Combination. 6892 Question number 15 Click here to read comments or post comments about this question
At which of the following sites is the characteristic triple helical structure of the collagen initially formed?
a) Extracellular space b) Golgi body c) Nucleus d) Rough endoplasmic reticulum e) Smooth endoplasmic reticulum
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The correct answer is B
Explanation Collagen formation begins with transcription of mRNA from appropriate DNA genes in the nucleus. While still within the nucleus is spliced. It is then transported through the cytoplasm to the ribosomes on the rough endoplasmic reticulum. Individual chains are the ribosomes, with the ends feeding into the endoplasmic reticulum lumen. Within the lumen, glycosylation of the individual c hai The material then moves toward the Golgi bodies (whose lumens are connected to the endoplasmic reticulum) where the triple heli procollagen form. The procollagen is then secreted into the extracellular space, where cleavage of pro -peptides and cross- linking triple helices occurs, maturing the collagen. The extracellular space (choice A) is the site of procollagen cleavage and cross- linkin nucleus (choice C) is the site of mRNA transcription and splicing. The rough endoplasmic reti culum (choice D) is the site of chain and glycosylation. The smooth endoplasmic reticulum (choice E) does not participate in collagen synthesis
Combination. 6853 Question number 16 Click here to read comments or post comments about this question
A 6-month-old boy is brought to the pediatrician by his parents, who are first cousins. This is their first child. Physical examinatio small, thin, lethargic infant with slightly misshapen long bones. His features are somewhat coarse. Joint movements are restricted, are clouded, and his gums are underdeveloped. His liver is not enlarged. Serum levels of acid hydrolases are found to be elevated. most likely has a defect in which of the following metabolic activities?
a) Degradation of dermatan sulfate a nd heparan sulfate b) Degradation of gangliosides c) Degradation of glycogen d) Degradation of sphingomyelin e) Phosphorylation of mannose moieties
You have not attempted this question.
The correct answer is E
Explanation The patient has I-cell disease, also known as mucolipidosis II, which is due to a defective UDP-N-acetylglucosamine-1-phosphotr enzyme that phosphorylates mannose on enzymes destined for lysosomes. Proteins coded by nuclear DNA are synthesized on cyto ribosomes, which may be either "free" or associated with the endoplasmic reticulum to form the rough endoplastic reticulum (RE synthesized on the RER are transferred into the Golgi apparatus, where they undergo further modifications that determine whether part of the Golgi apparatus, become part of the plasma membrane, or are shipped to lysosomes or mitochondria. Prot eins not mark transport to a specific intracellular site follow the default pathway and are exported into the extracellular compartment. The signal of the acid hydrolases (and probably other enzymes) to the lysosomes is phosphorylation of a terminal mannose moiety on an N-li oligosaccharide to form mannose 6-phosphate. In I-cell disease, this terminal mannose moiety is not phosphorylated, and the acid follow the default pathway and are secreted. Deficiency of alpha-L-iduronidase results in lysosomal accumulation of dermatan sul heparan sulfate (choice A) in several conditions such as mucopolysaccharidosis I, Hurler's disease, or Hurler's/Scheie disease. Hex A deficiency (Tay-Sachs disease) is one example of a condition in which ganglioside accumulation occurs (choice B). There are a diseases in which glycogen degradation (choice C) is defective. These are coll ectively termed glycogen storage diseases since they abnormal cellular accumulation of glycogen. In Pompe's disease, or type II glycogen storage disease, a lysosomal glucosidase i s d resulting in lysosomal glycogen accumulation. Deficiency of sphingomyelinase (choice D), an enzyme involved in degradation of sphingomyelin, results in Niemann-Pick disease. Phosphorylation of tyrosine moieties (choice F) is unrelated to lysosomes or lyso
enzymes; however, decreased ability to phosphorylate tyrosine moieties might be associated with diabetes or dwarfism. .
Combination. 6934 Question number 17 Click here to read comments or post comments about this question
A child has a history of recurrent infections with organisms having polysaccharide antigens (i.e., Streptococcus pneumoniae and H influenzae). This susceptibility can be explained by a deficiency of
a) C3 nephritic factor b) C5 c) IgG subclass 2 d) myeloperoxidase in phagocytic cells e) secretory IgA
You have not attempted this question.
The correct answer is C
Explanation IgG is the predominant antibody in the secondary immune response. IgG subclass 2 is directed against polysaccharide antigens an in the host defense against encapsulated bacteria. C3 nephritic factor (choice A) is an IgG autoantibody that binds to C3 convertas resistant to inactivation. This leads to persistently low serum complement levels and is associated with Type II membranoprolifera glomerulonephritis. C5 (choice B) is a component of the complement system. C5a is an anaphylatoxin that effects vasodilatation i inflammation. It is also chemotactic for neutrophils and monocytes and increases the expression of adhesion molecules. A deficien would affect the acute inflammatory response against any microorganism or foreign substance. Myeloperoxidase in phagocytic cel is an element of the oxygen-dependent pathway present in phagocytic cells that effectively kills bacterial cells. The hydrogen pero complex is considered the most efficient bactericidal system in neutrophils. Chronic granulomatous disease is associated with a de NADPH oxidase, which converts molecular oxygen to superoxide (the first step in the myeloperoxidase system). Patients are sus c granulomatous infections and staphylococcal infections. Secretory IgA (choice E) is the immunoglobulin associated with mucous Selective IgA deficiency is the most common hereditary immunodeficiency. In this disorder, there i s failure of the B cell to switch chain class from IgM to IgA. Patients have an increased incidence of sinopulmonary infections, diarrhea, allergies, and autoimmu
Combination. 1185 Question number 18 Click here to read comments or post comments about this question
Which of the following is true of the optic disc?
a) no arteries pass through it b) no veins pass through it c) it appears dark r ed on fundoscopy d) contains a concentration of photoreceptors e) it is normally less than 1cm in diameter
You have not attempted this question.
The correct answer is E
Explanation This is the point at which axons leave the eyeball and join the optic nerve. Also, arteries enter and veins leave the retina at the opti are no photoreceptors here, hence it is known as the 'blind spot'. It is a pinky-yellow oval, approximately 2mm in diameter, and sit nasal retina 
Combination. 1189 Question number 19 Click here to read comments or post comments about this question
what suspensory ligaments connect the outer edge of the lens of the eye with the ciliary processes?
a) zonnules of Zinn b) zonnules of Schlemm c) cruciate ligaments d) ligaments of Treitz e) ciliary ligaments
You have not attempted this question.
The correct answer is A
Explanation Also known as the suspensory ligament, the Zonnules of Zinn comprise a network of collagen fibres which connect the outer edge with the ciliary processes. In this hammock of fine fibres lies the lens. To the right is the margin of the vitreous humour, to the left posterior chamber, which lies between the zonnules and the iris. Below in the ciliar y processes lie cells which are excreting aq ueo which flows to the pupil.
Combination. 6852 Question number 20 Click here to read comments or post comments about this question
A 35-year-old woman notices a change in the appearance of a mole on her neck. Physical examination reveals that the lesion is an irregular, nodular, superficial mass with a variegated appearance. Biopsy demonstrates a primary malignant tumor. Which of the following factors is most predictive of the patient's long term prognosis?
a) Circumference of lesion b) Darkness of lesion c) Degree of color variation
d) Depth of lesion e) Sharpness of border between lesion and adjacent skin
You have not attempted this question.
The correct answer is D
Explanation The lesion is a malignant melanoma. Melanomas can develop either de novo or in an existing mole. Sunlight exposure is a signific factor and fair-skinned persons are at increased risk of developing melanoma. The most significant factor for long term prognosis i of the lesion, since the superficial dermis lies about 1 mm under the skin surface, and penetration to this depth is associated with a incidence of metastasis than is seen with a more superficial location. The circumference of the lesion (choice A) is much less impo depth, since one form of melanoma (superficial spreading) can still have good prognosis despite large size, if it has not extended t the superficial dermal lymphatic bed. The darkness (choice B) or degree of variation in color (choice C) do not have prognostic si once melanoma is diagnosed. Irregularity, or fuzziness at the border (choice E) of a mole-like lesion is a good clue to potential ma does not affect prognosis once a melanoma i s diagnosed.
A 10-year-old male presents to the pediatrician because of problems while eating. He can chew food but has problems swallowing the chewed pieces, and feels them in his throat. A radiographic study is performed that shows normal musculature but abnormal esophageal peristalsis. No masses are seen. Which of the following nerves should be tested for abnormalities? A. Hypoglossal and phrenic B. Hypoglossal and splanchnic C. Glossopharyngeal and vagus D. Phrenic and vagus E. Splanchnic and vagus Answer -------------------------------------------------------------------------------2A 40-year-old man with adult polycystic kidney disease is brought to the emergency room in a coma. CT scan of the head demonstrates a subarachnoid hemorrhage without parenchymal hemorrhage. Which of the following is the most likely source of the bleeding? A. AV malformation B. Bridging veins C. Charcot-Bouchard aneurysm D. Circle of Willis
E. Middle meningeal artery Answer -------------------------------------------------------------------------------3An unconscious patient with sepsis in the intensive care unit undergoes a 2-hour period of severe hypotension. Blood chemistries taken during the following 48 hours show rising creatine kinase MB fraction (CK-MB), peaking at 5 times the upper limit of normal. ECG findings are equivocal, with some degree of flat S -T segment depression over several leads. Which of the following is the most likely diagnosis? A. Prinzmetal angina B. Stable angina C. Subendocardial infarction D. Transmural infarction E. Unstable angina Answer -------------------------------------------------------------------------------4A 65 year-old man is admitted to the coronary care unit with a diagnosis of a large myocardial infarct (MI) of the left ventricle. On his 6th postinfarct day, he goes into shock and dies, manifesting signs and symptoms of cardiac tamponade. Which of the following complications is the most likely cause of this patient's dea th? A. Aortic dissection B. Extension of previous MI C. Fatal arrhythmia D. Rupture of the left ventricular wall E. Rupture of papillary muscle Answer -------------------------------------------------------------------------------5A newborn appears normal at birth, but develops vomiting and diarrhea accompanied by jaundice and hepatomegaly within the first few weeks of life. Within months, the baby has obvious cataracts and ascites. The infant is switched to a milk-free diet, which stabilizes but does not completely reverse his condition. By one year of age, he has developed mental retardation. Which of the following is the most likely diagnosis? A. Cystic fibrosis B. Galactosemia C. McArdle's disease D. Von Gierke's disease E. Wilson's disease Answer
-------------------------------------------------------------------------------6A 25-year-old man presents with headache, dizziness, and claudication. Blood pressure measurements reveal hypertension in the upper limbs and hypotension in the lower limbs. Which of the following additional findings would be most likely in this case? A. Aortic valvular stenosis B. Notching of inferior margins of ribs C. Patent ductus arteriosus D. Pulmonary valvular stenosis E. Vasculitis involving the aortic arch Answer -------------------------------------------------------------------------------7A patient has a tiny (0.2 cm), but exquisitely painful tumor under the nail of her index finger. Prior to surgery to remove it, local anesthetic block to a branch of which of the following nerves would be most likely to achieve adequate anesthesia? A. Axillary nerve B. Median nerve C. Musculocutaneous nerve D. Radial nerve E. Ulnar nerve Answer -------------------------------------------------------------------------------8Tissue from a spontaneous abortion is submitted to the laboratory, where an astute pathologist notes the presence of mature fetal tissue that contains Barr bodies. The fetus may have had which of the following genotypes? A. Classic Turner syndrome (45, X) B. Edward's syndrome (47, XY+1Cool C. Klinefelter's syndrome (47, XXY) D. Normal male (46, XY) E. XYY syndrome (47, XYY) Answer --------------------------------------------------------------------------------
9A 78-year-old woman is brought to the emergency department because of slowly developing confusion over the past ten days. Careful physical examination demonstrates a relatively small laceration of the scalp. CT of the head would be most likely to reveal which of the following? A. Epidural hematoma
B. Mixed parenchymal and subarachnoid hemorrhage C. Multiple tiny hemorrhages of the putamen D. Subarachnoid hemorrhage E. Subdural hematoma Answer -------------------------------------------------------------------------------10A 22-year-old woman presents to her physician with amenorrhea, weight loss, anxiety, tremor, heat intolerance and palpitations. Laboratory examination is consistent with hyperthyroidism, and the physician prescribes propylthiouracil. The patient's response to propylthiouracil is disappointing, and the symptoms recur, then worsen. Subtotal thyroidectomy is successfully performed, but following the surgery, the woman is extremely hoarse, and can barely speak above a whisper. This hoarseness is most probably related to damage to a branch which of the following cranial nerves? A. Facial B. Glossopharyngeal C. Hypoglossal D. Trigeminal E. Vagus Answer -------------------------------------------------------------------------------11A 24-year-old female is brought to the emergency room after threatening to kill herself by cutting her wrists. She has multiple scars on her wrists, which she admits were caused by prior suicide attempts. She states she is very angry at her boyfriend, who left her for another woman. She previously thought her boyfriend was an angel and now she thinks he is a monster. She feels very empty inside. While smiling, she states that she is depressed. During the interview, she drops to the ground, but continues to talk while lying on the floor . She believes nobody understands her. What is her underlying personality disorder? A. Antisocial B. Borderline C. Histrionic D. Narcissistic E. Schizoid Answer -------------------------------------------------------------------------------12A high school basketball player passes out in the middle of a game. He is rushed to the emergency room, where he regains consciousness. He
claims that just before he fainted, he had difficulty breathing and experienced palpitations. On physical exam, he has a bifid apical impulse and a coarse systolic murmur at the left sternal border. The echocardiogram reveals ventricular hypertrophy with asymmetric septal thickening. Which of the following would increase the intensity of his heart murmur? A. Elevating his legs B. Increasing sympathetic tone C. Performing the Valsalva maneuver D. Squatting Answer -------------------------------------------------------------------------------13A 63-year-old man complains of trouble swallowing and hoarseness. On physical exam, he is noted to have ptosis and a constricted pupil on the left, and a diminished gag reflex. Neurological examination shows decreased pain and temperature sensation on the left side of his face and on the right side of his body. Which of the following vessels is most likely occluded? A. Anterior inferior cerebellar artery (AICA) B. Anterior spinal artery C. Middle cerebral artery (MCA) D. Posterior cerebral artery (PCA) E. Posterior inferior cerebellar artery (PICA) Answer -------------------------------------------------------------------------------14Examination, at autopsy, of the brain of a man who died in an intensive care unit demonstrates bilateral, linear, parasagittal areas of coagulative necrosis in the junctional zone between the anterior and medial cerebral arterial systems. Which of the following is the most likely etiology? A. Bacterial infection B. Fungal infection C. Ischemia D. Tumor E. Viral infection Answer -------------------------------------------------------------------------------15A 55-year-old woman presents to her physician after several episodes of syncope. Physical examination is remarkable for a low-pitched "plopping" sound during mid-systole. Two-dimensional echocardiography demonstrates a
ball-valve type obstruction of the mitral valve. Which of the following would most likely be observed if the cause of the obstruction were biopsied? A. Benign glandular tissue B. Densely packed smooth muscle C. Densely packed striated muscle D. Malignant glandular tissue E. Scattered mesenchymal cells in a myxoid background Answer -------------------------------------------------------------------------------16The presence of which of the following features in an atherosclerotic plaque indicates that it has become a complicated lesion? A. Cholesterol crystals B. Chronic inflammatory cells C. Intimal smooth muscle D. Lines of Zahn E. Necrotic cell debris Answer -------------------------------------------------------------------------------17A 46-year-old woman presents to her physician with "double vision" and is unable to adduct her right eye on attempted left lateral gaze. Convergence is intact. Both direct and consensual light reflexes are normal. Which of the following structures is most likely to be affected? A. Left oculomotor nerve B. Medial longitudinal fasciculus C. Right abducens nerve D. Right oculomotor nerve E. Right trochlear nerve Answer -------------------------------------------------------------------------------18A patient arrives in the emergency room after having suffered severe head trauma in a motorcycle accident. Radiographic studies of the head reveal a basilar skull fracture in the region of the foramen ovale. Which of the following functional losses would most likely be related to this injury? A. Loss of abduction of the eye B. Loss of sensation over the forehead C. Loss of sensation over the zygoma D. Loss of taste sensation on the anterior 2/3 of the tongue E. Paralysis of muscles of mastication Answer
-------------------------------------------------------------------------------19A 64-year-old man has a myocardial infarction, and is hospitalized. He is seen by a cardiologist, who orders echocardiographic studies, which demonstrate a portion of the apex of the left ventricle that bulges outward during systole and inward during diastole. This finding is most likely related to disease involving which of the following structures? A. Aortic valve B. Circumflex artery C. Left anterior descending artery D. Mitral valve E. Tricuspid valve Answer -------------------------------------------------------------------------------20A mailman gets a severe bite wound from a pit bull guarding a junkyard. The wound is cleansed and he receives a booster injection of tetanus toxoid and an injection of penicillin G. Several days later, the wound is inflamed and purulent. The exudate is cultured on blood agar and yields gram-negative rods. Antibiotic sensitivity tests are pending. The most likely agent to be isolated is A. Bartonella henselae B. Brucella canis C. Clostridium tetani D. Pasteurella multocida E. Toxocara canis Answer -------------------------------------------------------------------------------21A 7-year-old boy is referred to a specialty clinic because of digestive problems. He often experiences severe abdominal cramps after eating a high fat meal. He is worked up and diagnosed with a genetic defect resulting in a deficiency of lipoprotein lipase. Which of the following substances would most likely be elevated in this patient's plasma following a fatty meal? A. Albumin-bound free fatty acids B. Chylomicrons C. HDL D. LDL E. Unesterified fatty acids Answer -------------------------------------------------------------------------------22A 10-year-old girl who is a suspected victim of child abuse is
referred to a psychologist for evaluation. As part of her workup, the patient is asked to construct a story based on pictures. Which of the following psychometric measures was utilized? A. Minnesota Multiphasic Personality Inventory B. Myers-Briggs Personality Inventory C. Rorschach Test D. Thematic Apperception Test E. Type A and B Behavior Patterns Test Answer -------------------------------------------------------------------------------23Which of the following enzymes is located at arrow 1 in the electron micrograph above? A. Carnitine acyltransferase II B. Fatty acyl CoA synthetase C. Glucose-6-phosphate dehydrogenase D. Hexokinase E. Pyruvate kinase Answer -------------------------------------------------------------------------------24A 22-year-old female college student is brought into the emergency room by the police, who found her walking back and forth across a busy street, talking to herself. The young woman appears to be oriented with respect to person, place, and time. Her first hospital admission was two months ago for a similar condition. During a psychiatric interview, she has difficulty concentrating, and seems to hear voices . A phone call to her sister provides the additional information that the girl dropped out of school three months ago and has been living on the street. Urine toxicology is n This patient is most likely exhibiting the signs and symptoms of A. schizoaffective disorder B. schizoid personality disorder C. schizophrenia D. schizophreniform disorder E. schizotypal personality disorder Answer -------------------------------------------------------------------------------25A 42-year-old man has just been informed that he has poorly differentiated small cell carcinoma of the lung. When asked if he understands the serious nature of his illness, the patient proceeds to tell his physician how excited he is about renovating his home. This patient is exhibiting
A. denial B. displacement C. projection D. rationalization E. reaction formation F. sublimation Answer -------------------------------------------------------------------------------26An increase in which of the following best explains the mechanism by which the cardiac output increases in severe anemia? A. Arteriolar diameter B. Blood viscosity C. Peripheral vascular resistance D. Splanchnic blood flow E. Tissue oxygen tension Answer -------------------------------------------------------------------------------27A 2-year-old retarded child is evaluated by a metabolic specialist. The child's history is significant for failure to thrive and progressive neurologic deterioration, including deafness and blindness. Physical examination is remarkable for hepatosplenomegaly, as well as a cherry-red spot on funduscopic examination. These symptoms are consistent with a diagnosis of A. Hunter syndrome B. Niemann-Pick disease C. Pompe's disease D. tyrosinosis E. von Gierke's disease Answer -------------------------------------------------------------------------------28An 8-month-old female child is brought to medical attention because her first four teeth show several discrete, discolored, circumferential bands that show very little enamel. Excessive levels of which of the following may have produced this defect? A. Bilirubin B. Fluoride C. Parathormone D. Thyroid hormone E. Vitamin C Answer --------------------------------------------------------------------------------
29Which of the following complications is currently the major limitation to the long-term success of cardiac transplantation? A. Allograft rejection B. Graft arteriosclerosis C. Graft atherosclerosis D. Opportunistic infections E. Lymphoma Answer -------------------------------------------------------------------------------30A child develops a tumor of the cerebellum. Biopsy reveals evidence of both neuronal and glial differentiation. Which of the following is the most likely diagnosis? A. Astrocytoma B. Glioblastoma multiforme C. Medulloblastoma D. Meningioma E. Oligodendroglioma Answer -------------------------------------------------------------------------------31A 56-year-old man visits his physician with complaints of complete exhaustion after mowing the lawn in his small front yard. He also complains of dizziness, irritability, difficulty sleeping, and loss of libido. On physical examination, the man's skin, conjunctiva, and oral mucosa are pale. A blood test indicates the man's hemoglobin is 7 g/dL. Which of the following findings is also likely to be present in this man? A. Bradycardia B. Cyanosis C. Low stroke volume D. Warm hands E. Wide pulse pressure Answer -------------------------------------------------------------------------------32A 55-year-old man had been in good health since receiving a heart transplant for severe atherosclerotic disease. Five years after transplantation, the patient died suddenly, without any premonitory symptoms, while working in his garden. He had been maintained on cyclosporin since his transplant. Which of the following complications would most likely be found at autopsy in the transplanted heart? A. Allograft rejection
B. Atherosclerosis of coronary arteries C. Graft vascular disease D. Hyaline arteriolosclerosis E. Hyperplastic arteriolosclerosis Answer -------------------------------------------------------------------------------33An elderly lady is brought to the emergency room after drinking insecticide that she thought was tea. After her stomach is pumped , her sense of smell is tested and it is found that she can not distinguish common smells (e.g., an orange, coffee). CT scan of the head demonstrates a mass in the olfactory groove area. The axons likely compressed by this mass project to which of the following structures? A. Insula B. Nucleus ambiguus C. Post-central gyrus D. Pre-central gyrus E. Pyriform cortex Answer -------------------------------------------------------------------------------34A 27-year-old man develops bilateral parotid gland swelling and orchitis, and is generally ill with fever of 102° F. Which of the following substances is most likely to be significantly elevated in the patient's serum? A. Alanine aminotransferase (ALT) B. Amylase C. Aspartate aminotransferase (AST) D. Ceruloplasmin E. Creatine phosphokinase, MB isoenzyme (CPK-MB) Answer -------------------------------------------------------------------------------35A 55-year-old man presents to the emergency room with crushing substernal pain and left shoulder pain of 2 hours duration. The pain is not relieved by sublingual nitroglycerin, and the electrocardiogram shows ST elevation in several leads. Aspirin and streptokinase therapy are initiated, and the patient is admitted to the intensive care unit. The next morning, serum cardiac enzymes are elevated to 4 times the upper limit of normal, and the electrocardiographic changes are still present. Which of the following is the most likely diagnosis?
A. Prinzmetal's angina B. Stable angina C. Subendocardial infarction D. Transmural infarction E. Unstable angina Answer -------------------------------------------------------------------------------36Which of the following amino acids is post-translationally hydroxylated in the cytoplasm of fibroblasts? A. Cysteine B. Glycine C. Proline D. Serine E. Tyrosine Answer -------------------------------------------------------------------------------37Microscopic examination of a cancer cell reveals a cell in an abnormal telophase in which three clusters of chromosomes are seen. An abnormality of which of the following would be most likely to produce this alteration? A. Chiasma B. Mitotic spindle C. Mosaicism D. Polar body E. Synapsis Answer -------------------------------------------------------------------------------38A 58-year-old man with fainting spells and exercise intolerance is found to have a bicuspid aortic valve with marked aortic stenosis. Which of the following physical findings would be prominent in this patient? A. Diastolic murmur B. Heave at left parasternal border C. Loud S2 heart sound D. Loud S3 heart sound E. Weak peripheral pulse Answer -------------------------------------------------------------------------------39A 57-year-old female is found unconscious on her kitchen floor after having suffered a myocardial infarction. She has pulmonary
edema and distended jugular and peripheral veins. A midsystolic gallop is heard upon chest auscultation. EKG shows prominent Q waves in leads II, III, and aVF. Which of the following is most consistent with the patient's condition? Preload Cardiac output PAWP CVP Vascular resistance Mixed venous oxygen A. Increased Decreased Decreased Increased Increased Decreased B. Increased Increased Decreased Decreased Decreased Increased C. Increased Decreased Increased Increased Increased Decreased D. Increased Increased Increased Increased Decreased Decreased E. Decreased Decreased Increased Decreased Increased Decreased F. Decreased Increased Decreased Increased Decreased Increased G. Decreased Decreased Increased Decreased Decreased Decreased Answer --------------------------------------------------------------------------------
40A 48-year-old man complaining of chest pain is brought to the emergency room. Physical examination followed by echocardiography demonstrates aortic stenosis. His coronary blood flow is increased. Which of the following is the most likely explanation for the increased coronary blood flow in this individual? A. Decreased left ventricular oxygen consumption B. Decreased left ventricular pressure C. Decreased left ventricular work D. Increased cardiac tissue adenosine concentration E. Increased cardiac tissue oxygen concentration Answer -------------------------------------------------------------------------------41A 45-year-old man presents to the emergency department with severe headache and vomiting. A CT scan shows a well-circumscribed cystic lesion within the 3rd ventricle; there is no calcium deposition. The cyst is surgically removed. On histologic examination, the wall of the cyst consists of a single layer of mucin-producing columnar epithelium with a ciliated apical surface. Which of the following is the most likely diagnosis? A. Colloid cyst B. Craniopharyngioma C. Cysticercosis D. Echinococcus cyst E. Pilocytic astrocytoma Answer --------------------------------------------------------------------------------
42A 36-year-old female is brought to the emergency room by her husband who says that she "complained of a severe headache then lost consciousness." She has a history of hyp and had been on several different medications. The examining physician notes that she is unable to m arms and legs, but can blink her eyes. When the physician asks her to blink twice if she can hear him, s promptly does so. In which of the following structures is this woman's lesion most likely located? A. Cervical spinal cord B. Medulla oblongata C. Midbrain D. Pons E. Thalamus Answer -------------------------------------------------------------------------------43A 71-year-old man has been in excellent health, and practicing competently as an attorney. He is brought to the emergency room following a motor vehicle accident. A workup, including imaging of the spine, thorax, and head, is negative, but the patient is admitted for overnight observation. His injuries include several lacerations to the face and extremities as well as several contusions to the thorax. Three weeks later, he is admitted to the hospital for confusion. A neurologic exam is normal except that he is not oriented to time or place, and can recall only 1 out of 6 objects after 3 minutes. Which of the following is the most likely diagnosis? A. Alzheimer's disease B. Brain metastases C. Epidural hematoma D. Normal pressure hydrocephalus E. Subdural hematoma Answer -------------------------------------------------------------------------------44A work diagram showing changes in left ventricular volume and pressure during one cardiac cycle is shown above for a normal heart (diagram A) and following aortic valvular disease (diagram B). Diagram B shows which of the following compared to diagram A? A. Decreased work for a greater stroke volume B. Decreased work for a lower stroke volume C. Decreased work for the same stroke volume D. Increased work for a greater stroke volume E. Increased work for a lower stroke volume F. Increased work for the same stroke volume Answer --------------------------------------------------------------------------------
45An 80-year-old woman dies after a long history of progressive memory loss, apraxia, and recurrent episodes of confusion. In the last months of life she was bedridden and unable to recognize familiar faces and objects. The pathologist identifies numerous flame-shaped intracytoplasmic inclusions in neurons of the neocortex and hippocampus. These consist of paired helical filaments (PHFs) on electron microscopy. Which of the following biochemical changes most likely accounts for the development of PHFs in this condition? A. Abnormal degradation of amyloid precursor protein (APP) B. Abnormal phosphorylation of tau C. Accumulation of advanced glycosylation end (AGE) products D. Increased expression of APP E. Precipitation of insoluble a-tubulin Answer -------------------------------------------------------------------------------46The activity of which of the following enzymes is directly affected by citrate? A. Fructose-2,6-bisphosphatase B. Isocitrate dehydrogenase C. Phosphofructokinase I D. Pyruvate carboxylase E. 6-phosphogluconate dehydrogenase Answer -------------------------------------------------------------------------------47While a physician is using a water-filled syringe to expel wax from t he ear canal of an elderly patient, the man suddenly faints. This event can be explained by the fact that the posterior half of the external ear canal receives sensory innervation from the A. auricular branch of the vagus nerve B. auriculotemporal nerve C. greater auricular nerve D. lesser occipital nerve E. vestibulocochlear nerve Answer -------------------------------------------------------------------------------48Which of the following structures is found only in Gram-negative microorganisms? A. Cell envelope B. Exotoxin C. Peptidoglycan D. Periplasmic space
E. Teichoic acids Answer -------------------------------------------------------------------------------49A scientist wishes to study free radical production under ischemic conditions. He decides to produce cerebral ischemia by tying off an artery of the brain. Ligation of which of the following arteries would be most likely to produce significant ischemic damage? A. Anterior cerebral artery at its origin from the internal carotid artery B. Anterior communicating artery C. Middle cerebral artery at its origin from the internal carotid artery D. Posterior cerebral artery at its origin from the basilar artery E. Posterior communicating artery Answer -------------------------------------------------------------------------------50A 52-year-old woman has long-standing rheumatoid arthritis (RA) and is being treated with corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs). Which of the following cardiac complications may arise in this clinical setting? A. Constrictive pericarditis B. Dilated cardiomyopathy C. Hypersensitivity myocarditis D. Hypertrophic cardiomyopathy E. Restrictive cardiomyopathy Answer -------------------------------------------------------------------------------Answers -------------------------------------------------------------------------------1The correct answer is E. The upper 2/3 of the esophagus contains striated muscle. It is derived from t pharyngeal arches and innervated by the vagus nerve (CN X). The lower 1/3 contains smooth muscle f splanchnic mesoderm and is innervated by the splanchnic plexus. The hypoglossal nerve (choices A and B), or CN XII, moves the tongue. The phrenic nerve (choices A and D), derived from C3, C4, and C5, innervates the muscle of the diaphr The glossopharyngeal nerve (choice C), or CN IX, functions in taste, swallowing, and sa livation, as well monitoring the activity of the carotid body. -------------------------------------------------------------------------------2The correct answer is D. Two relationships are useful in solving this problem. The first relationship is polycystic kidney disease has a specific association with berry aneurysms involving the circle of Willis branches. The second relationship is that spontaneous subarachnoid hemorrhages are most often the bleeding from berry aneurysms. The berry aneurysms develop at sites of congenital weakness (near b points) of the relatively unsupported vessels of the circle of Willis. AV malformations (choice A) tend to produce mixed parenchymal and subarachnoid hemorrhages.
Rupture of bridging veins (choice B) produces a subdural hematoma. Rupture of Charcot-Bouchard aneurysms (choice C) can be seen with hypertension (which may compli polycystic kidney disease). Such rupture produces intraparenchymal hemorrhage, which if severe, ma to the subarachnoid space. Rupture of the middle meningeal artery (choice E) produces epidural hematoma --------------------------------------------------------------------------------3The correct answer is C. The high seru indicates that the patient has sustained an infarction rather than angina. Subendocardial, rather than transmural, infarction is most likely in the setting of known, prolonged severe hypotension, and the eq nature of the ECG findings confirms this diagnosis. Subendocardial infarction occurs in settings of gen poor perfusion complicated by increased demand or transient vasospasm. Subendocardial muscle tiss especially vulnerable because it is farthest from the arterial supply. In Prinzmetal angina (choice A) and stable angina (choice B), the CK-MB would not be expected to incr significantly. Transmural infarction (choice D) is not specifically expected in the setting of shock. It produces charac ECG changes that are usually localized (unless a very large infarct has occurred) to a few leads. In unstable angina (choice E), an increase in cardiac enzymes may be s een, but is usually less than 2 ti upper limit of normal. --------------------------------------------------------------------------------4The correct answer is D. Rupture of th ventricular wall is a frequently fatal complication that may occur in the first week after myocardial inf (MI). At this stage, the infarcted area is composed of friable necrotic myocardium and early granulatio is during this crucial phase, therefore, that rupture usually occurs. Blood rushes out, filling the pericar and causing compression of the left ventricle. Cardiac tamponade ensues, and the patient usually dies cardiogenic shock. Aortic dissection (choice A) is not a complication of MI, although cardiac tamponade may also follow t condition when dissection works its way back toward the aortic root. Aortic dissection usually develo aortas affected by cystic medial degeneration (CMD), which is due to fragmentation of elastic laminae accumulation of myxoid material in the aortic media. CMD may be either sporadic or associated with syndrome. Extension of a previous MI (choice B) may occur in the first few hours or days after MI. It may aggrava precipitate cardiogenic shock and/or arrhythmias, but it does not cause cardiac tamponade. Arrhythmias (choice C) are frequent complications of MI and are often fatal, producing cardiac a rrest (ventricular fibrillation) or aggravating cardiac dysfunction. If infarction involves papillary muscles, these may rupture (choice E). This complication is followed by dysfunction and may manifest with signs of mitral regurgitation and acute congestive heart failure. --------------------------------------------------------------------------------5The correct answer is B. Galactosemia autosomal recessive disease caused by a deficiency of galactose-1-phosphate uridyltransferase, which necessary for the metabolism of the galactose derived from milk lactose. The condition should be susp infants with growth failure, cataracts, liver disease, aminoaciduria, and mental retardation. A reducing (galactose) is usually present in the urine. Most of the pathology is related to the toxic effects of galact phosphate. Treatment involves strict dietary lactose restriction, which consists of more than simply w of milk products, because lactose is also present in many non-diary foods. Strict adherence to the diet strikingly alter the course of this disease. Cystic fibrosis (choice A) is associated with maldigestion, pancreatic disease, and pulmonary disease. McArdle's disease (choice C) is a glycogen storage disease that selectively affects muscle.
Von Gierke's disease (choice D) is a glycogen storage disease affecting the liver and kidneys. Wilson's disease (choice E) is a caused by a metabolic abnormality in the handling of copper that ca n c cirrhosis and brain damage, and usually presents in adolescence. -------------------------------------------------------------------------------6The correct answer is B. The adult form of aortic coarctation is caused by stenosis in the aortic arch j to the left subclavian artery. This leads to hypertension proximal to, and hypotension distal to, the ste segment. Hypertension in the upper part of the body manifests with headache, dizziness, and other ne symptoms. Hypotension in the lower part of the body results in signs and symptoms of ischemia, most claudication, i.e., recurrent pain due to ischemia of leg muscles. In addition, collateral arteries between precoarctation and postcoarctation aorta (eg, the intercostal and internal mammary arteries) enlarge establish communication between aortic segments proximal and distal to stenosis. Enlarged intercosta produce notching of the inferior margins of the ribs, which can be detected on x-ray and is diagnostic condition. Remember that the infantile form of aortic coarctation is associated with patent ductus arte whereas the adult form is not. Aortic valvular stenosis (choice A) at this age would most likely be caused by a congenitally malforme usually a valve with two cusps or a single cusp. Aortic stenosis manifests with systolic hypotension, re syncope, and hypertrophy/dilatation of the left ventricle. Low systolic pressure is present in the entire The isolated form of patent ductus arteriosus (choice C) leads to shunting of blood from the aorta (hig vessel) to the pulmonary artery (low-pressure vessel). Eventually, chronic cor pulmonale develops wit resultant right-sided heart failure. Pulmonary valvular stenosis (choice D) is a rare form of congenital heart disease that leads to chronic pulmonale and heart failure. Vasculitis involving the aortic arch (choice E) is found in Takayasu arteritis, in which chronic inflamm changes develop in the aortic arch and its branches (brachiocephalic trunk, left common carotid, and l subclavian arteries). This condition causes stenosis of these arteries; therefore, there will be signs and symptoms of ischemia to the upper part of the body. Since the radial pulses are very weak or absent, t disorder is also known as pulseless disease. --------------------------------------------------------------------------------7The correct answer is B. The tumor in is probably a glomus tumor, which is a benign tumor notorious for producing pain far out of proportio small size. The question is a little tricky (but important clinically for obvious reasons) because it turns the most distal aspect of the dorsal skin of the fingers, including the nail beds, is innervated by the pal nerves rather than the dorsal digital nerves. Specifically, the median nerve through its palmar digital n supplies the nail beds of the thumb, index finger, middle finger, and hal f of the ring finger. The axillary nerve (choice A), musculocutaneous nerve (choice C), and radial nerves (choice D) do not nail beds. The radial nerve does supply the more proximal skin of the back of the index finger. The ulnar nerve ( supplies the nail beds of the small and half of the ring finger. --------------------------------------------------------------------------------8.The correct answer is C. The Barr bod chromatin body, is an inactivated X chromosome seen as a small, perinuclear, dark-staining dot in som with two or more X chromosomes. Barr bodies are seen in any individual born with at least two X chro including normal females. (47, XXY), the classic karyotype of Klinefelter's syndrome, is defined as male hypogonadism due to the presence of a Y chromosome and two or more X's. As in normal females, one chromosomes becomes a Barr body in Klinefelter's syndrome. Classic Turner syndrome females (choice A) and genotypically normal males (choice D) have o nly one
chromosome. Thus, no X chromosome is inactivated, and somatic cells do not show any Barr bodies. (47, XY+1Cool is the karyotype of an Edward's syndrome (choice B) fetus. Although this trisomic phen associated with a characteristic syndrome of physical abnormalities, there is no programmed inactivat extra chromosome 18. Thus, no Barr body is produced. XYY syndrome (choice E) is not associated with inactivation of any X chromosomes, so Barr bodies are present. Like a trisomy involving any of the non-sex-linked chromosomes, the duplicated chromosome expressed in its entirety. --------------------------------------------------------------------------------9The correct answer is E. This history is typical for subdural hematoma. Usually, the patient is elderly or alcoh olic and has some degree of brai causing the brain to pull slightly away from the skull. This stretches the bridging (penetrating) veins t the skull to connect to the cranial venous sinuses, leaving them very vulnerable to rupture after minor trauma. This type of hematoma is due to venous, rather than arterial, hemorrhage and thus tends to de rather slowly. Epidural hematoma (choice A) is seen following severe head trauma c ausing laceration of the middle artery. Mixed parenchymal and subarachnoid hemorrhage (choice B) can be seen with bleeding from AV malf Multiple tiny hemorrhages of the putamen (choice C) are intraparenchymal hemorrhages associated hypertension. Subarachnoid hemorrhage (choice D) can be seen with bleeding from ruptured berry aneurysms. --------------------------------------------------------------------------------10The correct answer is E. The recurre laryngeal nerves are branches of the vagus (CN X), and supply all intrinsic muscles of the larynx excep cricothyroid. The right recurrent laryngeal nerve recurs around the right subclavian artery. The left re laryngeal nerve recurs in the thorax around the arch of the aorta and ligamentum arteriosum. Both ne ascend to the larynx by passing between the trachea and esophagus, in close proximity to the thyroid recurrent laryngeal nerves are therefore particularly vulnerable during thyroid surgery, and damage extreme hoarseness. The facial nerve (choice A) innervates the muscles of facial expression, the stapedius muscle, and the l submandibular and sublingual glands. It also mediates taste sensation from the anterior two-thirds of tongue. The glossopharyngeal nerve (choice B) innervates the stylopharyngeus muscle and the parotid gland. afferents supply the carotid sinus baroreceptors and carotid body chemoreceptors, and mediate taste posterior one-third of the tongue. Somatosensory fibers supply pain, temperature, and touch informat the posterior one-third of the tongue, upper pharynx, middle ear, and eustachian tube. The hypoglossal nerve (choice C) innervates the intrinsic muscles of the tongue, the genioglossus, hyp and styloglossus muscles. The trigeminal nerve (choice D) receives sensory information from the face and also innervates the m mastication. --------------------------------------------------------------------------------11The correct answer is B. Characterist borderline personality disorder include frantic behavior to avoid abandonment, unstable interpersona relationships, alternating between idealization and devaluation (splitting), recurrent suicidal gestures types of self-mutilatory behavior, feelings of emptiness, and inappropriate intense anger. An antisocial patient (choice A) does not confirm to social norms, is deceitful, impulsive, reckless, irres and lacks remorse for wrongdoings. One symptom that would suggest histrionic personality disorder (choice C) in this patient is her theatr
exaggeration of her emotions by talking while lying on the floor. A histrionic patient might present wit attention-seeking and/or seductive and provocative behavior, but the presence of splitting, recurrent gestures and anger argue strongly for the diagnosis of borderline personality disorder. A narcissistic patient (choice D) is grandiose and preoccupied with success, feels special a nd requires admiration, feels entitled, takes advantage of others, lacks empathy, and is arrogant. A schizoid patient (choice E) is usually not interested in relationships or pleasurable activities, is a lon friends, is emotionally cold, and is indifferent to praise or criticism. --------------------------------------------------------------------------------12The correct answer is C. This patient hypertrophic cardiomyopathy-the most common cause of sudden cardiac death in young patients. It u causes problems during exertion. Clues to the diagnosis include: dyspnea, palpitations, bifid apical imp coarse systolic murmur at the left sternal border, and ventricular hypertrophy with asymmetric septal thickening on echocardiogram. Left ventricular outflow obstruction typically plays an important role i pathophysiology of this condition. Maneuvers that decrease preload, such as the Valsalva maneuver, w accentuate the heart murmur because they result in less ventricular filling, contributing to greater out obstruction. Elevating his legs (choice A), increasing sympathetic tone (choice B), and s quatting (choice D) would a venous return and would therefore diminish the murmur. --------------------------------------------------------------------------------13The correct answer is E. The signs an symptoms in this patient are consistent with occlusion of the posterior inferior cerebellar artery (PIC a branch of the vertebral artery (which is itself a branch of the subclavian artery). Occlusion of PICA ca lateral medullary syndrome characterized by deficits in pain and temperature sensation over the cont body (spinothalamic tract dysfunction); ipsilateral dysphagia, hoarseness, a nd diminished gag reflex (interruption of the vagal and glossopharyngeal pathways); vertigo, diplopia, nystagmus, and vomitin (vestibular dysfunction); ipsilateral Horner's syndrome (disruption of descending sympathetic fibers); ipsilateral loss of pain and temperature sensation of the face (lesion of the spinal tract and nucleus of t trigeminal nerve). AICA (choice A) is a branch of the basilar artery. Occlusion of this artery produces a lateral inferior po syndrome, which is characterized by ipsilateral facial paralysis due to a lesion of the facial nucleus, ips cochlear nucleus damage leading to sensorineural deafness, vestibular involvement leading to nystag spinal trigeminal involvement leading to ipsilateral pain and temperature loss of the face. Also, there i ipsilateral dystaxia due to damage to the middle and inferior cerebellar peduncles. The anterior spinal artery (choice B) is a branch of the vertebral artery. Occlusion produces the media medullary syndrome, characterized by contralateral hemiparesis of the lower extremities and trunk d corticospinal tract involvement. Medial lemniscus involvement leads to diminished proprioception on contralateral side, and ipsilateral paralysis of the tongue ensues from damage to the hypoglossal nucle The MCA (choice C) is a terminal branch of the internal carotid artery. Occlusion results in contralater arm paralysis and sensory loss. Aphasia is produced if the dominant hemisphere is affected, left-sided ensues if the right parietal lobe is affected, and quadrantanopsia or homonymous hemianopsia occur is damage to the optic radiations. The PCA (choice D) arises from the terminal bifurcation of the basilar artery. Occlusion results in a ho hemianopsia of the contralateral visual field. Often, there is macular sparing. --------------------------------------------------------------------------------14The correct answer is C. The distincti of necrosis described in the question stem are border zone (watershed) infarcts. They occur as the res severe ischemia, which most profoundly affects the relatively poorly perfused areas at the boundaries
major arterial territories. The areas of necrosis described in the question stem are those most commo observed, although similar infarcts involving border zones in the brain stem are sometimes also se en. Bacterial infection (choice A) tends to produce either meningitis, cerebritis, or localized infections suc abscesses. Fungal infection (choice B) tends to produce either meningitis, vasculitis, granulomas, or abscesses. Tumor (choice D) tends to produce localized masses. Viral infection (choice E) may have a variety of patterns, including meningitis, diffuse encephalitis, or l necrosis, but would not be expected to produce a distinctive linear pattern. --------------------------------------------------------------------------------15The correct answer is E. The most co primary cardiac tumor of adults is atrial myxoma, which typically occurs as a single lesion in the left at may intermittently obstruct the mitral valve. Histologically, these tumors are composed of scatte red mesenchymal cells in a prominent myxoid background. Benign glandular tissue (choice A) suggests an adenoma, which is not usually found in the heart. Densely packed smooth muscle (choice B) suggests a leiomyoma, which is not usually found in the hea Densely packed striated muscle (choice C) suggests rhabdomyoma, which is the most common primar tumor in children, not adults. Malignant glandular tissue (choice D) suggests carcinoma, which can be metasta tic to the heart, but do usually cause a ball-valve obstruction. --------------------------------------------------------------------------------16The correct answer is D. Complicated indicate advanced atherosclerotic disease. They arise in atherosclerotic plaques, and render them mor susceptible to sudden occlusion and acute infarction of the supplied tissues. Commonly, the plaque ulc ruptures, and the exposed surfaces, being highly thrombogenic, precipitate thrombus formation. Thro typified by the lines of Zahn, alternating layers of platelets and fibrin (the pale lines) and layers of bloo dark lines). Beyond thrombus formation, other features of a complicated plaque include hemorrhage i lesion itself, and microembolism by cholesterol crystals or calcified debris. Furthermore, the weakene underlying the plaque may develop an aneurysmal dilatation. In general, the clinical significance of atherosclerosis is related to the consequences of complicated lesio ns. The incorrect options all include features of atheromatous plaques, but do not indicate complicated les Beneath the endothelium of a plaque there is a fibrous cap composed of smooth muscle (choice C), chr inflammatory cells (choice B) and lipid laden macrophages (foam cells), as well as extracellular materi The core of the lesion, which lies between the intima and the media, is composed of necrotic cellular d (choice E), with cholesterol crystals (choice A), calcium, and more foam cells. -------------------------------------------------------------------------------17The correct answer is B. This patient is suffering from internuclear ophthalmoplegia (INO), which is a lesion of the medial longitudinal fasciculus (MLF). The medial longitudinal fasciculus (MLF) connects oculomotor (III), trochlear (IV), and abducens (VI) nuclei and is essential for conjugate gaze. A lesion i will result in the inability to medially rotate the ipsilateral eye on attempted lateral gaze. However, a l the motor fibers of the right oculomotor nerve would also lead to the same symptoms. The way to trul distinguish between an INO from a lesion of the medial rectus muscle or a lesion of the motor fibers of to determine whether the patient can converge her eyes. If the innervation of the medial rectus muscle interrupted, the patient will not be able to move the ipsilateral eye medially for either conjugate or dys (convergence) movements. However, if the lesion is in the MLF, this would only a ffect conjugate move not convergence, asin this patient. The left oculomotor nerve (choice A) is intact because the light reflexes are normal, and there is no des
of any eye movement disorders of the left eye. A lesion of the right abducens nerve (choice C) would result in paralysis of the lateral rectus muscle. T lead to an inability to abduct the right eye. The right oculomotor nerve (choice D) innervates the medial rectus muscle, which would lead to an in adduct the right eye when looking toward the left. (CN III also innervates the superior rectus, inferior inferior oblique extraocular muscles.) However, a patient with a lesion of this nerve would a lso be una converge. A patient with a lesion of CN III would also be expected to have the affected eye look "down because of the unopposed actions of the lateral rectus and superior oblique muscles, and ptosis resulti denervation of the levator palpebrae muscle. Additionally, a lesion of the right oculomotor nerve could light reflexes and produce mydriasis if the parasympathetic fibers of this nerve were damaged. The trochlear nerve (choice E) innervates the superior oblique muscle, which depresses, intorts, and a eye. A lesion of this nerve theoretically could produce a slight extorsion of the eye and a weakness of d gaze. However, a lesion of this nerve often produces only minimal symptoms because of the preserved muscles that are innervated by the unaffected oculomotor nerve, and because of a compensatory head --------------------------------------------------------------------------------18The correct answer is E. The mandib passes through the foramen ovale and may be injured by this fracture. The mandibular nerve is respo the innervation of all of the muscles of mastication: the masseter, the temporalis, the medial pterygoid, lateral pterygoid muscles. Abduction of the eye (choice A) is produced by the lateral rectus muscle, which is innervated by the ab nerve. The abducens nerve leaves the cranial cavity and enters the orbit by passing through the superi fissure. Sensation in the skin over the forehead (choice B) is provided by the ophthalmic division of the trigem The ophthalmic division leaves the cranial cavity and enters the orbit by passing through the superior fissure. Sensation in the skin over the zygoma (choice C) is provided by the maxillary division of the trigemina The maxillary division leaves the cranial cavity and enters the pterygopalatine fossa by passing throug foramen rotundum. Taste sensation on the anterior 2/3 of the tongue (choice D) is provided by the chordae tympani, a bra facial nerve. The facial nerve leaves the cranial cavity and enters the temporal bone by passing into th auditory meatus. The chordae tympani leave the temporal bone and enter the infratemporal fossa by p through the petrotympanic fissure. --------------------------------------------------------------------------------19The correct answer is C. The motion is called "paradoxical movement" and occurs when a portion of the ventricular wall is infarcted and ca longer contract during systole. The site of infarction described is in the distribution of the left anterior descending artery. Valvular disease, including that of the aortic valve (choice A), mitral valve (choice D), or tricuspid valv E) will not cause localized paradoxical movement. The circumflex artery (choice B) supplies the superior part of the posterior wall of the heart, anastom with the right coronary artery. --------------------------------------------------------------------------------20The correct answer is D. Pasteurella is a gram-negative rod that is normal flora of the oral cavity of dogs and cats. It often causes a local abs following introduction under the skin by an animal bite. Most cases occur in children who are injured playing with a pet. Bartonella henselae (choice A) is a very small, gram-negative bacterium that is closely related to the ri
although it is able to grow on lifeless media. It is the cause of cat-scratch disease (a local, chronic lymp most commonly seen in children) and bacillary angiomatosis (seen particularly in AIDS patients). In th patient population, the organism causes proliferation of blood and lymphatic vessels causing a charact "mulberry" lesion in the skin and subcutaneous tissues of the a fflicted individual. Brucella canis (choice B) is a gram-negative rod that is a zoonotic agent. Its normal host is the dog, but gains access to humans, it causes an undulating febrile disease with malaise, lymphadenopathy and hepatosplenomegaly. The normal route of exposure is via ingestion of the organism. Clostridium tetani (choice C) is a gram-positive spore-forming anaerobic rod. It causes tetanus (a spas paralysis caused by tetanospasmin, which blocks the release of the inhibitory neurotransmitters glyci gamma-aminobutyric acid [GABA]). There may be no lesion at the site of inoculation, and exudation w extremely rare. Toxocara canis (choice E), a common intestinal parasite of dogs, is a metazoan parasite that causes vis migrans. Young children are most likely to be affected, as they are most likely to ingest soil contaminat eggs of the parasite --------------------------------------------------------------------------------21The correct answer is B. After eating meal, triglycerides are processed by the intestinal mucosal cells. They are assembled in chylomicrons eventually sent into the circulation for delivery to adipocytes and other cells. Chylomicrons are too lar cells, but are degraded while in the circulation by lipoprotein lipase. A defect in this enzyme would res accumulation of chylomicrons in the plasma. Albumin-bound free fatty acids (choice A) is incorrect because fatty acids leave the intestine esterified triglycerides in chylomicrons. HDL (choice C) is not a carrier of dietary fat from the intestine. LDL (choice D) would be not be elevated in this patient after a high fat meal. However, VLDL would be the patient ate a high carbohydrate meal. In this situation, the carbohydrate would be converted into f liver and sent out into circulation as VLDL. VLDL would be unable to be degraded to LDL and, therefor accumulate. A defect in lipoprotein lipase would cause a decrease, not an elevation of unesterified fatty acids (choi the chylomicrons contain esterified fatty acids. --------------------------------------------------------------------------------22The correct answer is D. The Themat Apperception test is a projective test employing pictures depicting ambiguous interpersonal situation examinee is asked to interpret. Psychodynamic theory suggests that since the stimuli are vague, the pa projects his or her own thoughts, feelings, and conflicts into his or her responses, providing the exami into the patient's thought and memory content. The Minnesota Multiphasic Personality Inventory (MMPI; choice A), which uses true and false items, is popular objective personality test. The Myers-Briggs Personality Inventory (choice B) is based on Jungian theory and assesses basic dime personality (extroversion); it is used extensively in occupational counseling. The patient selects prefer adjectives from groups of choices. The Rorschach Test (choice C) is another projective test that involves asking patients to describe what when presented with a series of black and white inkblots. The Type A and B Behavior Patterns Test (choice E) assesses the amount of "driven quality" a person life. Type A's are always "running out of time." This is a verbal test that resembles an interview. --------------------------------------------------------------------------------23The correct answer is A. Arrow 1 indi inner mitochondrial membrane. Carnitine acyltransferase II is located on the inner face of the inner
mitochondrial membrane. It reforms fatty acyl CoA in the mitochondrial matrix (arrow 5) from acyl ca thus preparing it for mitochondrial oxidation. The acyl groups on carnitine are derived from acyl CoA synthesized in the outer mitochondrial membrane, which are made from free fatty acids circulating in Fatty acyl CoA synthetases (choice B) are located in the outer mitochondrial membrane, indicated by a Glucose-6-phosphate dehydrogenase, the first enzyme in the pentose phosphate pathway (choice C), h the first enzyme in the glycolytic pathway (choice D), and pyruvate kinase (choice E), which produces from phosphoenolpyruvate in glycolysis, are all located in the cytosol, indicated by arrow 3. Arrow 4 indicates smooth endoplasmic reticulum. --------------------------------------------------------------------------------24The correct answer is D. The patient i suffering from schizophreniform disorder. There has been a marked decline in the level of functioning was endangering herself in the middle of the street. Schizophreniform disorder is characterized by schizophrenia-like symptoms, but the duration of symptoms is less than six months (but more than on Fully developed psychotic symptoms are typical. In schizoaffective disorder (choice A), alterations in mood are present during a substantial portion of t Although schizoid personality disorder (choice B) produces detachment from social relationships and characterized by restriction of emotional expression, it is not accompanied by a marked decline in occ functioning. If the symptoms do not remit after six months or more, then the diagnosis of schizophrenia (choice C) made. Schizotypal personality disorder (choice E) is characterized by eccentricities of behavior, odd beliefs o thinking, and difficulties with social and interpersonal relationships. Unlike schizophrenia, schizotypal personality disorder is not characterized by a formal thought disorder. --------------------------------------------------------------------------------25The correct answer is A. This patient denial about his serious illness, and by talking about something totally unrelated, he is trying to avoid news he has just received. Displacement (choice B) involves the transferring of feelings to an inappropriate person, situation, or (e.g., a man who has been yelled at by his boss takes out his anger on his wife). Projection (choice C) is the attribution of one's own traits to someone else (e.g., a philandering husban his wife of having an affair). Rationalization (choice D) involves creating explanations for an action or thought, usually to avoid self Reaction formation (choice E) is the unconscious changing of a feeling or idea to its opposite (e.g., a m very friendly toward a coworker when in fact he is unconsciously jealous). Sublimation (choice F) involves turning an unacceptable impulse into an acceptable one (e.g., someone aggressive impulses becomes a professional boxer). --------------------------------------------------------------------------------26The correct answer is A. In severe an diminished transport of oxygen in the blood leads to hypoxia in the tissues. The hypoxia (compare to c causes small arteries and arterioles to dilate, which allows greater-than-normal amounts of blood to r the heart. In severe anemia, the viscosity of blood (choice B) may decrease by 50% or more because bl viscosity depends largely on the concentration of red blood cells. This decrease in viscosity lowers the to blood flow in the peripheral tissues (i.e., decreases peripheral vascular resistance, choice C) allowin greater amounts of blood to return to the heart. Blood is often shunted away from the splanchnic vascular bed (choice D) in anemia, which can cause gastrointestinal problems. --------------------------------------------------------------------------------27The correct answer is B. Hepatosplen