Patients’ inability to speak due to intubation through their vocal cords should be explained discount levitra soft 20mg free shipping erectile dysfunction 21. Humidification Nasal epithelium has a rich venous supply covering the nasal conchae; air turbulence maximises exposure for heat and moisture exchange quality 20mg levitra soft wellbutrin xl impotence, inspired air normally reaching body temperature just below the carina (Jackson 1996); thus the human airway (a) warms discount levitra soft 20 mg with mastercard erectile dysfunction meds online, (b) moistens, and (c) filters inspired air. Endotracheal intubation bypasses these normal physiological mechanisms, necessitating artificial replacement. Hot air transports more water vapour than cold air and so fully saturated room air/gas (100 per cent relative humidity) will not be fully saturated once warmed to body temperature. Gas not fully saturated absorbs moisture from airway surfaces, causing dehydration, making mucus more viscid. Viscid mucus increases: ■ risk of chest infection ■ risk of airway encrustation/obstruction ■ airway resistance and work of breathing ■ surfactant dysfunction Gas should therefore be heated and fully saturated exogenously; tracheal gas temperature should be 32–36°C. Heated water baths provide an ideal medium for bacterial incubation, particularly pseudomonas. Water bath humidifiers may cause overhumidification, mucosal burns, hyperthermia and water intoxification (Jackson 1996). Where exogenous heat is used, temperature of inspired air should be continuously monitored. Current dilemmas between humidification and infection control lack an ideal solution. Saline lavage to remove encrusted secretions can cause various problems (discussed below). However pulmonary oedema from increased capillary permeability may limit hydration of critically ill patients. Airway management 43 Suction Intubation bypasses non-specific mucus and cilial defences, while impaired cough reflexes from critical illness, antitussives and sedation, enable accumulation of lower respiratory tract secretions, reducing/obstructing airway patency (increasing work of breathing) and providing media for bacterial growth. Endotracheal suction can remove accumulated secretions, but can also cause: ■ infection ■ trauma ■ hypoxia ■ atelectasis Post-discharge surveys consistently identify patient anxiety and discomfort from suction (e. Puntillo 1990), and so it should never be a ‘routine’ procedure (Ashurst 1997); nurses should evaluate benefits against dangers. The changes made in endotracheal suction practice in the 1980s necessitate caution when reading older literature. Indications for suction include: ■ rattling/bubbling on auscultation ■ sudden increases in airway pressure ■ audible ‘bubbling’ from the back of the throat ■ sudden hypoxia (e. Disconnecting ventilation (inevitable unless closed-circuit suction systems are used) causes arterial desaturation, especially when patients are dependent on high levels of oxygen; preoxygenating all patients (3–5 minutes of 100 per cent oxygen) minimises risks. Although intended to remove bacteria, suction catheters can introduce/displace bacteria into lower airways. Respiratory pathogens sprayed into the environment through patients’ coughing or from suction catheters can infect others (e. Gowns, gloves, masks and goggles may protect staff, but efficacy of each needs evaluation, and their use delays suction procedures. Negative (suction) pressure damages delicate tracheal epithelium, causing possible ■ haemorrhage ■ oedema ■ stenosis ■ metaplasia. Negative pressure should be sufficient to clear secretions, but low enough to minimise trauma. Suction pressures, Intensive care nursing 44 usually measured in kilopascals (kPa) but sometimes in millimetres of mercury (mmHg), should be displayed on equipment. Intermittent release of negative pressure during suctioning has no advantage (Czarnik et al. Disconnection from ventilation and negative pressure from suction can cause hypoxia through ■ removal of oxygen supply ■ removal of oxygen-rich air from airways ■ alveolar collapse. Suction passes should therefore be as brief as possible (maximum 15 seconds), with rapid reconnection of ventilation. Nurses are recommended to hold their own breath during each pass: when they need oxygen, so will their patient. Hypoxia from bronchoconstriction (sympathetic stress response) usually follows endotracheal suction. Although Wood’s review (1998) found no proven benefit to routine preoxygenation, evidence is sparse, and failure to preoxygenate is probably more dangerous than routine preoxygenation. Many ventilators include time-limited control for delivery of 100 per cent oxygen; using these prevents inadvertent delivery of toxic levels continuing after stabilisation. If FiO2 is increased manually, it should be returned to baseline levels once PaO2 is restored. Catheters Removing oral secretions is easiest and safest with Yankauer catheters; angling the head to enable drainage of secretions into the cheek avoids trauma to the delicate soft palate. Endotracheal (soft) catheters should remove the maximum amount of secretions in the quickest possible time with minimal trauma. The practice of reusing disposable catheters for more than one pass seems to be based on anecdotal evidence that infection risks are not increased. Without substantive evidence, nurses reusing catheters should consider their professional accountability, and the legal liabilities of reusing equipment labelled by manufacturers as single-use (de Jong 1996). Using clean (rather than sterile) gloves for suction similarly appears based on anecdotal claims that infection rates are not significantly increased. Gloves of any sort protect (universal precautions) nurses, and clean gloves are both quicker to put on and cheaper; with gloved hands not touching catheter tips, infection risks appear small, but any substantive evidence to support this is lacking (Odell et al. Ventilation continues during catheter insertion and so catheters should be advanced more carefully to reduce trauma (passes should not be slowed so much that patient discomfort is increased). Concerns that they create reservoirs for microbial colonisation appear to be unfounded (Adams et al. Nurses’ concerns that closed circuit catheters may be more difficult to manipulate (Graziano et al. Closed circuit systems can be cost effective if they replace sufficient numbers of disposable items. Most manufacturers recommend replacement after 24 hours; Quirke (1998) found 48-hour changes safe and suggests that further research may support weekly changes; however, staff should remember their legal liability if flouting manufacturer’s recommendations. Widespread practice of saline instillation to loosen secretions has little support beyond anecdotal literature. Mucus is not water soluble and so will not easily mix with saline; encrustations on dentures can be difficult to remove after soaking overnight, and a few seconds contact with saline seems unlikely to significantly loosen airway encrustations. Ackerman (1993) found saline instillation reduced PaO2, possibly from bronchospasm or creating a fluid barrier to gas perfusion. However Ackerman’s methodology alternated use and non-use of saline in the same patients, ignoring possible late complications of consolidation through inadequate removal of mucus. Temperature differentials between cold fluids and airways may trigger bronchospasm so that warming fluids (from hand heat) may reduce complications (Gunderson & Stoeckle 1995). There may be individual cases where saline is indicated, but what those indications currently are remains unclear. Substantial research evidence is needed before saline instillation can be recommended.
Reticular tissue: Literally translated as “web-like” or “net-like generic levitra soft 20 mg overnight delivery erectile dysfunction gel treatment,” reticular tissue is made up of slender buy generic levitra soft 20 mg line buying erectile dysfunction pills online, branching reticular fibers with reticular cells overlaying them order levitra soft 20mg with amex erectile dysfunction medications in india. Its intricate structure makes it a particularly good filter, which explains why it’s found inside the spleen, lymph nodes, and bone marrow. Part I: Building Blocks of the Body 52 Cartilage: These firm but flexible tissues, made up of collagen and elastic fibers, have no blood vessels or nerve cells (a state called non-vascular or avascular). Cartilage contains openings called lacunae (from the Latin word lacus for “lake” or “pit”) that enclose mature cells called chondrocytes, which are preceded by cells called chondroblasts. A membrane known as the perichondrium surrounds cartilage tissue, which also contains a gelatinous protein called chondrin. There are three types of cartilage: • Hyaline cartilage: The most abundant cartilage in the body, it’s elastic and made up of a uniform matrix pocked with chondrocytes. It lays the founda- tion for the embryonic skeleton, forms the rib (or costal) cartilages, makes up nose cartilage, and covers the articulating surfaces of bones. The sponge-like structure, with the lacunae and chondro- cytes lined up within the fibers, makes it a good shock absorber. It’s found in the intervertebral discs of the vertebral column and in the symphysis pubis at the front of the pelvis. This structure, which makes up the ear lobe and other structures where a specific form is important, tends to bounce back to its original shape after being bent. Bone, or osseous, tissue: Essentially, bone is mineralized connective tissue formed into repeating patterns called Haversian systems. In the center of each system is a large opening, the Haversian canal, that contains blood vessels, lymph vessels, and nerves. The central canal is surrounded by thin membranes called lamellae that contain the lacunae, which in turn contain osteocytes (bone cells). Smaller canali- culi connect the lacunae and circulate tissue fluids from the blood vessels to nour- ish the osteocytes. Like other connec- tive tissues, it has an extracellular matrix — in this case, plasma — in which are suspended erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets). Erythrocytes are concave on both sides and contain a pigment, hemoglobin, which supplies oxygen to the body’s cells and takes carbon dioxide away. There are approximately 5 million erythrocytes per cubic millimeter of whole blood. Thrombocytes, which number approximately 250,000 per cubic millimeter, are fragments of cells used in blood clotting. Leukocytes are large phagocytic cells (literally “cell that eats”) that are part of the body’s immune system. There are, however, relatively few of them — less than 10,000 per cubic millimeter. Thrombocytes Flexing It: Muscle Tissue Although we review how muscles work in Chapter 6, in histology you should know that muscle tissue is made up of fibers known as myocytes. The cytoplasm within the fibers is called sarcoplasm, and within that sarcoplasm are minute myofibrils that contain the protein filaments actin and myosin. These filaments slide past each other during a muscle contraction, shortening the fiber. Following are the three types of muscle tissue (see Figure 4-3): Smooth muscle tissue: This type of tissue contracts without conscious control. Made up of spindle-shaped fibers with large, centrally located nuclei, it’s found in the walls of internal organs, or viscera. Smooth muscle gets its name from the fact that, unlike other muscle tissue types, it is not striated. Cardiac muscle tissue: Also known as myocardium, cardiac muscle tissue is made of branching fibers, each with a central nucleus and alternating light and dark striations. As with smooth muscle, cardiac muscle tissue contractions occur through the autonomic nervous system (involuntary control). Skeletal, or striated, muscle tissue: Biceps, triceps, pecs — these are the mus- cles that bodybuilders focus on. As the name implies, skeletal muscles attach to the skeleton and are used throughout the central nervous system for movement. Muscle fibers are cylindrical with several nuclei in each cell (which makes them multinucleated) and cross-striations throughout. Part I: Building Blocks of the Body 54 Figure 4-3: Muscle tissues: Smooth, cardiac, and skeletal. Smooth muscle cell Intercalated disc Muscle fiber Nuclei Nucleus Nuclei Illustration by Imagineering Media Services Inc. Deltoid Getting the Signal Across: Nerve Tissue There’s only one type of nerve tissue and only one primary type of cell in it: the neuron. Nerve tissue is unique in that it can both generate and conduct electrical sig- nals in the body. That process starts when sense receptors receive a stimulus that causes electrical impulses to be sent through finger-like cytoplasmic projections called Chapter 4: The Study of Tissues: Histology 55 dendrites. From there, the impulse moves through the body of the cell and into another type of cytoplasmic projection (or nerve process) called an axon that hands the signal off to the next cell down the line. The cytoplasmic projection of a neuron that carries impulses away from the cell body is called a. Smooth muscle Part I: Building Blocks of the Body 56 Answers to Questions on Histology The following are answers to the practice questions presented in this chapter. Tubules of the kidney i A tissue that’s one layer thick but appears to be multilayered and is composed of cells taller than they are wide is c. To arrive at the correct answer, consider this question one piece at a time: pseudo is “false,” stratified means “layered” (so you have “false-layered”), and columns are taller than they are wide. Knowing that the Greek word thrombos means “clot” can help you spot the correct answer in this question. Intercalated discs, as you should or will know from studying the circulatory system, are involved in conducting signals for the heart to pump. Chapter 4: The Study of Tissues: Histology 57 C Skeletal muscle tissue has prominent lines across the fiber called d. The other answer choices contain striated tissue, which technically means that they aren’t smooth. F The cytoplasmic projection of a neuron that carries impulses away from the cell body is called c. Each neuron cell usually has only one axon, although it may branch off several times. First we focus on how bones are formed before broadening the view to the axial skeleton (the parts that line up from head to toe) and the appendicular skeleton (the parts that reach out from the central axis). You review how muscles attach to that framework and watch the body take shape before wrapping this newly layered package in the body’s largest single organ: the skin.
Topics organizational 20 mg levitra soft fast delivery erectile dysfunction doctor london, systems design generic 20mg levitra soft adderall xr impotence, and other applied Attributed to Charles Stangor Saylor levitra soft 20mg lowest price erectile dysfunction under 40. The goal is to understand the psychological factors that influence performance in sports, including the role of exercise and team Sports psychologists work in gyms, schools, professional Sports psychology interactions. Psychology in Everyday Life: How to Effectively Learn and Remember One way that the findings of psychological research may be particularly helpful to you is in terms of improving your learning and study skills. Psychological research has provided a substantial amount of knowledge about the principles of learning and memory. This information can help you do better in this and other courses, and can also help you better learn new concepts and techniques in other areas of your life. The most important thing you can learn in college is how to better study, learn, and remember. These skills will help you throughout your life, as you learn new jobs and take on other responsibilities. There are substantial individual differences in learning and memory, such that some people learn faster than others. But even if it takes you longer to learn than you think it should, the extra time you put into studying is well worth the effort. And you can learn to learn—learning to effectively study and to remember information is just like learning any other skill, such as playing a sport or a video game. You cannot learn well when you are tired, when you are under stress, or if you are abusing alcohol or drugs. Eat moderately and nutritiously, and avoid drugs that can impair memory, particularly alcohol. There is no evidence that stimulants such as caffeine, amphetamines, or any of the many ―memory enhancing drugs‖ on the market will help you learn (Gold,  Cahill, & Wenk, 2002; McDaniel, Maier, & Einstein, 2002). Memory supplements are usually no more effective than drinking a can of sugared soda, which also releases glucose and thus improves memory slightly. One active approach is rehearsal—repeating the information that is to be learned over and over again. Although simple repetition does help us learn, psychological research has found that we acquire information most effectively when we actively think about or elaborate on its meaning and relate the material to something else. When you study, try to elaborate by connecting the information to other things that you already know. If you want to remember the different schools of psychology, for instance, try to think about how each of the approaches is different from the others. As you make the comparisons among the approaches, determine what is most important about each one and then relate it to the features of the other approaches. In an important study showing the effectiveness of  elaborative encoding, Rogers, Kuiper, and Kirker (1977) found that students learned information best when they related it to aspects of themselves (a phenomenon known as the self-reference effect). This research suggests that imagining how the material relates to your own interests and goals will help you learn it. An approach known as the method of loci involves linking each of the pieces of information that you need to remember to places that you are familiar with. Then you could put the behaviorists in the bedroom, the structuralists in the living room, and the functionalists in the kitchen. Then when you need to remember the information, you retrieve the mental image of your house and should be able to ―see‖ each of the people in each of the areas. One of the most fundamental principles of learning is known as the spacing effect. Both humans and animals more easily remember or learn material when they study the material in several shorter study periods over a longer period of time, rather than studying it just once for a long period of time. Psychologists have also found that performance is improved when people set difficult yet realistic goals for themselves  (Locke & Latham, 2006). Set realistic goals for the time you are going to spend studying and what you are going to learn, and try to stick to those goals. Do a small amount every day, and by the end of the week you will have accomplished a lot. Research suggests that our metacognition may make us overconfident, leading us to believe that we have learned material even when we have not. Testing yourself by attempting to retrieve information in an active manner is better than simply studying the material because it will help you determine if you really know it. Learning is an important skill, and following the previously mentioned guidelines will likely help you learn better. What type of questions can psychologists answer that philosophers might not be able to answer as completely or as accurately? Explain why you think psychologists can answer these questions better than philosophers can. Choose one of the major questions of psychology and provide some evidence from your own experience that supports one side or the other. Choose two of the fields of psychology discussed in this section and explain how they differ in their approaches to understanding behavior and the level of explanation at which they are focused. The spandrels of San Marco and the Panglossian paradigm: A critique of the adaptationist programme. Unconscious cerebral initiative and the role of conscious will in voluntary action. On the inference of personal authorship: Enhancing experienced agency by priming effect information. Effects of subliminal priming of self and God on self- attribution of authorship for events. The cognitive neuroscience paradigm: A unifying metatheoretical framework for the science and practice of clinical psychology. Tightness-looseness revisited: Some preliminary analyses in Japan and the United States. Most psychologists work in research laboratories, hospitals, and other field settings where they study the behavior of humans and animals. Some psychologists are researchers and others are practitioners, but all psychologists use scientific methods to inform their work. Although it is easy to think that everyday situations have commonsense answers, scientific studies have found that people are not always as good at predicting outcomes as they often think they are. The hindsight bias leads us to think that we could have predicted events that we could not actually have predicted. Employing the scientific method allows psychologists to objectively and systematically understand human behavior. Psychologists study behavior at different levels of explanation, ranging from lower biological levels to higher social and cultural levels.
Subsequently levitra soft 20mg without a prescription erectile dysfunction normal age, he returned to Leipzig and earned his Instead cheap levitra soft 20mg erectile dysfunction doctor memphis, he attempted further application of psychologi- doctorate with Wundt discount 20mg levitra soft with amex erectile dysfunction drug coupons, although his correspondence with cal testing when he founded the Psychological Corpora- his parents revealed that Cattell did not hold Wundt in tion, a company organized to promote commercial psy- high esteem as a scientist. His entrepreneurial abilities failed him ters also depict Cattell as arrogant, self-confident, and in this endeavor, however; the company earned only disrespectful of others. After he left, the or- proved on existing psychological instrumentation and in- ganization began to prosper, and today, the Psychologi- vented new ways to study psychological processes. Cattell contin- After leaving Germany, Cattell taught briefly in the ued his work as a spokesperson for applied psychology United States, then traveled to England and worked with until his death. Raymond Bernard Cattell 1905-1998 American psychologist who designed personality and intelligence tests and espoused controversial theories of eugenics. In a career spanning over half a century he wrote more than 50 books and 500 research articles, and his contributions to personality and intelligence testing are widely regarded as invaluable. Yet some of his theories about natural selection, particularly as put forth in a philos- ophy known as Beyondism, were attacked as racist and caused a bitter controversy only months before his death. Cattell was born in Hilltop, England, on March 20, Raymond Cattell (Archives of the History of American 1905. He attended the University of London, where he received his undergraduate degree in chemistry in 1924 and his Ph. He Cattell retired from the University of Illinois in 1973 taught briefly and worked at a psychology clinic until and after five years in Colorado moved to Hawaii. There, 1937, when he moved to the United States to take a teach- he accepted a part-time position at the University of ing position at Columbia University. From there he moved Hawaii, where he continued to teach, conduct research, on to Clark University and Harvard before arriving in 1946 and write. He also took the opportunity to spend leisure at the University of Illinois, where he stayed for 27 years. Innovator of personality tests Beyondism and a storm of controvery During the Second World War, in addition to his teaching duties, Cattell worked in the Adjutant General’s The publication of Beyondism: Religion from Sci- office, where he devised psychological tests for the mili- ence in 1987 dramatically altered the remainder of Cat- tary. Throughout his career, Cattell created a number of tell’s life as well as his scientific legacy. Cattell intended such tests to measure intelligence and to assess personal- the book to be a discussion of his theories on evolution ity traits. However, his advocacy of eugenics personality traits, such as emotional stability (easily (the study of improving the human race), was extremely upset vs. Cattell measured with what Cattell calls “second-order factors,” claimed, for example, that among the tenets of Be- including extroversion, anxiety, and independence. The yondism was the idea that races as we know them today test is still widely used by corporations and institutions would not exist in the future. The fact that Cattell had ac- knowledged Arthur Jensen and William Shockley— two scientists who had claimed that blacks were geneti- cally less intelligent than whites—in his book only fur- thered people’s suspicions. Cattell, ninety-two years old and in failing health, attempted to resolve the furor by declining the award. He asserted that he detested racism, and that he had only ever advo- cated voluntary eugenics. His health declined further, and he died quietly on February 2, 1998, at home in Hawaii. Milite Further Reading The brain and spinal cord comprise the central nervous Cattell, Raymond B. At the right is a magnified view of the spinal cord York Praeger Publishers, 1987. Factor Analysis: An Introduction and individual axon covered with a myelin sheath. The junction between the axon of one cell and the dendrite of another is a minute gap, eighteen millionths of an inch wide, which is called a synapse. Central nervous system The spinal cord is a long bundle of neural tissue In humans, that portion of the nervous system that continuous with the brain that occupies the interior lies within the brain and spinal cord; it receives im- canal of the spinal column and functions as the primary pulses from nerve cells throughout the body, regu- lates bodily functions, and directs behavior. It is the origin of 31 bilateral pairs of spinal nerves which radiate outward from the central nervous system The central nervous system contains billions of through openings between adjacent vertebrae. The spinal nerve cells, called neurons, and a greater number of sup- cord receives signals from the peripheral senses and re- port cells, or glia. Its sensory neurons, which send the only function of glial cells—whose name means sense data to the brain, are called afferent, or receptor, “glue”—was to hold the neurons together, but current re- neurons; motor neurons, which receive motor commands search suggests a more active role in facilitating commu- from the brain, are called efferent, or effector, neurons. The neurons, which consist of three elements— dendrites, cell body, and axon—send electrical impulses The brain is a mass of neural tissue that occupies the from cell to cell along pathways which receive, process, cranial cavity of the skull and functions as the center of store, and retrieve information. It is com- posed of three primary divisions: the forebrain, midbrain, Cerebral cortex and hindbrain, which are divided into the left and right hemispheres and control multiple functions such as re- See Brain ceiving sensory messages, movement, language, regulat- ing involuntary body processes, producing emotions, thinking, and memory. The first division, the forebrain, is the largest and most complicated of the brain structures and is responsible for most types of complex mental ac- Character tivity and behavior. It is involved in a huge array of re- sponses, including initiating movements, receiving sensa- General term in psychology used to describe be- tions, emoting, thinking, talking, creating, and imagining. Its parts, which are covered by the Character is most often used in reference to a set of cerebral cortex, include the corpus callosum, striatum, basic innate, developed, and acquired motivations that septum, hippocampus, and amygdala. These qualities of an in- dividual’s motivation are shaped during all stages of The midbrain, or mesencephalon, is the small area childhood. Its three sections are the traits that make up individual’s character are normally tectum, tegmentum, and crus cerebri. The term brain have been shown to control smooth and reflexive character is sometimes used as roughly synonymous movements, and it is important in the regulation of atten- with the term personality, although such usage does lit- tion, sleep, and arousal. Some psy- cephalon), which is basically a continuation of the spinal chologists believe that differences in character among in- cord, is the part of the brain that receives incoming mes- dividuals largely reflect affective, or emotional, differ- sages first. Lying beneath the cerebral hemispheres, it con- ences, that are the result of biochemical or other organic sists of three structures: the cerebellum, the medulla, and variations. Many psychologists claim that character, to the pons, which control such vital functions of the auto- some extent, is a function of experience. These psychol- nomic nervous system as breathing, blood pressure, and ogists, generally, believe that, as the early behavior of an heart rate. The cerebellum, a large convoluted structure at- individual directed toward a primary, instinctive goal is tached to the back surface of the brain stem, receives infor- modified by environmental circumstances, the motiva- mation from hundreds of thousands of sensory receptors in tional system of the individual is also modified, and the the eyes, ears, skin, muscles, and joints, and uses the infor- character of the individual is affected. There is some dis- mation to regulate coordination, balance, and movement, pute among psychologists about whether, or to what ex- especially finely coordinated movements such as threading tent, character may be controlled by conscious or ratio- a needle or tracking a moving target. The medulla, situated nal decisions, and about whether, or to what extent, char- just above the spinal cord, controls heartbeat and breathing acter may be dominated by unconscious or irrational and contains the reticular formation which extends into and forces. The pons, a band of nerve fibers connect- among psychologists that, while much research remains ing the midbrain, medulla (hindbrain), and cerebrum, con- to be done to delineate the genetic, instinctive, organic, trols sleep and dreaming. The pons and medulla, because cognitive, and other aspects of character, the develop- of their shape and position at the base of the brain, are ment of a reasonably stable and harmonious character is often referred to as the brainstem. Further Reading Character education, a periodic but recurring theme Changeux, Jean-Pierre. New York: Pantheon for schools to teach basic values and moral reasoning to Books, 1985.