A number of changes in trace mineral metabolism are noted during sepsis. Which of the following change(s) may be observed in a septic or trauma patient? a. Plasma iron levels are noted to decrease b. Plasma copper levels are noted to decrease c. Plasma serum zinc levels may decrease d. Administration of iron is appropriate

A number of changes in trace mineral metabolism are noted during sepsis. Which of the following change(s) may be observed in a septic or trauma patient? a. Plasma iron levels are noted to decrease b. Plasma copper levels are noted to decrease c. Plasma serum zinc levels may decrease d. Administration of iron is appropriate
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Answer: a, c  Changes in the balance of magnesium, inorganic phosphate, zinc, and potassium generally follow alterations in nitrogen balance. Although the iron-binding capacity of transferrin is usually unchanged in early infection, iron disappears from the plasma, especially during severe pyogenic infection; similar alterations are observed in serum zinc levels. The administration of iron to the infected host, especially early into the disease, is contraindicated, however, because increased serum iron concentrations may impair resistance. Unlike iron and zinc, copper levels generally rise, and the increased plasma concentrations can be ascribed almost entirely to the levels of the ceruloplasmin produced by the liver
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Which of the following statement(s) is/are true concerning metabolic derangements in sepsis and the systemic inflammatory response syndrome which may follow progressive shock? a. Alterations in glucose metabolism lead to the development of efficient substrate utilization b. A progressive rise in serum triglyceride levels result from less efficient clearance and increased hepatic lipogenesis c. A net negative nitrogen balance occurs due to the oxidative metabolism of proteins to meet energy needs d. The serum aromatic amino acids fall rapidly as they are actively used in oxidative metabolism

Description : Which of the following statement(s) is/are true concerning metabolic derangements in sepsis and the systemic inflammatory response syndrome which may follow progressive shock? a. Alterations in glucose ... The serum aromatic amino acids fall rapidly as they are actively used in oxidative metabolism

Last Answer : Answer: b, c A broad spectrum of metabolic abnormalities become apparent in sepsis and the systemic inflammatory response syndrome following shock. Disruption of the normal cycles of carbohydrate, ... acetyl coenzyme A. This results in reduced serum level of leucine, isoleucine and valine

A 59-year-old trauma patient has suffered multiple septic complications including severe pneumonia, intraabdominal abscess, and major wound infection. He has now developed signs of multisystem organ failure. Which of the following statement(s) is/are true concerning necessary changes to be made in his nutritional management? a. Carbohydrate load should be reduced in the face of respiratory failure b. In patients with renal failure, protein intake should be diminished c. During hemodialysis protein intake should be limited to the same extent d. In patients with hepatic failure, carbohydrate load should be increased

Description : A 59-year-old trauma patient has suffered multiple septic complications including severe pneumonia, intraabdominal abscess, and major wound infection. He has now developed signs of multisystem organ ... the same extent d. In patients with hepatic failure, carbohydrate load should be increased

Last Answer : Answer: a, b The most severe complication of sepsis is multiple system organ dysfunction syndrome, which may result in death. The development of organ failure requires changes in the ... should be provided as fat emulsion. If encephalopathy develops, protein load should also be reduced0

Answer: b Metabolic response to injury results in increased energy expenditure. If energy intake is less than expenditure, oxidation of body fat stores and erosion of lean body mass will occur with resultant loss of weight. When weight loss exceeds 10–15% of body weight, the complications of malnutrition interact with disease processes, with increased morbidity and mortality rates. The goal of nutritional support is maintenance of body cell mass and limitation of weight loss to less than 10% preinjury. The major impact of nutritional support in the trauma patient is to aid host defense. Under-nutrition may compromise the available host defense mechanism and may thus increase the likelihood of invasive sepsis, multiple organ system failure, and death. Resuscitation, oxygenation and arrest

Description : Answer: b Metabolic response to injury results in increased energy expenditure. If energy intake is less than expenditure, oxidation of body fat stores and erosion of lean body mass will occur ... requirements, caloric requirements should be distributed at a ratio of 70% as glucose and 30% as fat

Last Answer : Which of the following statement(s) is/are true concerning body fuel reserves? a. The largest fuel reserve in the body is skeletal muscle b. Fat provides about 9 calories/gram c. Free glucose and glycogen stores are a trivial fuel reserve d. Body protein is a valuable storage form of energy

Sepsis causes a marked metabolic response. Which of the following statement(s) is/are true concerning the metabolic response to sepsis? a. Oxygen consumption is increased in the face of infection b. In a patient with a maximal metabolic rate secondary to trauma, the presence of infection will increase the rate further c. Metabolic rate increases at a rate of approximately 10% for each increase of 1°C in central temperature d. The extent of increase in oxygen consumption relates to the severity of the infection

Description : Sepsis causes a marked metabolic response. Which of the following statement(s) is/are true concerning the metabolic response to sepsis? a. Oxygen consumption is increased in the face of infection ... d. The extent of increase in oxygen consumption relates to the severity of the infection

Last Answer : Answer: a, c, d Oxygen consumption is usually elevated in the infected patient. The extent of this increase is related to the severity of the infection, with peak elevations reaching 50% ... suggest that the metabolic rate increases 10% to 13% for each elevation of 1°C in central temperature

Antithrombin III deficiency is a commonly observed hypercoaguable state. Which of the following statement(s) is/are true concerning this condition? a. A patient with this deficiency usually presents with thrombosis while on heparin or exhibits an inability to become adequately anticoagulated with heparin b. This deficiency may be either congenital or acquired c. Thrombotic episodes are related to predisposing events such as operations, childbirth, and infections d. Treatment involves acutely the administration of fresh frozen plasma followed by long-term treatment with Coumadin

Description : Antithrombin III deficiency is a commonly observed hypercoaguable state. Which of the following statement(s) is/are true concerning this condition? a. A patient with this deficiency usually ... involves acutely the administration of fresh frozen plasma followed by long-term treatment with Coumadin

Last Answer : Answer: a, b, c, d Antithrombin III deficiency accounts for about 2% of venous thrombotic event. This deficiency has been described in patients with pulmonary embolism, mesenteric venous ... is established, fresh frozen plasma should be administered followed by long-term treatment with Coumadin

The following statement(s) is/are true concerning gram-negative bacterial sepsis. a. Mortality due to this condition has almost been eliminated due to therapeutic intervention with antibiotics, aggressive hemodynamic monitoring and fluid resuscitation b. Recent series have noted a decrease in the incidence of this condition c. Predisposing factors include old age, malnutrition, and immunosuppression d. Pseudomonas bacteremia is the most common cause of gram-negative sepsis e. Polymicrobial sepsis is generally considered a more serious problem than sepsis due to a single organism

Description : The following statement(s) is/are true concerning gram-negative bacterial sepsis. a. Mortality due to this condition has almost been eliminated due to therapeutic intervention with antibiotics, aggressive ... sepsis is generally considered a more serious problem than sepsis due to a single organism

Last Answer : Answer: c, e Gram-negative bacterial sepsis is a serious disease process that produces substantial morbidity and mortality in both normal and immunocompromised patients (10% to 20% and ... and most investigators agree that polymicrobial sepsis is more lethal than infection with a single organism

Which of the following metabolic effects may be observed in patients with sepsis? a. Increased gluconeogenesis b. Accelerated proteolysis c. Increased lipolysis d. Impaired gut metabolism of glutamine

Description : Which of the following metabolic effects may be observed in patients with sepsis? a. Increased gluconeogenesis b. Accelerated proteolysis c. Increased lipolysis d. Impaired gut metabolism of glutamine

Last Answer : Answer: a, b, c, d A number of metabolic responses to sepsis have been defined. Glucose production is increased in infected patients which appears to be additive to the ... metabolism of lipids from peripheral fat stores is especially prominent during a period of inadequate nutritional support

Answer: a, b, c, d Free oxygen radicals are chemical species that are intermediates in the normal process of cellular respiration. Oxidants that are free radicals have been implicated as initiators of reactions which lead to a variety of cellular injuries. Oxidants are derived from several sources, notably phagocytes. Among the effects of oxygen free radicals are membrane lipid peroxidation, DNA strand breaks, cytoskeletal disassembly and inhibition of glucose metabolism leading to decreased cellular ATP concentrations. (Figure 6-16) 187 Which of the following acute-phase protein levels are increased in human plasma following acute inflammation? a. C-reactive protein b. Serum amyloid c. a -Proteinase inhibitor d. Fibrinogen e. Albumin

Description : Answer: a, b, c, d Free oxygen radicals are chemical species that are intermediates in the normal process of cellular respiration. Oxidants that are free radicals have been implicated as initiators of ... a. C-reactive protein b. Serum amyloid c. a -Proteinase inhibitor d. Fibrinogen e. Albumin

Last Answer : Answer: a, b, c, d The acute-phase response is a series of homeostatic responses of the organism to tissue injury in infection and inflammation. After an inflammatory stimulus occurs, a number ... 30% to 50% of the level before injury. The reason for the decrease in production is poorly understood

Which of the following statements about the role of the gut in shock and sepsis are true? A. Selective decontamination of the digestive tract with the use of oral antibiotics has been shown to reduce nosocomial pneumonias and to improve mortality rates. B. Enteral nutrition, as compared with parenteral nutrition, preserves the villus architecture of the gut. C. Gut dysfunction may be an effect of shock, but it may also contribute to the development of MODS by the mechanism of bacterial translocation. D. As compared with parenteral nutrition, enteral nutrition is associated with a reduction in septic morbidity.

Description : Which of the following statements about the role of the gut in shock and sepsis are true? A. Selective decontamination of the digestive tract with the use of oral antibiotics has been ... As compared with parenteral nutrition, enteral nutrition is associated with a reduction in septic morbidity.

Last Answer : Answer: BCD DISCUSSION: The gut has a vital role in the pathophysiology of shock. The splanchnic circulation is very vulnerable to the circulatory redistribution that occurs in shock, thus, gut ... , enteral feeding is more cost effective and is associated with a lower rate of septic morbidity

Which of the following statements about septic shock are true? A. A circulating myocardial depressant factor may account for the cardiac dysfunction sometimes seen with shock due to sepsis or SIRS. B. A cardiac index (CI) of 6 liters per minute per square meter of body surface, a pulmonary capillary wedge pressure of 15 mm. Hg, and a systemic vascular resistance index (SVRI) of 800 dynes-sec/(cm 5-m 2) is a hemodynamic profile consistent with septic shock. C. An increase in SvO 2 in septic patients may be explained by the finding of anatomic arteriovenous shunts. D. Results of human trials employing antimediator therapy, such as antiendotoxin antibodies, IL-1 receptor antagonist, and tumor necrosis factor (TNF) antibodies, have confirmed animal studies that demonstrate a significant im

Description : Which of the following statements about septic shock are true? A. A circulating myocardial depressant factor may account for the cardiac dysfunction sometimes seen with shock due to sepsis or ... animal studies that demonstrate a significant improvement in survival with the use of such agents.

Last Answer : Answer: AB DISCUSSION: Shock due to sepsis or SIRS frequently manifests as a hyperdynamic cardiovascular response, consisting of an elevated CI and a decreased SVR or SVRI. Occasionally, ... been encouraging thus far in human clinical trials, despite the promising results from many animal studies

A 67-year-old male with advanced cholangiocarcinoma develops gram-negative sepsis. Excessive bleeding is noted around vascular catheters and from needle puncture sites. The diagnosis of disseminated intervascular coagulation (DIC) is considered. Which of the following laboratory test(s) is/are indicative of DIC? a. Decreased platelet count b. Decreased fibrinogen level c. Normal prothrombin time d. Elevated fibrin split products

Description : A 67-year-old male with advanced cholangiocarcinoma develops gram-negative sepsis. Excessive bleeding is noted around vascular catheters and from needle puncture sites. The diagnosis of disseminated ... b. Decreased fibrinogen level c. Normal prothrombin time d. Elevated fibrin split products

Last Answer : Answer: a, b, d Disseminated intravascular coagulation (DIC) is the primary form of acute thrombosis. Causes of this syndrome include abruptio placenta, gram-positive and gram-negative sepsis, ... decline in the platelet count and fibrinogen level, along with an elevation of fibrin split products

Infectious disease transmission during blood transfusions is of clinical significance to surgeons and of major importance to patients contemplating surgery potentially associated with the need for blood administration. Which of the following statement(s) is/are true concerning the transmission of infectious disease during blood transfusions? a. Post-transfusion hepatitis is usually due to hepatitis B b. Hepatitis and HIV transmission is greatest with the administration of pooled plasma products such as serum albumin c. The most important cause of post-transfusion disease in immunosuppressed patients is CMV infection d. The risk of HIV transmission in blood transfusions is significantly less than the risk of hepatitis transmission

Description : Infectious disease transmission during blood transfusions is of clinical significance to surgeons and of major importance to patients contemplating surgery potentially associated with the need for ... transmission in blood transfusions is significantly less than the risk of hepatitis transmission

Last Answer : Answer: c, d The most common infectious diseases transmitted during blood transfusions include viral hepatitis, CMV, and HIV infection. Post-transfusion hepatitis in 90% of cases consists of ... infectious disease transmission, the risks of HIV transmission is markedly less than that of hepatitis

Which of the following statement(s) is/are true concerning the management of a patient with hemophilia A undergoing an elective surgical operation? a. Concentrates of factor VIII should be given several days prior to elective surgery b. The half-life of factor VIII concentrates is less than 24 hours c. A dose of 40–50 IU/kg of factor VIII concentrate should be given prior to the planned surgical procedure d. Factor VIII concentration administration should be given for the first 24 hours after surgery but may then be stopped if no abnormal bleeding has been observed e. A new recombinant preparation of factor VIII offers the advantage of being virus-free

Description : Which of the following statement(s) is/are true concerning the management of a patient with hemophilia A undergoing an elective surgical operation? a. Concentrates of factor VIII should be given ... observed e. A new recombinant preparation of factor VIII offers the advantage of being virus-free

Last Answer : Answer: b, c, e Although the half-life of factor VIII is 2.9 days in normal individuals, the half-life of factor VIII concentrates is 9 to l8 hours. Levels of 80% to ... infection in the hemophilia population. A new recombinant preparation of factor VIII offers the advantage of being virus-free

Which of the following complications of TPN are appropriately managed with the listed treatment? a. Air embolism—place patient in reverse Trendelenburg and the left lateral decubitus position and aspirate venous air b. Hyperchloremic metabolic acidosis—give sodium and potassium as acetate salts c. Carbon dioxide retention—decrease glucose calories and replace with fat d. Line sepsis—intravenous antibiotics

Description : Which of the following complications of TPN are appropriately managed with the listed treatment? a. Air embolism-place patient in reverse Trendelenburg and the left lateral decubitus position ... dioxide retention-decrease glucose calories and replace with fat d. Line sepsis-intravenous antibiotics

Last Answer : Answer: b, c A number of complications of TPN can occur which can be divided into three types: mechanical, metabolic, and infectious

Which of the following statement(s) concerning laboratory studies used in monitoring a patient with intravenous heparinization is/are correct? a. The platelet count should be followed because of the risk of heparin-associated thrombocytopenia b. The prothrombin time should be observed if prolonged treatment is necessary c. The activated partial thromboplastin time (aPTT) should be maintained at approximately 1.5 times normal d. The serum creatinine should be measured daily to allow adjustments in dose based on renal function

Description : Which of the following statement(s) concerning laboratory studies used in monitoring a patient with intravenous heparinization is/are correct? a. The platelet count should be followed because of the ... serum creatinine should be measured daily to allow adjustments in dose based on renal function

Last Answer : Answer: a, c In monitoring the effect of heparin, an activated partial thromboplastin time (aPTT) of 1.5 control or a thrombin clotting time (TCT) of 2 times control reflects adequate ... system. Therefore the dose of heparin need not be adjusted in cases of liver or renal dysfunction

Which of the following statements regarding cytokines is incorrect? A. Cytokines act directly on target cells and may potentiate the actions of one another. B. Interleukin 1 (IL-1) is a major proinflammatory mediator with multiple effects, including regulation of skeletal muscle proteolysis in patients with sepsis or significant injury. C. Platelet-activating factor (PAF) is a major cytokine that results in platelet aggregation, bronchoconstriction, and increased vascular permeability. D. Tumor necrosis factor alpha (TNF-a), despite its short plasma half-life, appears to be a principal mediator in the evolution of sepsis and the multiple organ dysfunction syndrome because of its multiple actions and the secondary cascades that it stimulates.

Description : Which of the following statements regarding cytokines is incorrect? A. Cytokines act directly on target cells and may potentiate the actions of one another. B. Interleukin 1 (IL-1) ... organ dysfunction syndrome because of its multiple actions and the secondary cascades that it stimulates.

Last Answer : Answer: C DISCUSSION: Cytokines are soluble peptide molecules that are synthesized and secreted by a number of cell types in response to injury, inflammation, and infection. Cytokines, which ... is thought to play a central role in the stress response, particularly in response to endotoxemia

The following statement(s) is/are true concerning initial microbiologic diagnostic techniques. a. Appropriate expeditious transport of specimens to the microbiology laboratory is essential for obtaining accurate clinical information b. The use of potassium hydroxide in preparing a specimen slide for light microscopy will be useful in identification of anaerobic bacteria c. Antibiotic sensitivity is determined by exposing the specific microorganism to varying amounts of antibiotic with the concentration of the antibiotic inhibiting growth referred to as the MIC (minimal inhibitory concentration) d. Serum levels of antimicrobial agents should achieve in excess of a 4-to 8-fold increase over the MIC to be considered clinically efficacious.

Description : The following statement(s) is/are true concerning initial microbiologic diagnostic techniques. a. Appropriate expeditious transport of specimens to the microbiology laboratory is essential for obtaining accurate ... a 4-to 8-fold increase over the MIC to be considered clinically efficacious.

Last Answer : Answer: a, c, d Because most surgical infections are polymicrobial, specimens should be cultured for aerobic and anaerobic bacteria, as well as fungi. Although aerobic and aerotolerant ... fold increase over MIC during the peak serum level have been demonstrated to be clinically efficacious

Which of the following statements about delivery-dependent oxygen consumption are true? A. Below the critical oxygen delivery (D(overdot)O 2crit), one would expect to see a decrease in the lactate-pyruvate ratio. B. D(overdot)O 2crit may be increased in patients with sepsis. C. A desirable goal in the treatment of shock is to achieve delivery-independent oxygen consumption. D. The oxygen extraction ratio remains constant as long as oxygen delivery remains above D(overdot)O 2crit.

Description : Which of the following statements about delivery-dependent oxygen consumption are true? A. Below the critical oxygen delivery (D(overdot)O 2crit), one would expect to see a decrease in the ... oxygen extraction ratio remains constant as long as oxygen delivery remains above D(overdot)O 2crit.

Last Answer : Answer: BC DISCUSSION: Oxygen consumption is said to be delivery dependent below a critical point, D(overdot)O 2crit, at which anaerobic metabolism supervenes. Above this point, oxygen ... the therapeutic benefit of trying to achieve supranormal oxygen delivery has not been firmly established

Glucose overload results in increased CO 2 production. Which of the following statements are true? A. In patients with respiratory insufficiency, administration of glucose as a principal calorie source is contraindicated. B. In patients with pulmonary infection and sepsis, calorie support should consist of 95% fat and 5% glucose. C. In Askanazi's study, increased CO 2 production and difficulty in weaning was associated only with pronounced overfeeding. D. CO 2 production should be measured in most patients who are supported by respirators in intensive care units and are receiving nutritional support.

Description : Glucose overload results in increased CO 2 production. Which of the following statements are true? A. In patients with respiratory insufficiency, administration of glucose as a principal calorie ... who are supported by respirators in intensive care units and are receiving nutritional support.

Last Answer : Answer: C DISCUSSION: Few papers have excited as much interest as that by Askanazi, Kinney, and co-workers, which demonstrated that glucose calories given to patients with severe respiratory ... the caloric requirement and glucose for the remainder, without much fear of excessive CO 2 production

A 55-year-old male undergoes a total abdominal colectomy. Which of the following statement(s) is/are true concerning the hormonal response to the surgical procedure? a. Adrenocorticotropic hormone (ACTH) is secreted from the anterior pituitary gland b. ACTH stimulation results in elevation of serum cortisol levels for up to a week after the operation c. An increased secretion of aldosterone and ADH may contribute to postoperative fluid retention d. An increase in serum insulin and a fall in glucagon accelerate hepatic glucose production and maintain gluconeogenesis

Description : A 55-year-old male undergoes a total abdominal colectomy. Which of the following statement(s) is/are true concerning the hormonal response to the surgical procedure? a. Adrenocorticotropic ... in serum insulin and a fall in glucagon accelerate hepatic glucose production and maintain gluconeogenesis

Last Answer : Answer: a, c One of the earliest consequence of a surgical procedure is the rise in levels of circulating cortisol that occur in response to a sudden outpouring of ACTH ... hepatic glucose production, and, with other hormones (epinephrine and glucocorticoids), gluconeogenesis is maintained

In contrast to a patient undergoing an elective operation, which of the following statement(s) is/are true concerning a patient who has suffered a multiple trauma? a. Basal metabolic rates are similar b. The patient is highly sensitive to insulin c. Utilization of the amino acids, glutamine and alanine, is similar to their composition in skeletal muscle d. Fat and protein stores are rapidly depleted

Description : In contrast to a patient undergoing an elective operation, which of the following statement(s) is/are true concerning a patient who has suffered a multiple trauma? a. Basal metabolic rates are ... is similar to their composition in skeletal muscle d. Fat and protein stores are rapidly depleted

Last Answer : Answer: b, d The degree of hypermetabolism is generally related to the severity of injury. Patients with long-bone fractures have a 15-25% increase in metabolic rate, whereas metabolic ... in injured subjects, if unfed, severely injured patients rapidly deplete their fat and protein stores

Which of the following statement(s) is/are true concerning tumor necrosis factor (TNF)? a. TNF is a product of activated macrophages secreted in response to contact with endotoxin or lipopolysaccharide, antibody complexes, or inflammatory stimuli b. The liver and gut appear to be a major source of TNF following hypoperfusion c. Circulating levels of TNF correlate well with severity of tissue injury in shock d. Recently completed clinical trials of anti-TNF antibody in septic patients shows a marked improvement in survival

Description : Which of the following statement(s) is/are true concerning tumor necrosis factor (TNF)? a. TNF is a product of activated macrophages secreted in response to contact with endotoxin or ... completed clinical trials of anti-TNF antibody in septic patients shows a marked improvement in survival

Last Answer : Answer: a, b Tumor necrosis factor (TNF), a protein product of activated macrophages, is secreted in response to contact with endotoxin or lipopolysaccharide, antibody complexes, or ... patients utilizing infusion of monoclonal antibodies to the TNF molecule have shown no overall survival benefit

The complement system consists of a series of serum proteins that exist in a quiescent or very low-level state of activation in the uninfected host. Which of the following statement(s) is/are true concerning complement activation? a. The alternate (properdin) pathway of complement activation can occur directly through contact with fungal or bacterial cell wall compounds b. Complement component fragments may serve to decrease vascular permeability c. Excessive complement activation can produce deleterious effects d. Fragments of certain complement components serve as chemoattractants to additional cellular components of the host defense mechanism

Description : The complement system consists of a series of serum proteins that exist in a quiescent or very low-level state of activation in the uninfected host. Which of the following ... certain complement components serve as chemoattractants to additional cellular components of the host defense mechanism

Last Answer : Answer: a, c, d Complement activation can occur through either classic or alternate (properdin) pathways, both of which eventuate in deposition of terminal complement pathway components on the ... and release of lysosomal enzymes that can directly damage certain target tissues, such as the lung

Which of the following statements(s) is/are true concerning human energy requirement? a. In normal subjects, less than 5% of basal energy requirement is spent on cardiac output and the work of breathing b. Mechanical ventilation can decrease the energy expenditure for normal respiration c. For a 70 kg male, average resting energy consumption is almost 1500 kcal/day d. Similar increases in energy expenditures are associated with elective surgery and trauma or thermal injury

Description : Which of the following statements(s) is/are true concerning human energy requirement? a. In normal subjects, less than 5% of basal energy requirement is spent on cardiac output and the ... d. Similar increases in energy expenditures are associated with elective surgery and trauma or thermal injury

Last Answer : Answer: a, c Basal energy requirements are measured with the subject at rest when no external work is being done; the energy is used mainly for transport and synthetic work within cells. A ... average-sized adult who sustains a major burn rarely may require more than 3500 kcal/day for maintenance

The use of antibiotics can be based on either the clinical course of a patient without the benefit of well-defined microbiologic data (empiric therapy), or targeted at specific identified pathogens once sensitivity reports are available (directed therapy). The following statement(s) is/are true concerning these therapies. a. The issue of toxic side effects of antibiotics is only important in dealing with emperic therapy b. Single agent therapy is generally inferior to specific multi-drug therapy (aminoglycoside plus an antianaerobic agent) for the treatment of secondary bacterial peritonitis due to appendicitis, diverticulitis, penetrating gastrointestinal injury, or anastomotic leak c. With the empiric use of antibiotics, a diligent search for the septic source should be undertaken and co

Description : The use of antibiotics can be based on either the clinical course of a patient without the benefit of well-defined microbiologic data (empiric therapy), or targeted at ... which polymicrobial infection is identified, specifically-directed treatment for the predominant organism is satisfactory

Last Answer : Answer: c The use of empiric therapy without the benefit of well-defined microbiologic data is appropriate when there is sufficient clinical evidence to support the diagnosis such that it would ... components of the infection if the body site is such that these microorganisms may be present

Which of the following statement(s) is/are true concerning protein/amino acid metabolism in man? a. The major source of amino acids is breakdown of circulating proteins b. The recommended daily allowance for protein may triple in critically ill patients c. Urinary nitrogen losses will approach 0 in the face of protein starvation d. Negative nitrogen balance refers to a decrease in nitrogen taken into the body versus the amount of nitrogen lost

Description : Which of the following statement(s) is/are true concerning protein/amino acid metabolism in man? a. The major source of amino acids is breakdown of circulating proteins b. The recommended daily ... balance refers to a decrease in nitrogen taken into the body versus the amount of nitrogen lost

Last Answer : Answer: b, d About 15% of the total body weight is made up of proteins, about half of which are intracellular and half extracellular. In man and other animals, dietary protein is the source of ... is exceeded by the amount of nitrogen lost in the urine, stool, skin, wounds, and fistula drainage

Increasing evidence has implicated gram-negative bacterial lipopolysaccharide (LPS endotoxin) as the portion of the gram-negative bacterial cell membrane responsible for many, if not all the toxic effects that occur during gram-negative bacterial sepsis. The following statement(s) is/are true concerning LPS and the host response. a. The LPS molecule can in itself cause physiologic responses similar to that seen during gram-negative bacterial sepsis b. LPS triggers host macrophages to release a variety of cytokines including TNF-a, IL-1a, and IL-1b, IL-6, and IFN-a c. Excessive cytokine production is not associated with detrimental consequences d. TNFa and IL-1b appear to be the primary mediators within the host, exerting deleterious effects on the host when excessive amounts reach the syst

Description : Increasing evidence has implicated gram-negative bacterial lipopolysaccharide (LPS endotoxin) as the portion of the gram-negative bacterial cell membrane responsible for many, if not all the ... host, exerting deleterious effects on the host when excessive amounts reach the systemic circulation

Last Answer : Answer: a, b, d The LPS molecule exerts diverse effects on the mammalian host. Immunologic responses to LPS include nonspecific polyclonal B-cell proliferation, macrophage activation and ... deleterious effects on the host only after large amounts are secreted and reach the systemic circulation

Answer: e The role of nutritional support in the cancer patient remains an important component of overall therapy. Preoperative nutritional support should be given only to those patients who do not require an emergency operation and who have severe weight loss (> 15% of pre-illness body weight) and a serum albumen < 2.9 mg%. Preoperative nutrition (enteral or parenteral) should not be given for longer than 7 to 10 days. Enteral nutrition is always the preferred route of feeding cancer patients if the GI tract is functional. There are several benefits of using the bowel lumen for nutrient delivery. The trophic effects of enteral feeding on small bowel mucosa have been well described. The integrity of the mucosal lining is maintained and it may provide an effective barrier to intraluminal

Description : Answer: e The role of nutritional support in the cancer patient remains an important component of overall therapy. Preoperative nutritional support should be given only to those patients who ... of bowel rest; this atrophy is not reversed by currently available total parenteral nutrition solutions

Last Answer : Which of the following hormones can be expected to be released as part of the stress response? a. Antidiuretic hormone (ADH) b. Aldosterone c. Insulin d. Epinephrine nswer: a, b, d ... This hormone has the exact opposite effect of insulin, which promotes glucose storage and uptake by the cells

Essential fatty acid deficiency may complicate total parenteral nutrition (TPN). Which of the following statements are true? A. Essential fatty acid deficiency may be prevented by the administration of 1% to 2% of total calories as fat emulsion. B. Fat-free parenteral nutrition results in the appearance of plasma abnormalities, indicating essential fatty acid deficiency, within 7 to 10 days of initiation. C. An abnormal plasma eicosatrienoic-arachidonic acid ratio is always associated with essential fatty acid deficiency. D. Following initiation of fat-free parenteral nutrition, dry, scaly skin associated with a maculopapular rash indicates essential fatty acid deficiency.

Description : Essential fatty acid deficiency may complicate total parenteral nutrition (TPN). Which of the following statements are true? A. Essential fatty acid deficiency may be prevented by the ... , dry, scaly skin associated with a maculopapular rash indicates essential fatty acid deficiency.

Last Answer : Answer: BD DISCUSSION: Biochemical evidence of essential fatty acid deficiency may occur as early as 7 to 10 days following initiation of fat-free parenteral nutrition. The decrease in ... essential to the diagnosis of essential fatty acid deficiency, but this plasma abnormality is often present

Under certain circumstances, the gut may become a source of sepsis and serve as the motor of systemic inflammatory response syndrome. Microbial translocation is the process by which microorganisms migrate across the mucosal barrier to invade the host. Which of the following mechanisms can promote bacterial translocation? a. An increased number of gut bacteria b. Altered intestinal mucosal permeability c. Decreased host defense mechanisms d. Lack of enteral feeding

Description : Under certain circumstances, the gut may become a source of sepsis and serve as the motor of systemic inflammatory response syndrome. Microbial translocation is the process by which microorganisms ... intestinal mucosal permeability c. Decreased host defense mechanisms d. Lack of enteral feeding

Last Answer : Answer: a, b, c, d 99 Translocation is promoted in three general ways: 1) altered permeability of the intestinal mucosa as caused by shock, sepsis, distant injury, or cell toxins; 2) ... trauma patient d. Fifty percent of non-nitrogen caloric requirements should be provided in the form of fat

Which of the following statement(s) is/are true concerning the assessment of protein reserve? a. Conventional serum proteins such as albumin and globulin are early indicators of malnutrition b. The total lymphocyte count reflects immune status and not nutrition c. Antigen skin testing reflects patient immunity and not nutrition d. Measurement of urea excretion in urine can be used as a measurement of protein breakdown

Description : Which of the following statement(s) is/are true concerning the assessment of protein reserve? a. Conventional serum proteins such as albumin and globulin are early indicators of malnutrition b. The ... d. Measurement of urea excretion in urine can be used as a measurement of protein breakdown

Last Answer : Answer: d Since protein is the functional and structural chemical of the body, most nutritional assessment techniques are estimates of protein reserves. The actual nitrogen balance can ... patients convert from reactive to anergic, and reactivity can be restored by nutritional repletion

Bleeding complications are frequently associated with fibrinolytic therapy. Which of the following statement(s) concerning complications of fibrinolytic therapy is/are true? a. Careful monitoring of prothrombin time and aPTT time are necessary to avoid bleeding complications b. A level of serum fibrinogen less than 100 mg/dl is associated with an increased risk of bleeding c. Recent (less than 10 days) major surgery is a contraindication to systemic but not regional fibrinolytic therapy d. A patient with a cerebrovascular event occurring less than two months ago can be treated with fibrinolytic therapy if head CT scan is normal

Description : Bleeding complications are frequently associated with fibrinolytic therapy. Which of the following statement(s) concerning complications of fibrinolytic therapy is/are true? a. Careful monitoring of prothrombin time ... months ago can be treated with fibrinolytic therapy if head CT scan is normal

Last Answer : Answer: b Fibrinolytic therapy induces a hemostatic defect through a combination of factors. Hypofibrinogenemia and fibrin degradation products inhibit fibrin polymerization and, in combination ... is considered a major relative contraindication to either regional or systemic thrombolytic therapy

Which of the following statement(s) is/are true concerning ischemia reperfusion injury? a. During ischemia, ATP degradation results in increased plasma and intracellular levels of hypoxanthine and xanthene b. Oxygen free radicals such as the superoxide radical are involved in the expression of the proinflammatory phenotype of endothelial cells, macrophages and neutrophils c. The intracellular adhesion molecule-1 (ICAN-1) contributes to injury and disruption of the endothelial lining, with extensive capillary leak and resultant interstitial edema d. Animal models have demonstrated that passive immunization with antibodies to neutrophil adhesive complex lessen the ischemic/reperfusion microvascular injury

Description : Which of the following statement(s) is/are true concerning ischemia reperfusion injury? a. During ischemia, ATP degradation results in increased plasma and intracellular levels of ... immunization with antibodies to neutrophil adhesive complex lessen the ischemic/reperfusion microvascular injury

Last Answer : Answer: a, b, c, d During the ischemia and hypoperfusion phase, degradation of ATP stores essential to maintain cell integrity and significant loss of diffusible ... either the neutrophil adhesive complex or the endothelial selectins dramatically lessens ischemia/reperfusion microvascular injury

Tests of coagulation are used to monitor anticoagulation treatment and detect intrinsic abnormalities in coagulation. Which of the following statement(s) is/are true concerning coagulation tests? a. Prothrombin time (PT) measures both the intrinsic and extrinsic clotting pathways and fibrinogen b. Activated partial thromboplastin time (aPTT) can be used to monitor both oral anticoagulation with Warfarin and intravenous anticoagulation with heparin c. Thrombin clotting time (TCT) is a measurement of the time it takes for exogenously administered thrombin to turn plasma fibrinogen into fibrin clot d. Whole blood activated clotting time (ACT) is a measurement of the ability of whole blood to clot and is used to monitor heparin levels intraoperatively during cardiovascular and peripheral vascu

Description : Tests of coagulation are used to monitor anticoagulation treatment and detect intrinsic abnormalities in coagulation. Which of the following statement(s) is/are true concerning ... is used to monitor heparin levels intraoperatively during cardiovascular and peripheral vascular operations

Last Answer : Answer: a, c, d Coagulation tests include prothrombin time (PT), which measures the intrinsic and extrinsic pathways of fibrinogen production and is the most common method for ... more while for peripheral vascular applications, values of 250 seconds or greater are considered appropriate

A 16-year-old boy suffers a mid-gut volvulus with massive loss of small intestine. Which of the following statement(s) is/are true concerning his nutritional requirements and management? a. If at least 18 inches of residual small intestine survives, the patient may tolerate some form of enteral nutrition b. A nutritional regimen consisting of supplemental glutamine, growth hormone, and a modified high carbohydrate, low fat diet may be beneficial in this patient c. The regimen described above may decrease the cost of care d. TPN needs will increase after discontinuation of growth hormone

Description : A 16-year-old boy suffers a mid-gut volvulus with massive loss of small intestine. Which of the following statement(s) is/are true concerning his nutritional requirements and management? a. If ... above may decrease the cost of care d. TPN needs will increase after discontinuation of growth hormone

Last Answer : Answer: a, b, c Prior to the availability of TPN, most patients developing short bowel syndrome from either surgery or catastrophic event died. In selected patients, however, with ... the growth hormone did not increase TPN needs in patients once they had undergone successful gut rehabilitation

Which of the following statements are true of the multiple organ dysfunction syndrome (MODS)? A. The “two-hit” model proposes that secondary MODS may be produced when even a relatively minor second insult reactivates, in a more amplified form, the systemic inflammatory response that was primed by an initial insult to the host. B. The systemic inflammatory response syndrome (SIRS), shock due to sepsis or SIRS, and MODS may be regarded as a continuum of illness severity. C. Prolonged stimulation or activation of Kupffer cells in the liver is thought to be a critical factor in the sustained, uncontrolled release of inflammatory mediators. D. The incidence of MODS in intensive care units has decreased owing to increased awareness, prevention, and treatment of the syndrome.

Description : Which of the following statements are true of the multiple organ dysfunction syndrome (MODS)? A. The two-hit model proposes that secondary MODS may be produced when even a relatively ... intensive care units has decreased owing to increased awareness, prevention, and treatment of the syndrome.

Last Answer : Answer: ABC DISCUSSION: MODS is part of a clinical continuum that begins with the systemic inflammatory response syndrome, which is the host's stress response to any major insult such ... pathogenesis of MODS, the incidence of MODS continues to increase without a significant improvement in outcome

Von Willebrand’s disease is a common, congenital bleeding disorder. Which of the following statement(s) is/are true concerning Von Willebrand’s disease? a. As in hemophilia, it is much more common in men b. A history of spontaneous bleeding is common c. Screening laboratory tests will include a prolonged aPTT with a normal prothrombin time d. Pre-treatment for elective surgery require administration of cryoprecipitate to achieve levels of 23–50% of normal

Description : Von Willebrand's disease is a common, congenital bleeding disorder. Which of the following statement(s) is/are true concerning Von Willebrand's disease? a. As in hemophilia, it is ... -treatment for elective surgery require administration of cryoprecipitate to achieve levels of 23-50% of normal

Last Answer : Answer: c, d Von Willebrand's factor is an adhesive protein that mediates platelet adhesion to collagen. In addition, it protects and prevents the rapid removal of factor VIII ... platelet aggregation responses to ristocetin. The most reliable source of Von Willebrand's factor is cryoprecipitate

Ketorolac: A. Is a nonsteroidal anti-inflammatory drug (NSAID) approved for intravenous, intramuscular, and oral administration. B. Can be used indefinitely for postoperative analgesia. C. Can cause renal dysfunction. D. May decrease surgical blood loss.

Description : Ketorolac: A. Is a nonsteroidal anti-inflammatory drug (NSAID) approved for intravenous, intramuscular, and oral administration. B. Can be used indefinitely for postoperative analgesia. C. Can cause renal dysfunction. D. May decrease surgical blood loss.

Last Answer : Answer: AC DISCUSSION: Ketorolac tromethamine, an NSAID, is approved by the FDA for intravenous, intramuscular, and oral administration. The agent is an effective analgesic with minimal side ... Additionally, it is recommended that ketorolac should not be used for more than 5 consecutive days

The use of prophylactic antibiotics has become commonplace. Which of the following statement(s) is/are true concerning the prophylactic use of antibiotics? a. The appropriate use of prophylactic antibiotics must include the initiation of the agent prior to the surgical procedure b. Continuing the antibiotic into the postoperative period has led to improved results in antibiotic prophylaxis c. The prophylactic administration of broad-spectrum agents (third-generation cephalosporins) has been shown to be particularly advantageous d. The topical use of antimicrobial agents is of no advantage in the prophylactic setting

Description : The use of prophylactic antibiotics has become commonplace. Which of the following statement(s) is/are true concerning the prophylactic use of antibiotics? a. The appropriate use of prophylactic ... d. The topical use of antimicrobial agents is of no advantage in the prophylactic setting

Last Answer : Answer: a Intravenous administration of an antibiotic is clearly indicated for patients undergoing clean contaminated operations. These antibiotics should be administered prior to surgery ... of antimicrobial agents is equivalent to the administration of intravenous antimicrobial agent antibiotics

Which of the following statement(s) is/are true concerning the neuroendocrine responses to shock? a. Sympathetic nerve endings release epinephrine which is responsible for greater than 80% of systemic vascular resistance b. Endogenous epinephrine is the primary contributor to systemic vascular resistance c. Increased pancreatic secretion of glucagon contributes to glucose intolerance associated with injury and sepsis d. The renin-angiotensin axis further augments the sympathetic-mediated vasoconstriction

Description : Which of the following statement(s) is/are true concerning the neuroendocrine responses to shock? a. Sympathetic nerve endings release epinephrine which is responsible for greater than 80% ... injury and sepsis d. The renin-angiotensin axis further augments the sympathetic-mediated vasoconstriction

Last Answer : Answer: c, d The neuroendocrine response to shock attempts to achieve restoration of effective blood volume, mobilization of metabolic substrates, and maintenance of central ... . Angiotensin II is an extremely effective vasoconstrictor that further augments sympathetic-mediated vasoconstriction

All of the following are true about neurogenic shock except: A. There is a decrease in systemic vascular resistance and an increase in venous capacitance. B. Tachycardia or bradycardia may be observed, along with hypotension. C. The use of an alpha agonist such as phenylephrine is the mainstay of treatment. D. Severe head injury, spinal cord injury, and high spinal anesthesia may all cause neurogenic shock.

Description : All of the following are true about neurogenic shock except: A. There is a decrease in systemic vascular resistance and an increase in venous capacitance. B. Tachycardia or bradycardia may be ... Severe head injury, spinal cord injury, and high spinal anesthesia may all cause neurogenic shock.

Last Answer : Answer: C DISCUSSION: Neurogenic shock occurs when severe head injury, spinal cord injury, or pharmacologic sympathetic blockade leads to sympathetic denervation and loss of vasomotor tone. ... of treatment. The use of alpha-adrenergic agonist is infrequently necessary to treat neurogenic shock

Which of the following statement(s) is/are true concerning the pulmonary response to shock? a. The acute pulmonary vascular response to shock differs markedly from that of systemic vasculature b. The pulmonary edema of ARDS occurs in the face of elevated left heart pressures c. The initial physiologic changes of ARDS involve the capillary endothelial cells and the type I pneumocyte d. Mechanisms proposed in the pathogenesis of ARDS include injury from mediators of inflammation elsewhere and from activated cellular elements e. A decrease in lung compliance may result from the loss of type I pneumocytes

Description : Which of the following statement(s) is/are true concerning the pulmonary response to shock? a. The acute pulmonary vascular response to shock differs markedly from that of systemic vasculature b. The ... elements e. A decrease in lung compliance may result from the loss of type I pneumocytes

Last Answer : Answer: c, d, e Contributing pathophysiologic processes to the pulmonary manifestations of shock include the pulmonary component of the cardiovascular response, disruption of the normal ... injury from mediators of inflammation elaborated elsewhere, and from activated cellular blood elements

Thrombolytic therapy has become a useful adjunct in the management of peripheral arterial occlusion. In this setting, direct intraarterial administration rather than intravenous has been advocated to decrease the risk of systemic bleeding. Which of the following true statement(s) concerning the use of thrombolytic agents for arterial occlusion is/are true? a. A standard technique involves infusing high-dose urokinase, 4000 units per minute for 1–2 hours, directly into the clot by a catheter embedded in the thrombus b. If progress is made, further fibrinolytic therapy is given at 1000 to 2000 units per minute until clot lysis has occurred c. The usual infusion time by the above-stated technique is usually in excess of 24 hours d. Successful clot lysis occurs more frequently in arterial graf

Description : Thrombolytic therapy has become a useful adjunct in the management of peripheral arterial occlusion. In this setting, direct intraarterial administration rather than intravenous has been advocated ... may be indicated for situations where complete clot evacuation cannot be accomplished surgically

Last Answer : Answer: a, b, e The most popular method for intraarterial thrombolytic therapy for arterial occlusion involves passing a guidewire through the thrombus with arteriographic guidance and ... acute arterial occlusion) or when distal vasculative is occluded and precludes appropriate inflow patency

A 35 year old male presents with weakness and tiredness. He is noted to be hyertensive. Electrolytes show a hypokalaemia and a hypomagnesaemia. What investigation would you select for this patient? 1) Colonoscopy 2) Plasma renin toaldosterone ratio 3) Serum amylase 4) Serum calcium 5) Oral glucose tolerance test

Description : A 35 year old male presents with weakness and tiredness. He is noted to be hyertensive. Electrolytes show a hypokalaemia and a hypomagnesaemia. What investigation would you select for this patient? ... Plasma renin toaldosterone ratio 3) Serum amylase 4) Serum calcium 5) Oral glucose tolerance test

Last Answer : Answers-2 The hypokalaemic hypertension with hypomagnesaemia suggests primary hyperaldosteronism. The most reliable assessment for this would be renin to aldosterone ratio.

A major problem in nutritional support is identifying patients at risk. Recent studies suggest that these patients can be identified. Which of the following findings identify the patient at risk? A. Weight loss of greater than 10% over 2 to 4 months. B. Serum albumin of less than 3 gm. per 100 ml. in the hydrated state. C. Malnutrition as identified by global assessment. D. Serum transferrin of less than 220 mg. per 100 ml. E. Functional impairment by history.

Description : A major problem in nutritional support is identifying patients at risk. Recent studies suggest that these patients can be identified. Which of the following findings identify the patient at risk? A. Weight ... transferrin of less than 220 mg. per 100 ml. E. Functional impairment by history.

Last Answer : Answer: ABCDE DISCUSSION: All of these are at least partially correct. It is not clear whether weight loss of 10% or 15% is the required threshold, but it certainly is close. Serum ... the hands of an experienced observer is quite a reasonable way of approaching and identifying patients at risk

Which of the following statements concerning perioperative nutrition is true concerning the above-described patient? a. Since the patient’s weight had been stable with no preoperative nutritional deficit, 5% dextrose intravenous solutions are adequate for the initial postoperative source of nutrition b. Preoperative immunologic status should be determined including total peripheral lymphocyte count and delayed hypersensitivity reaction to determine skin-test response to common antigens c. Routine postoperative fluid administration with intravenous 5% glucose solutions can provide the calories to meet basal energy requirements d. A jejunal feeding catheter should be placed at the time of surgery for postoperative enteral feeding

Description : Which of the following statements concerning perioperative nutrition is true concerning the above-described patient? a. Since the patient's weight had been stable with no preoperative nutritional deficit ... feeding catheter should be placed at the time of surgery for postoperative enteral feeding

Last Answer : Answer: a Most patients undergoing elective operations are adequately nourished. Unless the patient has suffered significant preoperative malnutrition, characterized by weight loss greater than ... gastrointestinal surgery, this technique would not appear indicated in the patient described above

Which of the following statements are true of a patient with hyperglycemia and hyponatremia? A. The sodium concentration must be corrected by 5 mEq. per 100 mg. per 100 ml. elevation in blood glucose. B. With normal renal function, this patient is likely to be volume overloaded. C. Proper fluid therapy would be unlikely to include potassium administration. D. Insulin administration will increase the potassium content of cells. E. Early in treatment adequate urine output is a reliable measure of adequate volume resuscitation.

Description : Which of the following statements are true of a patient with hyperglycemia and hyponatremia? A. The sodium concentration must be corrected by 5 mEq. per 100 mg. per 100 ml. elevation in blood ... . E. Early in treatment adequate urine output is a reliable measure of adequate volume resuscitation.

Last Answer : Answer: D DISCUSSION: Each 100-mg. per 100 ml. elevation in blood glucose causes a fall in serum sodium concentration of approximately 2 mEq. per liter. Excess serum glucose ... correction of the patient's associated acidosis produce movement of potassium ions into the intracellular compartment

The transport of proteins out of the cell is termed exocytosis. Which of the following statement(s) is/are true concerning this process? a. Secretory vesicles fuse with the plasma membrane b. The process can occur in either a constitutive or regulated process c. A regulated secretion is triggered by a stimulus, most likely a hormone or a neurotransmitter d. A decrease in cytoplasmic calcium occurs as part of the secretion process

Description : The transport of proteins out of the cell is termed exocytosis. Which of the following statement(s) is/are true concerning this process? a. Secretory vesicles fuse with the plasma membrane b. ... or a neurotransmitter d. A decrease in cytoplasmic calcium occurs as part of the secretion process

Last Answer : Answer: a, b, c Transport vesicles that bud off the Golgi network carry both material to be secreted from the cell and protein destined to become components of the plasma ... but may also involve generation of diacylglycerol or production of cyclic AMP which activate kinases or phosphatases

Which of the following statement(s) is/are true concerning cellular ion channels? a. Ion channels are transmembrane proteins that form pores that can conduct ions across the plasma membrane b. Ion channels are formed by membrane-spanning peptides that are arranged so that polar moieties line a central core c. Ion channel proteins undergo conformational changes between open states and closed states d. Ion channels can be blocked

Description : Which of the following statement(s) is/are true concerning cellular ion channels? a. Ion channels are transmembrane proteins that form pores that can conduct ions across the plasma membrane b. ... undergo conformational changes between open states and closed states d. Ion channels can be blocked

Last Answer : Answer: a, b, c, d Ion channels are transmembrane proteins that form pores that can conduct ions across the plasma membrane. Ion channels are formed by membrane-spanning peptides that are arranged ... be blocked by ions or organic compounds that enter the channel, bind there, and occlude the pore

A striking feature of living cells is a marked difference between the composition of the cytosol and the extracellular milieu. Which of the following statement(s) concerning the mechanisms of maintenance of these differences is/are true? a. The cell membrane is able to maintain a 10,000 fold gradient between the extracellular concentration of ionized calcium and the intracellular concentration b. The key to these differences is the fact that the plasma membrane is normally impermeable to sodium, potassium and calcium c. The selectivity of biologic membranes is highly consistent and seldom changes d. The selectivity of cell membranes relates only to ions and not organic compounds

Description : A striking feature of living cells is a marked difference between the composition of the cytosol and the extracellular milieu. Which of the following statement(s) concerning the mechanisms of maintenance ... d. The selectivity of cell membranes relates only to ions and not organic compounds

Last Answer : Answer: a The survival of the cell requires that cytosolic composition be maintained within narrow limits, despite the constant influx of nutrients and the simultaneous outflow of waste. A ... be altered drastically as a result of regulatory or signaling processes that occur within the cell