NBME STEP 1 ANATOMY
EMBRYOLOGY 1. A young couple has been unable to achieve a viable pregnancy. Semen analysis shows normal quality and quantity of sperm. The woman has regular menstrual cycles and takes no contraceptives. Biopsy of her nasal sinus mucosa shows epithelial cells with the majority of cilia bent at half their length. The most likely functional cause for this couple's infertility is a deficiency in which of the following? A)
Capacitation of spermatozoa
B)
Completion of meiosis by ovulated oocytes
C)
Implantation into the uterus
D)
Migration of conceptus
E)
Mobility of spermatozoa
Rp: D) Immotile Ciliary syndrome or Cartagener syndrome, Characterized by: Infertility
Respiratory problems Situs Inversus
NEURO 2. A 55-year-old man is hospitalized after having a stroke. The MRI of the head is obtained 3 days later. The patient most likely has which of the following signs on the right?
A) B) C) D) E)
Homonymous hemianopia and numbness of the face Weakness of the upper limb and aphasia Weakness of the upper and lower limbs Weakness of the face, upper and lower limbs Weakness of the face and dysarthria
GROSS 3.
Acting bilaterally, the external oblique muscles produce which movement of the vertebral column?
A) B) C) D)
Extension Flexion Lateral flexion Rotation
B) Flexion The "External Abdominal Oblique Muscle" lies on the sides and front of the abdomen and is the largest and the most superficial of the three flat muscles in this area. It is broad, thin and irregularly four-sided and occupies the lateral walls of the abdomen, stretching across to the front. Both sides, acting together, flex the vertebral column by drawing the pubis toward the Xiphoid process.
NEURO 4. A 78-year-old woman has a 2-month history of flailing movements of the limbs on one side. There is no family history of a similar movement disorder. Which of the following structures is most likely to be involved? A) B) C) D) E) F)
Cerebellar hemisphere Cingulate cortex Primary motor cortex Striatum Substantia nigra Subthalamic nucleus Hemibalismus
CARDIO 5. A 73-year-old man with a history of angina is undergoing cardiac catheterization via the right femoral artery. As the pig-tail catheter is advanced into the apex of the left ventricle, which of the following valves will be crossed? A) B) C) D)
Aortic Mitral Pulmonary Tricuspid
RENAL 6. A male neonate has a palpable midabdominal mass. Abdominal ultrasonography shows no kidneys in the normal anatomic position and a single U-shaped renal mass with two collecting systems near the aortic bifurcation. Which of the following embryologic events best explains this finding? A) B) C) D) E)
Division of the metanephric diverticulum Failed development of the ureteric bud Failed differentiation of the urogenital sinus Fusion of the metanephric masses Normal development of two ureteric buds
D)
Fusion of the metanephric masses
HORSESHOE KIDNEY: Occurring 1 in every 400 live births, horseshoe kidney is the mc renal anomaly. There is a 2:1 male to female predominance. Horseshoe kidneys develop following a midline fusion of the paired metanephric masses prior to assent within the pelvis or lower aspect of the abdomen. The midline connection or isthmus may represent a Fibrotic band or functioning renal parenchyma involving the lower poles of both kidneys. Assent of the horseshoe kidney is stopped short when it becomes hooked under the origin of the inferior mesenteric artery. Horseshoe kidney is associated with numerous renal vascular anomalies and an increased incidence of other urinary tract abnormalities including UPJ obstruction, duplication anomalies and stone formation http://www.uhrad.com/ctarc/ct215.htm
NEURO 7. A 28-year-old man reports extremely familiar thoughts (déjà vu) just before he has a seizure. Which labeled area in the diagram is the most likely site of the causal lesion?
a) b) c) d) e) f) Temporal Lobe Answer: f) Scientists have, however, associated déjà vu closely with the brain's temporal lobe1. This attachment was based on accounts from persons with temporal-lobe epilepsy. Individuals experiencing seizures caused by the condition have a tendency to experience déjà vu immediately before and during the convulsions. Following the aura, a temporal lobe complex partial seizure begins with a wide-eyed, motionless stare, dilated pupils, and behavioral arrest. Oral alimentary automatisms such as lip smacking, chewing, and swallowing may be noted. Manual automatisms or unilateral dystonic posturing of a limb also may be observed. http://www.emedicine.com/neuro/topic365.htm RESPIRATORY 8. A 4-cm bronchogenic cyst is an incidental finding at autopsy of a 55-year-old man. The cyst most likely arose from which of the following embryologic structures? A) Allantois B) Foregut C) Mesonephric (wolffian) duct D) Metanephric duct E) Omphalomesenteric duct Answer B) Foregut Bronchogenic cysts develop from an abnormal budding of the ventral foregut between the 26th and 40th week of gestation. As such, they are often more appropriately termed foregut duplication cysts. Bronchogenic cysts are developmental abnormalities of the primitive foregut that are usually found above the diaphragm, especially in the mediastinum and particularly posterior to the carina. Rarely, they can occur in a subdiaphragmatic location, and a retroperitoneal position is distinctly unusual.
Embryo 9. A 14-year-old girl is brought to the physician's office by her mother who is concerned that the girl has not begun to menstruate. Physical examination shows normal breast development, no pubic hair, normal female external genitalia, bilateral inguinal hernias, and a vagina that ends in a blind pouch, and no palpable uterus or ovaries. Ultrasound examination confirms the absence of internal female genitalia. The underlying problem in this patient is related to which of the following? A) Defective androgen receptors B) Excess production of fetal estrogen C) Excess production of fetal progesterone D) Insufficient fetal testosterone production E) Insufficient production of paramesonephric (müllerian) inhibitory factor during fetal development Answer A) Defective Androgen Receptors Complete Androgen Insensitivity Syndrome, occurs when a fetus with a 46 XY genotype develops testes and female external genitalia with a rudimentary vagina; the uterine tubes and uterus are generally absent. The MCC is a mutation in the androgen receptor gene that renders the androgen receptor inactive. Androgen insensitivity syndrome, complete: A genetic disorder that makes XY fetuses insensitive (unresponsive) to androgens (male hormones). Instead, they are born looking externally like normal girls. Internally, there is a short blind-pouch vagina and no uterus, fallopian tubes or ovaries. There are testes in the abdomen or the inguinal canal. The complete androgen insensitivity syndrome is usually detected at puberty when a girl should but does not begin to menstruate. Many of the girls with this syndrome have no pubic or axillary (armpit) hair, they have luxuriant scalp hair without temporal (male-pattern) balding. They are sterile and cannot bear children. They are at high risk for osteoporosis and so should take estrogen replacement therapy. The gene for the syndrome is on the X chromosome in band Xq11-q12. The gene codes for the androgen receptor (also called the dihydrotestosterone receptor). This gene is mutant in the complete androgen insensitivity syndrome. Because of the mutation, the cells cannot respond to androgen. If a woman has the mutation on one of her X chromosomes, the risk for each of her XY offspring to receive the gene and have the syndrome is one-half (50%). Ref: Kaplan Anatomy pg 207http://www.medterms.com/script/main/art.asp?articlekey=14428 RENAL 10. A 3-week-old female infant with dehydration develops bilateral renal vein thrombosis, but only the right kidney infarcts. Collateral drainage via which of the following veins most likely prevented infarction of the left kidney? A) Left ovarian B) Left third lumbar C) Splenic D) Superior mesenteric Answer A) Left ovarian vein: Left ovarian vein opens into the left renal vein, thus, easily can give rise to collaterals. Right O.V. opens into IVC. This is the reason why in males, Varicocele are more common on left side. Left test vein drains into L renal vein (smaller caliber than IVC). So blood is backed-up and cause varicocele
NEURO 11. A 48-year-old man comes to his physician because his wife noticed that his right pupil is "small." Physical examination shows that the right pupil is constricted and does not react to light. His left pupil is normal. These findings are most likely due to a lesion involving which of the following structures on the right? A) Cervical spinal cord B) Frontal eye fields C) Lateral geniculate nucleus D) Optic tract E) Visual cortex Answer: A) Cervical spinal cord Problems with pupils can think of 2 lesions: CN 3 lesion causes Ptosis with dilated pupils Sympathetic lesion causes Ptosis with constricted pupils. If we analyze the answers: Option B) Frontal Eye Field; is located in the posterior part of the middle frontal gyrus (Brodmann's area 8). It regulates voluntary contralateral horizontal gaze. A lesion here would give us ipsilateral conjugate deviation of the eyes. (Away from the lesion) Options C) Lateral Geniculate Nucleus D) Optic tract and E) Visual cortex (Brodmann's area 17) Would give us a contralateral component or other clinical features not present on this patient
Therefore having only Myosis on this pt we could think about another known condition called Horner's Syndrome which in this case could explain the clinic signs of the patient and gives us so for the answer A) As we know Horner syndrome is due to paralysis of the cervical sympathetic nerves
The symptoms of Horner's syndrome include: * Drooping of the upper eyelid * Swelling of the lower eyelid * Sinking of the eyeball * an absence of sweat on the same side of the face as the affected eye * the pupil becomes smaller (miotic) * each iris may be a different color HISTOLOGY 12. A fluorescent molecule of 2000 daltons is microinjected into a single cell of an epithelial layer. When the layer is examined in a fluorescence microscope, the molecule remains confined to that cell. However, when a fluorescent molecule of 800 daltons is injected into a single cell of an epithelial layer, it quickly appears in the adjacent cells. Which of the following is responsible for the spread of the smaller molecule? A) Desmosomes (maculae adherentes) B) Focal contacts C) Gap junctions D) Intermediate junctions E) Tight junctions (zonulae occludentes) Answer: C) Gap junctions Gap junctions; Protienaceous tubes that connect adjacent cells. These tubes allow material to pass from one cell to the next without having to pass through the plasma membranes of the cells. Dissolved substances such as ions or glucose can pass through the gap junctions. Large organelles such as mitochondria cannot pass.
NEURO-HISTO 13. The largest collection of neurons in the central nervous system that use norepinephrine as a neurotransmitter is found in the A) B) C) D) E)
Basal nucleus (of Meynert) Locus ceruleus Raphe nuclei substantia nigra Ventral tegmental area
Answer: B) Locus Ceruleus One biochemical explanation for panic is that there is an over-activity in what's called the locus ceruleus. The locus ceruleus is the part of the brain that triggers a response to danger. It's like our brain's alarm system. People who get panic attacks can be thought of as unwittingly sending alarms to this part of the brain. A trigger-happy locus ceruleus could wreak havoc with a person's perspective. The locus coeruleus is a melanin containing, blue nucleus which resides on the dorsal wall of the upper pons, surrounded by the fourth ventricle. This nucleus is one of the main sources of norepinephrine in the
brain, and is composed of mostly medium sized neurons. The melanin granules inside the LC are what contribute to its blue color and is also known as the nucleus pigmentosus pontus (which means heavy pigment in cells, located on the pons). The neuromelanin is formed by the polymerization of norepinephrine and is analagous to the black dopamine based neuromelanin in the substantia nigra.
NEURO 14. CSF Cerebrospinal fluid leaving the ventricular system through the median aperture (of Magendie) collects in which labeled space in the sagittal MRI of the head?
A)
B)
C)
D)
E)
F)
G)
Answer: G) Cisterna Magna From the lateral ventricles, CSF passes into the third ventricle through the interventricular foramen. Very little reflux of CSF into the contralateral lateral ventricle is said to occur. From the third ventricle, the CSF reaches the fourth ventricle via the narrow cerebral aqueduct. CSF then leaves the ventricular system at the level of the medulla oblongata through 3 apertures; the midline foramen (of Magendie) and the paired lateral foramina (of Lushka). These apertures open into enlargements of the subarachnoid space known as the cisterna magna and the cisterna pontis, respectively.
NEURO 15. A 45-year-old woman says that her feet feel hot. The skin of her feet is pink, dry, and hot. Which of the following fibers are most likely to be disrupted? A) Autonomic afferent B) Postganglionic sympathetic C) Preganglionic parasympathetic D) Somatic cutaneous afferent
GASTRO 16. The diagram shows a liver lobule. Long-term destruction of the hepatocytes, collapse of the histologic architecture, and production of fibrous material in the areas indicated by the arrow is most likely to result in which of the following?
A) B) C) D) E)
Decreased intestinal motility Gallstones Increased central venous pressure Increased hepatic venous pressure Increased portal pressure
E)
Increased portal pressure
OTORRINO- HISTO 17. A 6-year-old boy says his left ear hurts. His mother says that he has been tugging the ear. The external canal and tympanic membrane appear normal, but the tympanic membrane does not move when the pressure in the nasopharynx is increased. Which of the following is the most likely cause of these findings? A) B) C) D) E)
Auditory tube obstruction Cholesteatoma Otitis externa Purulent otitis media Serous otitis media
A) Auditory tube obstruction Obstruction or blockage of the eustachian tube results in a negative middle ear pressure, with retraction (sucking in) or the eardrum membrane. In the adult this is usually accompanied by some ear discomfort, a fullness or pressure feeling and may result in a mild hearing impairment and head noise (tinnitus). There may be no symptoms in children. If the obstruction is prolonged, fluid may be drawn from the mucous membrane of the middle ear, creating a condition we call serous otitis media (fluid in the middle ear). This occurs frequently in children in connection with an upper respiratory infection and accounts for the hearing impairment associated with this condition. The eustachian tubes of young children are shorter and more horizontal than in adults. Its opening is often blocked by enlarged adenoids
HEAD AND NECK
18. A previously healthy 2-year-old boy has a 1x2-cm mass at the midline of the neck immediately above the larynx. The mass is not tender and moves when he swallows. The mass is most likely to be A) B) C) D) E)
A branchial cleft cyst Lymphadenopathy A submental abscess A thyroglossal duct cyst The thyroid gland
D)
A thyroglossal duct cyst
NEURO 19. An examiner strokes a wisp of cotton across a patient's left cornea. There is no response. The examiner then strokes the cotton across the patient's right eye; both eyes blink. The most likely explanation of these findings is damage to which of the following cranial nerves on the left? A) B) C) D) E)
Optic Oculomotor Trigeminal Abducens Facial
C)
Trigeminal
MALE REPROD 20. A 45-year-old man who has five children comes to the physician to discuss a vasectomy and asks about what to expect. Which of the following is most likely to occur during the first 4 weeks following the procedure? A) B) C) D) E)
Atrophy of the testes Erectile disorder Numbness of the posterior scrotum Presence of viable sperm in ejaculate Significantly decreased volume of ejaculate
D)
Presence of viable sperm in ejaculate
PREGNANCY PROBLEMS 21. A 22-year-old woman who is pregnant with her first child comes to the physician's office for a routine visit at 24 weeks' gestation. The size of her uterus has increased very little during the past 4 weeks. Ultrasonography shows little fluid in the amniotic sac. Which of the following fetal organ systems is most likely to be malfunctioning? A) Cardiovascular B) Central nervous C) Gastrointestinal D) Hepatic E) Renal Answer: E) Bilateral renal agenesis (Potters Sd) leads to Oligohydramnios, lack of urine production. Ref: Qbank 22. NEURO
The vertebral angiogram shown is from a 40-year-old man. The abnormality is marked by "X." Which of the following clinical findings is most likely to be present? A) B) C) D) E)
Aphasia Ataxic limb movements Resting tremor Spastic hemiparesis Visual field defect
Answer: A) Aphasia Left middle cerebral artery is affected. Ref: page 436 anatomy NEURO 23. During an experiment on the cough reflex in humans, a subject inhales air containing different amounts of particles that will impact and adhere to mucus primarily in the trachea. Blockade of which of the following afferent pathways would most likely prevent this subject's reflex to initiate a cough? A) B) C) D) E)
Glossopharyngeal Laryngeal Olfactory Trigeminal Vagal
Answer: E) X Vagus Lesion in Vagus results in loss of cough reflex, gag reflex (with IX), hoarseness/fixed vocal cord. Ref: Kaplan Anatomy page 359
THORAX
24. A 24-year-old man is brought to the emergency department after being stabbed in the chest. Examination shows a stab wound in the fourth intercostal space on the left, immediately lateral to the sternum. Which of the following structures is most likely injured? A) B) C) D) E)
Pulmonary trunk Right atrium Right ventricle Superior vena cava Thoracic aorta
Answer: C) Right Ventricle The 4th ICS space is the best place to auscultate the Tricuspide Valve; also the anterior wall of the heart is formed primarily by the right ventricle. Ref: Kaplan pg 145-146 and images at pages 156 and 159 GASTRO 25. A 4-year-old boy has had constipation and painful defecation since birth. Impacted fecal matter is palpable in the lower abdomen. Examination of tissue obtained on biopsy of the rectum shows absence of cells of the myenteric plexus. The most likely cause is a defect in which of the following developmental events? A) B) C) D) E) F)
Alar plate maturation Anterior neuropore closure Neural crest migration Paravertebral ganglion formation Posterior neuropore closure Recanalization of the bowel
Answer: is C) Neural Crest Migration Hirschprung’s Disease results from the failure of the neural crest cells to form the myenteric plexus in the sigmoid colon and rectum. This condition is associated with loss of peristalsis, fecal retention, and abdominal distention. Ref: Kaplan anatomy pg 180 NEURO 26. A 50-year-old woman with a history of hypertension suddenly develops a severe headache and collapses while shopping. She is intubated and mechanical ventilation is started because of irregular respirations. A CT scan of the head shows a massive intracerebral hemorrhage with blood extending into the ventricles and subarachnoid space. The following morning she is unresponsive to all stimuli. Her pupils are fixed and dilated, oculocephalic reflexes are absent, and she has no spontaneous respirations. An EEG confirms electrocerebral inactivity. Which of the following best describes her level of neurologic functioning? A) Brain death B) Cataplexy C) Limbic encephalopathy D) Persistent vegetative state A) Brain death • Absence of cerebral and brain stem function • Pupillary’s responses are absent, and eye movements cannot be elicited by the vestibulo-ocular reflex or by irrigating the ears with cold water. • The corneal and gag reflex are absent, and there is no facial or tongue movement. • The limbs are flaccid, and there is no movement, although primitive withdrawal movements in response to local painful stimuli, mediated at a spinal cord level, can occur.
• Apnea Test: An apnea test should be performed to ascertain that no respirations occur at a PCO2 level of at least 60 mmHg. The patient oxygenation should be maintained with giving 100% oxygen by a cannula inserted into endotracheal tube as the PCO2 rises. The inability to develop respiration is consistent with medullary failure. • Some causes must be ruled out • Body temperature must be above 32 C to rule out hypothermia • No chance of drug intoxication or neuromuscular blockade • Patient is not in shock • Persistence of brain dysfunction • Six hours with a confirmatory isoelectric EEG or electrocerebral silence, performed according to the technical standards of the American Electroencephalographic Society • Twelve hours without a confirmatory EEG • Twenty-four hours for anoxic brain injury without a confirmatory isoeletric EEG GASTRO 27. Four months after a cholecystectomy for removal of gallstones, a 43-year-old woman has recurrent episodes of biliary colic. After endoscopic sphincterotomy, the episodes of colic do not recur. Which of the following defects in the sphincter of Oddi best explains this patient's course? A)
Inability of smooth muscle to contract
B)
Inability of the enteric nervous system to activate excitatory motoneurons
C)
Loss of enteric inhibitory motor innervation
D)
Reflux of duodenal contents into the common bile duct
E)
Release of vasoactive intestinal polypeptide
Answer: C) See article: http://www.joplink.net/prev/200111/200111_04.pdf VIP Vasoactive intestinal peptide is produced by cells in the parasympathetic ganglia of sphincters, gallbladder and small intestine. Stimuli for its release include Vagal; stimulation and intestinal distention. It promotes water and electrolyte secretion by jejunum, ileum and colon (via cAMP), relaxation of smooth muscle and sphincters, stimulation of pancreatic bicarbonate secretion and intestinal dilation. It inhibits secretion of gastric acid and gastrin. UPPER LIMB 28. As the result of a fall onto a hard surface, a 20-year-old woman sustains a fracture of the medial humeral epicondyle, and a nerve is injured. Which action will be most affected by this nerve injury? A) B) C) D) E)
Adduction of all digits Extension of all digits Flexion of all digits Pronation of the forearm Supination of the forearm
Answer: D) Pronation of the forearm The Median Nerve maybe injured in this lesion. No loss of power of any of the arm muscles; loss of forearm pronation, wrist flexion, finger flexion and several thumb movements; eventually tenar atrophy. First aid pg 116 NEURO
29. Which of the following cells share a common progenitor cell with macrophages? a) Astrocytes b) Ependymal cells c) Microglia d) Muller’s fibers e) Oligodendrocytes C) Microglia They are both derived from mesoderm UPPERLIMB 30. A 36-year-old man has acute pain in the right upper arm and shoulder. Acute supraspinatus tendinitis is suspected. Which of the following physical examination maneuvers of the right shoulder is most likely to reproduce the pain, thus supporting the diagnosis? a) Abduction b) Adduction c) Extension d) External rotation e) Flexion f) Internal rotation Answer: c) Extension EMBRYO 31. Which of the following human cells is 1N and haploid? a) Germinal epithelial cell b) Primary spermatocyte c) Spermatid d) Type A1 Spermatogonium e) Type B spermatogonium Answer: c) Spermatid Primordial cells arrive in the male gonad at week 4. They remain dormant until puberty. They will differentiate in type A and type B spermatogonia (2N) Type B enter meiosis Primary spermatocyte (4N) which form 2 Secondary spermatocyte (2N each), they form 2 spermatids each with 1N, then enter spermiogenesis and become sperm. Therefore: Primary Spermatocyte is 4N Type A and type B Spermatogonium are 2N cells
32. NEURO Figure…
A patient with the lesion indicated by the arrow in the figure is expected to have which of the following types of hemianopia? A ) Binasal B ) Bitemporal C ) Homonymous D ) Monocular Answer: c) Homonymous Until optic chiasm the are Heteronymous Back from there they are homonymous GASTRO 33. A 70-year-old man has severe atherosclerotic disease of the abdominal aorta that obstructs the ostia of the superior and inferior mesenteric arteries. He has intermittent episodes of abdominal pain and bloody diarrhea. Which of the following regions of the bowel is likely to be most severely affected? A) B) C) D) E)
Ascending colon Descending colon Hepatic flexure Splenic flexure Transverse colon
Answer: D)
Splenic flexure
EMBRYO 34. The drawing is of a cross section through the trunk of a human embryo at 5 weeks' gestation. Which labeled structure contains muscle precursor cells derived from the somites?
A) B) C) D) E) F) G) H) I) HEAD AND NECK 35. A full-term male neonate is born with a 4x4-cm mass posterior to the right sternocleidomastoid muscle. Delivery was uncomplicated and Apgar scores were 9 and 9 at 1 and 5 minutes, respectively. The mass is unilocular and filled with watery fluid; no other abnormalities are present. The most likely diagnosis is A) Branchial cyst B) Cystic hygroma C) Preauricular sinus D) Thyroglossal duct cyst E) Zenker's diverticulum Answer: A)
Branchial cyst
EMBRYO 36. A 35-year-old woman at 18 weeks' gestation has an increased serum α-fetoprotein concentration. Which of the following has the greatest influence in determining the predictive value of this test for neural tube defects? A) Concentration of α-fetoprotein in maternal serum B) Maternal history of monozygotic twin pregnancies C) Prevalence of neural tube defects in the population in question D) Sensitivity of the test E) Specificity of the test E)
Sensitivity of the test
GASTRO
37. A 47-year-old man undergoes resection of his entire stomach for intractable bleeding from a gastric ulcer. After recovery, he is at increased risk for which of the following? A) B) C) D) E)
Copper deficiency Vitamin A deficiency Vitamin B6 (pyridoxine) deficiency Vitamin B12 (cyanocobalamin) deficiency Vitamin C deficiency
D)
Vitamin B12 (cyanocobalamin) deficiency
RENAL 38. A 37-year-old woman has a renal cell carcinoma confined within the fascia of the right kidney. During nephrectomy using a posterolateral approach, which of the following layers is normally incised? A) B) C) D) E)
Costal pleura Diaphragmatic pleura Parietal peritoneum Transversalis fascia Visceral peritoneum
Answer: D) Kidney is retroperitoneal EMBRYO
39. A neonate is born with the abnormality shown. Abnormally robust activity of which of the following processes is the most likely cause of this malformation? A) B) C) D) E)
Angiogenesis Cell adhesion Cell migration Gastrulation Somitogenesis
Answer: A)
EMBRYO 40. The genotype of the cells of the chorionic villi that comprise the human placenta is
A) B) C) D)
Fetal Maternal Maternal and fetal Paternal
A) • •
Fetal Placenta fetal component: chorionic plate and villi Maternal component: decidua basalis, maternal blood vessels from the Decidua conduct blood into the intervillous spaces of the placenta where floating villi are present The placental barrier: maternal blood is separated from fetal blood by cytotrophoblast, syncytiotrophoblast a basement membrane and a fetal capillary endothelium. Kaplan anatomy page 84 GROSS 41. The structure indicated by letter X on the MRI of the head lies within which bony region?
A) B) C) D) E) F)
Anterior cranial fossa Maxillary sinus Middle cranial fossa Orbital cavity Posterior cranial fossa Pterygopalatine fossa
Answer: C)
GROSS
Middle cranial fossa
42. A 3-year-old boy has an abdominal cryptorchid testis that cannot be brought down into the scrotal sac. The testis should be removed to decrease his risk for which of the following? A) Abnormal hormonal secretion B) Infection C) Intestinal obstruction D) Malignancy E) Psychological impairment Answer: D) Cryptorchidism is associated with a significantly increased risk of later development of testicular carcinoma, typically in the third decade of life. This risk is substantially reduced, if not completely eliminated, if surgical repositioning of the testes is performed in early childhood. Ref: Qbank NEURO 21. Over a period of 3 years, a 40-year-old man develops generalized dystonic, hyperkinetic movements and progressive dementia. His mother and one sister have a similar disease, but his father and another sister are healthy. Which of the following lesions is most likely to be present in the central nervous system of the patient and his affected family members? A ) Atrophy of the caudate nuclei B ) Loss of pigmented cells in the substantia nigra C ) Microglial nodules and multinucleated giant cells in the white matter D ) Neurofibrillary tangles in the cortical neurons E ) Spongiform changes in the cerebral cortex A) Atrophy of the caudate nucleus
NEURO 43. Which labeled area in the drawing of the left hemisphere of the cerebral cortex controls understanding of written and spoken language?
A E
) )
B F
) )
Answer: E) Wernicke’s Area
C G
) )
D
)
NEURO 44. A 45-year-old woman has had bilateral loss of pain and temperature sensations on her trunk and upper limbs for several years. She has no motor deficit. Which of the following long pathways are most likely to be affected? A ) Lateral corticospinal tracts B ) Posterior columns C ) Reticulospinal tracts D ) Spinothalamic tracts E ) Vestibulospinal tracts D
)
Spinothalamic tracts
