...TASK 1 – PHYSICAL PROPERTIES OF SOME ELEMENTS AND COMPOUNDS | |Test for | | | | |Substances | | | |Electro |Thermal conductivity|Solubility – is it |Melting point? |Boiling point | | |conductivity: does | |soluble in water? | | | | |it conduct | | | | | | |electricity? | | | | | | | | | | | | | |As solids |In solutions | | | | | |Potassium chloride | |Slightly conductive | |__ |7700C |15000C | |Sodium chloride | |Quite | |Soluble |14650C |8010C | | | |Conductive | | |266900F |1473.40F | |HCL | |Slightly conductive | ...
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...be pumped to its respective destination. The human heart begins to beat, on average, at 21 days after conception and is one of the first functioning organs of the human embryo. The average heart in an adult human weighs approximately 300 grams and resembles the size of the individuals closed fist (Tortora, G.J. 2006). The heart is enclosed in a fibrous protective sac called the pericardium. The pericardium is composed of two layers; the outermost layer being dense connective tissue while the inner layer is composed of serous epithelium that provides for lubrication of the beating heart muscle. The heart is composed of involuntary muscle that differs from both skeletal and smooth muscle, this type of muscle is known as cardiac muscle. Cardiac muscle performs in a combination of the two previously mentioned muscle groups in that it is controlled by the CNS...
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...ASSESSMENT with authorized materials. Students are allowed to bring two A4 size sheets of notes/formulae written on both sides. 6. All questions carry equal marks. PAGE 2 ME3291 QUESTION 1 The heat conduction equation in 1D is given by T/ t = b 2 T/ x2. Here T is the temperature and b is the thermal conductivity. You are interested to use the DuFort & Frankel discretization scheme to obtain the finite difference equation of the governing equation because you have heard of its inherent stable properties. The DuFort & Frankel scheme is given as: (Tpq+1 - Tpq-1)/(2 t) = (b / ( x)2) [Tp+1q – (Tpq-1 + Tpq+1) + Tp-1q]. where Tpq = T (p x, q t) is the finite difference representation. You are interested to use the von Neumann (Fourier) stability analysis to determine if it is inherently stable or otherwise. If otherwise, then you show the criterion for the limit of stability. You may assume that Tpq = q ei ph where is the amplification factor, is a particular spatial Fourier mode, i is the complex number (-1)0.5, and h x in the analysis. (a) Determine the (quadratic) equation for (10 marks) (b) Hence or otherwise, determine the possible range of r ( t/( x)2) so that there is no source or sink in the governing heat conduction equation. ≤ 1.0 since (15 marks) PAGE 3 ME3291 QUESTION 2 The one-dimensional wave...
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...Cardiac Muscle Tissue and It’s Function There are different types of muscle tissue in the body. I will be focusing on cardiac muscle tissue and its functions. Cardiac muscle is located in the heart wall and its major function is to pump blood throughout the body. If you were to put cardiac muscle and skeletal side by side you would see that cardiac muscle fibers are shorter in length and less circular. They are described as: “Branched striated fibers with usually only one centrally located nucleus (occasionally two). (Jenkins&Tortora,(2012) p. 132) Cardiac muscle fibers connect to each other by intercalated discs. Intercalated disc are “Transverse thickenings of plasma membrane called intercalated disc which contain desmosomes and gap junctions.” (Jenkins&Tortora,(2012) p. 132) Desmosomes are the glue of the cardiac muscle they hold it together even through constant athletic movement. For example exercise, if there were no desmosomes in the cardiac muscle it would simple fall apart then minute you jumped on a treadmill or began and exercise routine. “Desmsomes strengthen tissues and hold fibers together during vigorous contractions.” (Jenkins&Tortora,(2012) p. 132) Gap junctions make it possible for action potentials to move through one muscle fiber to the next. “Gap junctions provide route for quick conduction of electrical signals throughout heart.” (Jenkins&Tortora,(2012) p. 132) We don’t have to tell our cardiac muscle to contract it does this all...
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...the heart after sudden cardiac arrest (SCA). The shock is needed to reset the heart after SCA. Cardiac arrest is a condition wherein the heart produces irregular rhythm and then stops beating. This is a medical emergency as the blood flow to the brain and internal organs will cease. If no immediate care is done for individuals having sudden cardiac arrest, the chances of survival will decrease since the condition may result in death within minutes. Automated external defibrillators make it possible for people to respond immediately to individuals that are having sudden cardiac arrest. This is one of the tools used by emergency medical responders and is used to provide electrical shock to “shockable” heart rhythms. What are “shockable” heart rhythms? The heart has its own electrical system that triggers the contraction of the heart muscles. It is responsible for the control of all of the events that occur in the heart during pumping out of blood to the circulation. When there are problems within the heart, blood vessels and electrolytes may cause a disruption of the electrical system and may result in arrhythmia. Arrhythmias are problems with the conduction of electricity in the heart that causes abnormal heart rhythms. There are a number of arrhythmias but not all of them are treated with defibrillation. The only “shockable” arrhythmias are pulseless ventricular tachycardia and ventricular fibrillation. Both of these arrhythmias may cause cardiac arrest. Ventricular tachycardia...
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...ELECTROCARDIO-graphy (E.C.g.) Uses: - To detect arrhythmias To diagnose chamber hypertrophy To diagnose myocardial infarction Electrocardiogram is the graphic representation of electrical changes occurring in the cardiac muscle. It is recorded by using surface electrodes. These are of two types: Bipolar leads Unipolar leads Bipolar leads Lead I-Right wrist and left wrist Lead II –Right wrist and left ankle Lead III- Left wrist and left ankle Unipolar leads - Limb leads and chest leads a. Limb leads- aVR – right wrist aVL –left wrist aVF – left ankle b. Chest leads- V1-4th right intercostal space at the sternal border V2-4th left intercostal space at the sternal border V3- between V2 & V4 V4- at the midclavicular line in the left 5th intercostal space V5- at the anterior axillary line in the same horizontal plane V6- at the mid-axillary line in the same horizontal plane V3R - on the right side – position same as that of V3 V4R - on the right side – position same as that of V4 E.C.g. - - paper speed-25mm/sec horizontally 1mm(one small square)=0.04sec (one large square=0.04x5=0.2sec vertically 1mm=0.1mv P-wave- atrial depolarisation –upright width – 2.5mm=0.1sec QRS - ventricular de-polarisation width – 1-2.5mm=0.04-0.1sec average 0.08sec height – variable PR- interval-from...
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...the pithed frog. Table 1. Time between QRS and the start of ventricular contraction(s). 1. Observe the heart and describe its behavior. Is this behavior consistent with what is shown in the data above? Yes. The heart of the frog rhythmically contracts and relaxes. This behavior is supported by the general fluctuations observed force values and the consistent patterns of the ECG occurring in regular intervals. 2. Explain the basis for the delay between the atrial and ventricular contractions. The said delay is mainly caused by the A-V node and its adjacent conductive fibers, causing an overall delay of 0.13 second (Guyton and Hall 2006). Conduction in the transitional, nodal, and A-V bundles is dampened by the decreasing number of gap junctions along the pathway of conduction, creating great resistance against the conduction of excitatory ions from one fiber to another. This ensures that the atria completely empty blood into the ventricles before ventricular contraction occurs. 3. Describe the relationship between the ECG QRS complex and the beginning of ventricular contraction. What is the physiological significance of this relationship? A typical electrocardiogram normally exhibits P, Q, R, S, and T waves, all of which represent electrical voltages produced by the heart. The QRS waves occur as a result of the electrical depolarization of the right and left ventricles, an event that triggers ventricular contraction and the subsequent rise in ventricular pressure. This...
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...The muscular system derives of smooth muscles, skeletal muscles, and cardiac muscle. Smooth muscles are those that surround hollow organs while skeletal muscles attach the skeleton to form the flesh of the body and cardiac muscle is found only in the heart. Just like any other body system, there can be affective problems. Neuromuscular junction disorders impair the transmission of nerve signals to muscles. Myasthenia Gravis is the most common neuromuscular junction disorder. The discovery of Myasthenia Gravis was in early 1970’s and its condition causes a breakdown in communication between nerves and muscles. This characterization considers to cause highly changes of weakness of the skeletal muscles and it can be harder for operation. MG...
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...the concentration of calcium ions outside of cells is thousands of times higher than the concentration inside of cells. Embedded in the membrane of some cells are calcium channels. When these cells receive a certain signal, the channels open, letting calcium rush into the cell. The resulting increase in intracellular calcium has different effects in different types of cells. Calcium channel blockers prevent or reduce the opening of these channels and thereby reduce these effects CCBs used as medications primarily have three effects: • By acting on smooth muscle they reduce contraction of the arteries and cause an increase in arterial diameter, known as vasodilation. • By acting on cardiac muscles (myocardium), they reduce the force of contraction of the heart • By slowing down the conduction of electrical activity within the heart, they slow down the heart beat. These effects cause an overall decrease in blood pressure, since it depends on the force of contraction and resistance of the arteries. However, these drugs are associated with several side-effects and prolonged use of them can lead to complications. Therefore CCB’s are usually are not used alone but are part of a combination of drugs used for the treatment. Side effects of these drugs may include but are not limited to:...
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...The criteria for a Normal Sinus Rhythm is: • P-wave before each QRS with an interval of 0.12 to 0.20 seconds in duration. • A QRS width of 0.04 to 0.12 seconds • Q-T interval of less the 0.40 seconds. • The rate for a normal sinus rhythm is 60 to 100 beats a minute. Normal Sinus Rhythm P-R interval 0.12 to 0.20 seconds QRS duration 0.04 to 0.12 seconds Rate 60 to 100 beats a minute ________________________________________ If the rate is below 60 beats a minute but the rest is the same it is a Sinus Bradycardia. Brady- means slow.. Like your brain after you watch the Brady Bunch! Sinus Bradycardia P-R interval 0.12 to 0.20 seconds QRS duration 0.04 to 0.12 seconds Rate less than 60 beats a minute Yes... the QRS complexes look completely different... That's okay. I already said that we're all different. Relax. ________________________________________ If the rate is between 100 to 150 beats a minute with the same intervals it is a Sinus Tachycardia. Tachy- means fast. (Think of what happens to your heart rate when you sit on a tack) Sinus Tachycardia P-R interval 0.12 to 0.20 seconds QRS duration 0.04 to 0.12 seconds Rate 100 to 150 beats a minute ________________________________________ When the pattern becomes irregular with normal intervals it is a Sinus Arrhythmia Sinus Arrhythmia P-R interval 0.12 to 0.20 seconds QRS duration 0.04 to 0.12 seconds Rate 60 to 100 beats a minute, regular rhythm with periodic irregularity Atrial...
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...014CRNA Interview Preparation Q: Tell me about a time when you had to manage a difficult clinical situation. Q: Tell me about a time when you were working with someone who wasn't pulling their weight, and they had a different value system than yours. How did you deal with this person? Q: Tell me about a time when you failed. What happened, and how did you recover? Q: Tell me about a time when you had an ethical dilemma at work. What did you do? Q: Tell me about a time when you felt it was you against everyone else. You thought you were right and that everyone else was wrong. What did you do? Q: Why do you want to be a CRNA?** Q: What would make you a successful CRNA?** Q: How do you handle stress? Q: What kind of patients do you take care of? Your favorite and why?** Q: Tell us about your work experience.** Q: How do you describe success? Q: Do you foresee any barriers to your education? (finances, time commitments) Q: What does a CRNA do? How do you think your role as a CVICU nurse relates to the role and responsibilities of a CRNA?** Q: Where do you want to be in 5 years?**. Q: Why our program? Q: What questions do you have for us?** A: What do you look for in potential students? How does your program facilitate student research? I am very interested in teaching and education, how does your program prepare me to be an educator? What do you see as your school's strong points? On avg. how many intubations, art lines...
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...19 CASE The Case for Open Heart Surgery at Cabarrus Memorial Hospital Situation It was a clear, crisp October morning in Concord, North Carolina. The board of trustees of Cabarrus Memorial Hospital gathered in the windowless, walnut paneled boardroom for its monthly meet- ing (see Exhibit 19/1 for board members). Board chairman George Batte opened the meeting saying, “Because we do not have an open heart surgery program, patients needing open heart surgery or coronary angioplasty have to be transferred to another hospi- tal, causing inconvenience to the patient’s families and risks from delayed treatment. There are several questions we have to answer in addressing this issue. Should we add open heart surgery to the mix of cardiac services we offer? Does the hospital’s existing service area provide adequate patient volumes to support the program? What This case was written by Fred H. Campbell, The University of North Carolina at Charlotte, and Darise D. Caldwell, Executive Vice President and Chief Operating Officer, Northeast Medical Center. It is intended as a basis for classroom discussion rather than to illustrate either effective or ineffective handling of an administrative situation. Used with permission from Fred Campbell. 804 Exhibit 19/1: CMH Board of Trustees Mr. George A. Batte, Jr., Chairman (Retired Manufacturing Executive) Mr. L. D. Coltrane, III, Vice Chairman (Telephone Company President) Mr. Robert L. Wall (President, Cabarrus...
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...The conductive properties of cardiac tissue are an important part of an arrhythmogenic substrate. In a healthy heart rapid transmission of excitation and the refractory period, in which tissues remain unexcitable immediately following activation, work in concert to prevent reentry and arrhythmogenesis. Various diseases alter the conductive properties of myocardium, e.g. ischemia, creating favorable conditions for ectopy and reentry (Janse et al. 1980, Schalij et al. 1992, Wilders et al. 2000). Specifically, cardiomyopathies that cause a decrease in conduction velocity (CV), the rate of activation propagation through the myocardium, favor arrhythmogenesis by decreasing the critical wavelength necessary to foster reentry (Mines 1914). However,...
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...Tissues: An introduction Lab Report Part 1 This lab is divided into two different parts. Part 1 deals with the general characteristics of tissues, and part 2 asks you to interpret some photomicrographs taken of human tissue slides in our lab. Part one should be completed first, but you’ll probably get a lot of hints about the answers for part 2 if you’ve looked over the images and questions provided ahead of time to work on them. To do Part 1, download the following documents and have your textbook available. Part 1 Characteristics of tissues A. Epithelial Tissues What are five general characteristics which distinguish epithelial tissues? (1. Cellularity: tightly packed sheets of cells with little intercellular material between them 2. Basement membrane; the basal surface of ETs are anchored to underlying CT by a distinct basement membrane 3. Specialized contacts: tight junctions and desmosomes 4. Avascularity: contain no blood vessels; are nourished by nutrients which diffuse upward from underlying connective tissue through the basement membrane 5. Regeneration: high regeneration capacity due to rapid cell division ) Explain how the general morphology of epithelial cells may be deduced from the names of the epithelial tissues. (The names of the epithelial cells are characteristic of their structure: simple=single layer stratified=many layers squamous=flat cuboidal=cube shaped columnar=elongated ) Epithelial tissues specialized for secretion can be found...
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...Assignment 1 – (50 marks) Discuss the importance of body fluids and which one is considered to be the body’s internal environment. (4 marks) * Body fluids carry chemical communicators which organize actions amid cells, carry nutrients to cells, and carry waste products away from cells. They are the primary transport system between cells. The internal environment of the body is extracellular fluid, which refers to all of the fluids outside of our cells in our bodies – such as blood plasma, interstitial fluid, lymph and transcellular fluid. These fluids make up approximately 1/4 of body weight. Describe the three major types of lipids found in the body. (6 marks) * The three major types of lipids found in the body are triglycerides, phospholipids, and sterols (cholesterol). Triglycerides are fatty acids. Its functions include energy storage and the cushioning and insulating of the body and nerves. All nerves are wrapped in a myelin sheath; or lipid layer. Phospholipids are similar to triglycerides, but contain a phosphate group. It is a lipid bilayer – membranes in eukaryotic cells and the plasma membrane of cells. Sterols are made from lipids, but have no fatty acids in their structure. Cholesterol makes up sex hormones and carries lip-proteins. Describe briefly what is occurring at each step in the figure. (3 marks) * Name and briefly describe the cell shapes, arrangements, and functions of cell layers found in epithelial tissues. (3 marks) * In...
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