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

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
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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 concentration. Hydrostatic pressure is an important driving force only for certain specialized cells—the capillary endothelium and the glomerulus of the kidney. For most cells of the body, the transmembrane hydrostatic pressure is 0 and water moves only in response to water concentration gradients. Because the concentration of water is determined by the amount of dissolved solute, the difference in water concentration is typically expressed as a function of the difference in solute concentration or osmotic pressure difference. Because there are no specialized, energy-converting transport mechanisms for water, water is distributed at equilibrium. Water distribution is determined entirely by solute to solute distribution
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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

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

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

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

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

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

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

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

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

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

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

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 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

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

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

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

Which of the following statement(s) is/are correct concerning cell junctions? a. The major occluding junction is the tight junction or zonula occludens b. Tight junctions are usually located near the basal pole of the cell c. Desmosomes are button-like points of attachment which serve to weld together adjacent cells d. Gap junctions are a type of cell junction specialized for cell communication

Description : Which of the following statement(s) is/are correct concerning cell junctions? a. The major occluding junction is the tight junction or zonula occludens b. Tight junctions are usually located near ... adjacent cells d. Gap junctions are a type of cell junction specialized for cell communication

Last Answer : Answer: a, c, d Cell junctions are classified as occluding, anchoring, and communicating. The major occluding junction is the tight junction or zonula occludens which connects ... gap junction which is specialized for communication. This junction mediates both electrical and chemical coupling

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

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

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

Which of the following 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 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

An important step in protein synthesis is transcription. Which of the following statement(s) is/are true concerning this process? a. The first step in gene transcription involves separating the double helix of DNA by an enzyme known as DNA polymerase b. The initial product of DNA transcription is called heterogeneous nuclear RNA which codes directly for proteins c. After processing is complete, the mRNA is exported from the nucleus to the cytoplasm d. Only one protein can be produced from an initial mRNA strand

Description : An important step in protein synthesis is transcription. Which of the following statement(s) is/are true concerning this process? a. The first step in gene transcription involves separating the double helix ... nucleus to the cytoplasm d. Only one protein can be produced from an initial mRNA strand

Last Answer : Answer: c Transcription of a gene begins at an initiation site associated with a specific DNA sequence, termed a promoter region. After binding to DNA, the RNA polymerase opens up a short ... different proteins from the same gene. mRNA is exported from the nucleus only after processing is complete

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

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

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

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

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

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

Which of the following statement(s) is/are true concerning the 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

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

Description : The first line of host defense is the barrier presented to the external environment. Which of the following statement(s) is/are true concerning host barriers? a. Sebaceous glands secrete ... of the upper gastrointestinal tract d. Gut peristalsis serves to prevent microbial adherence and invasion

Last Answer : Answer: b, c, d The skin, mucus membranes, and epithelial layers of various organs of the body constitute effective physical barriers against microbial invasion. In certain portions of the ... very low pH within the stomach and gut peristalsis both serve to prevent microbial adherence and invasion

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

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 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

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

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

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

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 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

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

Cell membranes a. consist almost entirely of protein molecules b. are impermeable to fat-soluble substances c. in some tissues permit the transport of glucose at a greater rate in the presence of insulin d. are freely permeable to electrolytes but not to proteins e. have a stable composition throughout the life of the cell

Description : Cell membranes a. consist almost entirely of protein molecules b. are impermeable to fat-soluble substances c. in some tissues permit the transport of glucose at a greater rate in the presence of ... to electrolytes but not to proteins e. have a stable composition throughout the life of the cell

Last Answer : in some tissues permit the transport of glucose at a greater rate in the presence of insulin

Which of the following statement(s) concerning the gut microflora is/are correct? a. Gut microflora evolves constantly throughout development b. The gut microflora can contribute to the physical and chemical barriers at the mucus membrane level c. Most of the microorganisms found in the oropharynx eventually pass into the intestine d. In the colon, anaerobic organisms outnumber aerobic organisms in a ratio in excess of 100:1

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

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

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 DNA? a. DNA is contained only in the nucleus of the cell b. DNA strands are encoded by the sequence of four bases—adenine, guanine, cytosine and uridine c. The basic unit of information of DNA is the intron, a sequence of three bases d. There are an infinite number of possible codons

Description : Which of the following statement(s) is/are true concerning DNA? a. DNA is contained only in the nucleus of the cell b. DNA strands are encoded by the sequence of four bases-adenine, guanine, cytosine ... DNA is the intron, a sequence of three bases d. There are an infinite number of possible codons

Last Answer : Answer: a The genetic blueprint of an organism is carried in the nucleus of every cell, encoded by the sequence of four bases-adenine, guanine, cytosine and thymine, which together make up ... codons. Sixty-one of these code for amino acids and three are termination signals called stop codons

Which of the following statement(s) is/are true concerning pharmacologic agents used in the treatment of shock? a. The primary difference between dopamine and dobutamine is the absence of significant a adrenergic activity b. The renal and mesenteric vasoconstrictive effects of norepinephrine complicate and sometimes restrict its use c. The apparent paradoxical use of vasodilators, such as nitroprusside, in shock is indicated as a means to augment cardiac function d. Isoproterenol with its potent b-adrenergic effect, is a particularly useful agent in the treatment of all forms of shock

Description : Which of the following statement(s) is/are true concerning pharmacologic agents used in the treatment of shock? a. The primary difference between dopamine and dobutamine is the absence of significant a ... b-adrenergic effect, is a particularly useful agent in the treatment of all forms of shock

Last Answer : Answer: a, b, c Therapeutic adjustments of intravascular volume (preload) and systemic vascular resistance (afterload) form the basis of the treatment strategies for all ... careful constant monitoring of arterial pressure and repeated hemodynamic measurements with a pulmonary artery catheter

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

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

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

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 excessive scarring processes? a. Keloids occur randomly regardless of gender or race b. Hypertrophic scars and keloid are histologically different c. Keloids tend to develop early and hypertrophic scars late after the surgical injury d. Simple reexcision and closure of a hypertrophic scar can be useful in certain situations such as a wound closed by secondary intention

Description : Which of the following statement(s) is/are true concerning excessive scarring processes? a. Keloids occur randomly regardless of gender or race b. Hypertrophic scars and keloid are histologically different ... scar can be useful in certain situations such as a wound closed by secondary intention

Last Answer : Answer: d True keloids are uncommon and occur predominantly in dark skinned people with a genetic predisposition for keloid formation. In most cases, the gene appears to be ... subside. Hypertrophic scars usually develop within the first month after wounding and often subside gradually

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

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

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 HIV infection. a. Initial screening with ELISA is highly sensitive but can be associated with a false positive rate of 25% b. Treatment with azidothymidine (AZD) appears to prolong survival when administered early in the disease c. Predisposition to infection in HIV infection is primarily due to reduction in the number of helper T cells d. Common infections in patients with AIDS are Pneumocystis, carinii pneumonia, CMV pneumonitis, Cryptococcus meningitis, and disseminated infection due to atypical mycobacteria

Description : The following statement(s) is/are true concerning HIV infection. a. Initial screening with ELISA is highly sensitive but can be associated with a false positive rate of 25% b. ... , carinii pneumonia, CMV pneumonitis, Cryptococcus meningitis, and disseminated infection due to atypical mycobacteria

Last Answer : Answer: b, c, d Acquired immunodeficiency syndrome (AIDS) is a syndrome caused by the human retrovirus (HIV-1) that infects T lymphocytes and causes severe immunosuppression. Individuals who ... to prolong survival when administered early in the course of disease and is considered routine therapy

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