Chapter 2: Altered Cellular and Tissue Biology

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

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

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

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

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

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

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

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

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

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

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

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

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