By D. Musan. University of Pennsylvania.
Hyperkalemia reduces renal am- dose of NH4Cl and measuring the urine pH for the next monia synthesis 120mg silvitra erectile dysfunction pump how do they work, resulting in reduced net acid excretion several hours buy silvitra 120 mg cheap erectile dysfunction diagnosis code. The underlying dis- RTA involves daily administration of modest amounts of order is a result of inadequate production of aldosterone or alkali (HCO , citrate) sufficient to cover daily metabolic impaired aldosterone action. Metabolism If H ions were passively distributed across plasma + H membranes, intracellular pH would be lower than what is - + seen in most body cells. In skeletal muscle cells, for exam- CO2 CO2 ple, we can calculate from the Nernst equation (see Chap- ter 2) and a membrane potential of 90 mV that cytosolic H+ pH should be 5. From this discrepancy, two conclusions are clear: H ions are not at equilibrium across the plasma membrane, and the cell must use active mecha- H+ nisms to extrude H. H is extruded by Na /H exchangers, which are present in nearly all body + Na cells. Five different isoforms of these exchangers (desig- nated NHE1, NHE2, etc. The cell is one H for one Na and, therefore, function in an electri- acidified by the production of H from metabolism and the in- cally neutral fashion. Active extrusion of H keeps the in- flux of H from the ECF (favored by the inside negative plasma ternal pH within narrow limits. To maintain a stable intracellular pH, the The activity of the Na /H exchanger is regulated by cell must extrude hydrogen ions at a rate matching their input. Not surprisingly, an increase in intracellu- picted), which defend against excess acid or base. Acidosis is an abnormal process that tends to pro- The plasma membrane Na /H exchanger. If there is too much or too little CO2, intracellular pH in most body cells and is activated by a decrease a respiratory disturbance is present. Many hormones and growth factors, acting much or too little HCO3 , a metabolic (or nonrespiratory) via intracellular second messengers and protein kinases, can in- disturbance of acid-base balance is present. H also stimulates call the Henderson-Hasselbalch equation for the exchanger by protonating an activator site on the cyto- HCO3 /CO2: plasmic side of the exchanger, making the exchanger more effective in dealing with the threat of intracellular acidosis. In this way, they If the primary problem is a change in [HCO3 ] or PCO2, produce changes in intracellular pH, which may lead to the pH can be brought closer to normal by changing the changes in cell activity. For ex- Besides extruding H , the cell can deal with acids and ample, if PCO2 is primarily decreased, a decrease in plasma bases in other ways. In some cells, various HCO3 trans- [HCO3 ] will minimize the change in pH. These exchangers may be activated by of pH from normal; these adjustments are called compen- changes in intracellular pH. Compensations generally do not tein and organic phosphate buffers, which can bind or re- bring about normal blood pH. For example, the conversion of lactic acid to CO2 and water to glucose effectively disposes of acid. In Respiratory Acidosis Results From an addition, various cell organelles may sequester H. For ex- Accumulation of Carbon Dioxide ample, H -ATPase in endosomes and lysosomes pumps Respiratory acidosis is an abnormal process characterized H out of the cytosol into these organelles. In summary, ion transport, buffering mechanisms, and metabolic reac- by CO2 accumulation. The CO2 build-up pushes the fol- tions all ensure a relatively stable intracellular pH. Respiratory acidosis is usually caused by a failure to expire metabolically produced CO at an ade- Table 25. A a decrease in overall alveolar ventilation (hypoventilation) blood pH above 7. The range of pH values compatible with life is ap- or, as occurs commonly in lung disease, a mismatch be- tween ventilation and perfusion. Four simple acid-base disturbances may lead to an ab- occurs if a person breathes CO2-enriched air. In respiratory acidosis, more than “simple” indicates a single primary cause for the distur- 95% of the chemical buffering occurs within cells. The cells 440 PART VI RENAL PHYSIOLOGY AND BODY FLUIDS Directional Changes in Arterial Blood Plasma Values in the Four Simple Acid-Base Disturbancesa TABLE 25. For example, hemoglobin (Hb) in red blood cells ratory acidosis by adding more H to the urine and adding combines with H from H2CO3, minimizing the increase new HCO3 to the blood. Recall from Chapter 21 the buffering reaction: renal H secretion, which allows the reabsorption of all fil- tered HCO3. Excess H is excreted as titratable acid and H2CO3 HbO2 HHb O2 HCO3 (27) NH4 ; these processes add new HCO3 to the blood, This reaction raises the plasma [HCO3 ]. This compensation takes tory acidosis, such chemical buffering processes in the body several days to fully develop. Bicar- creases, on average, by 4 mEq/L for each 10 mm Hg rise in bonate is not a buffer for H2CO3 because the reaction PCO2 (see Table 25. This rise exceeds that seen with acute respiratory acidosis because of the renal addition of H2CO3 HCO3 HCO3 H2CO3 (28) HCO3 to the blood.
In this condition buy silvitra 120 mg overnight delivery erectile dysfunction doctor dallas, red streaks can be seen through the skin extending proximally from the infected area buy cheap silvitra 120 mg line erectile dysfunction drugs online. The term lymphoma is used to describe primary malignan- cies within lymphoid tissues. Lymphomas are generally classified as Hodgkin’s disease lymphomas or non-Hodgkin’s lym- phomas. Hodgkin’s disease manifests itself as swollen lymph Saccular aneurysm Fusiform aneurysm nodes in the neck and then progresses to involve the spleen, (a) liver, and bone marrow. Non-Hodgkin’s lymphomas include an array of specific and more obscure lymphatic cancers. The lymphatic system is also frequently infected by metas- tasizing carcinomas. Fragmented cells from the original tumor may enter the lymphatic ducts with the lymph and travel to the lymph nodes, where they may cause secondary cancerous growths. The surgical treat- ment involves the removal of the infected nodes, along with some of the healthy nodes downstream to ensure that the cancer is eliminated. Trauma to the Circulatory System Hemorrhage and shock are two clinical considerations that di- rectly involve the circulatory system. Knowledge of how to treat a victim experiencing these conditions is of paramount impor- tance in administering first aid. Techniques to control bleeding and to administer first aid to victims experiencing shock are pre- sented in the next two sections. Also review the important arter- (b) ial pressure points presented in figure 16. The following are recom- mended steps in treating a victim who is hemorrhaging. They are most common in the legs because the force of person down on a blanket (if available) and slightly elevate gravity tends to weaken the valves and overload the veins. If possible, elevate the site of bleeding cose veins can also occur in the rectum, in which case they are above the level of the trunk. Vein stripping is the surgical removal of su- shock, cover the victim with a blanket. It may develop as a result of trauma or as an aftermath of or debris from the wound. Apply direct pressure to the wound with a sterile bandage, clean cloth, or an article of clothing (fig. Disorders of the Lymphatic System Infections of the body are generally accompanied by a swelling septicemia: Gk. An inflamma- Hodgkin’s disease: from Thomas Hodgkin, English physician, 1798–1866 Van De Graaff: Human VI. Circulatory System © The McGraw−Hill Anatomy, Sixth Edition Body Companies, 2001 Chapter 16 Circulatory System 597 (a) FIGURE 16. Blood pressure is rect pressure and compression at an arterial pressure point. The eyes are staring and lusterless, possibly with di- wound with clean bandages or cloth lightly bound in place. If the bleeding does not stop and continues to seep through • State of being. The victim may be conscious or uncon- the dressing, do not remove the dressing. If conscious, he or she is likely to feel faint, weak, tional absorbent material on top of it and continue to and confused. If direct pressure does not stop the bleeding, the pressure especially if there has been considerable blood loss. In first-aid treatment for shock is essential and includes the follow- the case of a severe wound to the hand, for example, com- ing steps. Lay the person on be done while pressure continues to be applied to the his or her back with the feet elevated. Once the bleeding has stopped, leave the bandage in place and mental confusion. Get the victim to the victim has sustained an injury in which raising the the hospital or medical treatment center at once. If the weather is Shock is the medical condition that occurs when body tissues do cold, place a blanket under and over the person. It is often linked with weather is hot, position the person in the shade on top of a crushing injuries, heat stroke, heart attacks, poisoning, severe blanket. Loosen tight collars, belts, or other restrictive burns, and other life-threatening conditions. Do not give the person anything to drink, even if he tients experiencing shock include the following.
As de- scribed in the previous chapter discount silvitra 120mg amex erectile dysfunction stress treatment, the serous membranes associated with the lungs are called pleurae (see fig silvitra 120mg without prescription erectile dysfunction karachi. The serous It usually takes about 24 to 48 hours for food to travel the membranes of the abdominal cavity are called peritoneal mem- length of the GI tract. Along the posterior abdominal cavity, the pari- specific functions in preparing food for utilization (table 18. The mesentery so many people are malnourished that eating patterns have supports the GI tract, at the same time allowing the small intes- become a critical public health concern. Grossly overweight people are at greater risk for cardiovas- ture for the passage of intestinal nerves and vessels. People with good nutritional habits are better able to withstand mesocolon is a specific portion of the mesentery that supports trauma, are less likely to get sick, and are usually less seriously ill the large intestine (fig. The peritoneal covering continues around the intestinal viscera as the visceral peritoneum. The peritoneal cavity is the Knowledge Check space between the parietal and visceral portions of the peri- toneum. Which functional activities of the digestive system break peritoneum, and are therefore said to be retroperitoneal. Which functional activities move the food Retroperitoneal organs include most of the pancreas, the kid- through the GI tract? List in order the regions of the GI tract through which in- and the abdominal aorta. Digestive System © The McGraw−Hill Anatomy, Sixth Edition Body Companies, 2001 Chapter 18 Digestive System 637 In a female, however, it is not isolated from the outside, which pre- Notochord sents the potential for contamination through the entry of microorgan- Neural tube isms. A fairly common gynecological condition is pelvic inflammatory Aorta disease (PID), which results from the entry of pathogens into the peri- toneal cavity at the sites of the open-ended uterine (fallopian) tubes. Mesentery Parietal peritoneum Gut Peritoneal cavity Layers of the Gastrointestinal Tract Liver Visceral peritoneum The GI tract from the esophagus to the anal canal is composed of four layers, or tunics. Each tunic contains a dominant tissue type Body wall that performs specific functions in the digestive process. The four tunics of the GI tract, from the inside out, are the mucosa, sub- mucosa, muscularis, and serosa (fig. Umbilical cord Mucosa The mucosa, which lines the lumen of the GI tract, is both an absorptive and a secretory layer. External to the lamina propria are thin layers of smooth muscle called the muscularis mucosae, which provide limited involuntary churning movements. Specialized goblet cells in the mucosa throughout most of the GI tract se- Peritonitis is a bacterial inflammation of the peritoneum. Treatment usually involves the injection Submucosa of massive doses of antibiotics, and perhaps peritoneal intubation (insertion of a tube) to permit drainage. The relatively thick submucosa is a highly vascular layer of con- nective tissue serving the mucosa. Absorbed molecules that pass Extensions of the parietal peritoneum serve to suspend or through the columnar epithelial cells of the mucosa enter into anchor numerous organs within the peritoneal cavity (fig. In addition to The falciform (fal'sı˘-form) ligament, a serous membrane rein- blood vessels, the submucosa contains glands and nerve plexuses. Functions of the greater omentum include storing fat, cushioning visceral organs, sup- The tunica muscularis is responsible for segmental contractions porting lymph nodes, and protecting against the spread of infec- and peristaltic movement through the GI tract. In cases of localized inflammation, such as appendicitis, inner circular and an outer longitudinal layer of smooth muscle. It includes neurons and ganglia from both the sympathetic and parasympathetic divisions of the ANS. The peritoneal cavity provides a warm, moist, normally aseptic environment for the abdominal viscera. In a male, the peri- toneal cavity is totally closed off from the outside body environment. Digestive System © The McGraw−Hill Anatomy, Sixth Edition Body Companies, 2001 638 Unit 6 Maintenance of the Body Falciform ligament Lesser omentum Liver Gallbladder Stomach Liver Stomach Duodenum Parietal Transverse Transverse peritoneum colon colon underneath Descending colon Ascending Greater colon omentum Sigmoid colon Cecum (a) (b) Liver Lesser omentum Transverse Pancreas Greater colon Stomach omentum Duodenum Mesocolon Jejunum Transverse Jejunum colon Greater Mesentery Mesocolon omentum Mesentery Parietal Descending peritoneum Ileum Ileum colon Visceral Rectum peritoreum Sigmoid Vagina colon Urinary bladder (c) (d) FIGURE 18. Digestive System © The McGraw−Hill Anatomy, Sixth Edition Body Companies, 2001 Chapter 18 Digestive System 639 Tunica muscle muscularis muscle Exocrine gland in submucosa FIGURE 18. Vomiting, and in certain cases diarrhea, are reac- tions to substances that irritate the GI tract. Vomiting is a reflexive re- The outer serosa completes the wall of the GI tract. It is a bind- sponse to many toxic chemicals; thus, even though unpleasant, it ing and protective layer consisting of loose connective tissue cov- can be beneficial.
When upper extremities are involved discount silvitra 120 mg free shipping impotence only with wife, self-care skills Manifestations of Poliomyelitis may also be affected silvitra 120mg free shipping erectile dysfunction doctors in pa. If the trunk muscles are affected, a muscle imbalance may Individuals in the initial stages of polio result, lead to scoliosis (lateral curvature are acutely ill. Initial symptoms are usu- of the spine), which can interfere with ally nonspeciﬁc, such as gastrointestinal breathing as well as the functioning of or upper respiratory symptoms accompa- internal organs. Symptoms later progress to After the initial acute episode of polio- headache, stiff neck, and muscle pains. The degree of residual disability group of muscles are affected; in others, is dependent on the extent of the perma- paralysis is widespread and may include nent damage to nerves that has occurred. Extremity involvement is often asymmetrical, so that one extremi- Manifestations of Post-Polio Syndrome ty may have major paralysis while the opposite limb has only slight weakness or Poliomyelitis itself is not a progressive may not be affected at all. Consequently, many individu- cles are paralyzed, functions of sensation, als who contracted the disease 30 or more bowel and bladder control, and sexual years ago adapted to residual paralysis, response are left intact. Despite in- myelitis began to seek medical advice creasing decline, however, individuals will because of new symptoms that ranged not return to the level of disability they from mildly to severely debilitating. At experienced when polio was in its acute ﬁrst they were not taken seriously. With appropriate exercise, strength were classiﬁed as having “emotional dis- and function can be improved and dete- turbances,” or symptoms were merely rioration slowed, if not halted. Spinal tap or fecal sample can ety of symptoms in individuals who had be used to conﬁrm the diagnosis. The recovered from poliomyelitis many years diagnosis of post-polio syndrome is, at earlier. Symptoms of post-polio generalized fatigue syndrome may be difﬁcult to distinguish • new muscle weakness in muscles not from other degenerative disorders of mus- previously affected cles and joints, such as osteoarthritis or • muscle pain (myalgia) and/or joint osteoporosis. General medical evaluation, pain routine laboratory tests, electromyographic • respiratory difﬁculty studies (graphic record of the contraction The cause of post-polio syndrome is un- of a muscle as the result of electrical stim- known (Burk & Agre, 2000). It appears ulation), and nerve conduction studies may that most of the motor neurons original- help to identify and exclude other dis- ly damaged in the initial bout of polio are eases. Magnetic resonance imaging may be involved in post-polio syndrome and used to exclude other conditions of the that most individuals who had polio are spine that could cause similar symptoms at risk to develop the syndrome. Those No speciﬁc treatment is available to who had been able to walk without assis- alter the course of post-polio syndrome. Those who had used muscle weakness, fatigue, and pain should Conditions Affecting the Spinal Cord 93 ﬁrst have a thorough physical exam- reduction may be recommended to ination by a physician to rule out other reduce fatigue and stress on muscles and potential causes of symptoms. For those whose respiratory mus- is largely directed toward managing cles were also affected by the initial infec- symptoms and helping individuals main- tion, weight control can also help to tain functional status and independence prevent respiratory difﬁculty. Good health practices, including proper nutrition and adequate Psychosocial Issues in rest, are important. Post-Polio Syndrome Generalized fatigue is treated with lifestyle changes consisting of energy Since poliomyelitis is not a progressive conservation measures. Physical activities disease, many individuals believed their should be paced to prevent excessive recovery to be permanent and adapted fatigue. Individuals may require frequent and adjusted to the functional limitations rest periods throughout the day. Using and residual effects associated with the additional assistive devices, such as a condition, going on to lead full and pro- wheelchair rather than crutches, may ductive lives. Exercises unexpected symptoms associated with that are tolerable and that do not con- post-polio syndrome threaten their func- tribute to more weakness and fatigue may tion and independence and can be psy- be prescribed. Individuals frustrating for the individual, who again are instructed to exercise for short inter- must adjust and adapt to continuing func- vals, to rest between bouts of exercise, and tional limitations, the potential use of to exercise only every other day to pre- new assistive devices, and an alteration in vent excessive muscle fatigue. After regaining function previ- Individuals with respiratory difﬁculty ously through much physical and emo- may require noninvasive positive-pressure tional effort, being forced to deal again ventilation at night. Because individuals with disability symptoms that are much with post-polio syndrome are more sus- like the initial symptoms can be discour- ceptible to infectious diseases, pneumonia aging. Individuals may reject new assis- and inﬂuenza vaccines are usually recom- tive devices because they symbolize the mended. Changes in Vocational Issues in Post-Polio Syndrome orthotics or in the mode of ambulation may be required. Moving from braces or Many individuals with poliomyelitis have crutches to a wheelchair can also reduce achieved gainful employment and lived stress on joints. Although its cause re- number of alterations necessary in the mains unknown, evidence suggests that work setting. In some instances, depending both genetic and environmental factors on performance requirements, the individ- may play a role (Janson, Leone, & Freese, ual may be unable to perform all of the 2002; Nussbaum & Ellis, 2003). Thus altering job duties or retrain- son’s disease involves extensive degener- ing for other job duties may be necessary. Most of the ability to lift, reach, walk, or climb may disabling symptoms associated with be altered. Parkinson’s disease are due predominant- The symptoms of post-polio syndrome, ly to drastic reductions of dopamine lev- whether pain, weakness, or fatigue, may els in the brain.
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