Which of the following substances, not normally present in the circulation, trigger the initiating events in the hemostatic process? a. Thrombin b. Platelet factor 3 c. Tissue factor d. Collagen

Which of the following substances, not normally present in the circulation, trigger the initiating events in the hemostatic process? a. Thrombin b. Platelet factor 3 c. Tissue factor d. Collagen
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Answer: c, d  The initiating agents for hemostasis involve two substances that are not normally present in the circulation—collagen and tissue factor. Tissue factor is released from injured cells, beginning the activation of the extrinsic pathway of coagulation, while disruption of the protective endothelial barrier of blood vessels exposes the underlying collagen to the activation of platelets. In the bloodstream, tissue factor complexes with factor VII which then activates factor X to factor Xa. At the same time, activated platelets change from their discoid shape with their procoagulant phospholipid (termed platelet factor 3) buried on the inner side of the surface membrane to a spreading shape to allow for the externalization of platelet factor 3 activity. Activated factor X, activated factor V, ionized calcium and factor II (prothrombin) then assemble on the platelet phospholipid surface to form the so-called prothrombinase complex which catalyzes the formation of thrombin
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Hemostasis and the cessation of bleeding require which of the following processes? A. Adherence of platelets to exposed subendothelial glycoproteins and collagen with subsequent aggregation of platelets and formation of a hemostatic plug. B. Interaction of tissue factor with factor VII circulating in the plasma. C. The production of thrombin via the coagulation cascade with conversion of fibrinogen to fibrin. D. Cross-linking of fibrin by factor XIII.

Description : Hemostasis and the cessation of bleeding require which of the following processes? A. Adherence of platelets to exposed subendothelial glycoproteins and collagen with subsequent aggregation of platelets and ... conversion of fibrinogen to fibrin. D. Cross-linking of fibrin by factor XIII.

Last Answer : Answer: ABCD DISCUSSION: Hemostasis requires the interaction of platelets with the exposed subendothelial structures at the site of injury followed by aggregation of more platelets in that area. ... form a stable clot that incorporates the platelet plug and fibrin thrombus into a stable clot

Which of the following statement(s) is/are true concerning hemophilia A? a. Hemophilia A is inherited as a sex-linked recessive deficiency of factor VIII b. A positive family history for bleeding disorders present in all patients c. Laboratory tests reveal a prolongation of aPTT, prothrombin time (PT), thrombin clotting time and platelet aggregation d. Spontaneous bleeding is unusual with factor VIII levels greater than 10% of normal

Description : Which of the following statement(s) is/are true concerning hemophilia A? a. Hemophilia A is inherited as a sex-linked recessive deficiency of factor VIII b. A positive family history for ... platelet aggregation d. Spontaneous bleeding is unusual with factor VIII levels greater than 10% of normal

Last Answer : Answer: a, d Hemophilia A is inherited as a sex-linked recessive deficiency of factor VIII although 0% of cases are secondary to spontaneous mutation. The incidence of this abnormality is ... factor levels as low as 1% have been noted and patients are at risk for spontaneous bleeding

Laboratory monitoring of coagulation and anticoagulation includes testing of platelet function. Which of the following statements is/are true concerning tests of platelet function? a. A platelet count of 50,000/µL or more usually ensures hemostasis b. Bleeding time assays assessibility of platelets to perform hemostatic plugs and is determined from a sample of blood drawn in an EDTA coated test tube c. Aspirin therapy can be associated with a bleeding time in the range of 8–15 minutes d. Tests of platelet aggregation should be part of the standard preoperative evaluation of patients using aspirin

Description : Laboratory monitoring of coagulation and anticoagulation includes testing of platelet function. Which of the following statements is/are true concerning tests of platelet function? a. A ... platelet aggregation should be part of the standard preoperative evaluation of patients using aspirin

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Which of the following statement(s) is/are true concerning pharmacologic agents used to accelerate wound healing? a. A number of these agents are now currently approved for use in this country b. PDGF (platelet-derived growth factor) promotes fibroblast proliferation, chemotaxis, and collagenase synthesis c. PDGF has been demonstrated in a number of clinical trials to promote healing in chronic wounds d. Growth hormone functions by promoting fibroblast proliferation and collagen synthesis

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Mini-dose heparin has been shown to be useful in the prophylaxis of postoperative venous thrombosis. Mechanism(s) by which low-dose heparin is/are thought to protect against venous thrombosis include: a. Enhancement of antithrombin III activity b. A decrease in thrombin availability c. Inhibition of platelet aggregation and subsequent platelet release action d. A mild prolongation of activated partial thromboplastin time

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Last Answer : Answer: a, b, c Low-dose heparin is thought to protect against venous thrombosis through three different mechanisms. First, antithrombin III activity with its inhibition of activated Factor X is ... release reaction. The standard doses of heparin administered (5000 units bid) does not affect aPTT

Which of the following statement(s) is/are correct concerning the immunoinflammatory response to shock? a. The anaphylactoxins, C3a and C5a, are products of activation of only the classical pathway of the compliment cascade b. Eicosanoids, such as prostaglandins are stored in platelets and endothelial cells and released in response to inflammatory stimuli c. Thromboxane and PGI2 have similar effects d. Platelet-activating factor can be released by both circulating and fixed tissue cells

Description : Which of the following statement(s) is/are correct concerning the immunoinflammatory response to shock? a. The anaphylactoxins, C3a and C5a, are products of activation of only the classical pathway ... effects d. Platelet-activating factor can be released by both circulating and fixed tissue cells

Last Answer : Answer: d Inflammatory mediators have recently been recognized as playing a significant role in the clinical manifestations and progression of shock and the development ... increased pulmonary vascular resistance, bronchoconstriction, peripheral vasodilatation, and increased vascular permeability

Cytokines with clearly defined actions in acute inflammation and early tissue injury include which of the following? a. Cysteine-X-Cysteine (C-X-C) chemokines b. Tumor Necrosis Factor (TNFa) c. Transforming Growth Factor-b (TGF-b) d. Interleukin-6 (IL-6) e. Platelet Derived Growth Factor (PDGF)

Description : Cytokines with clearly defined actions in acute inflammation and early tissue injury include which of the following? a. Cysteine-X-Cysteine (C-X-C) chemokines b. Tumor Necrosis Factor (TNFa) c. Transforming Growth Factor-b (TGF-b) d. Interleukin-6 (IL-6) e. Platelet Derived Growth Factor (PDGF)

Last Answer : Answer: a, b, c, d, e Polypeptide mediators, such as TNFa and IL-1, are considered early response cytokines and are actively involved in the initiation of the ... of tissue repair. Thus, coagulation and platelet activation provide the initial foundation for subsequent cellular recruitment

True statements regarding eicosanoids include which of the following? A. Prostaglandins and thromboxanes are synthesized via the cyclo-oxygenase pathway. B. The vasoconstricting, platelet-aggregating, and bronchoconstricting effects of thromboxane A 2 are balanced by the actions of prostacyclin, which produces the opposite effects. C. Leukotriene synthesis is inhibited by the action of nonsteroidal anti-inflammatory drugs (NSAIDs). D. The principal prostaglandins have a short circulation half-life and exert most of their effects locally.

Description : True statements regarding eicosanoids include which of the following? A. Prostaglandins and thromboxanes are synthesized via the cyclo-oxygenase pathway. B. The vasoconstricting, platelet-aggregating, ... prostaglandins have a short circulation half-life and exert most of their effects locally.

Last Answer : Answer: ABD DISCUSSION: The eicosanoids are a group of compounds arising from the metabolism of arachidonic acid. The prostaglandins and thromboxanes are synthesized via the cyclo-oxygenase ... effects and may be involved in the physiologic responses associated with anaphylactic and septic shock

As thrombin generation proceeds, the body has natural anticoagulant systems opposing further thrombus formation. Natural anticoagulants include: a. Tissue plasminogen activator (TPA) b. Antithrombin III c. Activated protein C d. Heparin cofactor II

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Last Answer : Answer: b, c, d Just as thrombin generation is the key to coagulation, antithrombin III is the most central anticoagulant proteins. This glycoprotein binds to thrombin, preventing its removal of ... in the body. Therefore, TPA is part of the fibrinolytic system rather than a natural anticoagulant

Fatty acids are a major energy source for the body. Which of the following statement(s) is/are true concerning the use of fatty acids as an energy source? a. Fatty acids are stored in adipocytes as triglycerides b. Hormone-sensitive lipase is present only in adipose tissue c. Fatty acids are released into the circulation traveling freely in plasma d. Approximately 25% of total nonprotein caloric needs supplied via total parenteral nutrition should be in the form of fat

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Last Answer : Answer: a, b, d In most tissues, fatty acids are readily oxidized for energy. They are especially important energy sources for the heart, liver and skeletal muscle. In ... administered to patients receiving total parenteral nutrition should comprise about 5-30% of total nonprotein caloric needs

Which of the following tissues contain significant collagen useful for placing sutures to allow the prolonged tension necessary to maintain tissue approximation? a. Dermis b. Intestinal submucosa c. Muscular fascia d. Blood vessel wall

Description : Which of the following tissues contain significant collagen useful for placing sutures to allow the prolonged tension necessary to maintain tissue approximation? a. Dermis b. Intestinal submucosa c. Muscular fascia d. Blood vessel wall

Last Answer : Answer: a, b, c, d It takes at least three weeks for collagen to undergo sufficient remodeling and cross linking to attain moderate strength. Since most skin sutures are removed at one to ... , Scarpa's fascia, and blood vessel wall represent a partial list of tissues with high collagen content

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

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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

Platelet activating factor is: a. Generated by the action of phospholipase A2 on membrane phospholipids b. Antiinflammatory in most of its actions c. Synthesized by endothelial and other cells d. Exerts a variety of biologic effects which are platelet-independent

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Last Answer : Answer: a, c, d Like the eicosanoids, platelet-activating factor (PAF) is not stored in cells but is rapidly produced during inflammation. PAF exerts a variety of biologic effects ... and LTB4. There is considerable overlap and redundancy in the effects produced by PAF and eicosanoids

Products of platelet degranulation include: a. Tumor necrosis factor b. Interleukin-1 c. Transforming growth factor b d. Platelet-derived growth factor

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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.

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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

Which of the following statements regarding fibroblasts and their function in wound healing are true? a. IL-1 has both inhibitory and promotional effects on fibroblast growth b. TNFa stimulates fibroblast collagen synthesis c. IL-1 and TNFa have opposite effects on the healing of bone d. In human clinical trials, EGF (epithelial growth factor) has been demonstrated to accelerate epidermal regeneration in cutaneous wounds

Description : Which of the following statements regarding fibroblasts and their function in wound healing are true? a. IL-1 has both inhibitory and promotional effects on fibroblast growth b. TNFa ... EGF (epithelial growth factor) has been demonstrated to accelerate epidermal regeneration in cutaneous wounds

Last Answer : Answer: a, d IL-1 appears to be important in the process of normal wound repair. IL-1 has been shown to stimulate skin fibroblast and keratinocyte growth, as well as ... that recombinant EGF enhances keratinocyte migration. EGF is also a potent chemoattractant for granulation tissue fibroblasts

Which of the following statements regarding transforming growth factor b (TGF-b) are true? a. TGF-b expression is autoregulated b. TGF-b enhances collagen synthesis c. TGF-b inhibits extracellular matrix production d. TGF-b may inhibit or promote cellular proliferation

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Last Answer : Answer: a, b, d TGF-b appears to be one of the key cytokines in control of tissue repair. TGF-b is strongly chemotactic for neutrophils, T cells, monocytes, and fibroblasts. ... TGF-b stimulates the proliferation of densely plated human marrow fibroblasts, but is inhibitory at high concentrations

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 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

Which of the following statement(s) is/are true concerning heparin-associated thrombocytopenia? a. Heparin-associated thrombocytopenia occurs only in the face of over anticoagulation with heparin b. Severe thrombocytopenia (platelet count less than 100,000) is seen in less than 10% of patients treated with heparin c. Heparin-associated thrombocytopenia is due to the aggregation of platelets and may result in thrombosis or embolic episodes d. Heparin-associated thrombocytopenia may be seen within hours of initiation of heparin therapy

Description : Which of the following statement(s) is/are true concerning heparin-associated thrombocytopenia? a. Heparin-associated thrombocytopenia occurs only in the face of over anticoagulation with heparin b. ... d. Heparin-associated thrombocytopenia may be seen within hours of initiation of heparin therapy

Last Answer : Answer: b, c Heparin-associated thrombocytopenia occurs in 0.6% to 30% of patients who receive heparin, although severe thrombocytopenia (platelet counts less than 100,000) is seen in ... as coating on pulmonary artery catheters or low rate infusion into arterial catheters may cause this syndrome

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 cell types are not crucial for healing a clean, incisional wound? A. Macrophage. B. Platelet. C. Fibroblast. D. Polymorphonuclear leukocyte. E. Myofibroblast.

Description : Which of the following cell types are not crucial for healing a clean, incisional wound? A. Macrophage. B. Platelet. C. Fibroblast. D. Polymorphonuclear leukocyte. E. Myofibroblast.

Last Answer : Answer: DE DISCUSSION: Experimental studies have shown that healing may progress normally in the absence of polymorphonuclear leukocytes in an uninfected wound. In contrast, depletion of monocytes and ... wound contraction in open defects but have little if any role in clean, incisional wounds

The evaluation of a patient scheduled for elective surgery should always include the following as tests of hemostasis and coagulation: A. History and physical examination. B. Complete blood count (CBC), including platelet count. C. Prothrombin time (PT) and activated partial thromboplastin time (APTT). D. Studies of platelet aggregation with adenosine diphosphate (ADP) and epinephrine.

Description : The evaluation of a patient scheduled for elective surgery should always include the following as tests of hemostasis and coagulation: A. History and physical examination. B. Complete blood count ( ... (APTT). D. Studies of platelet aggregation with adenosine diphosphate (ADP) and epinephrine.

Last Answer : Answer: A DISCUSSION: The evaluation of most patients scheduled for elective surgery who do not have a history of significant bleeding disorders is somewhat controversial. An adequate history and ... suspected of having qualitative defects of platelet function (e.g., von Willebrand's disease)

Which of the following statement(s) is/are true concerning the remodeling phase of wound healing? a. Total collagen content increases steadily through this phase b. The normal adult ratio of collagen is approximately 4:1 of type I to type III collagen. c. Eventually a scar will achieve the strength of unwounded skin d. The proteoglycans are responsible for the ground substance of the extracellular matrix

Description : Which of the following statement(s) is/are true concerning the remodeling phase of wound healing? a. Total collagen content increases steadily through this phase b. The normal adult ratio ... unwounded skin d. The proteoglycans are responsible for the ground substance of the extracellular matrix

Last Answer : Answer: b, d The transition from the proliferative phase to the remodeling phase of wound healing is defined by reaching collagen equilibrium. Collagen accumulation within the wound becomes maximal by ... in strength for six months or more, eventually reaching 70% of the strength of unwounded skin

Which of the following statement(s) is/are true concerning the proliferative phase of wound healing? a. The macrophage is the predominant cell type b. The pink or purple-red appearance of a wound is due to ingrowth and proliferation of endothelial cells c. Collagen, the dominant structural molecule of the wound matrix, contains two unique amino acids, hydroxyproline and hydroxylysine d. The predominant collagen type in a scar is type 3

Description : Which of the following statement(s) is/are true concerning the proliferative phase of wound healing? a. The macrophage is the predominant cell type b. The pink or purple-red appearance of a wound ... amino acids, hydroxyproline and hydroxylysine d. The predominant collagen type in a scar is type 3

Last Answer : Answer: b, c The proliferative phase of wound healing begins with the formation of a provisional matrix of fibrin and fibronectin as part of the initial clot formation. Initially, the provisional ... The principal collagen type scar is type 1, with lesser amounts of type 3 collagen also present

Which of the following interfere with normal collagen formation or cross-linking? A. Beta-aminopropionitrile. B. Iron chelators. C. Vitamin C depletion. D. Proline analogs (e.g., cis-hydroxyproline). E. D-Penicillamine.

Description : Which of the following interfere with normal collagen formation or cross-linking? A. Beta-aminopropionitrile. B. Iron chelators. C. Vitamin C depletion. D. Proline analogs (e.g., cis-hydroxyproline). E. D-Penicillamine.

Last Answer : Answer: ABCDE DISCUSSION: Intramolecular and intermolecular cross-links are crucial for collagen structural stability. Formation of cross-links can be inhibited by two ... concentration, proline analogs prevent collagen formation with minimal effects on noncollagenase protein synthesis

Which of the following is/are true? A. Because of its thickness, the tensile strength of a healing wound on the eyelid is much less than one on the thick skin of the back. B. By 2 days, the experimental burst strength of skin is minimal since collagen has been formed in the wound but has not yet cross-linked. C. Wound strength reaches a plateau by 3 weeks. D. Wounds rarely, if ever, regain the strength of intact tissues.

Description : Which of the following is/are true? A. Because of its thickness, the tensile strength of a healing wound on the eyelid is much less than one on the thick skin of the back. B. By 2 days, ... strength reaches a plateau by 3 weeks. D. Wounds rarely, if ever, regain the strength of intact tissues.

Last Answer : Answer: BD DISCUSSION: Tensile strength measures load per cross-section area at rupture, whereas burst strength measures load required to break a wound, regardless of dimension. Therefore, skin wounds have ... a slower rate for more than a year. Wounds do not regain the strength of normal tissue

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 is an adhesion glycoprotein? A. Fibronectin. B. Tenascin. C. Laminin. D. Hyaluronic acid. E. Collagen type IV.

Description : Which of the following is an adhesion glycoprotein? A. Fibronectin. B. Tenascin. C. Laminin. D. Hyaluronic acid. E. Collagen type IV.

Last Answer : Answer: ABC DISCUSSION: Cell adhesion glycoproteins such as fibronectin, vitronectin, laminin, and tenascin provide a railroad track to facilitate epithelial and mesenchymal cell migration over the wound ... , and collagen type IV is a protein that is a crucial component of basement membrane

In contrast to adult wound healing with scar formation, which of the following are characteristic of scarless fetal skin repair? A. Matrix rich in hyaluronic acid. B. Increased inflammatory response. C. Increased production of TGF-b. D. No collagen deposition. E. Minimal angiogenesis.

Description : In contrast to adult wound healing with scar formation, which of the following are characteristic of scarless fetal skin repair? A. Matrix rich in hyaluronic acid. B. Increased inflammatory response. C. Increased production of TGF-b. D. No collagen deposition. E. Minimal angiogenesis.

Last Answer : Answer: AE DISCUSSION: The ability of a fetus to heal without scar formation depends on its gestational age at the time of injury and the size of the wound defect. In ... repair has possible clinical applications in the modulation of adult fibrotic diseases and abnormal scar-forming conditions

Factors that decrease collagen synthesis include all of the following except: A. Protein depletion. B. Infection. C. Anemia. D. Advanced age. E. Hypoxia.

Description : Factors that decrease collagen synthesis include all of the following except: A. Protein depletion. B. Infection. C. Anemia. D. Advanced age. E. Hypoxia.

Last Answer : Answer: C DISCUSSION: Collagen synthesis, an integral part of wound healing, is affected by many local and systemic factors. Protein depletion impairs fibroplasia. Hypoproteinemia leads to diminution of ... more than any other factor, wound infection is associated with the risk of wound failure

Which of the following statement(s) is/are true concerning carbon dioxide kinetics? a. The amount of carbon dioxide produced is equivalent to the amount of oxygen consumed b. Carbon dioxide levels in blood, present mostly as a bicarbonate ion, can quickly change c. Normally the amount of carbon dioxide excreted through the lung is exactly equal to the amount of carbon dioxide produced in peripheral tissues d. The amount of carbon dioxide excreted is a function of ventilation of perfused alveoli

Description : Which of the following statement(s) is/are true concerning carbon dioxide kinetics? a. The amount of carbon dioxide produced is equivalent to the amount of oxygen consumed b. Carbon dioxide levels ... tissues d. The amount of carbon dioxide excreted is a function of ventilation of perfused alveoli

Last Answer : Answer: a, c, d The total amount of carbon dioxide produced by systemic metabolism is roughly equivalent to the amount of oxygen consumed (100-120 cc/m2/min, 200 cc/min in a typical ... carbon dioxide excreted is a function of ventilation of perfused alveoli (i.e. the alveolar ventilation/min).

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

Which of the following statements regarding neutrophils are true? a. The neutrophil undergoes final maturation after release into the circulation b. Patients with chronic granulomatous disease have a defective neutrophil H-oxidase system c. Neutrophil killing of bacteria is achieved by oxidants, proteinases and cationic proteins d. The normal human neutrophil circulates in the blood for 7–10 days

Description : Which of the following statements regarding neutrophils are true? a. The neutrophil undergoes final maturation after release into the circulation b. Patients with chronic granulomatous disease have a defective ... proteins d. The normal human neutrophil circulates in the blood for 7-10 days

Last Answer : Answer: b, c The neutrophil is a migratory phagocytic cell that defends the host against bacteria and eliminates necrotic tissue. The neutrophil matures in the bone marrow and is ... phagocytose bacteria, they are unable to kill the intracellular microbes and chronic, unresolved infections result

A patient who has been taking quantities of aspirin might show increased post operative bleeding because aspirin inhibits:** A. Synthesis of thromboxane A2 and prevents platelet aggregation B. Synthesis of prostacyclin and prevents platelet aggregation C. Synthesis of prostaglandin and prevents production of blood platelets D. Thrombin and prevents formation of the fibrin network E. Increase the absorption of vitamin K and prevents synthesis of blood clotting factors

Description : A patient who has been taking quantities of aspirin might show increased post operative bleeding because aspirin inhibits:** A. Synthesis of thromboxane A2 and prevents platelet aggregation B. ... network E. Increase the absorption of vitamin K and prevents synthesis of blood clotting factors

Last Answer : A. Synthesis of thromboxane A2 and prevents platelet aggregation

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

A patient with gross fecal contamination and peritonitis from a ruptured sigmoid diverticulum has his midline wound left open to heal by secondary intention. Which of the following statement(s) describes this healing process? a. Wounds healing in this fashion have an altered sequence of healing compared to a primarily closed wound b. A bed of granulation tissue forms over exposed subcutaneous tissue c. Epithelialization is enhanced in the face of bacterial colonization d. The ability of a wound to form granulation tissue is dependent on the blood supply of the tissue

Description : A patient with gross fecal contamination and peritonitis from a ruptured sigmoid diverticulum has his midline wound left open to heal by secondary intention. Which of the following statement(s) describes this ... of a wound to form granulation tissue is dependent on the blood supply of the tissue

Last Answer : Answer: b, d Open wounds, whether they be ulcers or open surgical incisions closing by secondary intention, heal with the same sequence of inflammation, matrix deposition, epithelialization ... via bacterial and phagocytic cell products such as proteases, collagenases, elastases, and other enzymes

Which of the following statement(s) is/are true concerning the cell function of phagocytosis? a. Phagocytosis is a mechanistically distinct process of endocytosis performed by special cells to take up larger particles such as bacteria or erythrocytes b. Lymphocytes are the primary blood cell involved with this process c. The process involves a coating of the cytoplasmic surface known as clathrin d. Phagocytosis is performed only by white blood cells and tissue macrophages

Description : Which of the following statement(s) is/are true concerning the cell function of phagocytosis? a. Phagocytosis is a mechanistically distinct process of endocytosis performed by special cells to take ... known as clathrin d. Phagocytosis is performed only by white blood cells and tissue macrophages

Last Answer : Answer: a Phagocytosis is a specialized form of endocytosis by which large particles are internalized by specialized cells primarily macrophages and neutrophils. To be phagocytosed, particles ... the lumen of the thyroid follicle, thereby releasing the thyroid hormones, thyroxine triiodothyronine

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

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 neurohormonal arm of the stress response is well defined. Less is known about the inflammatory arm mediated primarily by cytokines. Which of the following statement(s) is/are true concerning this arm of the surgical stress response? a. Cytokines primarily work locally via direct cell-to-cell communication b. Cytokines are never detectable in the systemic bloodstream c. Cytokines are produced only by immune cells attracted to the site of injury d. Cytokine release may stimulate the release of other cytokines leading to an important cascade of events

Description : The neurohormonal arm of the stress response is well defined. Less is known about the inflammatory arm mediated primarily by cytokines. Which of the following statement(s) is/are true ... Cytokine release may stimulate the release of other cytokines leading to an important cascade of events

Last Answer : Answer: a, d Cytokines, which are produced at the site of injury by endothelial cells and by diverse immune cells throughout the body, also occupy a pivotal position in the stress response ... act as hormones and spill over into the systemic circulation and become detectable in the bloodstream

Which of the following statements about continuous cardiac output monitoring are true? A. Continuous cardiac output monitoring may unmask events not detected by intermittent cardiac output measurements. B. Continuous cardiac output monitoring by the thermodilution method requires continuous infusion of fluid injectate at a constant rate and temperature. C. The major advantage of the Fick method over the thermodilution method of calculating cardiac output is that it is noninvasive, requiring only the determination of oxygen consumption by respiratory gas analysis. D. The technique of thoracic electrical bioimpedance utilizes sensors to determine stroke volume by detecting changes in resistance to a small, applied alternating current.

Description : Which of the following statements about continuous cardiac output monitoring are true? A. Continuous cardiac output monitoring may unmask events not detected by intermittent cardiac output measurements. ... stroke volume by detecting changes in resistance to a small, applied alternating current.

Last Answer : Answer: AD DISCUSSION: Various techniques are available to measure cardiac output continuously. The advantages of continuous cardiac output monitoring, as compared with intermittent methods, are (1) ... function of the stroke volume, which then can be used to calculate the cardiac output

Which of the following statement(s) is/are true concerning oxygen consumption (O2)? a. O2 is normally 100–120 cc2/m2/min b. Resting O2 is controlled by the level of thyroid and catecholamine hormones c. Under steady state conditions the amount of oxygen consumed exceeds the amount of oxygen taken up by the pulmonary capillaries d. O2 is dependent on the status of pulmonary function

Description : Which of the following statement(s) is/are true concerning oxygen consumption (O2)? a. O2 is normally 100-120 cc2/m2/min b. Resting O2 is controlled by the level of thyroid and catecholamine ... of oxygen taken up by the pulmonary capillaries d. O2 is dependent on the status of pulmonary function

Last Answer : Answer: a, b Oxygen consumed in the process of metabolism is expressed as the volume of oxygen per minute (O2). O2 is normally 100-120 cc2/m2/min, or 200 cc/min for a typical adult. ... , so we measure O2 across the lung and assume that it is exactly the amount consumed in the systemic metabolism

Which of the following statement(s) is/are true concerning CO2 transfer in the lung? a. Carbon dioxide excretion is a direct function of alveolar ventilation b. Normally end tidal CO2 should be identical to PaCO2 c. The gradient between end tidal and arterial CO2 can be an indirect measure of nonperfused alveoli d. Positive pressure ventilation under normal airway pressures creates a significant end tidal PaCO2 gradient

Description : Which of the following statement(s) is/are true concerning CO2 transfer in the lung? a. Carbon dioxide excretion is a direct function of alveolar ventilation b. Normally end tidal ... d. Positive pressure ventilation under normal airway pressures creates a significant end tidal PaCO2 gradient

Last Answer : Answer: a, b, c The amount of carbon dioxide excretion is directly related to alveolar ventilation. While oxygenation is a function of matching blood flow to alveoli, carbon dioxide excretion is ... high (over 30 cm H2O) and the compression volume is a significant component of each exhaled breath

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

Which of the following statement(s) is/are true concerning the multiorgan failure syndrome (MOFS)? a. Changes in the splanchnic and pulmonary microcirculation are critical to the development of MOFS b. Tissue fixed microphages, including the liver Kupffer cell, have little role in the development of MOFS c. MOFS represents systemic consequences of loss of homeostatic control of local inflammation and microcirculatory hypoperfusion d. The nature of MOFS is highly dependent upon the etiology of the underlying problem

Description : Which of the following statement(s) is/are true concerning the multiorgan failure syndrome (MOFS)? a. Changes in the splanchnic and pulmonary microcirculation are critical to the development of MOFS ... d. The nature of MOFS is highly dependent upon the etiology of the underlying problem

Last Answer : Answer: a, c The nature of multiorgan failure syndrome (MOFS) is that of a diffuse cellular injury, developing systemically as a consequence of losing homeostatic control of local ... of microorganism. In noninfectious cases, the response also appears independent of the specific underlying cause

If a necrotizing soft tissue infection is considered, therapy mandates: a. Empiric administration of antibiotics active against gram-positive, gram-negative, and anaerobic bacteria b. Due to usually resistant species, penicillin is not indicated c. Immediate operative intervention and aggressive resection of all involved tissues is mandatory d. The use of hyperbaric oxygen has been demonstrated to be clearly advantageous

Description : If a necrotizing soft tissue infection is considered, therapy mandates: a. Empiric administration of antibiotics active against gram-positive, gram-negative, and anaerobic bacteria b. Due to usually ... is mandatory d. The use of hyperbaric oxygen has been demonstrated to be clearly advantageous

Last Answer : Answer: a, c Identification of a necrotizing, soft tissue infection mandates immediate operative intervention with aggressive resection of all involved tissues and empiric ... remains without controlled trials demonstrating any additional benefits derived from hyperbaric oxygen therapy

A diabetic develops a severe perineal infection with skin necrosis, subcutaneous crepitance, and drainage of a thin, watery, grayish and foul-smelling fluid. Management should consist of: a. Gram stain of the fluid, which will likely demonstrate multiple bacteria including predominantly gram-positive rods b. A CT scan is indicated in a stable patient to define the extent of the disease c. Broad spectrum antibiotics followed with prompt extensive debridement is indicated d. A safe guideline is to resect infected necrotic tissue so that a several centimeter margin of grossly normal, healthy tissue can be achieved e. A colostomy is of little benefit in this situation

Description : A diabetic develops a severe perineal infection with skin necrosis, subcutaneous crepitance, and drainage of a thin, watery, grayish and foul-smelling fluid. Management should consist of: a. Gram stain ... normal, healthy tissue can be achieved e. A colostomy is of little benefit in this situation

Last Answer : Answer: a, b, c, d The presence of severe perineal infection (referred to as Fournier gangrene when this process involves the perineum and scrotum in males) is associated with a ... often provides improved wound care and patient management, although it is not invariably a positive outcome

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