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NUR 3129 Week 1 Quiz. 100%

Chapter 1: Cellular Biology NUR 3129 Quiz 1 MULTIPLE CHOICE 1. Which statement best describes the cellular function of metabolic absorption? a. Cells can produce proteins. c. Cells can take in and use nutrients. b. Cells can secrete digestive enzymes. d. Cells can synthesize fats. ANS: C In metabolic absorption, all cells take in and use nutrients and other substances from their surroundings. The remaining options are not inclusive in their descriptions of cellular metabolic absorption. PTS: 1 REF: Page 2 2. Most of a cell’s genetic information, including RNA and DNA, is contained in the: a. Mitochondria c. Nucleolus b. Ribosome d. Lysosome ANS: C The nucleus contains the nucleolus, a small dense structure composed largely of RNA, most of the cellular DNA, and the DNA-binding proteins, such as the histones, which regulate its activity. The other options do not contain most of a cell’s genetic information. PTS: 1 REF: Page 2 3. Which component of the cell produces hydrogen peroxide (H2O2) by using oxygen to remove hydrogen atoms from specific substrates in an oxidative reaction? a. Lysosomes c. Ribosomes b. Peroxisomes d. Oxyhydrosomes ANS: B Peroxisomes are so named because they usually contain enzymes that use oxygen to remove hydrogen atoms from specific substrates in an oxidative reaction that produces H2O2, which is a powerful oxidant and potentially destructive if it accumulates or escapes from peroxisomes. Ribosomes are RNA-protein complexes (nucleoproteins) that are synthesized in the nucleolus and secreted into the cytoplasm through pores in the nuclear envelope called nuclear pore complexes. Lysosomes are saclike structures that originate from the Golgi complex and contain more than 40 digestive enzymes called hydrolases, which catalyze bonds in proteins, lipids, nucleic acids, and carbohydrates. Oxyhydrosomes are involved in enzyme production. PTS: 1 REF: Page 8 4. Which cell component is capable of cellular autodigestion when it is released during cell injury? a. Ribosome c. Smooth endoplasmic reticulum b. Golgi complex d. Lysosomes ANS: D The lysosomal membrane acts as a protective shield between the powerful digestive enzymes within the lysosome and the cytoplasm, preventing their leakage into the cytoplasmic matrix. Disruption of the membrane by various treatments or cellular injury leads to a release of the lysosomal enzymes, which can then react with their specific substrates, causing cellular self-digestion. The other options do not correctly describe this process. PTS: 1 REF: Pages 7-8 5. What is the sequence of steps in the development of a digestive enzyme by the pancreas cells from the initial transcription to the release from the cell? a. The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the ribosome for synthesis, and is transported in a secretory vesicle to the cell membrane. b. The enzyme is transcribed from RNA by DNA in the nucleus, proceeds to the lysosome for synthesis, and is transported in an encapsulated membrane to the cell membrane. c. The enzyme is transcribed by the mitochondria in the nucleus, proceeds to the ribosome for synthesis, and is transported in a cytoskeleton to the cell membrane. d. The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the Golgi complex for synthesis, and is transported in a cytosol to the cell membrane. ANS: A The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the ribosome for synthesis, and is transported in a secretory vesicle to the cell membrane. The other options do not correctly describe this process. PTS: 1 REF: Page 7 | Figure 1-5 6. During which phase of the cell cycle is DNA synthesized? a. G1 c. G2 b. S d. M ANS: B The four designated phases of the cell cycle are: (1) the G1 phase (G = gap), which is the period between the M phase (M = mitosis) and the start of DNA synthesis; (2) the S phase (S = synthesis), during which DNA is synthesized in the cell nucleus; (3) the G2 phase, during which RNA and protein synthesis occurs, the period between the completion of DNA synthesis and the next phase (M); and (4) the M phase, which includes nuclear and cytoplasmic division. PTS: 1 REF: Page 37 7. What organic compound facilitates transportation across cell membranes by acting as receptors, transport channels for electrolytes, and enzymes to drive active pumps? a. Lipids c. Proteins b. Proteases d. Carbohydrates ANS: C Proteins act as (1) recognition and binding units (receptors) for substances moving in and out of the cell; (2) pores or transport channels for various electrically charged particles called ions or electrolytes and specific carriers for amino acids and monosaccharides; and (3) specific enzymes that drive active pumps that promote the concentration of certain ions, particularly potassium (K ), within the cell while keeping concentrations of other ions, for example, sodium (Na ), below the concentrations found in the extracellular environment. The other options do not correctly describe this process. PTS: 1 REF: Page 13 | Page 15 8. Understanding the various steps of proteolytic cascades, such as caspase-mediated apoptosis and complement cascades, may be useful in designing drug therapy for which human diseases? a. Cardiac and vascular disorders b. Autoimmune and malignant disorders c. Gastrointestinal and renal disorders d. Endocrine and gastrointestinal disorders ANS: B Understanding the various steps involved in this process is crucial for designing drug interventions. Dysregulation of proteases features prominently in many human diseases, including cancer, autoimmunity, and neurodegenerative disorders. The other options do not correctly describe this process. PTS: 1 REF: Page 15 9. Which structure prevents water-soluble molecules from entering cells across the plasma membrane? a. Carbohydrate chains c. Membrane channel proteins b. Glycoprotein channels d. Lipid bilayer ANS: D The bilayer’s structure accounts for one of the essential functions of the plasma membrane. It is impermeable to most water-soluble molecules (molecules that dissolve in water) because the water-soluble molecules are insoluble in the oily core region. The bilayer serves as a barrier to the diffusion of water and hydrophilic substances while allowing lipid-soluble molecules, such as oxygen (O2) and carbon dioxide (CO2), to diffuse through it readily. The other options do not correctly describe this process. PTS: 1 REF: Pages 12-13 10. The fluid mosaic model explains: a. How a cell membrane functions b. Why our bodies appear to be solid c. How tissue is differentiated d. How fluid moves between the intracellular and extracellular compartments ANS: A The fluid mosaic model accounts for the flexibility of cellular membranes, their self-sealing properties, and their impermeability to many substances. The remaining options do not explain the mosaic model. PTS: 1 REF: Page 12 | What's New box 11. Which form of cell communication is used to communicate within the cell itself and with other cells in direct physical contact? a. Protein channel (gap junction) b. Plasma membrane–bound signaling molecules (involving receptors) c. Hormone secretion such as neurotransmitters d. Extracellular chemical messengers such as ligands ANS: A Cells communicate by using hundreds of kinds of signal molecules, for example, insulin. Cells communicate in three main ways; they display plasma membrane–bound signaling molecules (receptors) that affect the cell itself and other cells in direct physical contact. The other options do not correctly describe this process. PTS: 1 REF: Page 20 12. Which mode of chemical signaling uses blood to transport communication to cells some distance away? a. Paracrine c. Neurotransmitter b. Autocrine d. Hormonal ANS: D Chemical signaling can be classified into three categories: (1) local-chemical mediator, (2) hormone, and (3) neurotransmitter. In the local-chemical mediator model, the secreted chemical acts on the cells in the immediate environment. Hormones are used for communication with distant target cells. For example, cells can secrete a chemical and rely on the blood system to deliver the signal to a distant cell. Finally, neurotransmitters are secreted by neurons to stimulate an adjoining cell. For example, a neuron might secrete acetylcholine to stimulate the movement of a muscle cell. PTS: 1 REF: Page 20 13. Which mode of chemical signaling uses local chemical mediators that are quickly taken up, destroyed, or immobilized? a. Paracrine c. Neurotransmitter b. Autocrine d. Hormone ANS: A In paracrine signaling, cells secrete local chemical mediators that are quickly taken up, destroyed, or immobilized. The other options do not correctly describe this process. PTS: 1 REF: Page 20 14. Neurotransmitters affect the postsynaptic membrane by binding to: a. Lipids c. Amphipathic lipids b. Ribosomes d. Receptors ANS: D In each type of chemical signaling, the target cell receives the signal by first attaching to its receptors. The other options do not correctly describe this process. PTS: 1 REF: Page 17 15. How do cells receive communication from the extracellular fluid surrounding them? a. Protein channel (gap junction) b. Plasma membrane–bound signaling molecules (involving receptors) c. Hormone secretion such as neurotransmitters d. Chemical messengers such as ligands ANS: D Cellular communication can occur by the binding of a chemical massager (a ligand) to a specific membrane receptor that is closely associated with the channel (e.g., G proteins). The other options do not correctly describe how cells communicate. PTS: 1 REF: Pages 21-22 16. When a second message is necessary for extracellular communication to be activated, it is provided by which one? a. Guanosine triphosphate (GTP) c. Adenosine triphosphate (ATP) b. Adenosine monophosphate (AMP) d. Guanosine diphosphate (GDP) ANS: B The two major second messenger pathways are cyclic AMP (cAMP) and calcium (Ca ). PTS: 1 REF: Pages 22-23 17. Under anaerobic conditions, what process provides energy for the cell? a. Oxidative phosphorylation c. Lactolysis b. Glycolysis d. Passive transport ANS: B Glycolysis produces a net of two molecules of ATP per glucose molecule through the process of oxidation or the removal and transfer of a pair of electrons. The other options do not correctly identify an anaerobic process that provides energy to the cell. PTS: 1 REF: Page 28 18. What is the mechanism by which the energy produced from carbohydrates, proteins, and lipids is transferred to adenosine triphosphate (ATP)? a. Anaerobic glycolysis c. Oxidative phosphorylation b. Oxidative cellular metabolism d. Tricarboxylic acid phosphorylation ANS: C Oxidative phosphorylation occurs in the mitochondria and is the mechanism by which the energy produced from carbohydrates, fats, and proteins is transferred to ATP. The other options do not correctly identify the mechanism described in the question. PTS: 1 REF: Pages 27-28 19. Passive transport is best described with which statement? a. Being driven by osmosis, hydrostatic pressure, and diffusion b. Involving receptors that can bind with substances being transported c. Being capable of transporting macromolecules d. Requiring energy generated by the cell ANS: A Water and small electrically uncharged molecules move easily through pores in the plasma membrane’s lipid bilayer. This process, called passive transport, naturally occurs through any semipermeable barrier. It is driven by osmosis, hydrostatic pressure, and diffusion, all of which depend on the laws of physics and do not require life. The other options do not correctly describe passive transport. PTS: 1 REF: Page 28 20. Active transport occurs across which type of membranes? a. Membranes that have a higher concentration of the solute on the outside of the cell b. Membranes that are semipermeable to water and small electrically uncharged molecules c. Membranes that have receptors that are capable of binding with the substances to be transported d. Membranes that have a cell membrane that is hydrophobic rather than hydrophilic ANS: C Some molecules are moved into the cell by mechanisms of active transport, which require receptors that are capable of recognizing and binding with the substance to be transported. Diffusion is the movement of a solute molecule from an area of greater solute concentration to an area of lesser solute concentration. Hydrostatic pressure is the mechanical force of water pushing against cellular membranes. Osmosis is the movement of water down a concentration gradient; that is, across a semipermeable membrane from a region of higher water concentration to a lower water concentration PTS: 1 REF: Page 28 21. Which method of transport uses transmembrane proteins with receptors with a high degree of specificity for the substance being transported? a. Active c. Transmembranous b. Mediated d. Passive ANS: B Mediated transport (passive and active) involves integral or transmembrane proteins with receptors having a high degree of specificity for the substance being transported. Inorganic anions and cations (e.g., Na , K , Ca , chloride [Cl–], bicarbonate [HCO3–]) and charged and uncharged organic compounds (e.g., amino acids, sugars) require specific transport systems to facilitate movement through different cellular membranes. The remaining options do not correctly identify the process described. PTS: 1 REF: Page 31 22. The movement of fluid across the arterial end of capillary membranes into the interstitial fluid surrounding the capillary is an example of which fluid movement process? a. Hydrostatic pressure c. Diffusion b. Osmosis d. Active transport ANS: A Hydrostatic pressure is the mechanical force of water pushing against cellular membranes. In the vascular system, hydrostatic pressure is the blood pressure generated in vessels by the contraction of the heart. Blood reaching the capillary bed has a hydrostatic pressure of 25 to 30 mm Hg, which is sufficient force to push water across the thin capillary membranes into the interstitial space. The remaining options do not correctly identify the process described. PTS: 1 REF: Pages 29-30 23. Why is osmolality preferred over osmolarity as the measurement of osmotic activity in the clinical assessment of individuals? a. Plasma contains sodium and chloride, which influence the volume of solution. b. Volume affects perfusion more than the weight of solutes. c. More of the weight of plasma is influenced by solutes, such as protein and glucose, rather than by water. d. Osmotic activity depends on the concentration of solutes present in plasma, such as proteins and glucose. ANS: C In plasma, less of the plasma weight is water; therefore the overall concentration of particles is greater. The osmolality will be greater than the osmolarity because of the smaller proportion of water. Osmolality is thus the preferred measure of osmotic activity in clinical assessment of individuals. PTS: 1 REF: Page 30 24. A patient who has diarrhea receives a 3% saline solution intravenously to replace the sodium and chloride lost in the stool. What effect will this fluid replacement have on cells? a. Become hydrated c. Shrink b. Swell or burst d. Divide ANS: C A hypertonic solution has a concentration of greater than 285 to 294 mOsm/kg. An example of a hypertonic solution is 3% saline solution. Water can be pulled out of the cells by a hypertonic solution; therefore the cells shrink. The remaining options do not correctly describe the effect identified in the stem. PTS: 1 REF: Page 31 25. The transport of glucose from the blood to the cell is accomplished by which process? a. Active-mediated transport (active transport) b. Active diffusion c. Passive osmosis d. Passive-mediated transport (facilitated diffusion) ANS: D Facilitated diffusion is the means by which glucose is transported from the blood to the cells. The remaining options do not correctly identify this process. PTS: 1 REF: Pages 31-32 26. Potassium and sodium are transported across plasma membranes by: a. Passive electrolyte channels b. Coupled channels c. Adenosine triphosphatase (ATPase) enzyme d. Diffusion ANS: C The exact mechanism for the transport of Na and K across the membrane is uncertain. One proposal is that ATPase enzyme induces the transporter protein to undergo several conformational changes, causing Na and K to move short distances (see Figure 1-29). The remaining options do not correctly describe the means by which K and Na are transported. PTS: 1 REF: Pages 32-33 27. What occurs during exocytosis? a. Macromolecules can be secreted across eukaryotic cell membranes. b. All substances are secreted into the cellular matrix. c. No repairs in the plasma membrane can take place. d. Solute molecules flow freely into and out of the cell. ANS: A In eukaryotic cells, secretion of macromolecules almost always occurs by exocytosis. The remaining options do not correctly describe exocytosis. PTS: 1 REF: Pages 35-36 28. Why is it possible for potassium to diffuse easily into and out of cells? a. Potassium has a greater concentration in the intracellular fluid (ICF). b. Sodium has a greater concentration in the extracellular fluid (ECF). c. The resting plasma membrane is more permeable to potassium. d. An excess of anions are inside the cell. ANS: C Because the resting plasma membrane is more permeable to K than to Na , K can easily diffuse from its area of higher concentration in the ICF to its area of lower concentration in the ECF. Because Na and K are both cations, the net result is an excess of anions inside the cell, resulting in the resting membrane potential. The remaining options do not correctly identify the process that most easily diffuses K . PTS: 1 REF: Page 36 29. The cellular uptake of the nutrient cholesterol depends on which process? a. Receptor-mediated exocytosis c. Receptor-mediated endocytosis b. Antiport system d. Passive transport ANS: C The cellular uptake of nutrients, such as cholesterol, for example, depends on receptor-mediated endocytosis. Nutrients are not transported via the other options. PTS: 1 REF: Page 33 30. What causes the rapid change in the resting membrane potential to initiate an action potential? a. Potassium gates open, and potassium rushes into the cell, changing the membrane potential from negative to positive. b. Sodium gates open, and sodium rushes into the cell, changing the membrane potential from negative to positive. c. Sodium gates close, allowing potassium into the cell to change the membrane potential from positive to negative. d. Potassium gates close, allowing sodium into the cell to change the membrane potential from positive to negative. ANS: B When a resting cell is stimulated through voltage-regulated channels, the cell membranes become more permeable to Na . A net Na moves into the cell, and the membrane potential decreases, or moves forward, from a negative value (in millivolts) to zero. The Na gates open, and Na rushes into the cell, causing the membrane potential to reduce to zero and then become positive (depolarization). The remaining options do not correctly describe the change that initiates an action potential. PTS: 1 REF: Page 36 31. The action of platelet-derived growth factor is to stimulate the production of which cells? a. Platelets c. Connective tissue cells b. Epidermal cells d. Fibroblast cells ANS: C Different types of cells require different factors; for example, platelet-derived growth factor stimulates the production of connective tissue cells. The remaining options do not correctly describe the action of platelet-derived growth factor. PTS: 1 REF: Page 39 32. The role of cytokines in cell reproduction is that they: a. Provide growth factor for tissue growth and development. b. Block progress of cell reproduction through the cell cycle. c. Restrain cell growth and development. d. Provide nutrients for cell growth and development. ANS: A Growth factors, also called cytokines, are peptides that transmit signals within and among cells. They have a major role in the regulation of tissue growth and development (see Table 1-6). The remaining options do not correctly describe the role of cytokines in cell reproduction. PTS: 1 REF: Pages 38-39 33. What is the process of cellular reproduction? a. The process often takes months or years to complete. b. Cellular reproduction typically has a short interphase. c. Two diploid cells, called daughter cells, have been formed. d. The process involves the interaction of male and female cells. ANS: C During telophase, the final stage, a new nuclear membrane is formed around each group of 46 chromosomes, the spindle fibers disappear, and the chromosomes begin to uncoil. Cytokinesis causes the cytoplasm to divide into roughly equal parts during this phase. At the end of telophase, two identical diploid cells, called daughter cells, have been formed from the original cell. PTS: 1 REF: Page 37 34. Which statement is true about eukaryotic cells? a. They lack distinct nucleus. b. They contain compartments called organelles. c. They lack an encasing nuclear membrane. d. They are smaller than the typical prokaryote cell. ANS: B Eukaryotic cells have a characteristic set of membrane-bound intracellular compartments called organelles that include a well-defined nucleus and are larger than prokaryotes. The remaining statements are not true regarding eukaryotic cells. PTS: 1 REF: Page 2 35. Which statement is true about phagocytosis? a. Phagocytosis is an example of exocytosis. b. Phagocytosis is dependent on small vesicles. c. Phagocytosis involves the ingestion of bacteria. d. Phagocytosis focuses on solute molecules. ANS: C In phagocytosis, the large molecular substances are engulfed by the plasma membrane and enter the cell so that they can be isolated and destroyed by lysosomal enzymes. Two types of endocytosis are designated, based on the size of the vesicle formed. Pinocytosis (cell drinking) involves the ingestion of fluids and solute molecules through the formation of small vesicles, and phagocytosis (cell eating) involves the ingestion of large particles, such as bacteria, through formation of large vesicles (also called vacuoles). Phagocytosis in an example of endocytosis, not exocytosis. PTS: 1 REF: Pages 33-34 36. A muscle cell possesses which specialized function? a. Movement c. Secretion b. Conductivity d. Respiration ANS: A A cell has the potential to differentiation and to gain the ability to perform one of eight specialized functions. Muscle cells can generate forces that produce motion. Nerves cells are capable of conductivity. Cells of the adrenal gland, testis, and ovary can secrete. Respiration is a function that all cells possess. PTS: 1 REF: Page 2 37. When a mucous gland cell creates a new substance from previously absorbed material, this process is known as which specialized cellular function? a. Excretion c. Reproduction b. Metabolic absorption d. Secretion ANS: D Certain cells, such as mucous gland cells, can synthesize new substances from substances they absorb and then secrete the new substances to serve elsewhere as needed. The other options are not used to describe the function described in the stem. PTS: 1 REF: Page 2 38. All cells are capable of what process? a. Excretion c. Metabolic absorption b. Movement d. Continuous division ANS: A All cells have the capacity to excrete, thus allowing them to rid themselves of waste products resulting from the metabolic breakdown of nutrients. The remaining options are not functions possessed by all cells. PTS: 1 REF: Page 2 MULTIPLE RESPONSE 39. What are the major chemical components of the cell membranes? (Select all that apply.) a. Lipids b. Sodium ions c. Carbohydrates d. DNA e. Proteins ANS: A, E The major chemical components of all cell membranes are lipids and proteins, but the percentage of each varies among different membranes. PTS: 1 REF: Page 12 40. Which cells lose their ability to replicate and divide? (Select all that apply.) a. Intestines b. Nerves c. Skin d. Lens of the eye e. Skeletal muscle ANS: B, D, E All types of cells undergo mitosis during the formation of the embryo, but many adult cells, such as nerve cells, lens cells of the eye, and muscle cells, lose their ability to replicate and divide. Intestines and skin cells retain their ability to replicate and divide. PTS: 1 REF: Page 37 41. Which statements are true concerning the process of facilitated diffusion? (Select all that apply). a. Facilitated diffusion is also referred to as passive mediated transport. b. This process expends no metabolic energy. c. Moving solute molecules through cellular membranes are involved in this process. d. Movement up a concentration gradient is necessary. e. Facilitated diffusion is the primary means for water transport. ANS: A, B, C In passive mediated transport, also called facilitated diffusion, the protein transporter moves solute molecules through cellular membranes without expending metabolic energy. Downward movement along a concentration gradient is necessary. Osmosis is the movement of water down a concentration gradient. PTS: 1 REF: Pages 31-32 42. Passive transport is dependent on: (Select all that apply.) a. Semipermeable barrier membrane b. The process of osmosis c. Diffusion as a driving force d. A living host e. Hydrostatic pressure ANS: A, B, C, E Passive transport naturally occurs through any semipermeable barrier. It is driven by osmosis, hydrostatic pressure, and diffusion, all of which depend on the laws of physics and do not require life. PTS: 1 REF: Page 28 43. What is the primary function of proteins? (Select all that apply.) a. Proteins are binding units. b. Proteins are transport channels. c. Proteins are ribonucleoproteins. d. Proteins provide cell surface markers. e. Proteins are chemical reaction catalysts. ANS: A, B, D, E Protein functions include (a) recognition and binding units (receptors) for substances moving in and out of the cell; (b) pores or transport channels; (c) enzymes that drive active pumps; (d) cell surface markers, such as glycoproteins; (e) cell adhesion molecules; and (f) catalysts of chemical reactions. PTS: 1 REF: Page 15 MATCHING Match the structure with its function. Answers may be used more than once. ______ A. Endoplasmic reticulum ______ B. Ribosome ______ C. Secretory vesicle ______ D. Lysosomes 44. Packages and transports proteins. 45. Fuses with the plasma membrane to release contents from the cell. 46. Synthesizes and transports lipids. 47. Provides energy to digest proteins into amino acids. 44. ANS: A PTS: 1 REF: Pages 5-6 MSC: The endoplasmic reticulum (endo = within; plasma = cytoplasm; reticulum = network) is a membrane factory that specializes in the synthesis and transport of the protein and lipid components of most of the cell's organelles. 45. ANS: C PTS: 1 REF: Pages 6-7 MSC: Proteins from the endoplasmic reticulum are processed and packaged into small membrane-bound sacs or vesicles called secretory vesicles that collect at the end of the membranous folds of the Golgi bodies. The secretory vesicles then break off from the Golgi complex and migrate to a variety of intracellular and extracellular destinations, including the plasma membrane. The vesicles fuse with the plasma membrane, and their contents are released from the cell. 46. ANS: A PTS: 1 REF: Pages 5-6 MSC: The endoplasmic reticulum (endo = within; plasma = cytoplasm; reticulum = network) is a membrane factory that specializes in the synthesis and transport of the protein and lipid components of most of the cell's organelles. 47. ANS: D PTS: 1 REF: Page 7 MSC: Lysosomes function as the intracellular digestive system (see Figure 1-6). Lysosomal enzymes are capable of digesting most cellular constituents down to their basic forms, such as amino acids, fatty acids, and sugars. Match the structure with its function. Answers may be used more than once. ______ A. Passive-mediated transport ______ B. Active-mediated transport ______ C. Osmosis 48. Movement of water 49. Protein carrier 50. Facilitated diffusion 48. ANS: C PTS: 1 REF: Page 30 MSC: Osmosis is the movement of water down a concentration gradient; that is, across a semipermeable membrane from a region of higher water concentration to a lower water concentration. 49. ANS: B PTS: 1 REF: Page 32 MSC: In active-mediated transport, also called active transport, the protein transporter moves molecules against, or up, the concentration gradient. Unlike passive-mediated transport, active-mediated transport requires the expenditure of energy. 50. ANS: A PTS: 1 REF: Pages 31-32 MSC: In passive-mediated transport, also called facilitated diffusion, the protein transporter moves solute molecules through cellular membranes without expending metabolic energy. Chapter 2: Altered Cellular and Tissue Biology MULTIPLE CHOICE 1. Which type of cell adaptation occurs when normal columnar ciliated epithelial cells of the bronchial lining have been replaced by stratified squamous epithelial cells? a. Hyperplasia c. Dysplasia b. Metaplasia d. Anaplasia ANS: B Metaplasia is the reversible replacement of one mature cell by another, sometimes a less differentiated cell type. The best example of metaplasia is the replacement of normal columnar ciliated epithelial cells of the bronchial (airway) lining by stratified squamous epithelial cells. The other options do not accurately describe the event in the question. PTS: 1 REF: Page 54 2. The loss of the adenosine triphosphate (ATP) during ischemia causes cells to: a. Shrink because of the influx of calcium (Ca). b. Shrink because of the influx of potassium chloride (KCl). c. Swell because of the influx of sodium chloride (NaCl). d. Swell because of the influx of nitric oxide (NO). ANS: C A reduction in ATP levels causes the plasma membrane’s sodium-potassium (Na –K ) pump and sodium-calcium exchange to fail, which leads to an intracellular accumulation of sodium and calcium and diffusion of potassium out of the cell. (The Na –K pump is discussed in Chapter 1.) Sodium and water can then freely enter the cell, and cellular swelling results. The other options do not accurately describe the result of ATP at the cellular level. PTS: 1 REF: Page 57 3. The mammary glands enlarge during pregnancy primarily as a consequence of hormonal: a. Atrophy c. Anaplasia b. Hyperplasia d. Dysplasia ANS: B Hormonal hyperplasia occurs chiefly in estrogen-dependent organs, such as the uterus and breast. The remaining options do not adequately describe the consequence of hormones on breast tissue during pregnancy. PTS: 1 REF: Page 53 4. Free radicals play a major role in the initiation and progression of which diseases? a. Cardiovascular diseases such as hypertension and ischemic heart disease b. Renal diseases such as acute tubular necrosis and glomerulonephritis c. Gastrointestinal diseases such as peptic ulcer disease and Crohn disease d. Muscular disease such as muscular dystrophy and fibromyalgia ANS: A Emerging data indicate that reactive oxygen species play major roles in the initiation and progression of cardiovascular alterations associated with hyperlipidemia, diabetes mellitus, hypertension, ischemic heart disease, and chronic heart failure. No current research connects the disorders mentioned in the other options to the effects of free radicals. PTS: 1 REF: Pages 59-60 5. Free radicals cause cell damage by: a. Stealing the cell’s oxygen to stabilize the electron, thus causing hypoxia b. Stimulating the release of lysosomal enzymes that digest the cell membranes c. Transferring one of its charged, stabilized atoms to the cell membrane, which causes lysis d. Giving up an electron, which causes injury to the chemical bonds of the cell membrane ANS: D A free radical is an electrically uncharged atom or group of atoms having an unpaired electron. Having one unpaired electron makes the molecule unstable; thus to stabilize, the molecule gives up an electron to another molecule or steals one. Therefore it is capable of forming injurious chemical bonds with proteins, lipids, or carbohydrates—key molecules in membranes and nucleic acids. The remaining options do not accurately describe the role played by free radicals in cell damage. PTS: 1 REF: Page 60 6. What is a consequence of plasma membrane damage to the mitochondria? a. Enzymatic digestion halts DNA synthesis. b. Influx of calcium ions halts ATP production. c. Edema from an influx in sodium causes a reduction in ATP production. d. Potassium shifts out of the mitochondria, which destroys the infrastructure. ANS: B The most serious consequence of plasma membrane damage is, as in hypoxic injury, to the mitochondria. An influx of calcium ions from the extracellular compartment activates multiple enzyme systems, resulting in cytoskeleton disruption, membrane damage, activation of inflammation, and eventually DNA degradation. Calcium ion accumulation in the mitochondria causes the mitochondria to swell, which is an occurrence that is associated with irreversible cellular injury. The injured mitochondria can no longer generate ATP, but they do continue to accumulate calcium ions. The remaining options do not accurately describe the consequence of plasma membrane damage to the mitochondria. PTS: 1 REF: Page 63 7. What is a consequence of leakage of lysosomal enzymes during chemical injury? a. Enzymatic digestion of the nucleus and nucleolus occurs, halting DNA synthesis. b. Influx of potassium ions into the mitochondria occurs, halting the ATP production. c. Edema of the Golgi body occurs, preventing the transport of proteins out of the cell. d. Shift of calcium out of the plasma membrane occurs, destroying the cytoskeleton. ANS: A Enzymatic digestion of cellular organelles, including the nucleus and nucleolus, ensues, halting the synthesis of DNA and ribonucleic acid (RNA). The remaining options do not accurately describe the consequence of lysosomal enzyme leakage during chemical injury. PTS: 1 REF: Page 63 8. Lead causes damage within the cell by interfering with the action of: a. Sodium and chloride c. Calcium b. Potassium d. ATP ANS: C Lead affects many different biologic activities at the cellular and molecular levels, many of which may be related to its ability to interfere with the functions of calcium. Lead does not appear to cause damage by interfering with the action of the other options. PTS: 1 REF: Page 66 9. Which statement is a description of the characteristics of apoptosis? a. Programmed cell death of scattered, single cells b. Characterized by swelling of the nucleus and cytoplasm c. Unpredictable patterns of cell death d. Results in benign malignancies ANS: A Apoptosis is an active process of cellular self-destruction, also known as programmed cell death, which is implicated in normal and pathologic tissue changes. The remaining options do not accurately describe the characteristics of apoptosis. PTS: 1 REF: Page 91 10. Lead poisoning affects the nervous system by: a. Interfering with the function of neurotransmitters b. Inhibiting the production of myelin around nerves c. Increasing the resting membrane potential d. Altering the transport of potassium into the nerves ANS: A Alterations in calcium may play a crucial role in the interference with neurotransmitters, which may cause hyperactive behavior and the proliferation of capillaries of the white matter and intercerebral arteries. The remaining options do not accurately describe the effects of lead poisoning of the nervous system. PTS: 1 REF: Page 66 11. Carbon monoxide causes tissue damage by: a. Competing with carbon dioxide so that it cannot be excreted b. Binding to hemoglobin so that it cannot carry oxygen c. Destroying the chemical bonds of hemoglobin so it cannot carry oxygen d. Removing iron from hemoglobin so it cannot carry oxygen ANS: B Because carbon monoxide’s affinity for hemoglobin is 200 times greater than that of oxygen, it quickly binds with the hemoglobin, preventing oxygen molecules from doing so. The remaining options do not accurately describe the means by which carbon monoxide damages tissue. PTS: 1 REF: Page 67 12. Acute alcoholism mainly affects which body system? a. Hepatic c. Renal b. Gastrointestinal d. Central nervous ANS: D Acute alcoholism mainly affects the central nervous system but may induce reversible hepatic and gastric changes. Other systems may evidentially be affected by chronic alcoholism. PTS: 1 REF: Page 68 13. During cell injury caused by hypoxia, an increase in the osmotic pressure occurs within the cell because: a. Plasma proteins enter the cell. b. The adenosine triphosphatase (ATPase)–driven pump is stronger during hypoxia. c. Sodium chloride enters the cell. d. An influx of glucose occurs through the injured cell membranes. ANS: C In hypoxic injury, movement of fluid and ions into the cell is associated with acute failure of metabolism and a loss of ATP production. Normally, the pump that transports sodium ions out of the cell is maintained by the presence of ATP and ATPase, the active-transport enzyme. In metabolic failure caused by hypoxia, reduced ATP and ATPase levels permit sodium to accumulate in the cell, whereas potassium diffuses outward. The increase of intracellular sodium increases osmotic pressure, which draws more water into the cell. (Transport mechanisms are described in Chapter 1.) The remaining options do not accurately describe the cell injury that results in increased osmotic pressure caused by hypoxia. PTS: 1 REF: Page 84 14. Which statement is true regarding the difference between subdural hematoma and epidural hematoma? a. No difference exists, and these terms may be correctly used interchangeably. b. A subdural hematoma occurs above the dura, whereas an epidural hematoma occurs under the dura. c. A subdural hematoma is often the result of shaken baby syndrome, whereas an epidural hematoma rapidly forms as a result of a skull fracture. d. A subdural hematoma usually forms from bleeding within the skull, such as an aneurysm eruption, whereas an epidural hematoma occurs from trauma outside the skull, such as a blunt force trauma. ANS: C A subdural hematoma is a collection of blood between the inner surface of the dura mater and the surface of the brain, resulting from the shearing of small veins that bridge the subdural space. Subdural hematomas can be the result of blows, falls, or sudden acceleration-deceleration of the head, which occurs in the shaken baby syndrome. An epidural hematoma is a collection of blood between the inner surface of the skull and the dura and is almost always associated with a skull fracture. The other options do not accurately describe the differences between the two hematomas. PTS: 1 REF: Page 72 | Table 2-6 15. What physiologic change occurs during heat exhaustion? a. Hemoconcentration occurs because of the loss of salt and water. b. Cramping of voluntary muscles occurs as a result of salt loss. c. Thermoregulation fails because of high core temperatures. d. Subcutaneous layers are damaged because of high core temperatures. ANS: A Heat exhaustion occurs when sufficient salt and water loss results in hemoconcentration. The other options do not accurately describe the physiologic changes that occur during heat exhaustion. PTS: 1 REF: Page 77 16. In hypoxic injury, sodium enters the cell and causes swelling because: a. The cell membrane permeability increases for sodium during periods of hypoxia. b. ATP is insufficient to maintain the pump that keeps sodium out of the cell. c. The lactic acid produced by the hypoxia binds with sodium in the cell. d. Sodium cannot be transported to the cell membrane during hypoxia. ANS: B In hypoxic injury, movement of fluid and ions into the cell is associated with acute failure of metabolism and a loss of ATP production. Normally, the presence of ATP and ATPase, the active-transport enzyme, maintains the pump that transports sodium ions out of the cell. In metabolic failure caused by hypoxia, reduced ATP and ATPase levels permit sodium to accumulate in the cell, whereas potassium diffuses outward. The other options do not accurately describe the cause of the swelling caused by hypoxia. PTS: 1 REF: Page 84 17. What is the most common site of lipid accumulation? a. Coronary arteries c. Liver b. Kidneys d. Subcutaneous tissue ANS: C Although lipids sometimes accumulate in heart and kidney cells, the most common site of intracellular lipid accumulation, or fatty change, is liver cells. Subcutaneous tissue is not a common site of lipid accumulation. PTS: 1 REF: Pages 84-85 18. What mechanisms occur in the liver cells as a result of lipid accumulation? a. Accumulation of lipids that obstruct the common bile duct, preventing flow of bile from the liver to the gallbladder b. Increased synthesis of triglycerides from fatty acids and decreased synthesis of apoproteins c. Increased binding of lipids with apoproteins to form lipoproteins d. Increased conversion of fatty acids to phospholipids ANS: B Lipid accumulation in liver cells occurs after cellular injury sets the following mechanisms in motion: increased synthesis of triglycerides from fatty acids (increases in the enzyme, -glycerophosphatase, which can accelerate triglyceride synthesis) and decreased synthesis of apoproteins (lipid-acceptor proteins). The other options do not accurately describe this event. PTS: 1 REF: Pages 84-85 19. Hemoprotein accumulations are a result of the excessive storage of: a. Iron, which is transferred from the cells to the bloodstream b. Hemoglobin, which is transferred from the bloodstream to the cells c. Albumin, which is transferred from the cells to the bloodstream d. Amino acids, which are transferred from the cells to the bloodstream ANS: A Excessive storage of iron, which is transferred to the cells from the bloodstream, causes hemoprotein accumulations in cells. Hemoglobin, albumin, or amino acids will not cause hemoprotein accumulations. PTS: 1 REF: Page 86 20. Hemosiderosis is a condition that results in the excess of what substance being stored as hemosiderin in cells of many organs and tissues? a. Hemoglobin c. Iron b. Ferritin d. Transferrin ANS: C Hemosiderosis is a condition that occurs only when excess iron is stored as hemosiderin in the cells of many organs and tissues. PTS: 1 REF: Page 86 21. What is the cause of free calcium in the cytosol that damages cell membranes by uncontrolled enzyme activation? a. Activation of endonuclease interferes with the binding of calcium to protein. b. Activation of phospholipases, to which calcium normally binds, degrades the proteins. c. An influx of phosphate ions competes with calcium for binding to proteins. d. Depletion of ATP normally pumps calcium from the cell. ANS: D If abnormal direct damage occurs to membranes or ATP is depleted, then calcium increases in the cytosol. The other options do not accurately describe the cause of free calcium in cytosol to damage cell membranes. PTS: 1 REF: Pages 57-58 | Page 87 | Figure 2-24 22. What two types of hearing loss are associated with noise? a. Acoustic trauma and noise-induced c. High frequency and acoustic trauma b. High frequency and low frequency d. Noise-induced and low frequency ANS: A Two types of hearing loss are associated with noise: (1) acoustic trauma or instantaneous damage caused by a single sharply rising wave of sound (e.g., gunfire), and (2) noise-induced hearing loss, the more common type, which is the result of prolonged exposure to intense sound (e.g., noise associated with the workplace and leisure-time activities). The remaining options are not related to noise but rather to the amplitude of the sound. PTS: 1 REF: Page 83 23. What type of necrosis results from ischemia of neurons and glial cells? a. Coagulative c. Caseous b. Liquefactive d. Gangrene ANS: B Liquefactive necrosis commonly results from ischemic injury to neurons and glial cells in the brain. The other types of necrosis are not related to ischemic injuries in the brain. PTS: 1 REF: Page 90 24. What type of necrosis is often associated with pulmonary tuberculosis? a. Bacteriologic c. Liquefactive b. Caseous d. Gangrenous ANS: B Caseous necrosis, which commonly results from tuberculous pulmonary infection, particularly Mycobacterium tuberculosis, is a combination of coagulative and liquefactive necrosis. The other types of necrosis are not observed in pulmonary tuberculosis. PTS: 1 REF: Page 90 25. What type of necrosis is associated with wet gangrene? a. Coagulative c. Caseous b. Liquefactive d. Gangrene ANS: B Wet gangrene develops only when neutrophils invade the site, causing liquefactive necrosis. PTS: 1 REF: Page 91 26. Current research supports the believe that, after heart muscle injury, the damage: a. Remains indefinitely because cardiac cells do not reproduce. b. Is repaired by newly matured cardiomyocytes. c. Gradually decreases in size as mitotic cell division occurs. d. Is replaced by hypertrophy of remaining cells. ANS: B The recent discovery that cardiac stem cells exist in the heart and differentiate into various cardiac cell lineages has profoundly changed the understanding of myocardial biology; it is now believed that bone marrow–derived cardiac stem cells or progenitor cells that have the ability to mature into cardiomyocytes may populate the heart after injury. The other options do not accurately describe the process that is believed to occur to address cardiac muscle damage. PTS: 1 REF: Page 52 | What's New box 27. After ovulation, the uterine endometrial cells divide under the influence of estrogen. This process is an example of hormonal: a. Hyperplasia c. Hypertrophy b. Dysplasia d. Anaplasia ANS: A Hormonal hyperplasia chiefly occurs in estrogen-dependent organs, such as the uterus and breast. After ovulation, for example, estrogen stimulates the endometrium to grow and thicken for reception of the fertilized ovum. The other options do not accurately describe the process identified in the question. PTS: 1 REF: Pages 51-53 28. The abnormal proliferation of cells in response to excessive hormonal stimulation is called: a. Dysplasia c. Hyperplasia b. Pathologic dysplasia d. Pathologic hyperplasia ANS: D Pathologic hyperplasia is the abnormal proliferation of normal cells and can occur as a response to excessive hormonal stimulation or the effects of growth factors on target cells (see Figure 2-4). The other options do not accurately identify the term for the results of excessive hormonal stimulation on cells. PTS: 1 REF: Page 53 29. Removal of part of the liver leads to the remaining liver cells undergoing compensatory: a. Atrophy c. Hyperplasia b. Metaplasia d. Dysplasia ANS: C Compensatory hyperplasia is an adaptive mechanism that enables certain organs to regenerate. For example, the removal of part of the liver leads to hyperplasia of the remaining liver cells (hepatocytes) to compensate for the loss. The other options do not accurately identify the compensatory process described in the question. PTS: 1 REF: Pages 52-53 30. What is the single most common cause of cellular injury? a. Hypoxic injury c. Infectious injury b. Chemical injury d. Genetic injury ANS: A Hypoxia, or lack of sufficient oxygen, is the single most common cause of cellular injury (see Figure 2-8). The other options are not a commonly observed as is the correct option. PTS: 1 REF: Page 56 31. During cell injury caused by hypoxia, sodium and water move into the cell because: a. Potassium moves out of the cell, and potassium and sodium are inversely related. b. The pump that transports sodium out of the cell cannot function because of a decrease in ATP levels. c. The osmotic pressure is increased, which pulls additional sodium across the cell membrane. d. Oxygen is not available to bind with sodium to maintain it outside of the cell. ANS: B A reduction in ATP levels causes the plasma membrane’s sodium-potassium (Na –K ) pump and sodium-calcium exchange to fail, which leads to an intracellular accumulation of sodium and calcium and diffusion of potassium out of the cell. (The Na –K pump is discussed in Chapter 1.) PTS: 1 REF: Page 57 32. In decompression sickness, emboli are formed by bubbles of: a. Oxygen c. Carbon monoxide b. Nitrogen d. Hydrogen ANS: B If water pressure is too rapidly reduced, the gases dissolved in blood bubble out of the solution, forming emboli. Oxygen is quickly redissolved, but nitrogen bubbles may persist and obstruct blood vessels. Ischemia, resulting from gas emboli, causes cellular hypoxia, particularly in the muscles, joints, and tendons, which are especially susceptible to changes in oxygen supply. The remaining options are not involved in the formation of decompression sickness emboli. PTS: 1 REF: Page 77 33. Which is an effect of ionizing radiation exposure? a. Respiratory distress c. DNA aberrations b. Sun intolerance d. Death ANS: C The effects of ionizing radiation may be acute or delayed. Acute effects of high doses, such as skin redness, skin damage, or chromosomal aberrations, occur within hours, days, or months. The delayed effects of low doses may not be evident for years. The other options are not commonly considered effects of radiation exposure. PTS: 1 REF: Pages 78-79 34. What is an example of compensatory hyperplasia? a. Hepatic cells increase cell division after part of the liver is excised. b. Skeletal muscle cells atrophy as a result of paralysis. c. The heart muscle enlarges as a result of hypertension. d. The size of the uterus increases during pregnancy. ANS: A Compensatory hyperplasia is an adaptive mechanism that enables certain organs to regenerate. For example, the removal of part of the liver leads to hyperplasia of the remaining liver cells (hepatocytes) to compensate for the loss. The other options do not accurately describe the term compensatory hyperplasia. PTS: 1 REF: Pages 52-53 35. It is true that nondividing cells are: a. Found in gastrointestinal lining c. Incapable of synthesizing DNA b. Affected by hyperplasia d. Affected by only hypertrophy ANS: A Gastrointestinal lining is made up of rapidly dividing cells. Hyperplasia and hypertrophy take place if the cells are capable of synthesizing DNA; however, only hypertrophy occurs in nondividing cells. PTS: 1 REF: Pages 51-53 36. Dysplasia refers to a(n): a. Abnormal increase in the number of a specific cell type b. True adaptive process at the cellular level c. Modification in the shape of a specific cell type d. Lack of oxygen at the cellular level ANS: C Dysplasia refers only to abnormal changes in the size, shape, and organization of mature cells. PTS: 1 REF: Pages 53-54 37. Current research has determined that chemical-induced cellular injury: a. Affects the permeability of the plasma membrane. b. Is often the result of the damage caused by reactive free radicals. c. Is rarely influenced by lipid peroxidation. d. Seldom involves the cell’s organelles. ANS: B Not all the mechanisms causing chemical-induced membrane destruction are known; however, the only two general mechanisms currently accepted include: (1) direct toxicity by combining with a molecular component of the cell membrane or organelles, and (2) reactive free radicals and lipid peroxidation. PTS: 1 REF: Pages 62-63 MULTIPLE RESPONSE 38. Which organs are affected by lead consumption? (Select all that apply.) a. Bones b. Muscles c. Pancreas d. Nerves e. Eyes ANS: A, D The only organ systems provided as options that are primarily affected by lead include the nervous system, bones, kidneys, teeth, cardiovascular, and reproductive and immune systems. PTS: 1 REF: Page 66 39. What effect does fetal alcohol syndrome have on newborns? (Select all that apply.) a. Failure of alveoli to open b. Cognitive impairment c. Incompetent semilunar values d. Esophageal stricture e. Facial anomalies ANS: B, E Fetal alcohol syndrome (FAS) can lead to growth restriction, cognitive impairment, facial anomalies, and ocular disturbances. The other options do not accurately describe the effects of FAS. PTS: 1 REF: Page 69 40. What organs are affected by the type of necrosis that results from either severe ischemia or chemical injury? (Select all that apply.) a. Lungs b. Brain c. Kidneys d. Muscles e. Heart ANS: C, E Coagulative necrosis, which occurs primarily in the kidneys, heart, and adrenal glands, is a common result of hypoxia from severe ischemia or hypoxia caused by chemical injury, especially the ingestion of mercuric chloride. The other options do not accurately identify organs affected by necrosis resulting from ischemia or chemical injury. PTS: 1 REF: Page 90 41. It is true that melanin is: (Select all that apply.) a. Rarely found in epithelial cells b. Found in cells called keratinocytes, which are present in the retina c. A factor in the prevention of certain types of cancer d. Most influential in managing the effects of short-term sunlight exposure e. Accumulated in specific cells found in the skin ANS: B, C, E Melanin accumulates in epithelial cells (keratinocytes) of the skin and retina and is an extremely important pigment because it protects the skin against long exposure to sunlight and is considered an essential factor in the prevention of skin cancer. PTS: 1 REF: Pages 85-86 42. Examples of adaptive cellular responses include: (Select all that apply.) a. Atrophy b. Dysplasia c. Hypertrophy d. Hyperplasia e. Metaplasia ANS: A, C, D, E Atrophy, hypertrophy, hyperplasia, and metaplasia are considered to be adaptive cellular responses. PTS: 1 REF: Page 50 43. Blunt force injuries would include a: (Select all that apply.) a. Bruise to the upper arm, resulting from a fall b. Simple tibia fracture sustained in a skiing accident c. Cut on the finger while slicing vegetables for a salad d. Spleen laceration caused by a punch during a physical fight e. Small caliber gunshot wound to the foot while target shooting ANS: A, B, D Blunt force injuries are the result of tearing, shearing, or crushing types of injuries, resulting in bruises, fractures, and lacerations caused by blows or impacts. Sharp force injuries include cuts. Gunshot wounds require the penetration of the skin and muscle by a bullet. PTS: 1 REF: Page 72 | Table 2-6 44. Which statements are true regarding the effects of marijuana use? (Select all that apply.) a. Smoking the drug results in greater absorption that eating it. b. Heavy use can result in psychomotor impairments. c. Smoking four “joints” a day equals smoking approximately 20 cigarettes. d. Research does not support marijuana use as a factor in developing lung cancer. e. Fetal development appears to be unharmed by marijuana use. ANS: A, B, C With marijuana smoking, approximately 50% of the potent agents are absorbed through the lungs; when marijuana is ingested, however, only 10% is absorbed. With heavy marijuana use, the following adverse effects have been reported: (1) alterations of sensory perceptions, cognitive and psychomotor impairment (e.g., inability to judge time, speed, distance); (2) smoking three or four joints per day is similar to smoking 20 cigarettes per day, in relation to the frequency of chronic bronchitis and may contribute to lung cancer; (3) data from animal studies only, indicate reproductive changes that include reduced fertility, decreased sperm motility, and decreased circulatory testosterone; (4) fetal abnormalities including low birth weight and increased frequency of childhood leukemia; (5) increased frequency of infectious illness, which is thought to be the result of depressed cell-mediated and humoral immunity. PTS: 1 REF: Page 70 | Table 2-5 Chapter 3: The Cellular Environment: Fluids and Electrolytes, Acids and Bases MULTIPLE CHOICE 1. Infants are most susceptible to significant losses in total body water because of an infant’s: a. High body surface–to–body size ratio b. Slow metabolic rate c. Kidneys are not mature enough to counter fluid losses d. Inability to communicate adequately when he or she is thirsty ANS: C Renal mechanisms that regulate fluid and electrolyte conservation are often not mature enough to counter the losses; consequently, dehydration may rapidly develop. Infants can be susceptible to changes in total body water because of their high metabolic rate and the turnover of body fluids caused by their greater body surface area in proportion to their total body size. The inability to communicate their thirst is a problem only when they are poorly cared for. PTS: 1 REF: Page 104 2. Obesity creates a greater risk for dehydration in people because: a. Adipose cells contain little water because fat is water repelling. b. The metabolic rate of obese adults is slower than the rate of lean adults. c. The rate of urine output of obese adults is higher than the rate of output of lean adults. d. The thirst receptors of the hypothalamus do not function effectively. ANS: A The percentage of total body water (TBW) varies with the amount of body fat and age. Because fat is water repelling (hydrophobic), very little water is contained in adipose cells. Individuals with more body fat have proportionately less TBW and tend to be more susceptible to fluid imbalances that cause dehydration. PTS: 1 REF: Page 104 3. A patient’s blood gases reveal the following findings: pH, 7.3; bicarbonate (HCO3) 27 mEq/L; carbon dioxide (CO2), 58 mm Hg. What is the interpretation of these gases? a. Respiratory alkalosis c. Respiratory acidosis b. Metabolic acidosis d. Metabolic alkalosis ANS: C The values provided in this question characterize only acute uncompensated respiratory acidosis. PTS: 1 REF: Pages 129-130 4. Water movement between the intracellular fluid (ICF) compartment and the extracellular fluid (ECF) compartment is primarily a function of: a. Osmotic forces c. Antidiuretic hormone b. Plasma oncotic pressure d. Hydrostatic forces ANS: A The movement of water between the ICF and ECF compartments is primarily a function of osmotic forces. (Osmosis and other mechanisms of passive transport are discussed in Chapter 1.) PTS: 1 REF: Page 105 5. In addition to osmosis, what force is involved in the movement of water between the plasma and interstitial fluid spaces? a. Oncotic pressure c. Net filtration b. Buffering d. Hydrostatic pressure ANS: D Water moves between the plasma and interstitial fluid through the forces of only osmosis and hydrostatic pressure, which occur across the capillary membrane. Buffers are substances that can absorb excessive acid or base to minimize pH fluctuations. Net filtration is a term used to identify fluid movement in relationship to the Starling hypothesis. Oncotic pressure encourages water to cross the barrier of capillaries to enter the circulatory system. PTS: 1 REF: Page 105 6. Venous obstruction is a cause of edema because of an increase in which pressure? a. Capillary hydrostatic c. Capillary oncotic b. Interstitial hydrostatic d. Interstitial oncotic ANS: A Venous obstruction can increase the hydrostatic pressure of fluid in the capillaries enough to cause fluid to escape into the interstitial spaces. The remaining options are not causes of edema resulting from venous obstruction. PTS: 1 REF: Page 106 7. At the arterial end of capillaries, fluid moves from the intravascular space into the interstitial space because the: a. Interstitial hydrostatic pressure is higher than the capillary hydrostatic pressure. b. Capillary hydrostatic pressure is higher than the capillary oncotic pressure. c. Interstitial oncotic pressure is higher than the interstitial hydrostatic pressure. d. Capillary oncotic pressure is lower than the interstitial hydrostatic pressure. ANS: B At the arterial end of capillaries, fluid moves from the intravascular space into the interstitial because capillary hydrostatic pressure is higher than the capillary oncotic pressure. PTS: 1 REF: Page 105 8. Low plasma albumin causes edema as a result of a reduction in which pressure? a. Capillary hydrostatic c. Plasma oncotic b. Interstitial hydrostatic d. Interstitial oncotic ANS: C Losses or diminished production of plasma albumin is the only option that contributes to a decrease in plasma oncotic pressure. PTS: 1 REF: Pages 106-107 9. Secretion of antidiuretic hormone (ADH) and the perception of thirst are stimulated by a(n): a. Decrease in serum sodium c. Increase in glomerular filtration rate b. Increase in plasma osmolality d. Decrease in osmoreceptor stimulation ANS: B Secretion of ADH and the perception of thirst are primary factors in the regulation of water balance. Thirst is a sensation that stimulates water-drinking behavior. Thirst is experienced when water loss equals 2% of an individual’s body weight or when osmotic pressure increases. The other options do not accurately describe how ADH and the perception of thirst are related. PTS: 1 REF: Page 109 10. Thirst activates osmoreceptors by an increase in which blood plasma? a. Antidiuretic hormone c. Hydrostatic pressure b. Aldosterone d. Osmotic pressure ANS: D Thirst is experienced when water loss equals 2% of an individual’s body weight or when osmotic pressure increases. Dry mouth, hyperosmolality, and plasma volume depletion activate osmoreceptors (neurons located in the hypothalamus that are stimulated by increased osmotic pressure). The other options do not accurately identify what increases to activate osmoreceptors. PTS: 1 REF: Page 109 11. It is true that natriuretic peptides: a. Decrease blood pressure and increase sodium and water excretion. b. Increase blood pressure and decrease sodium and water excretion. c. Increase heart rate and decrease potassium excretion. d. Decrease heart rate and increase potassium excretion. ANS: A Natriuretic peptides are hormones that include atrial natriuretic peptide (ANP) produced by the myocardial atria, brain natriuretic peptide (BNP) produced by the myocardial ventricles, and urodilatin within the kidney. Natriuretic peptides decrease blood pressure and increase sodium and water excretion. PTS: 1 REF: Page 109 12. When changes in total body water are accompanied by proportional changes in electrolytes, what type of alteration occurs? a. Isotonic c. Hypotonic b. Hypertonic d. Normotonic ANS: A Only isotonic alterations occur when proportional changes in electrolytes and water accompany changes in total body water . PTS: 1 REF: Pages 109-110 13. Which enzyme is secreted by the juxtaglomerular cells of the kidney when circulating blood volume is reduced? a. Angiotensin I c. Aldosterone b. Angiotensin II d. Renin ANS: D When circulating blood volume or blood pressure is reduced, renin, an enzyme secreted by the juxtaglomerular cells of the kidney, is released in response to sympathetic nerve stimulation and decreased perfusion of the renal vasculature. The other options are not released by the situation described in the question. PTS: 1 REF: Pages 108-109 14. What mechanism can cause hypernatremia? a. Syndrome of inappropriate antidiuretic hormone b. Hypersecretion of aldosterone c. Brief bouts of vomiting or diarrhea d. Excessive diuretic therapy ANS: B Hypernatremia occurs because of (1) inadequate free water intake, (2) inappropriate administration of hypertonic saline solution (e.g., sodium bicarbonate for treatment of acidosis during cardiac arrest), (3) high sodium levels as a result of oversecretion of aldosterone (as in primary hyperaldosteronism), or (4) Cushing syndrome (caused by the excess secretion of adrenocorticotropic hormone [ACTH], which also causes increased secretion of aldosterone). The other options do not result in hypernatremia. PTS: 1 REF: Page 111 15. What causes the clinical manifestations of confusion, convulsions, cerebral hemorrhage, and coma in hypernatremia? a. High sodium in the blood vessels pulls water out of the brain cells into the blood vessels, causing brain cells to shrink. b. High sodium in the brain cells pulls water out of the blood vessels into the brain cells, causing them to swell. c. High sodium in the blood vessels pulls potassium out of the brain cells, which slows the synapses in the brain. d. High sodium in the blood vessels draws chloride into the brain cells followed by water, causing the brain cells to swell. ANS: A Hypertonic (hyperosmolar) imbalances result in an extracellular fluid concentration greater than 0.9% salt solution (e.g., water loss or solute gain); cells shrink in a hypertonic fluid (see Table 3-7). This shrinking of cells results in the symptoms described in the question. The other options do not accurately describe the cause of these symptoms as they relate to hypernatremia. PTS: 1 REF: Page 111 16. Vomiting-induced metabolic alkalosis, resulting in the loss of chloride, causes: a. Retained sodium to bind with the chloride b. Hydrogen to move into the cell and exchange with potassium to maintain cation balan

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