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

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
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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 continual expenditure of energy. The maintenance of a steady-state, nonequilibrium cellular composition is possible because the plasma membrane is the site of energy converters, membrane proteins that function as biologic transport machines using energy derived from metabolic processes to perform transport work. The archetype for the biologic transport machine is the Na+-K+-ATPase, a membrane protein that hydrolyses cytosolic ATP and couples the resulting free energy to transport of Na+ and K+. A second equally important type of energy-converting transporter is one in which the energy inherent in a transmembrane ion gradient, usually that of Na+ can be used to drive the transport of a second species such as protons, calcium, amino acids, or glucose
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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 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 statement(s) is/are true concerning cellular ion channels? a. Ion channels are transmembrane proteins that form pores that can conduct ions across the plasma membrane b. Ion channels are formed by membrane-spanning peptides that are arranged so that polar moieties line a central core c. Ion channel proteins undergo conformational changes between open states and closed states d. Ion channels can be blocked

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

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

Which of the following statement(s) is/are true concerning the microvascular and cellular response to shock? a. Osmodically induced mobilization of intracellular fluid is the initial response to restore intravascular volume b. With larger volume hemorrhagic shock deterioration of normal cellular transmembrane potential occurs resulting in an increase in extracellular sodium and water c. The accumulation of anaerobic metabolites override normal homeostatic vasomotor tone and contribute to the maladaptive vasodilatation d. Abnormal intracellular calcium homeostasis may contribute to the cellular dysfunction of shock

Description : Which of the following statement(s) is/are true concerning the microvascular and cellular response to shock? a. Osmodically induced mobilization of intracellular fluid is the initial ... d. Abnormal intracellular calcium homeostasis may contribute to the cellular dysfunction of shock

Last Answer : Answer: c, d Moderate hypovolemia results in a relatively rapid spontaneous restitution of intravascular volume through expansion of the plasma space. This plasma expansion by ... potassium pump. Cellular dysfunction also appears to be related to abnormal intracellular calcium homeostasis

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

Cell regulation can be thought of as the effector side of cell communication. Most commonly cell regulation occurs by means of extracellular chemical messengers. Which of the following statement(s) is/are true concerning these messengers? a. Paracrine regulation involves a messenger which is produced and acts systemically b. The extracellular signal or stimulus is received by a receptor on or in the target cell c. Neurocrine regulation depends on a physical connection between the neuron and the target cell d. Most hormones, local mediators, and neurotransmitters readily cross the cell plasma membrane

Description : Cell regulation can be thought of as the effector side of cell communication. Most commonly cell regulation occurs by means of extracellular chemical messengers. Which of the following statement(s ... d. Most hormones, local mediators, and neurotransmitters readily cross the cell plasma membrane

Last Answer : Answer: b, c Depending on how the extracellular messenger arrives, cell regulation can be classified as paracrine, endocrine, or neurocrine. In paracrine regulation, a chemical messenger ... , local mediators, and neurotransmitters are water-soluble and cannot readily cross the plasma membrane

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

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

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

Which of the following statement(s) is/are true concerning cell membrane receptors? a. The largest family of cell surface receptors are the G-protein-linked receptors b. Activities of the G-protein involve binding and hydrolysis of ATP c. The G protein receptor generates an intracellular messenger commonly through the use adenylate cyclase d. Tyrosine kinase receptors are considered G-protein-linked receptors

Description : Which of the following statement(s) is/are true concerning cell membrane receptors? a. The largest family of cell surface receptors are the G-protein-linked receptors b. Activities of the ... through the use adenylate cyclase d. Tyrosine kinase receptors are considered G-protein-linked receptors

Last Answer : Answer: a, c All water-soluble regulatory molecules bind to the cell surface receptor proteins. Binding of the appropriate ligand evokes an intracellular signal which usually regulates ... are adenylate cyclase, which converts ATP to cAMP, and the polyphosphoinositide-specific phospholipase C

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

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

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

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

Description : 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 ... 25% of total nonprotein caloric needs supplied via total parenteral nutrition should be in the form of fat

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

Poisons like cyanide inhibit Na+ efflux and K+ influx during cellular transport. This inhibitory effect is reversed by an injection of ATP. This demonstrates that (a) ATP is the carrier protein in the transport system (b) energy for Na+-K+ exchange pump comes from ATP (c) ATP is hydrolysed by ATPase to release energy (d) Na+-K+ exchange pump operates in the cell.

Description : Poisons like cyanide inhibit Na+ efflux and K+ influx during cellular transport. This inhibitory effect is reversed by an injection of ATP. This demonstrates that (a) ATP is the carrier protein in the ... is hydrolysed by ATPase to release energy (d) Na+-K+ exchange pump operates in the cell.

Last Answer : (b) energy for Na+-K+ exchange pump comes from ATP

Which of the following statement(s) is/are true concerning metabolic derangements in sepsis and the systemic inflammatory response syndrome which may follow progressive shock? a. Alterations in glucose metabolism lead to the development of efficient substrate utilization b. A progressive rise in serum triglyceride levels result from less efficient clearance and increased hepatic lipogenesis c. A net negative nitrogen balance occurs due to the oxidative metabolism of proteins to meet energy needs d. The serum aromatic amino acids fall rapidly as they are actively used in oxidative metabolism

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

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

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

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

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

Which of the following statement(s) 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%

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

Interleukin-6 is recognized as the cytokine primarily responsible for the alteration in hepatic protein synthesis recognized as the acute phase response. Which of the following statement(s) is/are true concerning acute phase protein response to surgical stress? a. Glucocorticoid hormones inhibit this response b. Proteins such as albumin and transferrin which serve in serum transport are generally increased in this response c. Examples of acute phase proteins include fibrinogen and C-reactive protein d. In general, the physiologic role of acute phase proteins are to reduce the systemic effects of tissue damage

Description : Interleukin-6 is recognized as the cytokine primarily responsible for the alteration in hepatic protein synthesis recognized as the acute phase response. Which of the following statement(s) is/are true ... physiologic role of acute phase proteins are to reduce the systemic effects of tissue damage

Last Answer : Answer: c, d IL-6 is now recognized at the cytokine primarily responsible for the alteration in hepatic synthesis recognized as the acute phase response. Glucocorticoid hormones augment ... that generally inhibit the tissue destruction that is associated with the local initiation of inflammation

The resting membrane potential of a cell a. is dependent on the permeability of the cell membrane to K+ being greater than the permeability to Na+ b. falls to zero immediately when Na+, K+ ATPase in the membrane is inhibited c. is usually equal to the equilibrium potential for K+ d. is usually equal to the equilibrium potential for Na+ e. is markedly altered if the extracellular Na+ concentration is increased

Description : The resting membrane potential of a cell a. is dependent on the permeability of the cell membrane to K+ being greater than the permeability to Na+ b. falls to zero immediately when Na+ ... the equilibrium potential for Na+ e. is markedly altered if the extracellular Na+ concentration is increased

Last Answer : is dependent on the permeability of the cell membrane to K+ being greater than the permeability to Na+

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

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

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

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

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 statement(s) is/are true concerning translation of the mRNA message to protein synthesis? a. An adaptor molecule, tRNA, recognizes specific nucleic acid bases and unites them with specific amino acids b. Covalent attachment of tRNA to amino acids is energy dependent c. The formation of a peptide bond between the growing peptide chain and the free amino acid occurs in the free cytoplasm d. Complete protein synthesis takes hours

Description : Which of the following statement(s) is/are true concerning translation of the mRNA message to protein synthesis? a. An adaptor molecule, tRNA, recognizes specific nucleic acid bases and unites them ... and the free amino acid occurs in the free cytoplasm d. Complete protein synthesis takes hours

Last Answer : Answer: a, b The synthesis of protein involves conversion from a four-letter nucleotide language to one of 20 chemically distinct amino acids. This process is referred to as ... translation and be moving down the mRNA molecules simultaneously, thus increasing the rate of protein synthesis

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

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

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 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

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 carrier proteins? a. Carrier proteins are distinguished by three types of mechanisms: carrier-type, channel-type, and conduction-type b. Conformational changes in the membrane protein occur between the conducting and the nonconducting states c. A channel-type carrier protein has two states—closed and open d. Carrier-type transport proteins are equally accessible from either side of the membrane

Description : Which of the following statement(s) is/are true concerning carrier proteins? a. Carrier proteins are distinguished by three types of mechanisms: carrier-type, channel-type, and conduction-type b. ... and open d. Carrier-type transport proteins are equally accessible from either side of the membrane

Last Answer : Answer: b, c Most transport proteins appear to function as carriers, rather than channels. Important distinctions can be made between types of carrier proteins on the basis of transport kinetics. ... a carrier mechanism, the binding site is available only one side of the membrane at any instant

Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on (a) membrane potential (b) accumulation of Na+ ions (c) accumulation of K+ ions (d) proton gradient.

Description : Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on (a) membrane potential (b) accumulation of Na+ ions (c) accumulation of K+ ions (d) proton gradient.

Last Answer : (d) proton gradient

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

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

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

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

Answer: b, c The body contains fuel reserves which it can mobilize and utilize during times of starvation or stress. By far the greatest energy component is fat, which is calorically dense since it provides about 9 calories/gram. Body protein comprises the next largest mass of utilizable energy, but amino acids yield only about 4 kcal/gram. Unlike fat reserves, body protein is not a storage form of energy but rather serves as a structural functional component of the body; loss of body protein, if severe, is associated with functional consequences. Glycogen stored in muscle and liver and free glucose have a trivial caloric value of less than 1000 kcal for a 70 kg male

Description : Answer: b, c The body contains fuel reserves which it can mobilize and utilize during times of starvation or stress. By far the greatest energy component is fat, which is calorically dense since it ... liver and free glucose have a trivial caloric value of less than 1000 kcal for a 70 kg male

Last Answer : Which of the following statement(s) is/are true concerning the indications and administration of nutritional support to cancer patients? a. Preoperative nutritional support should be provided to all ... total parenteral nutrition solutions maintain integrity of the small bowel e. None of the above

A 67-year-old male presents with an intraabdominal abscess secondary to perforated sigmoid diverticulitis. The following statement(s) is/are true concerning his intraabdominal abscess. a. Culture will likely reveal a solitary organism b. Both aerobic and anaerobic islets are encountered in 50% of specimens c. The most common aerobic islet will be likely E. coli and other gram-negative enteric bacilli d. The most common anaerobic islet will be a Bacteroides species

Description : A 67-year-old male presents with an intraabdominal abscess secondary to perforated sigmoid diverticulitis. The following statement(s) is/are true concerning his intraabdominal abscess. a. Culture will ... gram-negative enteric bacilli d. The most common anaerobic islet will be a Bacteroides species

Last Answer : Answer: b, c, d Typically an intraabdominal infection results in perforation of a hollow viscus and the ensuing contamination of a normally sterile peritoneal cavity. The normal ... Bacteroides species (especially B. fragilis, Clostridium), and anaerobic cocci are most consistently isolated

A 68-year-old male who underwent a repair of an abdominal aortic aneurysm 5 days ago, develops tachycardia, tachypnea, hypotension with cool, pale, mottled cyanotic extremities. He is agitated and complains of shortness of breath. Which of the following statement(s) is/ are correct concerning his diagnosis and management? a. Myocardial ischemia secondary to preexisting coronary artery disease is most likely the underlying cause of this problem b. Invasive hemodynamic monitoring with a Swan-Gantz catheter will demonstrate a low cardiac output, a high systemic vascular resistance, and elevated cardiac filling pressures c. The use of morphine sulphate and nitrates should be part of the initial management d. The primary pharmacologic treatment involves the use of moderate doses of inotropic ag

Description : A 68-year-old male who underwent a repair of an abdominal aortic aneurysm 5 days ago, develops tachycardia, tachypnea, hypotension with cool, pale, mottled cyanotic extremities. He ... use of moderate doses of inotropic agents e. Afterload reduction with nitroprusside is absolutely contraindicated

Last Answer : Answer: a, b, d Intrinsic cardiogenic shock results from failure of the heart as an effective pump. Coronary artery disease is the most common cause of myocardial ... hemodynamic monitoring. Infusion of afterload-reducing agents can be administered in conjunction with inotropic support

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 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

Which of the following statements are true of oxidants? A. In addition to their pathophysiologic roles in inflammation, injury, and infection, oxidants also have physiologic roles. B. Oxidants may be generated from activated neutrophils and during reperfusion following a period of ischemia. C. The deleterious effects of oxidants include lipid peroxidation and cell membrane damage, oxidative damage to DNA, and inhibition of adenosine triphosphate (ATP) synthesis. D. The mechanism of ischemia-reperfusion injury involved the catalytic production of superoxide anion (O 2•) by the enzyme xanthine oxidase.

Description : Which of the following statements are true of oxidants? A. In addition to their pathophysiologic roles in inflammation, injury, and infection, oxidants also have physiologic roles. B. Oxidants may ... involved the catalytic production of superoxide anion (O 2 ) by the enzyme xanthine oxidase.

Last Answer : Answer: ABCD DISCUSSION: Oxidants are reactive oxygen metabolites that have both physiologic and pathophysiologic roles. As potent oxidizing agents, oxidants are involved in cytochrome P ... leukocyte infiltration and activation, causing further tissue damage by the release of cytotoxic proteases

Which of the following statement(s) is/are true concerning the antibody response to an invading antigen? a. All antibodies are composed of one type of heavy and one type of light protein chain b. The carboxyl terminus of the heavy chain is the antigen binding site c. Antibody of the immunoglobulin G class is the initial antibody produced in response to an antigenic stimulus d. Immunoglobulins A, D, and E play an active role in the circulating humoral response

Description : Which of the following statement(s) is/are true concerning the antibody response to an invading antigen? a. All antibodies are composed of one type of heavy and one type of light protein chain b. ... stimulus d. Immunoglobulins A, D, and E play an active role in the circulating humoral response

Last Answer : Answer: a Humoral defenses consist of antibody (immunoglobulin; Ig) and complement. All Ig classes (IgM, IgG, IgA, IgE, IgD) and IgG subclasses are composed of one type (M, G, A, E, D ... exist in smaller amounts in the circulation and do not appear to play a major role as host defense components

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

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

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

Which of the following statement(s) is/are correct concerning the management of an open wound? a. Frequent surgical debridement is usually necessary b. Water irrigation can effectively debride most wounds c. Hydrogen peroxide is particularly useful in the management of open wounds d. A number of the newer dressing products have clearly been shown to promote wound healing compared to simple moist occlusive dressing

Description : Which of the following statement(s) is/are correct concerning the management of an open wound? a. Frequent surgical debridement is usually necessary b. Water irrigation can effectively debride ... products have clearly been shown to promote wound healing compared to simple moist occlusive dressing

Last Answer : Answer: b Although there are numerous dressing products commercially available at present, no treatment has been demonstrated to improve healing beyond that of standard treatment which adheres to basic ... healing is achieved, there has been no evidence that one product is better than another

Which of the following statement(s) is/are true concerning the role of glutamine in total parenteral nutrition? a. Glutamine is an essential amino acid b. Glutamine appears to be of primary benefit in critical illness c. Glutamine is included in most standard TPN solutions d. Glutamine is the primary energy source for intestinal mucosal cells of the small bowel and colon

Description : Which of the following statement(s) is/are true concerning the role of glutamine in total parenteral nutrition? a. Glutamine is an essential amino acid b. Glutamine appears to be of primary ... . Glutamine is the primary energy source for intestinal mucosal cells of the small bowel and colon

Last Answer : Answer: b Glutamine is the most studied gut-specific nutrient. Glutamine has been classified as a nonessential or nutritionally dispensable amino acid since glutamine can be synthesized in adequate ... . In contrast to glutamine, short chain fatty acids are primary energy source for colonocytes

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

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

Which of the following statement(s) is/are true concerning the vascular response to injury? a. Vasoconstriction is an early event in the response to injury b. Vasodilatation is a detrimental response to injury with normal body processes working to avoid this process c. Vascular permeability is maintained to prevent further cellular injury d. Histamine, prostaglandin E2 (PGE2) and prostacyclin (PGI2) are important mediators of local vasoconstriction

Description : Which of the following statement(s) is/are true concerning the vascular response to injury? a. Vasoconstriction is an early event in the response to injury b. Vasodilatation is a ... Histamine, prostaglandin E2 (PGE2) and prostacyclin (PGI2) are important mediators of local vasoconstriction

Last Answer : Answer: a After wounding, there is transient vasoconstriction mediated by catecholamines, thromboxane, and prostaglandin F2 (PGF2a). This period of vasoconstriction lasts for only five to ten minutes. Once ... and mast cells and enhance the egress of cells and substrate into the wound and tissue

Which of the following statement(s) is/are true concerning wound contraction? a. Wound contraction accounts for similar rates of reduction of wound size regardless of their location b. The fibroblast, at the cellular level, is the primary force driving wound contraction c. Excessive wound contraction, when occurring over a joint, may lead to disability d. Actin microfillaments are found in fibroblasts and may play a role in wound contracture

Description : Which of the following statement(s) is/are true concerning wound contraction? a. Wound contraction accounts for similar rates of reduction of wound size regardless of their location b. The fibroblast ... d. Actin microfillaments are found in fibroblasts and may play a role in wound contracture

Last Answer : Answer: b, c, d Wound contraction is an important event which contrasts healing open wounds and closed incisions. When open wounds contract, the surrounding skin is pulled over the open wound ... number in contracting wounds and are felt to play an active role in the process of wound contraction

Which one of the following statements is true regarding digestion and absorption of food in humans? (a) Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions like Na+. (b) Chylomicrons are small lipoprotein particles that are transported from intestine into blood capillaries. (c) About 60% of starch is hydrolysed by salivary amylase in our mouth. (d) Oxyntic cells in our stomach secrete the proenzyme pepsinogen.

Description : Which one of the following statements is true regarding digestion and absorption of food in humans? (a) Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions ... amylase in our mouth. (d) Oxyntic cells in our stomach secrete the proenzyme pepsinogen.

Last Answer : (a) Fructose and amino acids are absorbed through intestinal mucosa with the help of carrier ions like Na