The first line of host defense is the barrier presented to the external environment. Which of the following statement(s) is/are true concerning host barriers? a. Sebaceous glands secrete chemical compounds that maintain a relatively high pH, providing effective bacterial stasis b. Within the respiratory tract, ciliary function serves to extrude microorganisms trapped within the mucus secretion layer c. The low pH within the stomach markedly decreases bacterial content of the upper gastrointestinal tract d. Gut peristalsis serves to prevent microbial adherence and invasion

The first line of host defense is the barrier presented to the external environment. Which of the following statement(s) is/are true concerning host barriers? a. Sebaceous glands secrete chemical compounds that maintain a relatively high pH, providing effective bacterial stasis b. Within the respiratory tract, ciliary function serves to extrude microorganisms trapped within the mucus secretion layer c. The low pH within the stomach markedly decreases bacterial content of the upper gastrointestinal tract d. Gut peristalsis serves to prevent microbial adherence and invasion
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Answer: b, c, d  The skin, mucus membranes, and epithelial layers of various organs of the body constitute effective physical barriers against microbial invasion. In certain portions of the body, these barriers have developed ancillary adaptations to increase the effectiveness of the barrier functions. Skin structures such as sebaceous glands secrete chemical compounds that serve to maintain a relatively low pH, providing effective bacterial stasis. Mucus secretion by specialized glands within the bronchi and gut provide a mucus layer that represents a physical and chemical barrier to microbial invasion. Within the respiratory tract, ciliary function serves to extrude microorganisms trapped within this mucus layer. In the alimentary track, the very low pH within the stomach and gut peristalsis both serve to prevent microbial adherence and invasion
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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) concerning the gut microflora is/are correct? a. Gut microflora evolves constantly throughout development b. The gut microflora can contribute to the physical and chemical barriers at the mucus membrane level c. Most of the microorganisms found in the oropharynx eventually pass into the intestine d. In the colon, anaerobic organisms outnumber aerobic organisms in a ratio in excess of 100:1

Description : Which of the following statement(s) concerning the gut microflora is/are correct? a. Gut microflora evolves constantly throughout development b. The gut microflora can contribute to the physical and ... the colon, anaerobic organisms outnumber aerobic organisms in a ratio in excess of 100:1

Last Answer : Answer: b, d The composition of the gut microflora is established in neonates after ingestion of microbes that are acquired during contamination from the birth canal and during initial feeding, and ... small number of aerobes are present, these microbes being outnumbered 100-300 to 1 by anaerobes

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

The following statement(s) is/are true concerning cellular defense mechanisms. a. Macrophages function solely as antigen processing cells in the initial reaction to exposure to an antigen b. Macrophages may become activated and secrete cytokines c. Macrophages serve as phagocytic cells in the tissues but not within the bloodstream d. Polymorphonucleocytes (PMNS) are normally present in only small numbers within the tissue and enter an area of infection through diapedesis

Description : The following statement(s) is/are true concerning cellular defense mechanisms. a. Macrophages function solely as antigen processing cells in the initial reaction to exposure to an antigen b. Macrophages ... in only small numbers within the tissue and enter an area of infection through diapedesis

Last Answer : Answer: b, d A wide variety of cell types serve to provide host defense at several levels. Macrophages act as the initial antigen processing cell that serves to ... through diapedesis after chemotactic stimuli are excluded by macrophages, bacterial breakdown products, and complement activation

Although TPN has major beneficial effects to the patient and specific organ systems, TPN has a downside which is related to intestinal disuse. Which of the following statement(s) is/are true concerning the effects of TPN on the GI tract? a. Patients receiving TPN have an accentuated systemic response to endotoxin challenge compared to enterally fed volunteers b. TPN can result in disruption of intestinal microflora c. In experimental models, bacterial translocation from the gut is increased d. Effects of TPN on the gut may lead to multiple organ failure

Description : Although TPN has major beneficial effects to the patient and specific organ systems, TPN has a downside which is related to intestinal disuse. Which of the following statement(s) is/are true concerning the ... from the gut is increased d. Effects of TPN on the gut may lead to multiple organ failure

Last Answer : Answer: a, b, c, d A number of studies have examined the effects of TPN on intestinal function and immunity. Although most of these studies have been done in animal models, ... the release of bacteria and/or cytokines leading to pronounced systemic responses and possibly multiple organ failure

Which of the following statement(s) is/are true concerning the effects of MOFS? a. Pulmonary dysfunction tends to arise early and may resolve within 7 to 10 days b. Unless the precipitating insult has prompted oliguric acute tubular necrosis, renal function tends to be maintained early in the course of MOFS c. Although hepatic dysfunction is common with MOFS, the GI tract plays little role in this process d. Intercurrent nosocomial infection, most commonly pulmonary, is a common complication providing a “second hit” to the patient

Description : Which of the following statement(s) is/are true concerning the effects of MOFS? a. Pulmonary dysfunction tends to arise early and may resolve within 7 to 10 days b. Unless the precipitating ... infection, most commonly pulmonary, is a common complication providing a second hit to the patient

Last Answer : Answer: a, b, d Pulmonary dysfunction typically arises early in the development of systemic inflammation and may represent mild relatively localized acute lung injury or it may be a prelude ... is marked by progressive rise in serum bilirubin levels after a latent period of several days

The following statement(s) is/are true concerning host defense mechanisms to intraabdominal infection. a. Bacterial clearance can occur via translymphatic absorption b. Phagocytic activity and bacterial killing can occur via resident phagocytic cells and an influx of PMNs c. A fibrinogen-rich inflammatory exudate is released into the peritoneal cavity, trapping large numbers of bacteria and other particulate matter d. Perforations of a bowel may be walled off but are seldom sealed by the omentum and other mobile viscera

Description : The following statement(s) is/are true concerning host defense mechanisms to intraabdominal infection. a. Bacterial clearance can occur via translymphatic absorption b. Phagocytic activity and bacterial killing can ... may be walled off but are seldom sealed by the omentum and other mobile viscera

Last Answer : Answer: a, b, c The introduction of microorganisms into the normally sterile peritoneal environment invoke several potent specialized host antimicrobial defense mechanisms. Bacterial clearance, ... the contaminated enteric contents walled off, preventing continued soilage of the peritoneal cavity

Cytokines are low-molecular-weight polypeptides exerting a wide variety of biologic effects at both local and systemic levels. Which of the following statement(s) is/are true concerning the production and actions of cytokines? a. Cytokines are produced solely by macrophages b. Cytokines act only on other cells within the same local environment c. Cytokines may have both protective and deleterious effects on the host d. Each specific cytokine is produced by a single cell type

Description : Cytokines are low-molecular-weight polypeptides exerting a wide variety of biologic effects at both local and systemic levels. Which of the following statement(s) is/are true concerning the production and ... effects on the host d. Each specific cytokine is produced by a single cell type

Last Answer : Answer: c Macrophages, endothelial cells, lymphocytes, and other cells secrete a large number of different compounds, termed cytokines, that are most probably evolved for the purpose of ... host defenses, exerting both salutatory and deleterious effects on the host, has become increasingly evident

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

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

External pneumatic compression has been advocated for the prevention of deep venous thrombosis during operative procedures. Which of the following statement(s) concerning the use of external pneumatic compression devices is/are true? a. Intermittent pneumatic compression is as effective as low-dose heparin in prevention of venous thrombosis b. These devices function by compressing the lower extremities therefore augmenting venous return c. Pneumatic compression devices may also exhibit their antithrombotic effect through stimulating local and systemic fibrinolysis d. The length of time that intermittent pneumatic compression should be used includes through the operation and for at least several days in the postoperative period

Description : External pneumatic compression has been advocated for the prevention of deep venous thrombosis during operative procedures. Which of the following statement(s) concerning the use of external pneumatic ... includes through the operation and for at least several days in the postoperative period

Last Answer : Answer: b, c, d In many well-controlled studies of venous prophylaxis, intermittent pneumatic compression has been found to be as effective as low-dose heparin therapy. In addition to augmentation ... be used through the operation and for at least five days in the face or prolonged immobilization

Which of the following is/are true concerning wound fibroblasts? A. Fibroblasts synthesize and secrete collagen molecules. B. Wound fibroblasts are derived from blood-borne precursor cells. C. Fibroblasts migrate to a wound along fibrin strands, which are used as a scaffold. D. Large amounts of fibrin or blood clot can act as a physical barrier to fibroblast penetration, which delays normal wound healing.

Description : Which of the following is/are true concerning wound fibroblasts? A. Fibroblasts synthesize and secrete collagen molecules. B. Wound fibroblasts are derived from blood-borne precursor cells. C. ... clot can act as a physical barrier to fibroblast penetration, which delays normal wound healing.

Last Answer : Answer: ACD DISCUSSION: Fibroblasts appear in the wound on about the third day of healing and begin to synthesize and secrete collagen molecules. Wound fibroblasts arrive from cells surrounding ... enzymes, and large amounts of fibrin and blood clot prevent fibroblasts from entering the wound

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

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

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 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

Reconstitution of the epithelial barrier (epithelialization) begins within hours of the initial injury. Which of the following statement(s) is/are true concerning the process of epithelialization? a. Bacteria, protein exudate, and necrotic tissue all will compromise this process b. Epithelial cells exhibit contact proliferation c. Epithelialization occurs only from the margins of the wound d. Visible scarring can occur only when the injury extends deeper than the superficial dermis

Description : Reconstitution of the epithelial barrier (epithelialization) begins within hours of the initial injury. Which of the following statement(s) is/are true concerning the process of epithelialization? a. ... d. Visible scarring can occur only when the injury extends deeper than the superficial dermis

Last Answer : Answer: a, d The initial step of epithelialization involves epithelial cells from the basal layer of the wound edge flattening and migrating across the wound, completing wound coverage within 24- ... abrasions and burns may scar significantly. Whenever the dermis is incised, a scar will form

Which of the following statements concerning monitoring techniques in the intensive care unit are true? A. Pulmonary artery and pulmonary capillary wedge pressure readings should be made at end inspiration, to minimize ventilatory artifacts. B. Continuous SvO 2 monitoring based on the technique of reflectance spectrophotometry has been shown to be accurate and reliable. C. Direct measurement of gastric intramucosal pH can be provided by gastrointestinal tonometry. D. Hyperlactatemia may be seen in a number of clinical conditions not associated with tissue hypoxia, including liver disease and hypermetabolic states.

Description : Which of the following statements concerning monitoring techniques in the intensive care unit are true? A. Pulmonary artery and pulmonary capillary wedge pressure readings should be made ... clinical conditions not associated with tissue hypoxia, including liver disease and hypermetabolic states.

Last Answer : Answer: BD DISCUSSION: Many different monitoring techniques may be used to assess the adequacy of therapy for shock. The pulmonary artery catheter can provide important hemodynamic and oxygen ... also be seen with liver disease, toxin ingestion, and hypermetabolic states not associated with shock

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

New treatment modalities designed to modulate host defense mechanisms that have been demonstrated conclusively to be of benefit include: a. Gut decontamination b. Anti-LPS antibody c. Anti-TNF antibody d. Thymopentin e. None of the above

Description : New treatment modalities designed to modulate host defense mechanisms that have been demonstrated conclusively to be of benefit include: a. Gut decontamination b. Anti-LPS antibody c. Anti-TNF antibody d. Thymopentin e. None of the above

Last Answer : Answer: e Selective gut decontamination involves the use of orally administered antibiotics that achieve a high intraluminal level directed against gram-negative aerobes and yeast, leaving ... but conclusive evidence that concurrent reduction of infection-related mortality occurs is not available

The following statement(s) is/are true concerning newer detection methods of systemic infection. a. Enzyme-linked immunosorbent assay (ELISA) is a rapid immunologic assay used for both antigen and antibody detection b. Southern, northern, and western immunoblot techniques are used to detect DNA, RNA, or proteins, respectively c. Polymerase chain reaction (PCR) is a sensitive assay used to detect small amounts of microbial DNA, thus detecting infection at its early stages d. Infectious agents currently detected using advanced molecular techniques include cytomegalovirus (CMV) and human immunodeficiency virus (HIV)

Description : The following statement(s) is/are true concerning newer detection methods of systemic infection. a. Enzyme-linked immunosorbent assay (ELISA) is a rapid immunologic assay used for ... detected using advanced molecular techniques include cytomegalovirus (CMV) and human immunodeficiency virus (HIV)

Last Answer : Answer: a, b, c, d Although the classic detection of infection based on clinical signs of infection and bacterial culture remain the most common clinical tools, increasing ... including CMV and HIV. Furthermore, preliminary investigations into possible detection of fungal pathogens are underway

There are a multitude of various dressings available. Which of the following statement(s) is/are true concerning options for surgical dressings? a. Hydrocolloids, such as karaya compounds, offer the primary advantage of increased absorptive ability b. Films, such as Op-site, provide a water impermeable environment to achieve a dry wound c. Impregnates are fine gauze impregnated with a variety of substances such as antibiotics or moisturizing agents that adhere tightly to the wound and do not require a secondary dressing d. Absorptive powders and paste are highly useful in debriding necrotic and fibrous material from wounds and absorbing wound serum

Description : There are a multitude of various dressings available. Which of the following statement(s) is/are true concerning options for surgical dressings? a. Hydrocolloids, such as karaya compounds, offer ... are highly useful in debriding necrotic and fibrous material from wounds and absorbing wound serum

Last Answer : Answer: a, d Although the simplest dressing of gauze and tape combined with the use of antibacterial ointment can achieve moist wound healing in most patients. A multitude of other ... agents have high absorbency for tissue wound fluid and debride necrotic and fibrous material from the wound

Which of the following statement(s) is/are true concerning the treatment of MOFS? a. Prevention and therapy of MOFS requires control of the infectious or inflammatory source b. Restoration of normal clinical parameters such as blood pressure, pulse rate, and urine output ensures optimal resuscitation in most patients c. Branch chain amino acids play and important role in the nutritional support of the patient d. Because of the nature of gut injury, total parenteral nutrition is preferred for most patients with MOFS

Description : Which of the following statement(s) is/are true concerning the treatment of MOFS? a. Prevention and therapy of MOFS requires control of the infectious or inflammatory source b. Restoration of normal ... of the nature of gut injury, total parenteral nutrition is preferred for most patients with MOFS

Last Answer : Answer: a, c The therapy of MOFS is directed towards interrupting the involving pathophysiologic process and providing an optimal physiologic environment for healing and recovery. ... Enteral absorption and processing of nutrients appears superior to TPN and lessens overall complications

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

A 32-year-old man suffers a spinal cord injury with a resultant paraplegia in a motorcycle accident. He presents to the emergency room with hypotension. Which of the following statement(s) is/are true concerning his diagnosis and management? a. The low blood pressure can be assumed to be due to neurogenic shock b. The sole cause of hypotension is the loss of sympathetic input to the venous system c. Despite significant hypotension, secondary organ injury will be uncommon d. There is no role for pharmacologic intervention to maintain blood pressure

Description : A 32-year-old man suffers a spinal cord injury with a resultant paraplegia in a motorcycle accident. He presents to the emergency room with hypotension. Which of the following statement(s) is/ ... injury will be uncommon d. There is no role for pharmacologic intervention to maintain blood pressure

Last Answer : Answer: c Neurogenic shock results from interruption of sympathetic vasomotor input and develops after spinal cord injury, spinal anesthesia, and severe head injury. Under normal conditions, baseline ... the cause is not neurogenic and search for occult blood loss or cardiogenic causes of shock

A 55-year-old renal transplant patient has been hospitalized in a Surgical Intensive Care Unit, receiving a prolonged course of antibiotics following an attack of acute cholecystitis. The following statement(s) is/are true concerning his management. a. Due to the potential risk of Candida infection, prophylaxis with oral nystatin should be instituted early in the patient’s course b. A Candida urinary tract infection should be treated with systemic amphotericin B c. Changes of Candida retinitis are of little significance d. The presence of a virulent Candida bacteremia should suggest a dosage reduction in immunosuppressive agents until the infection can be adequately controlled

Description : A 55-year-old renal transplant patient has been hospitalized in a Surgical Intensive Care Unit, receiving a prolonged course of antibiotics following an attack of acute cholecystitis. The ... suggest a dosage reduction in immunosuppressive agents until the infection can be adequately controlled

Last Answer : Answer: a, d Infections due to fungal pathogens have become increasingly common during the past decade, frequently occurring in patients undergoing prolonged hospitalization in the Surgical ... agents should be discontinued until evidence of infection is absolutely controlled or is eradicated

Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of the following statement(s) is/are true concerning intracellular receptors? a. The messengers or hormones must by lipophilic b. These intracellular receptors generally regulate protein synthesis c. The intracellular receptors are located entirely in the nucleus of the cell d. A heat-shock protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor

Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor

Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein

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

Which of the following statement(s) is/are true concerning oxygen kinetics in a critically ill, febrile patient? a. Oxygen consumption will likely exceed three times normal b. The high cardiac output and pulse rate are designed to increase oxygen delivery c. The hyperdynamic response may actually increase oxygen delivery to exceed the increase in oxygen consumption d. The patient can maintain adequate compensation as long as the oxygen delivery/oxygen consumption rate is greater than 2:1

Description : Which of the following statement(s) is/are true concerning oxygen kinetics in a critically ill, febrile patient? a. Oxygen consumption will likely exceed three times normal b. The high cardiac ... adequate compensation as long as the oxygen delivery/oxygen consumption rate is greater than 2:1

Last Answer : Answer: b, d In critically ill patients oxygen consumption may be elevated or depressed, but slight to moderate elevations in oxygen consumption is the most common abnormality in critically ill patients. ... however, and the patient will remain stable as long as the ratio is greater than 2:1

Which of the following statement(s) is/are true concerning the results of a National Institute of Health Consensus Conference on venous thrombosis and low-dose heparin prophylaxis? a. The odds of developing deep venous thrombosis with low-dose heparin prophylaxis decreases by 67% b. The risk of pulmonary embolism is decreased by almost 50% c. There is no increase in mortality from other causes found in patients treated with low-dose heparin d. There was no difference in the incidence of bleeding complications

Description : Which of the following statement(s) is/are true concerning the results of a National Institute of Health Consensus Conference on venous thrombosis and low-dose heparin prophylaxis? a. The odds of ... treated with low-dose heparin d. There was no difference in the incidence of bleeding complications

Last Answer : Answer: a, b, c In a metaanalysis of 70 randomized trials in 16,000 patients comparing low-dose heparin prophylaxis with standard therapy, the odds of developing deep venous thrombosis ... Similarly, the effectiveness of prophylaxis was not influenced by either two or three times daily dosage

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

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

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

Antibacterial agents can be classified with regard to their structure, mechanism of action, and activity pattern against various types of bacterial pathogens. Which of the following statement(s) is/are true concerning antimicrobial classes? a. Penicillins and cephalosporins share the compound structure of a b-lactam ring which binds to bacterial division plate proteins b. Tetracyclines and macrolides such as erythromycin inhibit bacterial ribosomal activity and therefore protein synthesis c. Aminoglycosides act in a similar fashion to tetracyclines and therefore are both bacteriostatic d. Sulfonamides and trimethoprim act synergistically to inhibit purine synthesis

Description : Antibacterial agents can be classified with regard to their structure, mechanism of action, and activity pattern against various types of bacterial pathogens. Which of the following ... are both bacteriostatic d. Sulfonamides and trimethoprim act synergistically to inhibit purine synthesis

Last Answer : Answer: a, b, d Penicillins, cephalosporins, and monobactams possess a b-lactam ring of some type and act to bind bacterial division plate proteins, thus inhibiting cell wall ... act in different mechanisms to inhibit protein synthesis, therefore two agents in combination act synergistically

Wounds are classified according to the likelihood of bacterial contamination. Which of the following statement(s) is/are true concerning wound classifications? a. A clean-contaminated wound would be that associated with an elective colon resection with adequate mechanical and antibiotic bowel preparation b. A contaminated wound would include a resection of obstructed bowel with gross spillage of intestinal contents c. In a clean wound, no viscus is entered d. Antibiotic prophylaxis should be administered for all clean-contaminated and contaminated wounds and selectively in patients involving a clean wound

Description : Wounds are classified according to the likelihood of bacterial contamination. Which of the following statement(s) is/are true concerning wound classifications? a. A clean-contaminated wound would ... all clean-contaminated and contaminated wounds and selectively in patients involving a clean wound

Last Answer : Answer: a, b, c, d Wounds are classified under three classes according to the likelihood of bacterial contamination: 1) clean (no viscus is entered; e.g., herniorrhaphy); 2) clean- ... tenet involves cases in which a prosthetic material may be used (artificial joint, heart valve, tissue patch)

Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results in selective thrombolysis at the fibrin clot surface. Which of the following statement(s) is/are true concerning agents used in thrombolytic therapy? a. Streptokinase is a bacterial protein which is antigenic in humans, resulting in allergic reactions in up to l5% of cases b. Tissue plasminogen activator acts directly on plasmin without an intermediate drug–plasmin complex c. The half-life of urokinase, streptokinase, and TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA

Description : Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results ... TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA

Last Answer : Answer: a, b, d Streptokinase is a bacterial protein produced by group C b-hemolytic streptococci. It is therefore antigenic in humans and can be associated with allergic reaction in ... one agent over the other. Streptokinase however, is markedly less expensive than either urokinase or TPA

Which of the following statement(s) is/are true concerning the role of antibiotics in wound care? a. Systemic antibiotics are indicated for all open wounds b. Bacterial resistance can occur with systemic but not topical antibiotics c. An indication for systemic antibiotic administration is a granulation tissue bacterial count in excess of greater than 105 organisms/gram of tissue on quantitative analysis d. Silver sulfadiazine is useful only for the management of burns

Description : Which of the following statement(s) is/are true concerning the role of antibiotics in wound care? a. Systemic antibiotics are indicated for all open wounds b. Bacterial resistance can occur with ... of tissue on quantitative analysis d. Silver sulfadiazine is useful only for the management of burns

Last Answer : Answer: c The role of antibiotics in wound care is controversial. All open wounds are colonized with bacteria. Only when surrounding tissue is invaded (cellulitis) are systemic antibiotics clearly ... of relevant drug-resistant plasmids in bacteria, and its low cost make it a good choice

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

There are two properties of the cell necessary to maintain nonequilibrium cellular composition; the first is selectivity and the second is energy conversion. Which of the following statement(s) is/are true concerning energy converting transport? a. The site of energy conversion and transport in the plasma membrane involves the phospholipid component b. The Na+-K++-ATPase derives energy from hydrolysis of extracellular ATP c. In some systems, energy inherent in the transmembrane ion gradient can be used to drive transport of a second species d. Examples of species transported via secondary active transport include hydrogen ions, calcium, amino acids and glucose

Description : There are two properties of the cell necessary to maintain nonequilibrium cellular composition; the first is selectivity and the second is energy conversion. Which of the following statement(s ... transported via secondary active transport include hydrogen ions, calcium, amino acids and glucose

Last Answer : Answer: c, d The selectivity of the plasma membrane, although impressive, cannot account for the nonequilibrium composition of living cells. A cell can be maintained in a nonequilibrium state only by ... to drive the transport of a second species such as protons, calcium, amino acids, or glucose

Which of the following statement(s) is/are true concerning the relationship between cardiac function and effective blood volume? a. A pulmonary capillary wedge pressure of 5–10 rules out fluid overload as a cause of pulmonary edema b. A shift to the right in the Frank-Starling curve is associated with compromised cardiac function c. Dilutional anemia may contribute to tachycardia even though blood volume and filling pressures are normal d. The sole purpose of a pulmonary artery catheter is to measure pulmonary artery pressure and cardiac output

Description : Which of the following statement(s) is/are true concerning the relationship between cardiac function and effective blood volume? a. A pulmonary capillary wedge pressure of 5-10 rules out ... sole purpose of a pulmonary artery catheter is to measure pulmonary artery pressure and cardiac output

Last Answer : Answer: b, c Although physical findings are often adequate to establish a diagnosis and institute management of cardiac failure, direct measurement of filling pressures of the right heart ( ... blood volume is normal, filling pressures are normal, and total body extracellular fluid is excessive

Platelets have a wide array of functions in inflammation. Which of the following are among these? a. Synthesis and release of vasoactive eicosanoids b. Release of chemotactic factors c. Adherence to and coating of bacterial and tumor cells d. Increase of vascular permeability e. Phagocytosis of bacteria

Description : Platelets have a wide array of functions in inflammation. Which of the following are among these? a. Synthesis and release of vasoactive eicosanoids b. Release of chemotactic factors c. ... coating of bacterial and tumor cells d. Increase of vascular permeability e. Phagocytosis of bacteria

Last Answer : Answer: a, b, c, d Platelets are anucleated cells derived from megakaryocytes in the bone marrow. Their central role in hemostasis is well known. Platelets possess a wide ... primitive precursor inflammatory cell. Platelets serve primarily as an amplifier or modulator of the inflammatory response

Which of the following statement(s) is/are true concerning the autoregulation necessary to maintain oxygen consumption and oxygen delivery? a. A change in oxygen consumption is followed by a proportionate change in oxygen delivery b. A change in oxygen delivery is followed by a change in oxygen consumption c. Increases in oxygen delivery are due solely to an increase in cardiac output d. The normal ratio of oxygen delivery to consumption is 2:1

Description : Which of the following statement(s) is/are true concerning the autoregulation necessary to maintain oxygen consumption and oxygen delivery? a. A change in oxygen consumption is followed by a proportionate ... increase in cardiac output d. The normal ratio of oxygen delivery to consumption is 2:1

Last Answer : Answer: a The relationships between oxygen consumption and oxygen delivery represent one of the most interesting regulation systems in homeostasis. First of all, if one of the three components ... in oxygen consumption. The normal ratio of oxygen delivery to consumption is approximately 5:1

Which of the following statement(s) is/are true concerning water movement across cell membranes? a. Water moves only actively through cell membrane transport proteins b. For most cells of the body, the transmembrane hydrostatic pressure is 0 c. Water distribution is determined entirely by solute distribution d. Specialized cells such as the glomerulus of the kidney actively transport water to maintain hydrostatic pressure

Description : Which of the following statement(s) is/are true concerning water movement across cell membranes? a. Water moves only actively through cell membrane transport proteins b. For most cells of ... cells such as the glomerulus of the kidney actively transport water to maintain hydrostatic pressure

Last Answer : Answer: b, c The energetics of water transport across cell membranes is simplified by the fact that water moves only passively due to gradients of hydrostatic pressure or water ... water is distributed at equilibrium. Water distribution is determined entirely by solute to solute distribution

Which of the following statement(s) is/are true concerning the cell plasma membrane? a. The plasma membrane is composed of amphipathic molecules b. The hydrophobic core of the lipid bilayer of the cell membrane contains specialized transport proteins which maintain the intracellular ionic milieu different from the extracellular fluid c. Plasma membrane proteins extend externally and bear phospholipid moieties which contribute to the cell coat d. The membrane proteins of nerve cells are highly voltage-dependent

Description : Which of the following statement(s) is/are true concerning the cell plasma membrane? a. The plasma membrane is composed of amphipathic molecules b. The hydrophobic core of the lipid bilayer of the ... contribute to the cell coat d. The membrane proteins of nerve cells are highly voltage-dependent

Last Answer : Answer: a, b, d The plasma membrane defines the boundary of the cell and serves to contain and concentrate enzymes and other macromolecule constituents. The plasma membrane is ... and bear carbohydrate moieties primarily as oligosaccharide chains that contribute to the cell coat or glycocalyx

Which of the following statements is not correct? (a) Oxyntic cells are present in the mucosa of stomach and secrete HCl. (b) Acini are present in the pancreas and secrete carboxypeptidase. (c) Brunner’s glands are present in the submucosa of stomach and secrete pepsinogen. (d) Goblet cells are present in the mucosa of intestine and secrete mucus

Description : Which of the following statements is not correct? (a) Oxyntic cells are present in the mucosa of stomach and secrete HCl. (b) Acini are present in the pancreas and secrete carboxypeptidase. (c ... and secrete pepsinogen. (d) Goblet cells are present in the mucosa of intestine and secrete mucus

Last Answer : (c) Brunner’s glands are present in the submucosa of stomach and secrete pepsinogen.

A 17-year-old patient involved in an automobile accident is paralyzed with multiple peripheral extremity injuries. Nutritional support is instituted with a transnasal feeding catheter. Which of the following statement(s) is/are true concerning the patient’s management? a. Feeding into the stomach results in stimulation of the biliary/pancreatic axis which is probably trophic for small bowel b. Gastric secretions will dilute the feedings increasing the risk of diarrhea c. The major risk in this patient is tracheobronchial aspiration d. Placement of the feeding catheter through the pylorus into the first portion of the duodenum reduces the risk of regurgitation and aspiration

Description : A 17-year-old patient involved in an automobile accident is paralyzed with multiple peripheral extremity injuries. Nutritional support is instituted with a transnasal feeding catheter. Which of the ... pylorus into the first portion of the duodenum reduces the risk of regurgitation and aspiration

Last Answer : Answer: a, c, d The use of transnasal feeding catheters for intragastric feeding or for duodenal intubation are popular adjuncts for providing nutritional support by the enteral route. The ... the fourth portion of the duodenum reduces the risk of regurgitation and aspiration of feeding formulas

The best understood intracellular messenger is cyclic AMP (cAMP). Which of the following statement(s) concerning this intracellular messenger is/are correct? a. Intracellular cyclic AMP is constantly degraded by a specific enzyme, cAMP phosphodiesterase b. Most of the actions of cAMP are mediated by activation of protein kinase A c. Intracellular levels of cAMP are relatively stable and change solely in response to activation of adenylate cyclase d. cAMP is the only cyclic nucleotide active as an intracellular messenger

Description : The best understood intracellular messenger is cyclic AMP (cAMP). Which of the following statement(s) concerning this intracellular messenger is/are correct? a. Intracellular cyclic AMP is constantly ... of adenylate cyclase d. cAMP is the only cyclic nucleotide active as an intracellular messenger

Last Answer : Answer: a, b The prototypic intracellular messenger is cAMP. To function as a mediator, the concentration of cAMP must change rapidly. In resting cells, cAMP is continuously being degraded by ... produce cGMP. Intracellular calcium ions also serve as second messengers in a large number of cells

The initiation of a humoral immune response involves a complex interaction of the antigen, cells and intercellular messengers. Which of the following statement(s) concerning the initiation of the humoral immune response is/are correct? a. Helper T lymphocytes stimulate B lymphocytes through secretion of cytokines such as interleukin 4 and 6 b. A number of cells can aid in presenting the antigen to the helper T cell including B lymphocytes and macrophages c. All antigens require coordinated efforts of the various cellular components of the immune system d. An antigen must be a living microorganism

Description : The initiation of a humoral immune response involves a complex interaction of the antigen, cells and intercellular messengers. Which of the following statement(s) concerning the initiation of the ... various cellular components of the immune system d. An antigen must be a living microorganism

Last Answer : Answer: a, b Stimulation of the immune system occurs after a variety of antigen-presenting cells (B lymphocytes, macrophages, dendritic cells, and Langerhans cells) act to engulf ... polysaccharides), most antigens require coordinated efforts of the various cellular components of the immune system

Which of the following statement(s) concerning intravenous nutritional support is/are true? a. Concentrations of glucose no higher than 5% should be used to avoid peripheral vein sclerosis b. A major disadvantage of the peripheral technique is limited caloric delivery c. If total parenteral nutrition is required, access to the superior vena cava via the external jugular vein is the most suitable site d. Venous thrombosis is an uncommon complication for long-term central vein catheterization

Description : Which of the following statement(s) concerning intravenous nutritional support is/are true? a. Concentrations of glucose no higher than 5% should be used to avoid peripheral vein sclerosis ... suitable site d. Venous thrombosis is an uncommon complication for long-term central vein catheterization

Last Answer : Answer: b Although peripheral access can be used for intravenous nutrition, the major disadvantage of this technique is limited caloric delivery to meet catabolic demands within tolerated fluid ... studies that use phlebography or radionucleotide venography indicate the incidence is as high as 35%

Anticancer drugs weaken host defence by: A. Damaging respiratory and gut epithelia B. Inducing granulocytopenia C. Altering resident microbial flora D. Both 'A' and 'B' are correct

Description : Anticancer drugs weaken host defence by: A. Damaging respiratory and gut epithelia B. Inducing granulocytopenia C. Altering resident microbial flora D. Both 'A' and 'B' are correct

Last Answer : D. Both 'A' and 'B' are correct