N. Julio. Southwest University.
In addition cytotec 200 mcg, the transcytosis process serves to re-export pathogens that have already passed the epithelial barrier cytotec 100mcg. The sIgA repertoire in the gut includes antibodies against commensal bacteria cytotec 200mcg, antibodies which are not normally found in the serum 100mcg cytotec. These antibodies help to enforce the policy: "Guys 200mcg cytotec, you may do whatever you want in the lumen 100 mcg cytotec, but enterocytes are off limits! In addition 200 mcg cytotec, B memory cells already have undergone germinal center development including class switch and somatic hypermutation cytotec 100 mcg, resulting in antibodies with higher-than-original affinities . On reinfection , only memory cells with higher affinities are selected, as their B cell receptors directly compete with soluble antibodies remaining from the original infection. Vaccination aims to artificially induce immunological memory to protect against primary infections by established pathogens. Consequently, it is of prime importance that these toxins be inactivated; going after the bacteria themselves is secondary. The polyvalent vaccine for babies starting at the age of two months therefore contains inactivated toxins, so-called toxoids, to generate neutralizing antibodies. In case of infection, no harm is done, as the antibody-coated toxins cannot bind to their cellular receptors. The virus enters the body via the enteral pathway, first replicating in intestinal epithelial cells, then spreading via the blood. In contrast, oral live-attenuated polio vaccine, developed a few years later by Albert Sabin, induces local immunity in the gut. Following immunization, attenuated virus can be spread to contacts of the vaccinee, resulting in protection of additional individuals. In many countries having eradicated indigenous polio, this risk is higher than that from imported wild polio infections. Therefore most developed countries, including Austria, switched back to inactivated vaccine a number of years ago. Oral vaccination remains the method of choice in countries with ongoing wild poliovirus circulation and lower vaccination rates. However, once polio is eradicated, live vaccination will have to be rapidly discontinued to eliminate the potential of reversion of attenuated strains to pathogenic strains. In deciding for or against a specific vaccination, it is imperative to quantify the risks of either decision. A small risk exists: many children develop a fever, some develop postvaccinal measles, a markedly attenuated form with a slight skin rash. A complication of encephalitis in extremely rare cases cannot be completely excluded, but if it exists, it certainly affects fewer than one in a million vaccinees (with events of this rarity, it is hard to establish causality). Mortality associated with encephalitis is about 15%, and lasting neurologic defects are common in those who overcome the disease. An extremely rare complication, subacute sclerosing panencephalitis, which manifests itself many years after the acute infection, is universally fatal. As a concrete illustration of the risks incurred by non- vaccinated persons serves a limited outbreak documented in the Netherlands in 1999: About 2300 cases (almost exclusively kids of parents opposing vaccination) were brought to the attention of authorities. Fifty-three had to be admitted to the hospital, of which 30 suffered from pneumonia, 4 from encephalitis and 19 from other complications. As soon as the fraction of people opposing vaccination exceeds a certain threshold, however, relative risk is reversed, as exemplified in the Dutch measles outbreak. Vaccination against hepatitis B virus, of paramount importance for medical personnel, relies on induction of neutralizing antibodies, which prevent the virus from entering liver cells. Attenuation of a human virus can be achieved by repeatedly passaging the original virus on animal cells, e. When used back in humans as a vaccine, it will have trouble replicating in human cells and only do so very slowly. For vaccines against bacterial infections, where the goal is to induce antibodies, the tendency is to reduce complexity. In the early days of vaccination, there was no other way than to use easy to produce, but biologically messy preparations of inactivated bacteria. Inevitably, these caused high rates of unwanted effects, which were partly responsible for the lingering reservations about vaccination in collective memory. To minimize the potential for side effects and complications, modern vaccines aim to use the lowest number of defined antigen molecules possible. Remember T cell help, required to "release the safety catch" from B cells to prevent production of unnecessary and 43 potentially dangerous antibodies. Vaccine- induced antibodies against capsular polysaccharides can solve this problem by efficient opsonization. But when the bacterial polysaccharides are purified and injected, especially in children, inadequate amounts of antibody are produced. Still, a vaccine molecule optimized along these lies by itself frequently fails to elicit a satisfactory immune response. This treatment finally attenuated the mycobacterium to an extent that it could be used as an anti-bacterial live vaccine. However, a protective effect is found only in 60-80% of those immunized, is only relative, and is of limited duration. In addition, it prevents easy diagnosis of tuberculosis by the Mendel-Mantoux skin test, as the immunized test positive. Here, only a select few primary immunodeficiencies are mentioned that should illustrate certain aspects of immune system functioning. If neither immunoglobulin genes nor T cell receptor genes are rearranged, the result is a total loss of adaptive immunity. Obviously, this only works extracellularly, but intracellular concentrations are rapidly equilibrated by nucleoside transporters. A functioning version of the gene was first introduced into T cells, later into hematopoietic stem cells. Expression of the enzyme was successful in part of the cells, but mostly that part was too small to cure immunodeficiency. The disease got some public awareness from the "bubble boy", a little boy who 45 was kept alive by isolation in a pathogen-free plastic bubble; he died in 1984 in an attempt to cure his disease by a bone marrow transplant. For gene therapy, a sound copy of this X-chromosomal gene was introduced into stem cells of affected boys by a retroviral vector. The boys successfully developed T cells and responded favorably to typical immunizations against diphtheria, tetanus and polio. As a quality control step in pre-B cells, the product of a rearranged heavy chain is brought to the surface together with a temporary, "surrogate" light chain. The affected boys suffer from recurrent infections with pyogenic bacteria such as Streptococcus pneumoniae. Here, normal numbers of B and T cells combine with high serum levels of T cell-independent IgM but a lack of other immunoglobulin isotypes. Children suffer from recurrent infections with extracellular bacteria, as well as with the parasite Pneumocystis jirovecii that is otherwise easily cleared by activated macrophages. Both class switch recombination and somatic hypermutation are initiated by this enzyme, which deaminates cytosine to form uracil. More severely affected children suffer from recurrent mucosal infections such as otitis media, paranasal sinusitis and bronchitis, as well as pneumonia and intestinal infections. The genetic basis of IgA deficiency is insufficiently understood, but some progress has recently been made. Defects in phagocytosis and complement Cooperation between antibodies, complement and phagocytes is essential to eliminate pyogenic bacteria that, for their polysaccharide capsule, are not readily recognized by neutrophils. The significance of this cooperation is underscored by the fact that deficiencies of either of these components result in severe infections with this type of pathogens. Several aspects of the complex processes of chemotaxis and phagocytosis can be affected by genetic defects. A deficiency of surface molecules such as integrins or the carbohydrate ligand of selectins prevents leukocytes from adhering to the endothelial vessel wall in inflamed tissue. Lack of an enzyme necessary to produce reactive oxygen species means pathogens are phagocytized, but not killed. Chediak-Higashi syndrome is caused by the deficiency of a vesicle transport protein, so that phagosomes fail to fuse with lysosomes. Defects in the membrane attack complex (C5-C9) predispose to severe infections with Neisseria meningitidis. Both seem to have jumped the species barrier form non-human primates to humans in th Africa during the 20 century. About 1% of Caucasian populations are homozygous, while the haplotype is far less common in African and Asian populations. Other routes of infection are by contaminated needles or blood transfusions and from an infected mother to her child before or during childbirth or by breast feeding. Some of its proteins are synthesized as polyprotein precursors that are subsequently cleaved to their final form by viral protease. After all components have been produced in sufficient quantities, they are packaged by self- assembly and leave the cell by budding. When this number falls below a critical threshold of 200, adaptive immunity is so weak that the patient starts to suffer from opportunistic infections with, e. A range of protease inhibitors is used; a virus strain may develop resistance by point mutations in its protease gene. The drug cocktail is effective but frequently causes unwanted side effects including mitochondrial dysfunction resulting in myopathy or pancreatitis or lipodystrophy (esthetically displeasing changes in the distribution of subcutaneous fat). This is not a question of popping two pills a day; therapy protocol is complex, requiring the patient to take medications at exact time points distributed over the entire day. If this is paired with intermittent selective pressure by therapy, resistant strains will emerge rapidly. The countries needing these medications most, especially in sub-Saharan Africa, are the ones least able to pay for them. Despite some programs to equip these countries at reduced prices, this discrepancy remains largely unsolved. By this process of "co-evolution", many pathogens developed strategies to elude host defense mechanisms. The difference between these types is mainly in capsular antigens, represented by polysaccharide patterns and branch points. Antibodies against one serotype are of no use against another serotype, although it is always the same organism, coming in a different disguise. A shift in outer appearance to evade immune mechanisms is even better exemplified by the influenza virus. Via the first, hemagglutinin (H), it binds to human cells; the second, neuraminidase (N), is required for the release of new virus particles from a producing cell and possibly also to enter a cell. There are at least 18 different variants of H and 9 of N, which are used to name different isolates, together with location and time of isolation. As soon as these mutations interfere with antibody binding, the slightly altered virus variant has a selective advantage over its peers and quickly spreads in a previously protected human population, causing a new wave of infections. The H-N-type is maintained: for example, isolate A/Syndey/1977/H3N2 drifts to reinvent itself as A/Moscow/1999/H3N2. At the first influenza infection, a child produces antibodies against all antigenic domains of this specific virus subtype. In the event of later infections, efficient antibody responses are only induced against domains that were already part of the first virus. The probable reason is that memory cells stemming from the first encounter with influenza are activated so quickly that the immune system is not able –or does not need to— activate new naive cells. In addition, influenza A viruses are not restricted to humans, but also infect pigs and fowl (chickens, ducks, swans, etc. Some subtypes of influenza A virus circulate mainly in humans, but many others are best adapted to fowl. The danger is a coinfection, be it in a human or a bird, with two influenza virus subtypes that leads to an exchange of genetic material. If that happens, a novel, human-adapted subtype may emerge against which nobody has any useful antibodies, leading to one of the dreaded pandemics. Such a pandemic during the period 1918-1920 took the lives of approximately 30 million people (out of a world population of 1. During the last ten years, the biggest perceived threat was the fowl-adapted influenza A subtype H5N1. First in Hong Kong in 1997, and several times later on in other places, it infected singular human individuals. A H5N1 epidemic in birds spread and reached western Europe in 2005, exposing more and more humans to the virus. Infected individuals contracted H5N1 from massive contact with infected fowl, and in all but a handful of cases did not transmit the virus to other humans. However, the latest pandemic was unexpectedly caused by a different virus which started to spread from Mexico in 2009. Here, the antigen shift mechanism had reassorted genome segments of swine-adapted influenza virus strains with human-adapted segments. The virus was of the H1N1-Type, yet the specific variants of H1 and N1 differed from those which had been around previously. In these young adults, the 1918 H1N1 caused an especially strong inflammatory response; lung alveoli quickly filled with exsudate, causing respiratory failure). Herpes simplex virus first replicates in the epithelial cells of the oral cavity, then infects the afferent neurons of the trigeminal nerve. Cytotoxic T cells quickly eliminate infected epithelial cells in a painful immune reaction, but some viruses go into hiding in the cell bodies of neurons in the trigeminal ganglion. In response to certain changes in exterior conditions, like exposure to sunlight, other infections or hormonal changes, the virus is reactivated by insufficiently understood mechanisms and reinfects the oral epithelium in the form of cold sores. Analogously, another virus from the herpes group, the varicella virus, sometimes causes herpes zoster after years of latency in spinal ganglia. This might be a useful evolutionary compromise, as the effects of an immune attack against neuronal cells might be even less desirable. Intracellularly propagating Listeria, for example, is able to commandeer a host "rocket propulsion system" of polymerizing actin to "shoot" itself into neighboring cells, thereby completely avoiding the threat of antibodies.
United Nations office on drugs and crime international network of drug dependence treatment and rehabilitation resource centers: Treatment cytotec 100 mcg. Predictors of help-seeking and the temporal relationship of help to recovery among treated and untreated recovered problem drinkers cytotec 200 mcg. A factor analytic study of influences of patterns of help-seeking among treated and untreated alcohol dependent persons 100 mcg cytotec. Department of Health and Human Services cytotec 200mcg, National Institutes of Health 100mcg cytotec, National Institute on Drug Abuse 200 mcg cytotec. Department of Health and Human Services cytotec 100mcg, Office of the Assistant Secretary for Planning and Evaluation 200mcg cytotec. Department of Health and Human Services , Substance Abuse and Mental Health Services Administration , Center for Substance Abuse Treatment. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Substance Abuse Treatment. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Substance Abuse Treatment, Division of Pharmacologic Therapies. How tobacco smoke causes disease: The biology and behavioral basis for smoking-attributable disease: A report of the Surgeon General. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health. Office on Disability - Substance abuse and disability: A companion to chapter 26 of healthy people 2010. Screening and assessing mental health and substance use disorders among youth in the juvenile justice system: A resource guide for practitioners. Practical implications of current domestic violence research: For law enforcement, prosecutors and judges. Occupational employment statistics: Occupational employment and wages, May 2011: 21-1011 Substance abuse and behavioral disorder counselors. Interim final rules under the Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act of 2008. Confidentiality and the Employee Assistance Program: A question and answer guide for federal employees. Screening and behavioral counseling interventions in primary care to reduce alcohol misuse: Recommendation statement. Counseling and interventions to prevent tobacco use and tobacco-caused disease in adults and pregnant women: U. Before prohibition: Images from the preprohibition era when many psychotropic substances were legally available in America and Europe. Six-month follow-up of computerized alcohol screening, brief intervention, and referral to treatment in the emergency department. The efficacy of motivational interviewing as a brief intervention for excessive drinking: A meta-analytic review. Genetic and environmental influences on cannabis use initiation and problematic use: A meta- analysis of twin studies. Low level of brain dopamine D2 receptors in methamphetamine abusers: Association with metabolism in the orbitofrontal cortex. The addicted human brain viewed in the light of imaging studies: Brain circuits and treatment strategies. The role of sexual trauma in the treatment of chemically dependent women: Addressing the relapse issue. Improving treatment through research: Directing attention to the role of development in adolescent treatment success. From first drug use to drug dependence: Developmental periods of risk for dependence upon marijuana, cocaine, and alcohol. Trajectories of change in adolescent substance use and symptomatology: Impact of paternal and maternal substance use disorders. On the learning curve: The emerging evidence supporting cognitive-behavioral therapies for adolescent substance abuse. A rewired brain: Many now see addiction as a chronic brain disease that requires new approaches to treatment. Adolescent marijuana use from 2002 to 2008: Higher in states with medical marijuana laws, cause still unclear. Substance abuse treatment organizations as mediators of social policy: Slowing the adoption of a congressionally approved medication. Smokeless tobacco cessation cluster randomized trial with rural high school males: Intervention interaction with baseline smoking. Medicaid chemical dependency patients in a commercial health plan: Do high medical costs come down over time? Individual and social/environmental predictors of alcohol and drug use 2 years following substance abuse treatment. Effects of a brief intervention for reducing violence and alcohol misuse among adolescents: A randomized controlled trial. Dopamine D2 receptor availability in opiate-dependent subjects before and after naloxone- precipitated withdrawal. Care for veterans with mental and substance use disorders: Good performance, but room to improve on many measures. Nipping early risk factors in the bud: Preventing substance abuse, delinquency, and violence in adolescence through interventions targeted at young children (0-8 years). Toward an alcohol treatment entry model: A comparison of problem drinkers in the general population and in treatment. A randomized trial of integrated group therapy versus group drug counseling for patients with bipolar disorder and substance dependence. Adjunctive counseling during brief and extended buprenorphine-naloxone treatment for prescription opioid dependence. Access to inpatient or residential substance abuse treatment among homeless adults with alcohol or other drug use disorders. Effect of oral nicotine dosing forms on cigarette withdrawal symptoms and craving: A systematic review. The accessibility of substance abuse treatment facilities in the United States for persons with disabilities. Recovery management and recovery-oriented systems of care: Scientific rationale and promising practices. The varieties of recovery experience: A primer for addiction treatment professionals and recovery advocates. Behavioral counseling interventions in primary care to reduce risky/harmful alcohol use by adults: A summary of the evidence for the U. The effect of substance abuse treatment on Medicaid expenditures among general assistance welfare clients in Washington state. Work stress, substance use, and depression among young adult workers: An examination of main and moderator effect model. Further evidence of an association between adolescent bipolar disorder with smoking and substance use disorders: A controlled study. Behavioral and emotional self-control: Relations to substance use in samples of middle and high school students. Depressive symptoms and cigarette smoking among middle adolescents: Prospective associations and intrapersonal and interpersonal influences. Adolescent temperament and lifetime psychiatric and substance abuse disorders assessed in young adulthood. Motivational enhancement therapy to improve treatment utilization and outcome in pregnant substance users. Behavioral couples therapy for female substance-abusing patients: Effects on substance use and relationship adjustment. Treating adolescents with substance use disorders: An overview of practice issues and treatment outcome. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Substance Abuse Treatment. Extended vs short-term buprenorphine-naloxone for treatment of opioid-addicted youth: A randomized trial. Service utilization during and after outpatient treatment for comorbid substance use disorder and depression. The multidimensional structure of internal barriers to substance abuse treatment and its invariance across gender, ethnicity, and age. Encouraging physicians to screen for and intervene in substance use disorders: Obstacles and strategies for change. Search for genetic markers and functional variants involved in the development of opiate and cocaine addiction and treatment. Improving the care of individuals with schizophrenia and substance use disorders: Consensus recommendations. Mental health professionals with a specialty in anxiety disorders: Knowledge, training, and perceived competence in smoking cessation practices. Currently, drug use and abuse is a very serious social and public health problem that generates great social concern. This is due to the widespread drug consumption in many sectors of the population, the decline in the age of usage initiation and the severity of the individual and community consequences of the phenomenon on the three levels considered in the current concept of health: physical, psychological and social. If a few years ago, speaking of the drug problem usually alluded to illegal drugs such as heroin, currently the concern has focused on the consumption of legal drugs such as alcohol and tobacco, which are considered the gateway to the consumption of other substances. Alcohol and tobacco are also considered the gateway to the use of substances whose consumption is increasing, cannabis and cocaine. Nevertheless, preventive and therapeutic action, given the continuous change and complexity of the phenomenon, is still insufficient. We review aspects such as the definition of drugs and addictive behavior, consumption patterns and the current status of the problem. Also presented are the criteria used to determine whether consumption or abuse of a substance is taking place. Finally, we review the main individual risk factors that favor substance consumption and integrate them into a comprehensive model. To understand the magnitude of the phenomenon it is necessary to know the basic physiological correlates of drug consumption. In this first unit general concepts on the pharmacodynamics and pharmacokinetics of drug consumption are addressed. The characteristics of the main psychoactive substances and their psychoactive effects and mechanisms are also presented. Others are the result of chemical processes carried out using natural products, like what occurs with alcoholic beverages, which are obtained from the fermentation or distillation of grain or fruit juice. There has also been a differentiation between soft and hard drugs, although currently that distinction is rarely used because of its scant utility and the fact that it can give rise to the erroneous interpretation that so-called soft drugs are not quite detrimental to health. The first group includes alcohol, opiates and psychotropic drugs such as hypnotics, anxiolytics and antipsychotics. In the third group, consisting of psychedelic drugs, are hallucinogens, cannabis, synthetic drugs and solvents (e. Central Nervous System Depressants a) Alcohol b) Hypnotics: Barbiturates and non-barbiturates c) Anxiolytics: diazepam d) Narcotic analgesics: i. Drug consumption becomes abusive at the appearance of dependence, which is defined as the set of physiological, behavioral and cognitive manifestations in which the use of a drug is a priority for the individual. This term is usually linked to tolerance, or the need to consume more of a substance to achieve the effects of previous consumption. It is a cluster of symptoms that affect an individual who is suddenly deprived of any toxin or drug on which he/she is physically dependent and which previously had been consumed on a regular basis. The quantity of symptoms, as well as their intensity and duration will depend on the type of drug, the length of time the person has consumed the substance and his/her physical and psychological state at the time of withdrawal. Physical dependence is a state of adaptation of the organism to the presence of the drug and is manifested by the appearance of intense physical discomfort (tremors, chills, insomnia, vomiting, pain in the muscles and bones, etc. This same physical discomfort occurs when the substance´s action on the organism is influenced by drugs designed to block its effects. Psychological dependence refers to the situation in which a person feels an emotional need and urge to consume a drug on a regular basis in order to feel good, be satisfied (obtain pleasure or avoid discomfort) although he/she does not need the substance physiologically. There are the so-called non-toxic addictions which involve dependency behavior with an evident syndrome of psychological withdrawal. There is, for example, addiction to gambling or pathological gambling and others such as technological addictions (internet, mobile, and video games), addiction to shopping, exercise or sex. These addictive behaviors share, if not all, some of the characteristics mentioned so far, with the peculiarity that there is not a mediating substance that produces physical changes in the subject. Effects of Drugs 4 José Pedro Espada and Daniel Lloret Irles As already mentioned, drugs act on the central nervous system (i. The physiological correlates and effects vary according to each substance; there are specific mechanisms that involve precise receptors for each substance type. When a substance enters the body it first affects the neuronal receptors, which are structures located within a neuron or in its membrane and are characterized by selective binding to a substance and the physiological effect that accompanies the union. The presence of a drug in the body affects the presynapse, altering the production/ release of neurotransmitters. During the next step, the drug affects the synapses, by increasing the presence of neurotransmitters in the synaptic space. The activity of the drug in the body over a period of time comprises the processes of absorption, distribution, localization in tissues, biotransformation and excretion. Central Nervous System Depressants Alcohol The two main types of alcohol based on their chemical composition are: methyl alcohol (methanol), which is the simplest of the alcohols and is used as a solvent, antifreeze and in industrial applications; and ethyl alcohol (ethanol), which is what alcoholic beverages contain.
The Accessory Structures The Liver The liver cytotec 200 mcg, often referred to by the word root hepat 100 mcg cytotec, is the largest glandular organ of the body (Figure 11-7) 200 mcg cytotec. It has a large right lobe and a smaller left lobe 100mcg cytotec; the right lobe includes two inferior smaller lobes cytotec 200mcg. The hepatic artery carries oxygenated blood cytotec 100 mcg, whereas the portal system of veins carries blood that is rich in the end products of digestion cytotec 100mcg. This most remarkable organ has so many functions that only some of its major activities can list here: 1 200mcg cytotec. When the blood sugar level 326 Human Anatomy and Physiology falls below normal , liver cells convert glycogen to glucose and release it into the bloodstream ; this serves to restore the normal concentration of blood sugar. The detoxification (removal of the poisonous properties) of harmful substances such as alcohol and certain drugs 8. The storage of some vitamins and iron The main digestive function of the liver is the production of bile. The salts contained in bile act like a detergent to emulsify fat, that is, to break up fat into small droplets that can be acted on more effectively by digestive enzymes. After collecting bile from the gallbladder, this 327 Human Anatomy and Physiology duct, now called common bile duct, delivers bile into the duodenum. The Gallbladder The gallbladder is a muscular sac on the inferior surface of the liver that serves as a storage pouch for bile. Although the liver may manufacture bile continuously, the body is likely to need it only a few times a day. Consequently, bile from the liver flows into the hepatic ducts and then up through the cystic duct connected with the gallbladder. When chyme enters the duodenum, the gallbladder contracts, squeezing bile through the cystic duct and into the common bile duct leading to the duodenum. The protein digesting enzymes are produced in inactive forms, which must be converted to active forms in the small intestine by other enzymes. The pancreas also produces large amounts of alkaline fluid, which neutralizes the chyme in the small intestine, thus protecting the lining of the digestive tract. These juices collect in a main duct that joins the common bile duct or empties into the duodenum near the common bile 328 Human Anatomy and Physiology duct. Also, in some cases of gallbladder disease, disease, infection may extend to the pancreas and cause abnormal activation of the pancreatic enzymes. In either circumstance, the pancreas suffers destruction by its own juice, and the outcome can be fatal; this condition is known as acute pancreatitis. The pancreas also functions as an endocrine gland, producing the hormones insulin and glucagons that regulate sugar metabolism. Digestion and Absorption of Carbohydrates, Fats, and Proteins Digestion Digestion, a complex process that occurs in the alimentary canal, consists of physical and chemical changes that prepare food for absorption. Mechanical digestion breaks food into tiny particles, mixes them with digestive juices, moves them 329 Human Anatomy and Physiology along the alimentary canal, and finally eliminates the digestive wastes from the body. Chewing or mastication, swallowing or deglutition, peristalsis, and defecation are the main processes of mechanical digestion. Chemical digestion breaks down large, nonabsorbable food molecules−molecules that are able to pass through the intestinal mucosa into blood and lymph. Chemical digestion consists of numerous chemical reactions catalyzed by enzymes in saliva, gastric juice, pancreatic juice, and intestinal juice. Carbohydrate Digestion Very little digestion of carbohydrates (starches and sugars) occurs before food reaches the small intestine. Salivary amylase usually has little time to do its work because so many of us swallow our food so fast. But after the food reaches the small intestine, pancreatic and intestinal juice enzymes digest the starches and sugars. A pancreatic enzyme (amylase) starts the process by changing starches into a double sugar, namely, maltose. Three intestinal enzymes−rnaltase, sucrase, and lactase−digest double sugars by changing them into simple sugars, chiefly glucose (dextrose). Maltase digests maltose (malt sugar), sucrase digests sucrose (ordinary cane sugar), and lactase digests lactose (milk sugar). The end product of carbohydrate 330 Human Anatomy and Physiology digestion is the so-called simple sugar; the most abundant is glucose. Two enzymes (renin and pepsin) in the gastric juice cause the giant protein molecules to break up into somewhat simpler compounds. Pepsinogen, a component of gastric juice, is converted into active pepsin enzyme by hydrochloric acid (also in gastric juice). In the intestine, other enzymes (trypsin in the pancreatic juice and peptidases in the intestinal juice) finish the job of protein digestion. When enzymes have split up the large protein molecule into its separate amino acids, protein digestion is completed. Fat Digestion Very little carbohydrate and fat digestion occurs before food reaches the small intestine. Most fats are undigested until after emulsification by bile in the duodenum (that is, fat droplets are broken into very small droplets). After this takes place, pancreatic lipase splits up the fat molecules into fatty acids and glycerol (glycerine). For example, the name amylase indicates that the enzyme digests carbohydrates (starches and sugars), protease indicates a protein- digesting enzyme, and lipase means a fat-digesting enzyme. When carbohydrate digestion has been completed, starches (polysaccharides) and double sugars (disaccharides) have been changed mainly to glucose, a simple sugar (monosaccharide). Absorption After food is digested, it is absorbed; that is, it moves through the mucous membrane lining of the small intestine into the blood and lymph. In other words, food absorption is the process by which molecules of amino acids, glucose, fatty acids, and glycerol goes from the inside of the intestines into the circulating fluids of the body. As long as food stays in the intestines, it cannot nourish the millions of cells that compose all other parts of the body. Their lives depend on the absorption of digested food and its transportation to them by the circulating blood. Table 11-1 Chemical Digestion Digestive juices and Substance Digested Resulting Products* enzymes (or hydrolysed) Saliva Starch (Polysaccharide) Maltose (disaccharide) Amylase Gastric Juice Proteins Partially digested Protease (Pepsin) proteins plus hydrochloric acid Pancreatic Juice Proteins (intact of Peptides Protease (trypsin) and partially digested) Fatty acids, amino Lipase Fats emulsified by bile acids and glycerol Amylase Starch Maltose Intestinal Juice Amino acids Peptidases Peptides Glucose and fructose Sucrase Sucrose (cane sugar) (simple sugars) Lactase Lactase (Milk sugar) Glucose and galactose Maltase Maltase (malt sugar) (Simple sugars Glucose *Substances underlined are end products of digestion (that is, completely digested foods ready for absorption) 333 Human Anatomy and Physiology Review Questions 1. If you inserted 9 inches of an enema tube through the anus, the tip of the tube would probably be in what structure? The urinary system consists of: - Two kidneys: this organ extracts wastes from the blood, balance body fluids and form urine. They 338 Human Anatomy and Physiology are protected at least partially by the last pair of ribs and capped by the adrenal gland. On the medial concave border is the hilus (small indented area) where blood vessels, nerves & ureters enter and leave the kidney. Covering and supporting each kidney are three layers of tissue: • Renal capsule – innermost, tough, fibrous layer • Adipose capsule – the middle layer composed of fat, giving the kidney protective cushion. The renal pelvis is the large collecting space with in the kidney formed from the expanded upper portion of the ureters. Filters (by hydrostatic presure) water, dissolved substances (minus most plasma proteins, blood cells) from blood plasma. The major functions of the kidneys are: 343 Human Anatomy and Physiology All the functions are directly or indirectly related to the formation of urine. The series of events leads to: - To the elimination of wastes - Regulation of total body water balance. Tubular secretion Average Comparison of filtration, re-absorption and excretion, here variation in urine composition will occur during variation in the daily diet, fluid intake, weather and exercise. The ureters pass between the parietal peritoneum and the body wall to the pelvic cavity, where they enter the pelvic cavity. The lumen of the ureters is composed of three layers: - Innermost, Tunica Mucosa - The middle, Tunica Muscularis (made of smooth muscle) - The outer, Tunica Adventitia 12. It is located on the floor of the pelvic cavity and 346 Human Anatomy and Physiology like the kidneys and ureters. The opening of ureters and urethra in the cavity of the bladder outline triangular area called the trigone. At the site where the urethra leaves the bladder, the smooth muscle in the wall of the bladder forms spiral, longitudinal and circular bundles which contract to prevent the bladder from emptying prematurely. Far there along the urethra in the middle membranous portion a circular sphincter of voluntary skeletal muscle form the external urethral sphincter. In male it pass through prostate, membranous portion (pelvic diaphragm muscle), spongy portion (that pass through corpus spongosus) and open at the tip of penis. However, it is composed of mainly water, urea, chloride, potassium, sodium, cretinin, phosphate, sulfates and uric acid. Proteins, glucose, casts (decomposed blood) and calculi from minerals are abnormal if present in urine. To maintain the proper osmotic concentration of the extra cellular fluid to excrete wastes and to maintain proper kidney function the body must excrete at least 450ml of urine per day. The volume and concentration of urine is controlled by: - Antidiuretic hormone - Aldestrone - The Renin – angiotensin mechanism 349 Human Anatomy and Physiology 12. Steps of urination are: Conscious desire to urinate Pelvic diaphram muscle relax Smooth muscle of Urinary bladder neck Moves Urinary bladder down, outlet Opens, wall Contracts & urine stretch, and wall stretch ejects Receptors are stimulated 350 Human Anatomy and Physiology Study Questions 1. The apex of each renal pyramid end in the a) Cortical region b) Papilla c) Juxta medullary region d) Capsule e) Tubule 2. The inner most layer of the ureters is the a) Mucosa b) Muscularis c) Adventitia d) Longitudinal layer e) Circular layer 3. The kidney function in all of the following except a) Acid – base balance b) An endocrine organ c) By removing metabolic waste d) By removing excess carbon dioxide e) By maintaining osmotic concentration 4. An increased volume of urine formation would follow:- a) Inhibition of tubular sodium re-absorption b) A fall in plasma osmolarity c) A fall in plasma volume d) a and b e) a, b and c 5. The volume or chemical makeup of these fluids whenever deviates even slightly from normal, disease results. The correct proportion of water and electrolytes in the water and proper acid base balance are necessary for life to exist. Loss of 10% of total body water usually produce lethargy, fever and dryness on mucous membrane and a 20% loss is fatal. Extra cellular fluids found as interstitial fluid (the immediate environment of body cells), blood plasma and lymph, cerebrospinal, synovial, fluids of the eye & ear, pleural, pericardial, peritoneal, gastrointestinal and glomerular filtrate of the kidney. The concentration of water in the interstitial fluid is slightly higher than the concentration of water in plasma. The plasma proteins are responsible for this difference 354 Human Anatomy and Physiology A B Figure: 13. Hydrostatic pressure: it is the force exerted by a fluid against the surface of the compartment containing fluid. Osmotic pressure: Is the pressure that must be applied to a solution on one side of a selectively permeable membrane to prevent the Osmotic flow of water across the membrane from a compartment of pure water. When there is shift in the pressure of water to wards the interstitial space, accumulation of fluid in the space occur. Such accumulation of water produces distention of the tissue which appears as puffiness on the surface of the body. Causes of edema may be plasma protean leakage decreased protein synthesis, increased capillary or venous hydrostatic pressure, obstructed lymphatic vessels and inflammatory reaction. Under normal condition water is taken in to and excreted from the body, so it matches to maintain homeostasis. Drinking of water is regulated by nervous mechanism (thirst center in the brain) together with hormonal mechanism (Antidiuretic hormone). Kidneys are the organs regulated by homeostatic feed back response they are responsible for excreting most of the water from the body. These three electrolytes are particularly important in maintaining body function and normal water distribution among the fluid compartment. Enzymes, hormones and the distribution 360 Human Anatomy and Physiology of ions can all be affected by the concentration of hydrogen H ion. H Homeostatic maintenance of an acceptable P range in the extra cellular fluid is accomplished by three mechanisms: 1. This task is accomplished in renal tubules, where + hydrogen & ammonium ions are secreted in to urine, when H is excreted sodium is exchanged. Movement of water from one body compartment to another is controlled by a) Atmospheric pressure b) Hydrostatic pressure c) Osmotic pressure d) a & c only e) b & c only 364 Human Anatomy and Physiology 4. The function of electrolytes in the body include a) Contributing to body structure b) Facilitating the movement of water between body compartments c) Maintaining acid – base balance d) a and b only e) a, b, & c 5. Reproduction by means of sexual intercourse produces new human beings and hereditary traits to be passed from both parents to their children’s. The sex hormones play an important role both in the development and function of the reproductive organ and in sexual behavior & drives. By third fetal month it stats is to descend and by the seventh month of fetal life it passes through the inguinal canal. Because the tests hang in scrotum out side the body their temperature is of cooler than the body temperature by 3 Degree Fahrenheit. Next to tunica albuginea is Tunica Vaginals, which is a continuation of membrane of abdomino-pelvic cavity. Each test contain 800 lightly coiled Semniferous Tubules which produce thousands of sperm each second. The germinal tissue contains two types of cells: spermatogenetic cell producing or developing the sperm cell and the sustentacular cell, which provide nourishment for the germinal sperm.
If you are better than the competition you can do the same as Google and not spend any money on advertising or marketing 100mcg cytotec. All the same: even homespun advertising can speed up the kick-off of a project 200mcg cytotec, and a bit of ballyhoo can help you get off your marks all the faster cytotec 100mcg. Grant yourself the luxury of offering your students the book for half-price at a class or lecture 100 mcg cytotec. You should also start a new folder with the heading “2nd Edition” 200 mcg cytotec, where you can collect the ideas and thoughts which your readers will enjoy next year cytotec 200mcg. Marketing There are three distribution channels for medical textbooks: bookstores cytotec 200 mcg, direct shipping to the reader and the sale of part editions to foundations or pharmaceutical companies cytotec 100 mcg. This would be a tragedy if we wanted to market poems or fiction , but fortunately we are producing medical textbooks , 90% of which are sold in specialist bookstores. This means that to cover the market as broadly as possible, it is sufficient to place your books in the 20 to 50 most important medical bookstores in your country. If you are asked about your terms and conditions, offer them 40% discount for the first order, 30% for subsequent orders. At a retail price of 40 Euro, for example, you could offer a base price of 28 Euro and reduce it to 25 Euro if 10 or more books are taken (with price increments according to country if shipping abroad). Direct shipment of books to the readers The direct shipment of books to the readers is the most troublesome distribution channel. In the case of domestic shipment, you should charge the normal retail price; for shipment abroad add 2 or 3 Euro for additional postage and packaging, because you have to cover these extra costs. In the case of direct ordering from the above address, the mailing costs are included in the price. The home stretch Foundations or pharmaceutical companies Both foundations and pharmaceutical companies can be considered as possible sponsors for your book. Medical textbooks are of interest for pharmaceutical companies if their products are assessed positively. As we mentioned earlier, this cannot be used as an excuse to practise fair- weather journalism along the lines of: I give your product a positive assessment and you buy my books (see the section “Leprosy”, Page 54). Less harmful, but a lot more embarrassing, are attitudes such as “well, you know I can just as well use the products of your competitors” in order to get rid of your own books. The number of books which a pharmaceutical company can buy up ranges from a few hundred to a few thousand – depending on the subject and the involvement of the company in the field about which you are writing. Ora et labora The time has come: you are holding the first copy of the book in your hands. What do you do in the meantime, as long as you don’t know what will become of your baby? It is best to carry on tinkering: pocket version, upgrading the website, removal of the copyright and – why not? Student You cannot own every book in which you want to read one chapter or another. The home stretch Bystander What is written in this book about medical textbooks can theoretically be applied to all texts: you can make them into a book and publish them free of charge on the internet at the same time. Whatever you do, the internet version provides cheap and effective advertising for the book version. But do not forget that the marketing of non-medical texts can be more difficult than is described here. Also, your target group may be more broadly scattered and 20 to 50 specialist bookstores – as in medicine – are not enough to organise distribution. Playground, creativity Pocket edition – Expansion of the website – Payment of authors’ fees – English edition – Removal of copyright – Blogs Pocket edition Medical textbooks are often heavy and unwieldy, because they soon consist of 500 to 800 pages. Everything in these books is important, but some chapters are more important for day-to-day practice than others. The advantages of pocket versions: The shortened version isn’t left on the bookshelf but is kept – as its name suggests – in the doctor’s coat pocket, where it is consulted frequently. So you should see if it is possible to find prospective sponsors for a pocket edition. With just a little work, you can achieve an amazing amount – and your readers will thank you for it. Expansion of the websites Remember that your website is an advertising medium for your book. Surf on the internet for a while to see if other websites on the same subject – whatever language they are in – offer information or services which could be of interest to you. A website is brought to life by being up-to-date, so the following supplements to your internet range are to be recommended: News Conference reports Diary of events 69 6. Playground, creativity Find out beforehand how much work is required for these additions, and in particular if you are able to maintain and update these new offers over a period of years. Authors’ fees Your enthusiasm for follow-up projects should not let you forget the most important thing: the payment of authors’ fees. Complete and utter openness is essential, especially if you have chosen a financing scheme where the author only receives a fee if the printing costs are covered. The English version If you write your text in English, it will be read by tens of thousands. Another good reason for translating a text into English is that this might be the only way to benefit from the copyright removal idea (see next section): Who speaks your language if it is not English? A book which is not translated into English is – globally speaking – being kept in a strait jacket. Removal of the copyright If you remove the copyright of your book, this is roughly what you tell the world: 70 Removal of the copyright “My dear colleagues, translate our book into any language of your choice except English and your mother tongue, and publish the translation. If you want, you can even publish it under your own name (of course, you must state the source clearly and visibly! After removal of the copyright, the text was translated into eight languages (http://sarsreference. The mailing lists of our various internet activities were crucial here: Amedeo (www. Playground, creativity actually meagre: a dozen translations for more than 100,000 e-mails sent. It would be a pity if the idea of copyright removal only failed because most people don’t have mailing lists of 100,000 or more e-mail addresses. The term is not quite correct linguistically, but everyone understands what it is about: we are bringing together those who release the books with those who want to translate them. Once again, we are using our mailing lists, which in March 2005 contained more than 170,000 e- mail addresses. A blog – also known as a weblog – is a website which is updated daily or several times a day. In the early days of blogs – at the end of the 90s – the authors (the bloggers) told tales of their surfing tours through the internet and wrote “internet diaries”. In addition, bloggers like to refer to the blogs of other bloggers, so that blogs are closely connected to each other. Nowadays, it is easy and costs nothing to create and maintain blogs directly on the internet. The result is blog inflation, and most blogs today are simply personally coloured depictions of life with more or less racy details from the blogger’s private life. However : we need to check out every new kind of technology in the world to see if it can be of use to us. For example: We document the development process of our project: Why are we writing? This paragraph repeats something which has already been said, that one is incomprehensible or too long-winded, in a third paragraph the linguistic standards have slipped. In the weeks before publication of this book, we gave daily accounts of everything about the project in an experimental blog. The question which we occasionally asked was: why, in addition to pre-publication (free online version) and publication (a book available for a fee), pre-pre-publication in a blog? Conclusion Whereas for some people a book is completed after the last sentence, for others the adventure begins at this point. The advertising and marketing of books alone is an experience from which doctors can learn a lot. Summary Editor/Publisher Produce a pocket edition – it will be consulted more often than a book weighing a kilogram. Something you have written in English will be read 10 to 100 times more often than a text which does not exist in English. Playground, creativity Author Ask yourself if you can contribute to the expansion of the website. Do you have any ideas as to how the website of the project can be supplemented by an intelligent blog? Students If English is not your mother tongue: get used to the idea that information is only circulated on a global level if it is written in English. Bystander The removal of copyright was one of the creative contributions of the internet towards spreading medical knowledge more quickly. The author is available to committed colleagues at all times (contact via the known e-mail addresses). Epilogue You have seen how quickly you have produced a book and a website with your team of authors. The seventh day 80 Materials Letter to your authors – Working with Word – Copyright removal A. Letter to your authors My dear friends, May we take this opportunity to remind you of the deadline for our book project: 30th September 2006 As in the past few years, we can guarantee an author’s fee of X € + Y€ (X Euro now, another Y Euro once printing costs have been covered). On condition that: your chapters are updated and the literature published up to August 2006 is integrated into the text; the text arrives here by 30th September; the citations are newly compiled and correctly formatted (see below for further details). Original documents The text must only be written in the Word document which we have enclosed here. Citations In the text, the citation is placed between round brackets, only giving the surname of the first author and the year (Hoffmann 2004). There are more details in these three lines than you may think: There is no full stop after the initials of first names; several initials are written together. If there are more than 6 authors, the first 3 are named, then comes a comma, followed by “et al” and finished with a full stop. Only the end digits of the last page number, which are necessary for clear identification, are given. Thus, 2423-2429 becomes 2423-9, 134-141 becomes 134-41, 1891-1901 becomes 1891-901. Working with Word Working with styles Font size and typeface should only be changed via the so-called templates. Compiling the reference lists Citations must be given according to a uniform pattern. Tables Tables serve to break up the text and summarise important information in a concise manner. Working with Word Planning a medical textbook Only write if you want your book to be No. Those who cannot perform this task themselves should delegate the job to a professional reader. Keyboard shortcuts You write the text with your fingers, so you should use the many keyboard shortcuts. Your hand then stays on the keyboard, and you save yourself the trouble of reaching for the mouse. However, the main page of the publication – be it the home page of a website or a book cover – must mention the source of the information in this way: Adapted from www. In addition, the authors of the individual chapters have to be mentioned at the beginning of every single chapter. The translation into any other language must reproduce the original documents faithfully. Pay the greatest attention when translating crucial information such as dosage, dosage schedules, therapeutic regimens, drug descriptions, etc. Translating the text into any language does not confer on you any exclusive rights for that given language. A doctor who publishes his own textbooks can earn many times what he would be paid in royalties by a publishing house. More important than this, however, is the fact that a doctor who writes and publishes wants his texts to be read by as many colleagues, students and patients as possible. Te best way to achieve this is through free parallel publication of these texts on the internet. Free Medical Information describes how to produce a successful medical textbook: from deﬁning the project, selecting the co- authors and ﬁxing the deadlines to building the website, printing, marketing, distributing, and negotiating with the sponsors. A book for future publishers and authors, for doctors and students Free – for all those who would like to know how medical textbooks are produced today. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters. All reasonable precautions have been taken by the World Health Organization to verify the information contained in this publication. However, the published material is being distributed without warranty of any kind, either expressed or implied.
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