applies the inhaler medication. By how much will the values change (will they return to normal)? 2. Select Plus Inhaler from the drop-down menu in the Patient Type box. 3. Select the patient’s breathing pattern as Unforced Breathing from the Breathing Pattern box. 4. After these selections are made and the existing spirogram screen clears, click the Start button and watch as the drum starts turning and a new spirogram develops as the paper rolls off the drum. 5. Repeat steps 5–7 of the Normal Breathing section. 6. Now consider the accuracy of your predictions (what changed versus what you expected to change). Compared to the values for the patient experiencing asthma symptoms: Has the FVC reduced or increased? Is it â€Å"normal†? ________ no no Has the FEV1 reduced or increased? Is it â€Å"normal†? _______ fev1 Which of these two changed more? ____________________ Explain the physiological reasons for the lung volumes and capacities that changed in the spirogram with the application of the medication. _________________________________ ________________________________________________ How much of an increase in FEV1 do you think is required for it to be considered significantly improved by the not sure medication? _______________________________________ when the feve1 is closer to normal? ________________________________________________ a. In moderate aerobic exercise, which do you predict will rv change more, the ERV or the IRV? _____________________ b. Do you predict that the respiratory rate will change yes significantly in moderate exercise? ____________________ c. Comparing heavy exercise to moderate exercise, what values do you predict will change when the body’s significantly increased metabolic demands are being met by the not sure respi ratory system? _________________________________ ________________________________________________ d. During heavy exercise, what will happen to the lung volumes and capacities that have been considered thus far? hey will increase ________________________________________________ e. yes Will the respiratory rate change? If so, how? _________ 1. Select Moderate Exercise from the drop-down menu in the Patient Type box. The existing spirogram clears. 2. Click the Start button and watch as the drum starts turning and a new spirogram develops. Half of the screen will fill with breathing volumes and capacities for moderate exercise. 3. When the trace pauses, click on the individual measure buttons that appear in the data table above each data column to measure the lung volume and lung capacity data. . Select Heavy Exercise from the drop-down menu in the Patient Type box. 5. Click the Start button and the trace will continue with the breathing pattern for heavy exercise. The trace ends as th e paper rolls to the right-hand edge of the screen. 6. Now click on the individual measure buttons that appear in the data table above each data column to measure the lung volume and lung capacity data. 7. Now consider the accuracy of your predictions (what changed versus what you expected to change). Which volumes changed the most and when? ___________ Compare the respiratory rate during moderate exercise with that seen during heavy exercise. __________________  ¦ Breathing During Exercise During moderate aerobic exercise, the human body has an increased metabolic demand, which is met in part by changes in respiration. During heavy exercise, further changes in respiration are required to meet the extreme metabolic demands of the body. Histology Review Supplement For a review of respiratory tissue, go to Exercise H: Histology Atlas & Review on the PhysioEx website to print out the Respiratory Tissue Review worksheet.