USMLE Step 1 – Uworld High Yield Notes Complete Test 2022/2023

USMLE Step 1 – Uworld High Yield Notes Complete Test 2022/2023 What are the two major microtubular motor proteins? Which does anterograde axonal transport, which does retrograde axonal transport? Correct Answer: Kine ...

USMLE Step 1 – Uworld High Yield Notes Complete Test 2022/2023 What are the two major microtubular motor proteins? Which does anterograde axonal transport, which does retrograde axonal transport? Correct Answer: Kinesin, Dynein Kinesin: Anterograde Dynein: Retrograde` What do you think, immunologically speaking, when you see someone with recurrent Neisseria infections? Correct Answer: Inability to form the membrane attack (MAC) complex this is a common complement deficiency What is the defect in Chronic Granulomatous disease? What is the pathophysiology? Correct Answer: NADPH Oxidase deficiency leads to the inability to kill intracellular organisms Characteristic triad of ataxia telangiectasia? Correct Answer: cerebellar ataxia, telangiectasias, increased risk of sinopulmonary infections What is the major immune deficiency of ataxia telangiectasia? Correct Answer: IgA deficiency, which predisposes to infections of the upper and lower airways (and other mucous membranes) There's a useful mnemonic for Ataxia Telangiectasia and the gene that's mutated. What is it? Correct Answer: ATM Ataxia Telangiectasia Mutated ATM gene is responsible for DNA break repair What is one reason that lead intoxication causes hypochromic anemia? Correct Answer: Mitochondrial iron transport is important for Heme synthesis! It's inhibited by lead. So you don't make heme in your mitochondria and you get hypochromic anemia. What is the biochemical problem in Lesch-Nyhan syndrome? (And, only if you got that right, what are the really cool symptoms of it?) Correct Answer: Defective purine catabolism, so buildup of purines. It's an X-linked recessive disorder with mutated HGPRT gene (hypoxanthine-guanine phosphoribosyltransferase, if you want to impress people). Now, if you got HGPRT and purine catabolism right, you can say: self-mutilating behavior on top of mental retardation, choreoathetoid (think Chorea) movements and spasticity. What is the defect in Niemann-Pick disease? What causes that? What is the common macular finding? Correct Answer: Sphingolipid degradation is defective Caused by an autosomal recessive defect in sphingomyelinase Cherry Spot on the macula? Niemann Pick's or Tay Sach's. If a baby gets exposed to an unclean knife (...) and subsequently develops rigid paralysis, what is the diagnosis, where do we think this might happen, and how do we prevent it? Correct Answer: Neonatal Tetanus Developing Countries Maternal immunization with tetanus toxoid is the best way to prevent it an adeuately immunized mom will transfer IgG's across the placenta to the neonate Which microtubule associated protein aids in anterograde transport of intracellular vesicles and organelles? Which end of the microtubule do they go towards? Correct Answer: Kinesin. Towards the (+) rapidly growing end. What is an early BRAIN finding of Ataxia-Telangiectasia and how does it manifest itself? Correct Answer: Cerebellar atrophy manifests as ataxia in the first years of life. High yield path association for Alzheimer's disease? Correct Answer: Neurofibrillary tangles in the neocortex High yield path association for Parkinson's disease? Correct Answer: Loss of neurons in the substantia nigra High yield path association for Huntington disease? Correct Answer: Atrophy of caudate nucleus What are the major manifestations of Ataxia-telangiectasia? Correct Answer: cerebellar ataxia, oculocutaneous tenlangiectasias, repeated sinopulmonary infections, and an increased incidence of malignancy If you heard: amenorrhea, bitemporal hemianopsia, and enlargement of the pituitary gland on brain imaging, what would you be thinking? Correct Answer: Prolactinoma, the most common pituitary adenoma. What embryological layer is the anterior pituitary derived from? Correct Answer: Surface ectoderm What is the most common congenital abnormality associated with the use of Sodium Valproate during pregnancy? Correct Answer: neural tube defects, e.g., meningocele because valproate inhibits intestinal folic acid absorption resulting in teratogenicity What is the characteristic histology of a craniopharyngioma? Correct Answer: On light microscopy, cysts are lined by stratified squamous epithelium, possibly with Keratin perals. Cysts are usually filled iwth a yellow, viscous fluid that's rich in cholesterol crystals. Where do craniopharyngyomas arise from? Correct Answer: Craniopharyngiomas are calcified cystic tumors that arise from remnants of Rathke's pouch (embryonic precuros of the anterior pituitary) Failure of what process leads due neural tube defects? What can be seen in the amniotic fluid due to leakage of fetal cebebrospinal fluid? Correct Answer: Failure of fusion of the neuropores. Alpha-fetoprotein and Acetylcholinesterase may appear in the amniotic fluid Can a competent patient refuse healthcare? Can a competent patient refuse knowledge of their potential health situation? Correct Answer: yes and yes What is the consensus and professional standard regarding the receiving of gifts from patients? Correct Answer: Don't do it. It's unethical to accept individual gifts from patients, especially of signficant value. AMA doesn't have clear cut answer, but they recommend careful consideration be used. some general guidelines: -cash gifts should never be accepted (this includes gift certificates) -a gift should never influence treatment -no specific dollar value is given; but as a rule of thumb, it shouldn't be above patient's or physician's means -psychiatrist must be super careful even with small gifts -maintain consistency among all patients -if physician would be embarrassed or uncomfortable if his colleagues found out about the gift, don't accept it Is displacement a mature or immature defense mechanism? What is displacement? Correct Answer: Immature. A patient redirects emotions from the person or object that's causing the emotions (e.g., wife), but who it woudl be completely unacceptable to direct those emotions toward, to a more acceptable, but still inappropriate, person or object (e.g., a wall or a vase). Is sublimation a mature or immature defense mechanism? How does it work? Correct Answer: Mature. Unacceptable drives are redirected toward completely acceptable targets. (Workout hard if you're angry) Is projection a mature or immature defense mechanism? What is it? Correct Answer: Immature. Unacceptable or personally disagreeable impulses are attributed to others; e.g., a student who wants to cheat on a test accuses his classmates of cheating. Or the gayness thing Is reaction formation immature or mature defense mechanism? what is it? Correct Answer: immature, where unacceptable feeligns are IGNORED and the opposite sentiment is adopted (forced). man who's mad at his wife instead compliments her dress Is splitting a mature or immature defense mechanism? what is it? Correct Answer: immature. frequently employed by patients with borderline personality disorder, everything is either "good or bad." What do you do if you suspect child abuse? Ask the parents or call child protective services? Correct Answer: Call Child Protective Services immediately! Psychologically speaking, what phenomenon is "white coat syndrome" associated with? Correct Answer: Classical Conditioning. In classical conditioning, a reflexive response normally elicited by an unconditioned stimulus becomes evocable by a second, formally neutral (conditioned) stimulus. What three things can patients with bulimia develop (hint: one isn't weight loss because bulimia doesn't work.)? Correct Answer: (1) bilateral partodi gland enlargement (2) erosion of tooth enamel* (3) irregular menses What is the pulmonary capillary wedge pressure and what does it indirectly measure? Correct Answer: Pressure in the pulmonary artey distal to the point of its occlusion by an inflated intravascular balloon. Since there's no significant blood flow towards the left atrium (LA) beyong this point of occlusion, the pressure at the tip of the "wedged" pulmonary artery catheter is an indirect measurement of LA Pressure. What would we expect, in a normal patient, the relationship to be between LA and LV pressure during diastole? Correct Answer: We would expect them to be nearly equale (both <12) since the open mitral valve offers minimal resistance to flow between the 2 chambers What is the characteristic finding via cardiac catheterization in a patient with mitral valve stenosis? I.e., if we see what value elevated while the other remains normal, when do we think "Mitral Valve Stenosis." Correct Answer: Cardiac Catheterization will reveal a LA end diastolic pressure (via pulmonary capillary wedge pressure) that is significantly greater than the LV end diastolic pressure (LVEDP). This abnormal pressure gradient implies increased resistance to flow between the LA and LV, i.e., mitral valve stenosis. Summarize the key points of pulmonary capillary wedge pressures (PCWP) and how it helps us diagnose mitral valve stenosis. Correct Answer: The Pulmonary capillary wedge pressure (PCWP) measures LAEDP. Under normal conditions, the LAEDP is nearly equal to the LVEDP. Mitral stenosis eleveates the LAEDP and PCWP relative to the LVEDP. Generally speaking, regarding blood flow through our vessels, the law of conservation of mass states that the total flow of mass into a contained system must be equal to the total outflow of mass from that system in a steady state. What equation helps us prove the following condition: to maintain a constant fluid flow througha tube with varying diametes, how are cross-sectional area and flow velocities related? Correct Answer: Volume in must equal volume out, right? Vol(in) = A1 * V1 ; Vol(out) = A2*V2 So any rearrangement of that equation holds true in a physiological system. A2 = A1*V1 / V2 for example, works. This applies for blood flow in the cardiovascular system. What do you think when you hear a patient who has a heart murmur presenting with the following physical exam findings: Bounding femoral pulses, carotid pulsations accompanied by head-bobbing. Correct Answer: Aortic Regurgitation How does the pathophysiology of aortic regurgitation explain the characteristic findings of these patients? And what are those findings again (2 major ones)? Correct Answer: (1) Bounding femoral pulses; (2) Carotid Pulsations with head-bobbing (de Musset sign) There is a large LVSV, a large regurgitant SV, and a large pulse pressure. Bounding femoeral and carotid pulses marked by abrupt distention and quick collapse ("water hammer" pulses) are the result of large pulse pressure the head bobbing is due to the transfer of mementum from htel arge left ventricular stroke volume to the head and neck What is the order of cardiac tissue conduction velocity from *fastest* to *slowest*? Correct Answer: Purkinje System Atrial Muscle Ventricular Muscle AV node What is the mnemonic to help you remember the order of cardiac tissue conduction velocity? Correct Answer: P ark (purkinje's) AT (atria) VENT ura (ventricles) AV enue (AV node) Where does Atrial Natriuretic Peptide (ANP) come from? In response to what? Correct Answer: Atrial Cardiomyocytes in response to atrial stretch, it is a signifier of volume expansion What is the ultimate action of ANP? Correct Answer: Lowers blood pressure through peripheral vasodilation, natriuresis, and diuresis. How does ANP affect the following organs: (1) kidney? (2) adrenal gland? (3) blood vessels? Correct Answer: (1) Dilates the afferent arterioles, increasing GFR and urinary excretion of sodium and water (diuresis); also limits sodium reabsorption (in proximal tubule) and inhibits renin secretion (2) restricts aldosterone secretion --> increase in sodium and water excretion by the kidneys