BRS Chapter 1 Flashcards
The illustration shows a section of the heart from a 45-year-old African-American man with long-standing hypertension who died of a “stroke.” Which of the following adaptive changes is exemplified in the illustration?
(A) Aplasia (B) Atrophy (C) Hyperplasia (D) Hypertrophy (E) Hypoplasia
The answer is D. The illustration shows marked hypertrophy of the left ventricle. Hypertrophy of this extent, often seen in hypertensive heart disease, is caused by increased workload from increased ventricular pressure. This organ enlargement is the result of an increase in size of the individual muscle cells.
A 16-year-old girl undergoes radiologic imaging of her abdomen and is found to have only one kidney. She had been entirely unaware of this problem. Which of the following terms is most descriptive of this finding?
(A) Agenesis
(B) Atrophy
(C) Hyperplasia (D) Hypoplasia (E) Metaplasia
The answer is A. The patient has renal agenesis, absence of the kidney due to failure of organ development. The congenital lack of one kidney differs from atrophy, in which a decrease in the size of an organ results from a decrease in the mass of preexisting cells. Unilateral renal agenesis is usually a harmless malformation, and the opposite kidney is often enlarged due to compensatory hypertrophy. Bilateral renal agenesis is incom- patible with life and is of special interest since it can lead to the Potter progression (see Chapter 17).
An impending myocardial infarction was successfully averted by thrombolytic (clot-dissolving) therapy in a 55-year-old man. Which of the following biochemical events most likely occurred during the period of hypoxia?
(A) Decreased hydrogen ion concentration
(B) Increase in oxidative phosphorylation
(C) Loss of intracellular Na+ and water
(D) Stimulation of ATP synthesis
(E) Stimulation of anaerobic glycolysis and glycogenolysis
The answer is E. The sequence of events in hypoxic cell damage is as follows: Hypoxia results in failure of oxidative phosphorylation, with resultant depletion of ATP and increase in adenosine monophosphate and adenosine diphosphate. Anaerobic glycolysis and glycogenolysis are stimulated (not inhibited) through increased phosphofructokinase and phosphorylase activities, respectively. This results in an accumulation of cell lactate, with a decrease in intracellular pH and depletion of cellular glycogen stores. Decreased availability of ATP also results in failure of the Na+K+-ATPase pump, which then leads to increased cell Na+ and water and decreased cell K+.
A 45-year-old man with a long his-
tory of alcoholism presents with severe epigastric pain, nausea, vomiting, fever,
and an increase in serum amylase. During
a previous hospitalization for a similar episode, computed tomography scanning demonstrated calcifications in the pancreas. A diagnosis of acute pancreatitis superim- posed on chronic pancreatitis was made. In this condition, which of the following types of necrosis is most characteristic?
(A) Caseous
(B) Coagulative (C) Enzymatic (D) Fibrinoid (E) Liquefactive
The answer is C. Pancreatic enzymatic fat necrosis represents autodigestion by proteolytic and lipolytic enzymes released from damaged parenchymal cells of the pancreas. Fatty acids liberated by the digestion of fat form calcium soaps, a process referred to as saponi- fication. The precipitated calcium in the soaps can be visualized by radiologic imaging.
A 29-year-old man hospitalized for acquired immunodeficiency syndrome (AIDS) is found to have pulmonary tubercu- losis. Which type of necrosis is found in the granulomatous lesions (clusters of modified macrophages) characteristic of this increas- ingly frequent complication of AIDS?
(A) Caseous
(B) Coagulative (C) Enzymatic (D) Fibrinoid (E) Liquefactive
The answer is C. Pancreatic enzymatic fat necrosis represents autodigestion by proteolytic and lipolytic enzymes released from damaged parenchymal cells of the pancreas. Fatty acids liberated by the digestion of fat form calcium soaps, a process referred to as saponi- fication. The precipitated calcium in the soaps can be visualized by radiologic imaging.
A 45-year-old woman is investigated for hypertension and is found to have enlargement of the left kidney. The right kidney is smaller than normal. Contrast studies reveal stenosis of the right renal artery. The size change in the right kidney is an example of which of the following adaptive changes?
(A) Aplasia
(B) Atrophy
(C) Hyperplasia (D) Hypertrophy (E) Metaplasia
The answer is B. The decreased size is due to restriction of the blood supply, one of the causes of atrophy. The increase in size of the opposite kidney is referred to as compen- satory hypertrophy. Unilateral renal artery stenosis is a well-known cause of secondary hypertension. In this setting, increased renin excretion and stimulation of the renin– angiotensin system results in a form of hypertension that is potentially curable by surgi- cal correction of the underlying vascular abnormality.
A 56-year-old man recovered from a myo- cardial infarction after his myocardium was entirely “saved” by immediate thrombolytic therapy. If it had been possible to examine microscopic sections of his heart during his ischemic episode, which of the following would be the most likely cellular change to be found?
(A) Karyolysis
(B) Karyorrhexis
(C) Pyknosis
(D) Swelling of the endoplasmic reticulum
The answer is D. If infarction is averted by immediate thrombolytic therapy, indicators of necrosis, such as karyorrhexis, pyknosis, and karyolysis, which represent irreversible changes, would not be expected. Swelling of the endoplasmic reticulum from increased cell water, one of the earliest ultrastructural changes observed in injured cells, is revers- ible and would be expected.
A 64-year-old woman presents with fever, chills, headache, neck stiffness, vomiting, and confusion. The Kernig sign (passive knee extension eliciting neck pain) and Brudzinski sign (passive neck flexion eliciting bilateral hip flexion) are both positive. Examination of the cerebrospinal fluid reveals changes con- sistent with bacterial meningitis, and brain imaging demonstrates a localized abscess. Which of the following types of necrosis is most characteristic of abscess formation?
(A) Caseous
(B) Coagulative (C) Enzymatic (D) Fibrinoid (E) Liquefactive
The answer is E. Liquefactive necrosis is characteristic of ischemic injury in the CNS and suppurative infections that cause abscess formation (see Chapter 2). The changes in the cerebrospinal spinal fluid characteristic of bacterial meningitis are detailed in Chapter 3.
A 20-year-old man presents with yellow- ing of the sclerae, skin, and oral mucosa. Which of the following accumulations underlies these findings? (A) Bilirubin (B) Hemosiderin (C) Lead (D) Melanin (E) Silver
The answer is A. Yellowing of the sclerae, skin, and oral mucosa are all characteristic of jaundice, the accumulation of bilirubin, the catabolic product of the heme moiety of hemoglobin. Jaundice can occur by diverse mechanisms: hemolytic (see Chapter 11), hepatocellular (see Chapter 16), or obstructive (see Chapter 16).
This figure illustrates the microscopic appearance of the heart of a 56-year-old man who died after a 24-hour hospitalization for severe “crushing” chest pain complicated by hypoten- sion and pulmonary edema. The type of necrosis shown is best described as
(A) caseous.
(B) coagulative. (C) fibrinoid. (D) gangrenous. (E) liquefactive.
The answer is B. The figure illustrates general preservation of myocardial architecture with some fragmentation, more intense cytoplasmic staining corresponding to increased cellular eosinophilia, and loss of nuclei, all of which are characteristics of coagulative necrosis.
The illustration is from a liver biopsy of a 34-year-old woman with a long history of alco-
holism. Which of the following is the best explanation for the changes shown here?
(A) Accumulation of triglycerides within hepatocytes
(B) Apoptosis with replacement of damaged cells by lipid-laden macrophages
(C) Bilirubin accumulation with mobiliza- tion of fat by bile salts
(D) Enzymatic fat necrosis with diges- tion of liver parenchyma by released enzymes
(E) Irreversible damage to mitochondria
The answer is A. The figure illustrates fatty change of the liver, which is characterized by the accumulation of intracellular parenchymal triglycerides. It is seen most frequently in the liver, heart, and kidney and is commonly secondary to alcoholism. Fatty change results from an imbalance between the uptake, utilization, and mobilization of fat from liver cells. Alcoholic fatty liver may be reversible with complete abstinence from alcohol.
A 45-year-old man is referred because of a recent diagnosis of hereditary hemochro- matosis. Which of the following is a correct statement about this disorder?
(A) Damage to organs results from abnormal deposition of lead
(B) It can progress to liver cirrhosis, diabe- tes mellitus, and skin pigmentation
(C) Most cases are due to spontaneous
mutations
(D) Skin hyperpigmentation is due to
bilirubin accumulation
(E) The TIBC is characteristically increased
The answer is B. In advanced form, primary (hereditary) hemochromatosis is character- ized by the triad of cirrhosis, diabetes, and hyperpigmentation, or so-called bronze dia- betes. The disease is most often caused by a mutation in the Hfe gene on chromosome 6 and is characteristically familial rather than sporadic. The manifestations of the disorder are the result of iron overload and deposition of hemosiderin in tissues such as the liver, pancreas, skin, joints, and pituitary. Laboratory abnormalities of note include increased serum iron and decreased TIBC. The skin hyperpigmentation is due largely to increases in melanin and to lesser accumulations of hemosiderin.
A 60-year-old woman with breast cancer and widespread bony metastases is found to have calcification of multiple organs. The calcifications are best described as
(A) dystrophic with decreased serum calcium.
(B) dystrophic with increased serum calcium.
(C) metastatic with decreased serum calcium.
(D) metastatic with increased serum calcium.
The answer is D. Metastatic calcification, or deposition of calcium in previously normal tissue, is caused by hypercalcemia. In this patient, tumor metastases to the bone with increased osteolytic activity caused mobilization of calcium and phosphate, resulting in hypercalcemia. Metastatic calcification should be contrasted with dystrophic calcifica- tion, in which the serum calcium concentration is normal and previously damaged tis- sues are the sites of deposition.
A 56-year-old man dies 24 hours after the onset of substernal chest pain radiating down his left arm to the ulnar aspect of his fingertips. Which of the following morpho- logic myocardial findings is an indicator of irreversible injury? (A) Cell blebs (B) Depletion of glycogen (C) Mitochondrial swelling (D) Myelin figures (E) Pyknotic nuclei
The answer is E. Myelin figures, cell blebs, mitochondrial swelling, and glycogen deple- tion are all signs of reversible injury. Nuclear changes such as pyknosis, karyorrhexis, and karyolysis are signs of cell death and are, of course, irreversible.
