integument system essays

integument system essays 1. Integument - a natural outer covering or coat, such as the skin or a membrane enclosing an organ 2. Protection - skin serves as a protective barrier from mechanical injury and penetration of harmful chemicals Defense - first line of defense against any disease organism Prevention of Dehydration - immersed in an internal sea carefully regulated, dilute salt, solution that is essential to life Maintenance of Body Temperature - by sweating it helps regulate the body temperature Excretion of Wastes - sweat glands also excrete excess water and waste Reception of Stimuli - sensors for stimuli of (touch, pressure, heat, cold, and pain) and sends message to central nervous system Vitamin D Synthesis - when ultraviolet rays hit the skin, a cholesterol compound is changed into Vitamin D 3. Epidermis - the outer most layer of the skin including dead cells of the stratum corneum and the living sub-layers of cell that give rise to them The epidermis contains: stratum, corneum. stratum granvlosm, stratum spinosum, and stratum basale. Dermis - the thick layer of skin composed of irregular, dense, connective tissue beneath the skin The dermis contains: ducts, eccrine sweat gland, connective tissue papilla, hair follicle, root, sebaceous gland, arrector pili muscle Subcutaneous Layer - the layer of loose connective tissue and apidase tissue beneath the skin The subcutaneous layer contains: loose connective tissue and appendage tissue. 4. keratin - a fibrous protein that forms the basic structural component of hair and nails. It is located between the phospholipid membranes to form the stratum corneum. Any one of a class of fibrous protein molecules that serve as structural units for various living tissues. The keratins are the major protein components of human hair. These proteins generally contain large quantities of the sulfur-containing amino acids, particularly cytosine. The helical k ...

Guide to Writing Argumentative Essay in Technology Advance Your Essay Writing

Guide to Writing Argumentative Essay in Technology Advance Your Essay Writing What is an Argumentative Essay in Technology? The aim of an argumentative essay on any topic requires you to provide a clear opinion about a certain issue as well as support it with relevant evidence. Considering the diverse peculiarities of different fields, it is crucial to consider various sides of your specific area and topic. Thus, you should explicitly present your viewpoint by regarding only a particular side of the issue as the compelling one. With the aforementioned academic concepts in mind, you can proceed to the essay writing on various areas, one of which is the field of Technology. As the area is widely analyzed from various perspectives, you can focus on any topic and write an argumentative paper in Technology. Choosing a Topic for an Argumentative Essay in Technology First and foremost, you should narrow down the broadness of the issue. As it is highly recommended for this type of writing to be straight to the point, you should come up with a topic that presents a specific issue in any technological aspect. In order to successfully write the essay, you should do the research and gain relevant expertise in the peculiarities of the subject. Moreover, the topic should be connected with something that you are passionate about so that you can present arguments from the perspective of a specialist. Some of the most captivating areas that you may want to dwell upon could concern the role of technology in reproduction and health, technical experiments on humans, as well as robotics and communication technology. Hence, the examples of the topics for your argumentative essay on technology could be the following: Should Mechanical Reproduction be Considered Ethically and Morally Appropriate? Technology Has to Be Used to Make Human Regeneration an Ultimate Reality; Genetic Engineering Has no Limits, and Its Research Can Never Go Too Far; The Technology of Brain-Controlled Mechanisms Could Have Dangerous Implications; Nanobot Drones Pose a Substantial Threat to the Existence of Humanity; Are Electronic Books More Practical Than the Paper Ones? Cloud Computing and Machine Learning Eradicate Conventional Methods in Education. Pre-Writing Tips Choosing a topic for an argumentative essay in Technology is a substantial challenge. However, you can ask the instructor to clarify the research area in order to eliminate the vagueness of your task and make it more specific. After the topic selection process, you can proceed with planning your argumentative essay. To fully grasp the requirements, carefully read the assignment sheet as well as any relevant information from the textbook. Besides, should the assignment be complicated, you can always consult the instructor. Considering that your task is to write an argumentative essay, you should recognize that it is necessary to provide your perspective of the issue and persuade the audience in the reasonability of the arguments. Next, after you defined the topic and understood your assignment, determine the idea of the topic, and get enough knowledge about it. When setting a topic idea of your argumentative essay in Technology, you should focus on different perspectives of the issue and present your position in the thesis statement. You will also need to find evidential support for the arguments regarding the topic, which implies searching for additional sources. The substantial amount of data on Technology for your essay can be found on the Internet. You can search for sources on the topic at Google Scholar, websites focused on research and technology news, or science magazines for a non-professional audience. In addition, you may find sources at your school or college library. While looking for the information, you should remember that all the data must be drawn from credible sources only. What is more, you have to consider logos, pathos, and ethos before starting your writing process. Make your arguments logical, consider the audiences emotions, and appeal to the moral values. All these features contribute to a better perception of your argumentative essay by readers. Hence, you should plan how you will implement these principles in advance. Finally, before proceeding to the writing process, connect the research data into a well-developed and structured outline of your essay. In particular, you should extract the relevant information and use it as evidence to support your arguments. Moreover, an outline will guide you through the huge amount of data and structure of your argumentative essay. Divide the paper into introduction, body paragraphs, and conclusion, think of the potential hook and topic sentences, as well as determine the way of audience-appealing techniques. This step is essential for your writing as it defines the structure, cohesiveness, and as a result, the effectiveness of your argumentative essay. Structure of an Argumentative Essay in Technology Similar to any argumentative essay, a paper in Technology should comply with the standard form of academic essay expanded with one or more refutation paragraphs. Thus, your essay should start with an introduction, present your arguments and counterarguments in the body paragraphs as well as refutation sections, and summarize your ideas in a conclusion. Even though a common approach to writing an argumentative essay is the five-paragraph method, the number of paragraphs may vary with the word count limit. In addition, your structure could be expanded due to the necessity to cover the topic effectively. Despite this fact, your writing should always include paragraphs with the argumentation of your position as well as the most potent aspects of the counter-side. With an outline, it would be easier to determine the proper structure of your Technology argumentative essay. Introduction The introductory paragraph of your essay should capture readers attention by providing general background knowledge on the chosen topic. In other words, you should be concise and introduce the issue in the most interesting and convincing way. As an example, if your topic focuses on the subject of brain-controlling technologies, you can underline the peculiarities of the rapid development of this innovation during the present time. If you introduce the issue in such a way, the audience will be aware of the topicality of the problem and its potential implications on humanity. This implies that the presentation of your essay may also appeal to the audiences emotions, which in turn makes the readers prone to empathize with your viewpoint. The last and the most influential part of the introduction is a thesis statement. It is usually written as the ending sentence of the introductory paragraph. As your thesis serves as a guide for your whole essay, it should comprise all critical ideas of your argumentation. You have to make sure that a thesis statement is clear and thoroughly answers the topic question. The central aspect of your thesis statement is that it should present your position towards the issue and provide the most persuasive arguments that support your point of view. Do not create a thesis statement similar to this example: ‘The technology of brain control is dangerous for society as it can get out of human monitoring reach.’ Such a thesis statement does not indicate any aspects of the technologys peculiarities and presents only a single and unreasoned argument of the issue. On the contrary, the following example is explicit and could be used in your Technology argumentative paper: ‘Despite being a beneficial and rapidly-developing innovation, brain-controlling technology poses a significant threat to international society due to the substantial complexity of its operation, harmful impact on peoples health, and relatively high maintenance costs.’ You can see that the issue is thoroughly analyzed and crucial technological, healthcare, as well as economic arguments for the brain-controlling technologys inefficiency are present in this thesis example. Moreover, the thesis presents a counter-argument of ones position as it underlines that innovation has benefits for humanity. Finally, such a thesis statement clearly indicates the structure of the further body paragraphs. Therefore, this thesis serves as a robust example and can be used in your argumentative essay in Technology. Body Paragraphs When you proceed with the body-section writing, it is crucial to ensure that you present only one idea in each paragraph. Each point of your thesis should be stated in the topic sentences of your body section. You have to explain your arguments and support them with relevant pieces of evidence. Besides, do not forget that all retrieved data in your argumentation essay in Technology must be drawn from relevant sources. Finally, body paragraphs will be more appealing to the audience if you provide opposing viewpoints and refute them with your argumentation. For the audience to consider the critical points in your argumentation, you should not only present the complete agreement or disagreement with the topic issue but also strengthen your opinion with the scientific evidence. As an example of one body paragraph, if your essay focus is the healthcare argument of the social danger of brain-controlling technology, you should underline the existing examples of the innovations negative implications on brain neurons and the skull. It is highly recommended to refer to statistics and other relative data that would support this particular argument. However, you should anticipate the attempt to refute the argument and answer it with a profound response. On the example of the aforementioned topic and the argument, you may acknowledge that the direct surgical intervention in the human brain can be substituted with the brain implants, which do not interfere with the brain’s structure. However, you can defy such a counter-argument by claiming that there is still a potential risk of brain damage as implants have to be installed onto the brain surface. Therefore, the refutation section makes you an unbiased researcher. Such an aspect captivates the readers and prevents their questioning of your essays credibility. By approaching the issue from both perspectives, you are guaranteed to show the relevant competency in the subject and make your argumentative essay in Technology more appealing to the audience. Conclusion The concluding section of your argumentative essay should bear resemblance with the introduction of your paper. Here, you are required to summarize a thesis statement and each argument from the body section. Similar to the introduction, the conclusion should appeal to the audiences emotions and enforce the argumentation of your opinion. You should also keep in mind that the paragraph only ties the central aspects of the essay and cannot introduce new arguments or facts. When writing a conclusion of your Technology paper, you can summarize your ideas and transfer their implications on the current state of affairs. In particular, in the concluding paragraph, you may appeal to the audience via a comparison of the contemporary technological achievements to those of the old times as well as the potential development of innovations in the future. However, the sphere of technology is extensive, and your conclusion always has to correspond to the topic and the issue you dwell upon throughout your essay. Hence, it is your last opportunity to appeal to the audience by presenting the peculiarities of your topics specific aspects. Post-Writing Tips Having written the last sentence of your Technology argumentative essay that does not mean that your task is finished. You should always proofread and revise the essay and correct grammar, punctuation, and stylistic errors. Next, reassure that all the sources are credible and you have used the appropriate citation style. There are also several key aspects that you have to consider while proofreading an argumentative essay in Technology. First and foremost, check whether you have provided a reasonable position towards the topic issue. As the aim of such type of academic writing is to state your viewpoint and support it with evidence, you have to ensure that the essay does not merely present naked facts. Then, analyze all the structural components of your paper. This stage is crucial as you have to ensure that your introduction provides sufficient background information and clear thesis statement; that body paragraphs contain topic sentences, relevant arguments, and the refutation section; that conclusion gives the summary of your argumentative paper and restates a thesis from the introduction. The structure of an essay is its essential part, and you have to make sure that all the components comply with the requirements. Finally, evaluate your successfulness of logos, pathos, and ethos usage. The best argumentative essays are those that are logical, appeal to the audiences emotions, and speak to the moral values. Your paper should incorporate all these factors in order not only to receive a high mark but to achieve the appreciation of the readers. Therefore, the above-mentioned post-writing tips will assist you in enhancing the quality of the argumentative essay in Technology. These recommendations will help you improve your writing skills and in turn, ensure that the readers are impressed with your paper.â€Æ' Argumentative Essays. (n.d.). Retrieved from https://owl.purdue.edu/owl/general_writing/academic_writing/essay_writing/argumentative_essays.html Fleming, G. (2019). Tips on How to Write a Solid Argument Essay. Retrieved from https://www.thoughtco.com/write-an-argument-essay-1856986 Gibson, E. (2016). The benefits and downsides of mind-controlled machines. Retrieved from bbc.com/future/story/20161111-the-benefits-and-downsides-of-mind-controlled-machines Kearney, V. (2019). 100 Technology Topics for Research Papers. Retrieved from https://owlcation.com/academia/100-Technology-Topics-for-Research-Paper Kearney, V. (2019). How to Write an Argumentative Essay Step by Step. Retrieved from https://owlcation.com/academia/How-to-Write-an-Argument-Essay

Free Essays on Indian Killer

1. A murder is stalking and killing White men in Seattle. By scalping and leaving two owl feathers behind after each killing, the killer made it looked like an Indian’s work. The murder of the White man in Fremont, the disappearance of David Roger, the kidnapping of the white young boy made many Native Indian confused and worry- Including John Smith, a born Indian raised by White but he has a very big influence of the Indians especially father Duncan (a Spokane Indian). Sherman used mystery and irony to portrait his novel. Even at the end of the novel, the author still doesn’t tell who’s the killer - - or killers. But one of the most ironic things that happened at the end of the novel that gives the readers a shocking experience is that John Smith killed himself. 2. Main Characters in this novel include: John Smith, Reggie Polatkin, Marie Polatkin 3. Many other minor characters are John’s parents, David Roger, Father Duncan, and etc. 4. Seattle, sometimes after the European take over the Indian’s land 5. Skipped. 6. There is a lot of rage in this book. Whites are either mean or racist dullards, while those who try to sympathize with Indians are to be disdained. The author also tried to be as mysterious as possible. As reading the novel, the readers’ mood is getting more eager to know who’s the killer. The description of John (sounds like he’s mentally ill) made the audience expect him to be the killer. 7. There are some scenes that are very violent and gross. Such as when the killer first killed the White man in Fremont, the killer swallowed the eyes ball of the victim and scalped him. The description is very detail so it’s really sick. There are also bad languages and unnecessary chapters to describe minor characters. 8. The author often used irony in this novel. For example, White people raised John Smith yet he has no influence by White. He yearned for his lost heritage and wanting to find his real ide... Free Essays on Indian Killer Free Essays on Indian Killer 1. A murder is stalking and killing White men in Seattle. By scalping and leaving two owl feathers behind after each killing, the killer made it looked like an Indian’s work. The murder of the White man in Fremont, the disappearance of David Roger, the kidnapping of the white young boy made many Native Indian confused and worry- Including John Smith, a born Indian raised by White but he has a very big influence of the Indians especially father Duncan (a Spokane Indian). Sherman used mystery and irony to portrait his novel. Even at the end of the novel, the author still doesn’t tell who’s the killer - - or killers. But one of the most ironic things that happened at the end of the novel that gives the readers a shocking experience is that John Smith killed himself. 2. Main Characters in this novel include: John Smith, Reggie Polatkin, Marie Polatkin 3. Many other minor characters are John’s parents, David Roger, Father Duncan, and etc. 4. Seattle, sometimes after the European take over the Indian’s land 5. Skipped. 6. There is a lot of rage in this book. Whites are either mean or racist dullards, while those who try to sympathize with Indians are to be disdained. The author also tried to be as mysterious as possible. As reading the novel, the readers’ mood is getting more eager to know who’s the killer. The description of John (sounds like he’s mentally ill) made the audience expect him to be the killer. 7. There are some scenes that are very violent and gross. Such as when the killer first killed the White man in Fremont, the killer swallowed the eyes ball of the victim and scalped him. The description is very detail so it’s really sick. There are also bad languages and unnecessary chapters to describe minor characters. 8. The author often used irony in this novel. For example, White people raised John Smith yet he has no influence by White. He yearned for his lost heritage and wanting to find his real ide...

Did women have a Renaissance in Early Modern Europe Essay - 1

Did women have a Renaissance in Early Modern Europe - Essay Example The early modern period saw many rapid changes in the way that society interacted with itself. Whereas the middle-aged should have been defined by dogmatic religious interpretation, the early modern period saw something of a relaxation of the means by which society and the laws that constrained it operated. Moreover, trade began to flourish and created the first exhibitions of what we might now term the middle class. Arts and literature came to be in greater and greater prevalence within this particular era due to the fact that the daily struggle to provide food, security, and basic human needs was simplified. Political theory and the means by which society was structured became less chaotic and more orderly. However, even though it might be tempting to state that each of these progressions somehow invariably impacted upon the plight of women, it is the assumption and understanding of this brief analysis that even though a great many societal changes were occurring during this time, the majority of these did not impact upon the rights and/or freedoms that women would otherwise experience. Instead, the benefits of this â€Å"early modern era†, as it was dumb, were almost invariably concentric upon the males within society. However, even though a low level of benefit was able to be derived by women during this period in time, the reduction in power that the church was able to exert over societal shareholders was necessarily a net in a fit with regard to the overall level of rights and privileges that women could exercise and experience within their respective societies. Naturally, this reduction in the church’s power existed to varying degrees based upon geography and/or ethnic/cultural determinants. Secondarily, as a direct result of the level of economic growth and the rise in the existence of the middle class, women of this particular class experienced a different type of lifestyle than those which had traditionally been confined to and constrain ed by abject poverty and/or the differential between the extraordinarily wealthy and carefree and those who struggled under varying forms of servitude to provide for the needs of themselves and for their families. Firstly, any study or examination of human rights and the progression of feminism denotes the fact that religion, by very definition, has traditionally negatively impacted upon the way and manner that these freedoms were experienced. Whether one considers the case of Islam, Christianity, Judaism, Hinduism, or any of the other world’s great religions, each of these has at its core a patriarchal respect which necessarily places women and their rights in a position of lesser importance (Andrea 275). In much the same way, medieval Europe was defined and structured along religious lines. This was so much the case that cultural differences between the French and the Italians, between the Germans and the Danes, and/or between the Swiss and the Poles were more concerned wit h whether or not a particular religion defined this interaction than they were with regard to the differential and cultures that necessarily existed between the two. For a large part of the dark/Middle Ages, the Roman Catholic Church had near unchallenged sway with regard to how people thought and believed in Europe. However, as a result of the challenge that Protestantism posed, the role and power of the Roman Catholic Church, and indeed the overall power that religion itself was able to project within this system were necessarily reduced. This is not say that Europe experienced anything like a miniature enlightenment during this period. Rather, the challenge of an alternate point of view led many individuals to challenge, at least on a personal level, whether or not the religion that they had so long clung to was effective in determining the mores and norms by which they would live. It is important to note at this juncture that even though Protestantism allowed for a deviation and distraction from the rigid constructs of Roman Catholicism, it was not necessarily any more friendly or

International Migration Term Paper Example | Topics and Well Written Essays - 1500 words

International Migration - Term Paper Example It is through migration that many international criminals are able to hide their activities. International migration also lead to pressure on social facilities in different countries and this often leads to conflicts between citizens. The entry of illegal immigrants in many countries leads to increase in petty offenders and criminals, when such illegal immigrants are unable to survive or find jobs abroad. The illegal migrants usually hide from the authorities in the host countries and they face cruel treatment but they also are unable to seek justice from the legal systems. Consequently, many criminal activities are committed against them by the citizens of such countries. The security of the host country is threatened when more people that had not been planned for by the security agents in all situations. The security facilities become overstretched and therefore unable to ensure adequate security to all members. Any country may risk capital flight when migrants move resources to th eir countries of origin. Consequently, economic resources are taken out of a country illegally to benefit other countries. Part 2 International migration produces benefits to their home countries and to the host countries depending on many situations. To their countries of origin, the migrants remit finances to their home countries. This often results into large sums of money being sent from well developed counties to developing countries. Such resources help in developing countries from which migrants came. International migration is more hurting to men due to pressure on men to provide in many families. The negative effects of international migration are loss of human resources, and the brain drain when countries lose their highly qualified people to other... The researcher of this term paper discusses international migration, that is the movement of people from one country to another due to many reasons. International migration has consisted of people moving from their country of birth for many reasons and this movement involves millions of people each year. The migrants range from less educated to highly educated professionals who move from their own countries that may have scarce resources. The low skilled workers also move to seek better wages abroad because the benefits outweigh the disadvantages. When people move from one country to another, they enter new countries whose laws they may not understand. Internal migration may also involve individuals whose characters are not known. It is through migration that many international criminals are able to hide their activities. International migration has remained one of the main issues that impact the lives of all people around the globe. International migration, that was discussed in the paper involves many issues that must be considered by those moving to foreign lands. The reseracher then concluds that this international movement of people has both positive and negative consequences to the individuals, their families, and the national economies as well. Legal migration can help boost the lives of individuals when all legal procedures are followed. Iover a million many countries deal with. Many countries have created legal provisions to curb the surge of illegal migrants to their borders.

Apple Company Essay Example | Topics and Well Written Essays - 1000 words

Apple Company - Essay Example It took Apple only five years from 2003 to 2008 to have the market value of its shares increased by as many as 25 times, as the value of Apple’s share in 2003 was $7.5 which increased to $180 in the year 2008. â€Å"At July 2008 prices, before the US Financial Crisis, Apple stock market capitalization was $160 billion. In January 2010 Apple shares topped the $210 mark† (Vertygo Team, 2011). The case study of Apple Company provides an excellent practical example of how the theoretical marketing principles can be brought to life by incorporating them into the business strategies, and their benefits can thus be obtained. This paper discusses the potential ways of integration of the marketing theory with practice, and explores the comprehensive marketing strategy adopted by the Apple Company that has led it to the profound success. The secret of Apple’s success lies beyond the design standards of its products as well as the core philosophy of Apple which suggests tha t â€Å"the user doesn’t always know what they want† (Tiojanco, 2012). ... potential hurdles in the way of integrating marketing theory with practice, and recognition of the measures that can be taken to overcome those obstacles. Subjectivity in the knowledge of marketing theory is introduced by the conflicting and complimenting marketing theories of different scholars and educationalists. There is not a single established way of marketing that has gained mutual consensus of all scholars and authors. In fact, different good practices have been explained in different books and literatures depending upon the context, circumstances, organizational objectives, and internal and external environmental and cultural factors that vary from one case study to another. However, there is a need to generalize certain marketing practices and principles that have been approved by a vast majority of scholars. Such marketing principles include but are not limited to improving the brand image by fulfilling corporate social responsibility, incorporating innovation and diversit y in the product design so that the product addresses the needs of a vast majority and diverse population of consumers, and selecting the right medium and the right time to advertise the products. Application of the marketing theory in practice requires understanding of difference between the role of advertisement and promotion. â€Å"[A]dvertising-like messages are used for longerterm strategic efforts to build brand awareness and attitude while promotion-like messages are designed for shorter-term tactical needs to stimulate an immediate sales response† (Percy, 2008, p. 28). Some of the hurdles in the integration of marketing theory with practice include lack of consistency between the organizational structure and the scope of work and organizational objectives, lack of involvement of

The Lungs Research Paper Example | Topics and Well Written Essays - 750 words

The Lungs - Research Paper Example The lungs are composed of a substance which is light, porous, have a spongy texture and are highly elastic. The surface has many polyhedral areas. The lungs are heavier in a male than in a female; the left lung is smaller than the right one in order to accommodate the heart. The lungs can be examined in terms of an apex, a base, three borders (anterior and inferior) and two surfaces (Costal and mediastinal). Each lung is conical in shape and is divided into lobes by interlobular fissures. The left lung is divided into the left superior or upper lobe and the left inferior or lower lobe. The right lung is divided into the right superior lobe, the right middle lobe and the right inferior lobe. Each lobe is further divided into pyramidal bronchopulmonary segments: ten in the right and eight in the left one. The root of each lung or the hilum connects the lung to the heart and the trachea. According to Gray (1918), â€Å"the bronchus, the pulmonary artery, the pulmonary veins, the bronch ial arteries and veins, the pulmonary plexuses of nerves, lymphatic vessels, bronchial lymph glands, and areolar tissue enter and leave the lungs through the root†. The trachea, or windpipe, reaches the thorax and is divided into the right and left bronchi. In the lungs the bronchi divide into large ventral and small dorsal branches. The bronchi are divided into smaller bronchi and bronchioles. Each bronchiole further splits into two or more respiratory bronchioles connected to alveolar ducts which, in turn, are connected to a cluster of small alveoli or air sacs. The pulmonary artery, the pulmonary veins, and the pulmonary capillaries supply deoxygenated blood to the lungs and remove oxygenated blood. The bronchial arteries and the bronchial vein supply oxygenated blood for the nutrition of the lung itself. All these arteries and veins enter and leave the lung through the hilum, as do the lymphatic vessels of the lungs. Pulmonary nodes, bronchopulmonary nodes and tracheobronc heal nodes are present. The lungs are supplied with nerves from the anterior and posterior pulmonary plexuses which have small ganglia on them. (Gray, 1918). The function of the lungs is to provide a continuous gas exchange between the inhaled air and the blood in pulmonary circulation. Oxygen is supplied and carbon dioxide is eliminated by exhalation. The exchange of gases takes place through simple diffusion: oxygen diffuses from the alveoli into the blood and CO2 diffuses from the blood into the alveoli. This diffusion requires a concentration, or pressure, gradient. The concentration of oxygen in the alveoli is kept higher than in the blood and the concentration of CO2 in the alveoli is kept lower than in the blood by the breathing of fresh air into the lungs. This breathing mechanism is generated by the respiratory muscles: the exterior intercostals located between the ribs, and the diaphragm which is a sheet separating the thorax from the abdomen. During inspiration the interc ostals and the diaphragm contract, the dimension of the thoracic cavity increases, air pressure in the lungs decreases and becomes slightly negative as compared to atmospheric pressure. This causes the air to move from the atmosphere into the lungs. During exhalation the muscles relax, lung volume decreases, pressure in the lungs increases and air is exhaled. The surface tension on the walls of the alveoli caused by water molecules is reduced by the pulmonary surfactant produced by the lungs. The exchange