UW Incorrect

Initial workup for hypertension

- Urinalysis (for occult hematuria and protein/creatinine ratio) - Chemistry panel - Lipid profile (for ASCVD risk stratification) - ECG (assess for CAD or LVH)

What is the intrapleural pressure at FRC?

-5cm H2O

Treatment of symptomatic hypovolemic hypernatremia

0.9% saline Mild cases can be treated with 5% dextrose in 0.45% saline 4424

Name the derivatives of pharyngeal arches (nerves, bones, and muscles)

1 - CN V, muscles of mastication, bones of mastication = mandible, maxilla - zygoma, malleus, incus 2 - CN VII, muscles of facial expression, lesser horn of the hyoid, styloid process, stapes 3 - CN IX, greater horn of the hyoid, stylopharyngeus 4-6 - CN X, Cricothyroid and thyroid cartilage, muscles of the larynx

Enzymes and compounds responsible for bruise color progression

1) Blue/purple: RBCs escaping into tramuatized tissue 2) Green: Heme --> biliverdin (via heme oxygenase) 3) Yellow: Biliverdin --> Unconjugated Bilirubin (biliverdin reductase) 4) Shuttled to liver on albumin for conjugation

What are two reasons for hypocalcemia in chronic renal failure

1) Decreased absorption of Ca in the kidney 2) Increased PO4 (less absorbed in kidney) --> Ca bound to PO4 in the blood

Name three functions of NADPH

1) Generation of glutathione 2) Respiratory burst 3) Biosynthesis of fatty acids, cholesterol, and steroids

What are the three mechanisms for metabolic acidosis correction in the kidney? What are the most important titratable acids?

1) Increased bicarb reabsorption from the PCT 2) Increased acid secretion 3) Increased acid buffer excretion Because secreting H+ causes a dramatic drop in urine pH, the kidney utilizes acid buffers to trap H+ and allow the excretion of much larger amounts of acid. Th two most important buffers are NH3 (most important) and HPO4. NH3 is generated by the PCT cells via metabolism of glutamine and combines with H+ to form NH4+ In DKA expect the following in the urine: Low bicarb, low pH, high NH4+, high H2PO4-

Workup of suspected hypercortisolism (Cushing syndrome)

1) Late-night salivary cortisol assay 2) 24-hour urine free cortisol measurement 3) Overnight low-dose dexamethasone suppression test Do not do an early morning cortisol level - it is insensitive 2/3 tests should be positive in Cushing syndrome - if so, --> test serum ACTH to determine if this ACTH dependent (pituitary ACTH, ectopic ACTH i.e. small cell) vs. ACTH independent (adrenal)

Steps involved in granuloma formation

1) Macrophage presents antigen to CD4+ T cell via MHC class II receptor 2) Macrophage secretes IL-12 which induces CD4+ cell --> Th1 subtype 3) Th1 cell secrete interferon gamma and TNF-alpha which convert macrophages to epithelioid histiocytes In caseating granuloma: 4) Macrophages increase phagolysosome acidification and secretion of proteases, nitric oxide, and reactive oxygen species in an attempt to destroy the organism, however, this also results in extensive collateral tissue damage --> caseous necrosis 1222

Provide two reasons why varicoceles are more common in the left scrotum.

1) The perpendicular angle of drainage into the left renal vein 2) The elevated pressure of the left renal vein due to its compression between the SMA and the aorta (nutcracker effect - not dissimilar to SMA syndrome)

What features distinguish colitis-associated carcinoma from sporadic CRC?

1) They tend to arise from non-polypoid dysplastic lesions 2) Multifocal in nature 3) Develop early p53 mutations and late APC gene mutations 4) Higher histological grade - appear mucinous and/or have signet ring morphology 5) Appear in younger patients

Name the three functions of thyroid peroxidase

1) catalyzes the oxidation of iodide (I-) --> iodine (I2) 2) Iodinates thyroglobulin 3) Iodotyrosine coupling reaction that forms T3 and T4 from MIT and DIT

What findings suggest severe aortic stenosis?

1. Mid to late systolic murmur (as opposed to early) 2. Soft S2 (rigid valve can't slam closed) 3. Pulsus parvus et tardus

Formula for resistance for parallel circuits?

1/R = 1/R1 + 1/R2 + ...

What exam finding would you expect from this x-ray? Involved in an MVA where her knee hit the dashboard

11659

How long does it take for a T cell response to mount in TB infection?

2-4 weeks following exposure 1217

Hepatitis B Serologies

2926

To which part of the tRNA molecule is the AA loaded?

3' OH end (CCA is the sequence - can carry amino acids) - note that this is the 5' --> 3' order so read "top to bottom" this would look like ACC.

Time required to reach steady state concentration (95% plasma steady state concentration) during continious infusion of a drug metabolized by first-order kinetics

4-5 half lives

Conditions associated with digital clubbing

4521 Pathophysiology: Megakaryocytes skip the normal route of fragmentation within pulmonary circulation (due to circulatory disruption from tumors, chronic lung inflammation) and enter the systemic circulation. They are entrapped in the distal fingertips due to their large size and releases PDGF and VEGF --> increase connective tissue hypertrophy and capillary permeability and vascularity --> clubbing

Splice site sequences for spliceosomes at the 5' and 3' positions?

5' = GU 3' = AG GUAG

How long does regular insulin last?

5-8 hours

Number of words that a 2yo should have

50-200 words 2 word sentences

Only rRNA that is not transcribed in the nucleolus

5S rRNA

When enzyme is responsible for turning cholesterol into bile acids?

7-alpha-hydroxylase

What's the earliest a serum pregnancy test will become positive? How about a urine test?

8 days for serum, 14 days for urine

What percentage of total GFR is expected 6 weeks after a nephrectomy?

80% The nephrons in the remaining kidney undergo significant hypertrophy enabling a return to 80% (from the initial 50% at nephrectomy)

What is neprilysin?

A metalloprotease that degrades ANP and BNP. Inhibition of neprilysin improves outcomes in patients with chronic systolic heart failure.

What is myocardial hibernation?

A state of chronic myocardial ischemia in which both myocardial metabolism and function are reduced to match a concomitant reduction in coronary blood flow. This results in LV systolic dysfunction that is partially or completely reversible by coronary revascularization.

What is the best indicator of mitral stenosis severity?

A2-to-opening snap time interval As MS worsens, LA pressure increase due to impaired movement of blood into the left ventricle. Higher pressure causes the valve to open more forcefully, and as a result, the opening snap occurs faster. The shorter the interval between A2 and OS, the worse the MS. 233

Treatments for AD

AChE inhibitors NMDA antagonists: memantine Antioxidants: Vitamin E (alpha-tocopherol)

Disease associated with a point mutation affecting the gene for neurophysin synthesis

AD hereditary hypothalamic DI Neurophysins are carrier proteins for moving oxytocin and ADH from their synthesis location (hypothalamic nuclei) to their site of release (axon terminals of the posterior pituitary).

Peutz-Jeghers syndrome

AD syndrome featuring numerous hamartomas throughout the GI tract, along with hyperpigmented mouth, lips, hands, genitalia. Associated with increased risk of breast and GI cancers.

Juvenile polyposis syndrome

AD syndrome in children (usually <5) featuring numerous hamartomatous polyps in the colon, stomach, small bowel. Associated with increased risk of CRC.

What type of leukemia is most associated with DIC?

APL

During normal skeletal muscle twitches, the ATP concentration does not fall appreciably because of which?

ATP is quickly regenerated from creatine phosphate

Complete desynchronization between P waves and QRS complexes. Regular rhythm and narrow QRS complexes. Which location is pacing the ventricles?

AV node 45-55 bpm AV nodal cells can become pacemakers in the setting of complete (third-degree) heart block, in which the SA node impulses cause atrial contraction while impulses generated by the AV node cause ventricular contraction.

Most common sites of atherosclerosis?

Abdominal aorta > Coronary artery > popliteal artery > internal carotid > circle of Willis

Lymph drainage of the testes

Abdominal para-aortic (retroperitoneal) lymph nodes

Pathogenesis of preeclampsia

Abnormal placental vasculature --> placental hypoxia and ischemia --> release of antiangiogenic factors in maternal circlation --> endothelial injury --> proteinuria

RBC type associated with abetalipoproteinemia

Acanthocyte

What substance directly stimulates the first enzyme involved in gluconeogenesis?

Acetyl CoA It activates pyruvate carboxylase to generate oxaloacetate. This regulation allows gluconeogenesis to proceed when there is lots of Acetyl-CoA, and the TCA cycle to proceed (instead of gluconeogenesis) when there is low Acetyl-CoA.

What type of gland (and specific gland) causes acne. How does it release its product?

Acne pathogenesis involves sebaceous glands which are holocrine glands. Holocrine glands release their contents by cell lysis, releasing the entire content of the cytoplasm and cell membrane. This is in contrast to sweat glands (apocrine and eccrine) which are merocrine glands and secrete their contents via endocytosis. Salivary glands are another example of merocrine glands. Mammary glands are apocrine glands and secrete via membrane-bound vesicles. Note: sweat apocrine glands were formerly thought to be apocrine, hence their name - they are actually merocrine.

Renal histologic findings in ethylene glycol poisoning

Acute tubular necrosis with vacuolar degeneration and ballooning of the proximal tubular cells. Presence of calcium oxalate stones Clinical findings include high anion gap metabolic acidosis, increased osmolar gap, calcium oxalate stones 887

Hypoketotic hypoglycemia

Acyl-CoA dehydrogenase deficiency 6610

How will adding enzyme to a reaction change the x and y-intercepts of a Lineweaver-Burke plot?

Adding enzyme will increase the Vmax of the reaction without affecting enzyme-ligand affinity (and thus not affecting Km). This would lead to a decrease in the y-intercept (y-intercept = 1/Vmax) and no change in the x-intercept (= -1/Km) An increase in Km moves it the x-intercept closer to 0 6616

Example of malignancy that tends not to invade the vasculature or stroma

Adenocarcinoma in situ Presents expectorating copious amounts of pale tan-colored fluid --> adenocarcinoma in situ (formerly bronchioalveolar carcinoma) is a preinvasive lesion characterized by growth along intact alveolar septa. It is malignant.

Menorrhagia and dysmenorrhea in the setting of a uniformly enlarged uterus

Adenomyosis = Endometrial glandular tissue within the myometrium. Leiomyoma would produce an irregularly enlarged uterus.

What enzyme would be increased in a tumor cell with a G alpha subunit that lacks GTPase activity?

Adenylyl cyclase GTPase activity inactivates G alpha subunits so they are not constitutively activating adenylyl cyclase.

What cells release leptin?

Adipocytes Thus when there is a leptin receptor knockout, the body will be insensitive to leptin --> obesity and increased leptin levels.

Common causes of nonbacterial thrombotic endocarditis?

Advanced malignancy most commonly Chronic inflammatory disorders: antiphospholipid syndrome, SLE, DIC in patients with sepsis. Often seen in mucinous adenocarcinomas which may relate to procoagulant effects of circulating mucin.

Mechanism of senile purpura

Age-related loss of elastic fibers in perivascular connective tissues --> minor abrasions that would normally only stretch the skin can rupture superficial blood vessels in the elderly --> ecchymoses

How does normal aging change chest wall compliance and lung compliance? How does it impact TLC, RV, and FVC?

Aging decreases chest wall compliance due to increased thoracic curvature due to osteoporosis and osteoarthritis and increases lung compliance due to loss of elastic recoil. Aging does not impact TLC, however it increases RV and decreases FVC 12100

Qhat benzodiazepines should you use for patients with advanced liver disease? Why?

All benzos are metabolized by the liver via oxidation and some produce active metabolites. Patients with liver disease should not be given benzos that produce active metabolites, but instead on of the following: LOT Lorazepam Oxazepam Temazepam

How does administration of synthetic T3 in the setting of primary hypothroidism affect levels of TSH, T4, T3, and reverse T3

All go down except for T3 Remember that reverse T3 is synthesized from T4 (can't be converted into T3). Exogenous T3 will inhibit the release of TSH --> inhibit T4 release --> reduced reverse T3

Serum concentrations of Ca, PO4, and PTH in osteoporosis

All normal

How will PaO2, SaO2, and Oxygen content be affected by CN poisoning?

All normal CN inhibits cellular oxidative phosphorylation by inhibiting Fe3+ in cytochrome c oxidase. lowering peripheral tissue O2 consumption. Venous oxygen content rises and the arterial-venous oxygen gradient falls.

Where are mitochondrial proteins synthesized?

All ribosomes begin protein translation in the cytoplasm but some translocate to the RER depending on the protein's target destination. Free ribosomes are responsible for synthesizing proteins destined for the cytosol, nucleosol, peroxisome matrix, and nuclear-encoded mitochondrial proteins. Attached ribosomes are responsible for most secretory proteins, cell membrane proteins, ad proteins within the ER, Golgi network, and lysosomes.

What are the embryologic derivatives of the medial umbilical ligament and the median umbilical ligament?

Allantoic duct --> Urachus --> Median umbilical ligament Umbilical arteries --> Medial umbilical ligaments

Define allelic heterogeneity

Allelic heterogeneity refers to conditions in which different mutations in a single gene can produce a similar phenotype. 6506

Transient recurrent pulmonary infiltrates and eventual bronchiectasis in an asthmatic patient.

Allergic bronchopulmonary aspergillosis

How are allocation bias and selection bias different?

Allocation bias is a bias in the way that subjects are assigned to treatment and control groups. Selection bias occurs when the studied sample doesn't represent the general population (because of nonrandom selection)

Most common location of a gastric ulcer

Along the lesser curvature of the stomach at the transitional zone between the gastric corpus and antrum (border between acid-secreting parietal cells and gastric-secreting G cells). Left and right gastric ulcers are the most likely to be involved.

4 major causes of hypoxemia (low PaÓ)

Alveolar hypoventilation V/Q mismatch Diffusion impairment Right to Left Shunt Only Alveolar hypoventilation has a normal A-a gradient. 1582

Neurotransmitter and receptor involved in first ANS synapse

Always Ach released onto nicotinic receptor regardless of parasympathetic/sympathetic

What causes amaurosis fugax? What produces a pale retina and a "cherry-red" macula?

Amaurosis fugax is a painless, transient, monocular vision loss caused by a small embolus to the ophthalmic artery. It usually only lasts a few seconds. Retinal artery occlusion (pictured) can cause a cherry red macula. It is caused by an athero or thromboembolism of the retinal artery. Predisposing conditions include atrial fibrillation, carotid artery stenosis, and giant cell arteritis. The vision loss is the entire visual field and is usually permanant.

Treatment of lyme disease in pregnant women?

Amoxicillin

Most common site of ectopic pregnancy

Ampulla

Antidote and mechanism for CN toxicity

Amyl Nitrite Amyl nitrite is an oxidizing agent that converts Fe2+ present on Hb to Fe3+, generating methemoglobin. CN's toxicity is caused by its ability to bind avidly to cytochrome C oxidase, inhibiting oxidative phosphorylation --> lactic acidosis and narrowing of the venous-arterial pO2 gradient Methemoglobin has a very high affinity for CN --> CN binds ferric iron more avidly than mitochondrial cytochrome c oxidase, diminishing its toxic effect.

Definition of the third heart sound S3?

An imbalance between the force with which blood is pushed into the ventricle and the ability of the ventricle to accommodate this blood flow.

HMO

An insurance plan with low monthly premiums, low copayments and deductibles, and low total cost for the patient. HMOs reduce utilization by confining patients to a limited panel of providers, requiring a referral from a primary care provider prior to specialist consultations, and denying payment for services that do not meet established guidelines. Point of Service are the next step up in monthly payments (with more flexibility in seeing physicians out of network) Preferred provider organization is the most expensive with the greatest flexibility in whom the patient can see.

What is an open reading frame?

An open reading frame is a continuous stretch of codons that code for a polypeptide without an intervening stop codon. Eukaryotes typically only have one open reading frame in a single mRNA transcript, whereas prokaryotes often have multiple open reading frames.

Large pleomorphic giant cell nests with occasional multinucleated cells on thyroid biopsy?

Anaplastic carcinoma

What innervates omohyoid?

Ansa cervicalis (C1-C3) It is not part of the brachial plexus. Interscalene nerve block can cause an ipsilateral diaphragmatic paralysis by anesthetizing roots of the phrenic nerve (C3-C5)

Arm injury resulting in flattening of the deltoid and protrusion of the acromion

Anterior dislocation of the humerus This is the most common dislocation in the body Commonly occurs with a blow to an externally rotated and abducted arm (throwing a football) and can result in axillary nerve damage.

Most commonly injured structure in an ankle sprain?

Anterior talofibular ligament - this occurs when the ankle is plantar-flexed and inverted.

What antibody is present in polymyositis/dermatomyositis (what is it actually targeting)

Anti-Jo-1 targets histidyl-tRNA synthetase Anti-smooth muscle is autoimmune hepatitis

Treatment of splenic abscess?

Antibiotics and splenectomy

Most important source of protection from infleunza reinfection

Antibodies against hemagglutinin (not neuraminidase)

What are Anti-Smith antibodies? What disease are they associated with?

Antibodies directed against snRNPs SLE

Through what mechanism do eosinophils contribute to host defense against parasites?

Antibody-dependent cell-mediated cytotoxicity NOT type I hypersensitivity After antibody has bound to a parasite, eosinophils can bind to the Fc region of the antibody which then induces degranulation of cytotoxic contents (MBP) In type I hypersensitivity, eosinophils contribute to the late-phase by synthesizing prostaglandins, leukotrienes, and cytokines.

Genetic Reassortment

Antigenic shift - seen with influenza virus epidemics and pandemics in which two viral strains exchange segments of their genomes. Differs from antigenic drift, which refers to point mutations that produce minor changes in product proteins that may allow immune evasion or increased infectivity.

What medications should be avoided in HCM?

Anything that decreases LV volume (reducing preload or afterload) which includes: Vasodilators: decrease SVR, leading to decreased afterload and lower LV volumes (dihydro calcium channel blockers, ACE inhibitors, nitrates) Diuretics: decrease LV venous filling (preload) and also result in greater outflow obstruction.

Most common cause of death in patients with Marfan's? What is the cause?

Aortic disease (aortic dissection) Caused by early-onset cystic medial degeneration of the aorta - will result in aneurysmal dilation in more than 75% of patients. Second most common cause of death is related to MVP and AR

Most common cause of aortic regurgitation?

Aortic root dilation or a bicuspid aortic valve

Familial dysbetalipoproteinemia

ApoE defect Elevated chylomicron and VLDL remnants Premature atherosclerosis, tuboeruptive and palmar xanthomas

Superficial hemangioma

Appear during the first weeks of life - grow rapidly and then frequently regress spontaneously by late childhood. Bright red when near the epidermis and more violacious when deeper

Cause of death in TCA overdose

Arrhythmias - TCAs inhibit fast sodium channels in cardiac myocytes (and His-Purkinje system). Refractory hypotension is another common cause of death due to alpha 1 blockade.

What is the major source of resistance in the vascular system?

Arterioles

ApoÈ protein

Associated with Alzheimer's disease

Most specific arrhythmia associated with digitalis (digoxin) toxicity

Atrial tachycardia with AV block. It causes increased ectopy and increased vagal tone.

Within what structure does the highlighted segment of the pacemaker lead lie?

Atrioventricular groove

First antidote given in organophosphate poisoning?

Atropine followed by pralidoxine

AML features

Auer rods due to myeloperoxidase+ (MPO+) APL = t(15;17) - responds to ATRA (vitamin A) --> stimulates promyelocytes to differentiate DIC is a common presentation

Aromatase Deficiency

Autosomal Recessive High androgens, low estrogen. Maternal virilization (hisutism) common. New born girls present with normal internal genitalia and ambiguous or male-type external genitalia. Aromatase activity: Andorstenedioene --> estrone Testosterone --> estradiol

Inheritance of Classic Galactosemia

Autosomal recessive

Difference between schizoid and avoidant personality disorder?

Avoidant desires relationships

Susceptibility to Giardia

B-cell disorders X-linked Bruton agammaglobulinemia Selective IgA deficiency Common varialbe immunideficiency

Oval macrocytes and hypersegemnted neutrophils on blood smear

B12 deficiency Megaloblastic anemia

Most common organism isolated from an intra-abdominal abscess from a perforated appendicitis?

Bacteroides Fragilis and E. Coli Not Staph! C. Albicans can be isolated from an infection resulting from perforation of the proximal bowel such as a perforated gastric ulcer.

What enzyme is responsible for the formation of pigmented gallstones?

Beta-glucoronidase - it is released by damaged hepatocytes and bacteria in infected bile. It deconjugates bilirubin, and the resulting free bilirubin precipitates with calcium in the bile to form pigment stones.

At what level should you insert a thoracentesis needle in the midclavicular line? Mid axillary? vertebral? What structures are at risk?

Between 6 and 8 Between 8 and 10 Between 10 and 12 The liver is at risk on the right at mid-axilllary. Other abdominal organs are also at risk. 844

Where do you insert the needle for lumbar puncture and what do you use as an anatomical landmark?

Between L4-L5 or L3-L4. You use the most superior aspect of the ILIAC CREST as a landmark. If you draw a horizontal line from this position you will be over L4.

Incomplete lateral fusion of the paramesonephric ducts results in what uterine anomaly?

Bicornuate uterus - characterized by an indentation in the center of the fundus. Failed involution of the PM ducts can result in a longitudinal uterine septum. 1831

Ejection click along with a soft murmur radiating to the neck. 34-year-old man with no symptoms

Bicuspid aortic valve

How does cardiac amyloidosis appear on H and E? What are the most common causes?

Biopsy reveals cross-sections of normal myocardial cells with areas of myocardium infiltrated by an amorphous and acellular pink material. Caused by deposition of insoluble proteins such as monoclonal light chains (AL amyloidosis), mutated transthyretin (familial ATTR amyloidosis), or WT transthyretin (senile systemic amyloidosis).

What are the urodynamic findings in a patient with MS who is recently experiencing urge incontinence (increasing urinary frequency and inability to control the urge to urinate)?

Bladder Hypertonicity There will be no residual volume after emptying, as the bladder contractility is normal but distensibility is poor. The bladder does not distend/relax properly due to loss of descending inhibitory control from the UMNs. In LMN disease, the bladder will be flaccid and have large residual volume after emptying and will typically have incontinence at the end of the day (pressure from a full bladder)

Failure of caudal fold closure

Bladder exstrophy

MOA of tetrodotoxin

Blocks VG Na+ channels in nerve cell membranes. Inhibits the passive transport of Na+ across the membrane.

What does intrapulmonary right-to-left shunt mean?

Blood flows from RA to LV without being oxygenated in the pulmonary vasculature (i.e. PE)

How do ventilation and perfusion change from apex to base?

Both increase but perfusion increases more meaning that V/Q decreases from apex to base.

Describe the mechanism of action of Clostridium difficile toxins.

Both toxins exert their effects by inactivating Rho-regulatory proteins involved in signal transduction and actin cytoskeletal maintenance. Toxin A causes more enterotoxicity (more intestinal inflammation and fluid secretion), while toxin B is more cytotoxic. Accoding to 1100: Toxin A recruits release of cytokinesThat's cause mucosalInflammation, fluid loss and diarrhea Toxin B - Induce is acting depolymerization, leading to a mucosal cell death, bowel wall necrosis and pseudomembrane formation

Fixed pupillary dilation, dry mouth, blurred vision, difficulty swallowing.

Botulism Not TCA toxicity! Remember that TCA only blocks muscarinic transmission - it would not explain the dysphagia which is caused by nicotinic blockade (or rather the inhibited release of Acetylcholine which produces BOTH antimuscarinic and antinicotinic symptoms). You must differentiate between muscarinic and nicotinic symptoms. If both are present, you know acetylcholine must be involved.

Where is PAH concentration lowest in the kidney?

Bowman's capsule PAH is never reabsorbed in any portion of the nephron and is only secreted (excretion > filtered) - thus the concentration will be lowest at the first stop = Bowman's space.

What type of brain lesions result in ipsilateral CN palsies and contralateral hemiparesis?

Brainstem lesions

Empiric treatment of neutropenic fever (ANC < 1500)

Broad-spectrum with pseudomonal coverage: Piperacillin-Tazobactam Cefepime Meropenem Draw blood cultures first

Segmental thrombosing vasculitis

Buerger's - thromboangiitis obliterans Caused by either direct endothelial cell toxicity from tobacco products or hypersensitivity. Vasculitis tends to extend into contiguous veins and nerves, encasing them in a fibrous tissue.

Difference between bulimia nervosa and binge-eating disorder

Bulimia includes compensatory behaviors (vomiting, exercise, etc.) DSM 5 requires binges and inappropriate compensatory behaviors at least once per week for 3 months for dx of bulimia.

Lipid vacuoles in lymphocytes

Burkitt's lymphoma

Symptoms of whipple disease

CAN Cardiac symptoms Arthralgias Neurologic symptoms PAS+, foamy macrophages in intestinal lamina propria, mesenteric nodes. Diarrhea/steatorrhea occur later in disease course. Most common in older men.

What is the receptor for LPS?

CD14 on monocytes and macrophages --> activation

Which cell types would predominate in a sarcoidosis patient's BAL fluid

CD4+

What mediates the damage to parietal cells in autoimmune gastritis

CD4+ cells cause the damage Antibodies to parietal cell components are also formed however they are not significantly involved in the pathogenesis (but are useful for dx)

Features of CLL

CD5+, CD23+ Most common adult leukemia Smudge cells (crushed little lymphocytes = CLL) Richter transformation = transformation to DLBCL Infection is the most common cause of death

What CNs does the PCA supply? What other structures are supplied and what is the most common clinical presentaiton?

CN 3 and 4 Most often presents with contralateral homonymous hemianopsia with macular sparing (from MCA collateral). It also supplies the thalamus, medial temporal lobe, splenium of the CC, and the occipital lobe.

What are the most common presentations of multiple myeloma?

CRAB hyperCalcemia Renal dysfunction Anemia lytic Bone lesions Fatigability, constipation, bone pain (commonly in back and ribs), elevated serum protein, and renal failure. Myeloma cast nephropathy is due to excess excretion of light chains (Bence Jones proteins). When levels exceed absorptive capacity, they precipitate as Tamm Horsfall protein and form casts that cause tubular obstruction and epithelial injury.

What types of cell junctions are cadherins involved in? What could you remove from the extracellular fluid to disrupt these interactions?

Cadherins are involved in adherens junctions and desmosomes. They are calcium dependent, and thus removing calcium would result in dissociation of cadherin-mediated junctions.

Describe the movement of Calcium in myocyte contraction--> relaxation

Calcium first enters via L-type calcium channels to mediate phase 2 of the AP. This calcium influx is sensed by the ryanodine receptors in the SR which triggers the further release of Calcium (CICR). This calcium then diffuses through the myofilament network and binds to troponin C. Tropomyosin is then moved out of the way so that myosin and actin can interact leading to contraction. During relaxation, the Na/Ca exchanger is responsible for most of the Efflux of Calcium. SERCA, an ATPase on the SR also returns Ca to the SR. Calmodulin is a calcium-binding regulatory protein that mediates many of the regulatory effects of Ca2+. It is important in excitation-contraction coupling in smooth muscle cells, which lack troponin - it is not involved in excitation-contraction in myocytes.

Rhomboid-shaped crystal on joint aspiration

Calcium pyrophosphate crystals = pseudogout Positively birefringent Blue when parallel Yellow when perpendicular Knee joint involved > 50% of the time

How do you calculate number needed to treat?

Calculate the absolute risk reduction and then take its inverse NNT = 1/Absolute risk reduction

Most common cause of acute gastroenteritis in children and adults in industrialized countries? What are the modes of transmission?

Campylobacter It is transmitted via fecal-oral route and can be acquired from: 1. Dometic animals (including pets!) 2. Contaminated food, such as undercooked poultry and unpasteurized milk. Remember that shigella is a human pathogen - it cannot be transmitted by domestic animals/pets. It is transmitted by fecal-oral route by dirty hands, fomites, and contaminated food.

What is electrical alternans

Can be seen in very large pericardial effusion or tamponade which produces a beat to beat variation in QRS amplitude due to the swinging motion of the heart in the pericardial fluid

How does prostate cancer spread to the lumbar vertebrae? Through which networks does this occur?

Cancer spreads to the bone hematogenously (not lymphatically!) Thus prostate cancer would likely spread to the spine via the prostatic venous plexus to the vertebral venous plexus. Remember that spread to the bone is hematogenous

Most common cause of HIV esophagitis?

Candida

MOA of capsaicin in the treatment of postherpetic neuralgia

Capsaicin causes excessive activation of TRPV1 (transmembrane cation receptor) resulting in buildup of intracellular calcium that causes long-lasting dysfunction of nociceptive nerve fibers (defunctionalization) It also causes the release of substance P - when applied chronically, this depletes substance P resulting in moderate pain reduction over time.

Islands or sheets of uniform cells with eosinophilic cytoplasm and oval-to-round stippled nuclei on biopsy of an appendix following appendicitis?

Carcinoid tumor

What does red safranin O stain?

Cartilage, Mast cell granules and mucin. The picture demonstrates articular cartilage with type II collagen stained red.

What is tick paralysis?

Caused by a neurotoxin present in tick saliva - typically presents with paresthesias and fatigue followed by ascending muscle paralysis,

Most common benign liver tumor? What are two other liver tumors (besides HCC) with strong associations?

Cavernous hemangioma is the most common - usually asx, arise at age 30-50, biopsy contraindicated Hepatic adenomas are associated with oral contraceptives and steroids. They will regress when you stop taking oral contraceptives. They can also rupture and cause sudden back pain. Angiosarcoma is associated with VAT - vinyl chloride, arsenic, and thorotrast.

What proceeds calcification of aortic valves in the elderly?

Cellular injury or death --> cellular necrosis Dystrophic calcification is a hallmark of cellular injury an death and occurs in all types of necrosis in the setting of normal calcium levels.

Central Cord Syndrome vs. Anterior cord syndrome

Central Cord = decreased sensation and motor function in the arms with relative sparing of the legs after forced hyperextension (whiplash) Anterior Cord = Bilateral hemiparesis below the level of the injury, bilateral diminished pain, temperature, and crude touch 1-2 levels below lesion, preserved proprioception/vibratory sensation/light touch due to sparing of posterior supply

Patient presents with moderate unilateral hearing loss, facial numbness, and asymmetric smile. What is the most likely location of the lesion?

Cerebellopontine angle - this is likely an acoustic schwannoma

Most common cause of spontaneous lobar hemorrhage in the elderly? Describe its pathogenesis and most common clinical presentation.

Cerebral amyloid angiopathy Beta-amyloid is deposited into the walls of small vessels which weakens them and makes them prone to rupture --> hemorrhage This is most often recurrent and involves the occipital or parietal lobes resulting in homonymous hemianopsia or hemisensory loss

What is the cause of coma in a patient with Reye syndrome?

Cerebral edema from encephalitis

How do you differentiate lacunar infarcts from Charcot-Bouchard aneurysm.

Charcot-Bouchard aneurysms are caused by chronic hypertension and involve the same small penetrating arterioles as lacunar stroke however, aneurysm rupture typically leads to intraparenchymal hemorrhage within deep brain structures which appear acutely as a relatively large intracerebral HYPERdensity on CT scan (pictured) Lacunar infarcts are small ISCHEMIC infarcts involving deep brain structure. They are most often due to lipohyalinosis, microatheroma formation, and hardening/thickening of vessel wall (hypertensive arteriolar sclerosis), which predisposes to thrombotic vessel occlusion. If there are no abnormalities on non-contrast CT, suspect a lacunar stroke. 22

Hammer toes, lower extremity weakness (foot drop), and sensory deficits. What is the pathophys?

Charcot-Marie-Tooth AKA Hereditary motor and sensory neuropathy - group of progressive hereditary nerve disorders related to the defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath. Typically autosomal dominant inheritance pattern and associated with foot deformities (eg, pes cavus, hammer toe), lower extremity weakness (eg, foot drop) and sensory de cits.

Treatment of Wilson disease

Chelation with penicillamine or trientine, oral zinc AR mutation in hepatocyte copper-transporting ATPase (ATP7B on chromosome 13) --> decreased copper excretion and incorporation into apoceruloplasmin --> decreased serum ceruloplasmin Copper accumulates especially in liver, brain, cornea, kidneys. Parkinsonism, Kayser-Fleischer rings

Most common eye-related complication of congenital CMV infection?

Chorioretinitis

Liver biopsy reveals finely granular, homogenous, pale eosinophilic, ground-glass appearance of cells. What is the diagnosis?

Chronic Hep B infection The cytoplasm is filled with Hep B surface antigen It almost looks like colloid

Most common causes of hemoptysis in developed nations

Chronic bronchitis Bronchogenic carcinoma Bronchiectasis

What conditions are associated with digital clubbing?

Chronic diseases causing hypoxia: 1) Lung diseases: lung cancer (esp large cell), Tb, CF, bronchiectasis, pulmonary hypertension, empyema. 2) Heart diseases - Cyanotic congenital heart diseases and bacterial endocarditis 3) Other: Inflammatory bowel, hyperthyroidism, malabsorption Not anemia! Anemia can cause pallor and koilonychia (spoon-shaped nails)

What increases at high altitudes and is responsible for increased oxygen delivery?

Chronic high altitude leads to an increase in EPO which will increase Hematocrit

Delayed sleep phase syndrome

Circadian rhythm disordered characterized by the inability to ally asleep at "normal" bedtimes, resulting in sleep-onset insomnia and excessive daytime sleepiness. Night owl

Pathophysiology of hepatorenal syndrome

Cirrhosis --> splanchnic arterial dilation --> drop in vascular resistance --> RAAS activation --> local renal vasoconstrction, decreased perfusion and GFR

What agent would use to treat infertility in PCOS? What is its MOA?

Clomiphene Clomiphene is an estrogen receptor modulator that decreases the negative feedback of circulating estrogen on the hypothalamus. This results in an increased release of FSH and LH, promoting ovulation. Progestin alone can be used to reduce endometrial hyperplasia in PCOS, however, unlike combined oral contraceptive therapy, it would not treat hirsutism and acne.

What cardiac anomaly are berry aneurysms associated with?

Coarctation of the aorta 31

What are cold agglutinins?

Cold agglutinins are cross-reacting IgM antibodies that agglutinate RBCs. They can be formed in mycoplasma infections since mycoplasma's unique phospholipid cell wall shares antigens with that of the RBC resulting in a cross-reaction that can produce a hemolytic anemia. Treatment of the infection will result in a decrease in the number of these cold agglutinin IgM antibodies and a resolution of the hemolytic anemia.

What does vWF bind to?

Collagen It binds and crosslinks Gp1b with exposed collagen.

Why is there macular sparing in occipital visual lesions?

Collaterals from the MCA

First step in a root cause analysis

Collecting data - mainly through interviewing multiple individuals involved in the steps leading to the outcome. You must establish the what, how, and why of an error before you can recommend changes.

First line treatment for menorrhagia due to von Willebrand disease?

Combined oral contraceptives

Most common congenital cardiac anomaly associated with Down syndrome

Complete atrioventricular canal defect Comprised of ASD, VSD, and a single atrioventricular valve. Caused by failure of fusion of the endocardial cushions. Significant left to right shunting occurs leading to symptoms of HF (tachypnea, poor feeding). Auscultatory findings of AV valve regurgitation include a holosystolic murmur and increased pulmonary venous return heard as a mid-diastolic rumble.

Snowstorm pattern on ultrasound

Complete molar pregnancy 46XX (rarely 46XY) - only paternal DNA No fetal tissue is present - only edematous villi This is in contrast to partial mole which is triploid karyotype (69, XXX, XXY) containing maternal and paternal DNA (extra from paternal). There will be fetal tissue, some edematous villi with trophoblastic proliferation and some normal-appearing villi. Choriocarcinoma has no villi - sheets of anaplastic cytotrophoblasts and syncytiotrophoblasts

Nests of uniform round cells at the basal portion of the epidermis that extend into the underlying dermis. The cells contain inconspicuous nucleoli and show no mitotic activity. What is the dx?

Compound melanocytic nevus The lesions appear as slightly rased papules with uniform pigmentation and symmetrical sharp borders. Distinguished from junction nevi, which are limited to the dermoepidermal junction, and intradermal nevi which are older lesions in which epidermal nests of nevus cells (benign neoplasm of melanocytes) have been lost and the remaining dermal cells lose tyrosinase activity producing a skin to tan colored, dome shaped, sometimes pedunculated nevus.

Next management step when the Wells indicates a high pre test probability?

Compression ultrasonography If the patient has features of PE and high pre-test probability, start empiric anticoagulation (need diagnostic confirmation if just suspect DVT)

Cardiac pathology associated with acromegaly

Concentric myocardial hypertrophy, diastolic dysfunction, left ventricular dilation, global hypokinesis. Complications include HF and arrythmias.

Serotonin Syndrome

Confusion, tachycardia, hypertension, clonus, agitation, tremor, hyperthermia, diaphoresis

2-4 week old child presents with strong preference to hold held tilted to one side. May also have a soft-tissue neck mass.

Congenital torticollis - most commonly the result of malposition of the head in utero or birth trauma. Most cases resolve with conservative therapy and stretching exercises.

Cardiac abnormalities associated with DiGeorge syndrome? What are the other abnormalities?

Conotruncal defects --> persistent truncus arteriosus Tetralogy of Fallot and interrupted aortic arch are also common. CATCH Conotruncal abnormalities Abnormal facies Thymic aplasia/hypoplasia - deficient T cell immunity Cleft palate Hypocalcemia - tetany/seizures

Fine motor skill milestones of a 3yo

Copy a circle and use utensils Walks up/down stairs with alternating feet, rides tricycle 3-word sentences, speech 75% intelligible Knows age/gender, imaginative play

Which blood vessels are typically affected in lobar hemorrhages?

Cortical branches - caused by amyloid angiopathy typically in the temporal or occipital lobes in elderly pts

Kidney manifestations of GPA

Crescentic glomerulonephritis (RPGN) type 3 (pauci-immune) Elevated serum c-ANCA "WeCeners" = C for c-ANCA and Crescentic and Cyclophashamide

Difference between aplastic anemia and aplastic crisis

Crisis only affects erythrocyte precursors (parvo infection) while aplastic anemia (despite its name) represent bone marrow failure with pancytopenia (not just anemia).

What causes dermatitis herpetiformis?

Cross-reactivity between anti-gliadin IgA antibodies and transglutaminase at the dermal basement membrane. Skin biopsy will demonstrate microabscesses at the dermal papillary tips, which coalesce to form subepidermal blisters. IF staining for IgA confirms the diagnosis.

Features of tuberous sclerosis

Cutaneous angiofibroma, brain hamartomas, and cardiac rhabdomyoma

Cheyne-Stokes breathing

Cyclic breathing in which apnea is followed by gradually increasing then decreasing tidal volumes until the next apneic period. Commonly seen in advanced CHF

Pharmacologic treatment of serotonin syndrome

Cyproheptadine - first generation antihistamine

Absent vas deferens

Cystic Fibrosis

Azoospermia

Cystic fibrosis

What is found in the microsome?

Cytochrome P450 enzymes Microsomal monooxygenase - responsible for converting pre-carcinogens into carcinogens as well as metabolizing the majority of other substance (makes them more soluble for excretion)

What type of urinary incontinence is common in DB 1? How could this be confirmed?

DB 1 can lead to autonomic neuropathy affecting the detrusor muscle innervation which results in overflow incontinence. Overflow incontinence can be caused by impaired detrusor contractility or bladder outlet obstruction. In this case, patients initially have infrequent urination due to loss of ANS afferent innervation and inability to sense a full bladder. As efferent involvement progresses, the patient will experience incomplete emptying, recurrent UTIs, and overflow incontinence. This can be confirmed with postvoid residual testing which will demonstrate elevated post void volumes.

How does diastolic heart failure impact ventricular compliance, ejection fraction, end-diastolic volume, and left ventricular filling pressure?

DHF decreases ventricular compliance causing an increase in LV filling pressure, and normal end-diastolic volume and EF. 93

What protein is responsible for removing RNA primers during DNA synthesis.

DNA Polymerase I It is the only DNA polymerase that has 5' --> 3' exonuclease activity enabling it to remove the RNA primers laid down by primase, and replace these primers with DNA (note it is not responsible for the lagging strand itself - this is the task of DNA pol III) while DNA polymerase III is responsible for producing the leading strand. DNA polymerase III does not have 5'-->3' exonuclease activity, and therefore can only proofread with 3'--->5' exonuclease activity, and not remove primers. 1471

What is DNA laddering

DNA laddering is the appearance 180bp fragments on gel electrophoresis - it is a sensitive indicator of apoptosis and thus may be absent in malignant cells that have the ability to evade apoptosis (BCL2 overexpression in follicular lymphoma).

What produces decorticate posturing?

Damage at or below the level of the red nucleus (i.e. the pons) Loss of excitation of the flexors --> extension predominates

What is the greatest concern in posterior and anterior knee dislocations

Damage to the popliteal artery It is more vulnerable than the tibial nerve because it is rigidly fixed proximal and distal to the knee joint by the adductor magnus and soleus muscles respectively. Popliteal artery gives rise to both the posterior tibial artery and the anterior tibial artery so damage will compromise both the DP and PT pulses.

Effect of Sickle Cell Disease on haptoglobin

Decreased Haptoglobin binds circulating hemoglobin and reduces renal excretion of free hemoglobin, preventing tubular injury. It will go down whenever there is hemolysis exposing Hb to the intravascular space. Lactate dehydrogenase indirect bilirubin will increase

What is the effect of prior MI on risk of rupture on subsequent MI

Decreased Myocardial fibrosis and coronary collateral circulation mediate this counterintuitive finding

What is the most significantly affected PFT in central obesity?

Decreased ERV (the amount that can be exhaled at FRC) and consequently decreased FRC RV is typically normal FEV1, FVC, and TLC are also typically decreased. 11900

Why does urge incontinence develop in normal pressure hydrocephalus?

Decreased absorption of CSF leads to expansion of the ventricles and subsequent distortion of the periventricular white matter. Bladder control is influenced by descending cortical fibers that run in the distended periventricular area - there is loss of cortical inhibition on the sacral micturition center leading to urge incontinence. 17

Cause of decreased ACh in Alzheimer's. Where is the most prominent?

Decreased activity of choline acetyltransferase in the nucleus basalis of Meynert. Tau tangles intracellular Senile plaques of beta amyloid extracellular

MOA of Combined oral contraceptive therapy in the treatment of hirsutism

Decreased androgen production (inhibits the release of LH from the pituitary thereby decreasing ovarian androgen production.)

Morphologic changes in an aging heart

Decreased in left ventricular cavity size (apex-base dimension), development of a sigmoid-shaped ventricular septum, myocardial atrophy with increased collagen deposition, and accumulation of cytoplasmic lipofuscin pigment within cardiomyocytes.

What causes an S4

Decreased left ventricular compliance - often associated with restrictive cardiomyopathy and left ventricular hypertrophy It occurs immediately before S1 and is thought to coincide with atrial contraction (produced by the resultant onrush of blood striking a stiff LV)

Impact of increased vascular resistance on venous return

Decreased venous return Also decreased CO from increased afterload 1624

What causes supine hypotension in pregnancy?

Decreased venous return due to compression of the IVC by the gravid uterus --> decreased preload --> decreased CO --> hypotension

Effect of hyperventilation on ICP

Decreases ICP by leading to vasoconstriction (increasing cerebral vascular resistance). This results in a decrease in cerebral blood volume. CÓ is a potent vasodilatory of cerebral vasculature. Tachypnea causes hypocapnia and cerebral vasoconstruction --> decreasing cerebral blood volume and ICP

Affect of insulin on ketogenesis

Decreases ketogenesis The absence of insulin is what enables the synthesis of excess ketone bodies in DKA (there is also an excess of counter-regulatory proteins = glucagon, cortisol, GH)

Effect of mitral stenosis on pulmonary vascular compliance

Decreases pulmonary vascular compliance Elevated LA pressures are transmitted back to the pulmonary circulation --> pulmonary vasoconstriction, reactive hypertrophy of the arterial muscle layer, and partial obliteration of the pulmonary capillary bed --> decreased compliance 234

Impact of increased dietary calcium intake on renal stone formation

Decreases the risk of stone formation Dietary calcium is ingested with oxalate in food and forms insoluble calcium oxalate salts that cannot be absorbed by the gut. Think of calcium as trapping oxalate in the gut. Increased urinary citrate helps reduce stone formation.

Impact of desmopressin on urea clearance

Decreases urea clearance Activation of V2 receptors activates urea transporters in the medullary collecting duct causing increased reabsorption of urea into the medullary interstitium - this rise in medullary osmotic gradient allows for the production of maximally concentrated urine (the whole point of ADH/desmopressin in the first place)

How do afterload and passive tension impact contraction velocity of skeletal muscle

Decreasing afterload causes an increase in contraction velocity Decreasing passive tension causes a decrease in contraction velocity. The passive tension exerted by a skeletal myocyte is positively correlated with its resting length. A decrease in passive tension generally implies a decrease in the fiber length and a decrease in maximal contraction velocity.

What artery is at risk of injury in a midshaft humerus fracture? Especially when there is extensor strength difficulty?

Deep brachial artery (profunda bracii) It courses with the radial nerve posteriorly

What are heinz bodies made of?

Denatured hemoglobin from oxidative stress

Pathophysiology of macular degeneration

Deposition of fatty material (drusen) behind the retina (dry) and subsequent neovascularization of the macula (wet) lead to central scotomas.

Bilateral proximal muscle weakness associated with a violaceous eruption on the eyelids and knuckles, elevated CK

Dermatomyositis

Number of amnions/chorions with dizygotic twins

Dichorionic/diamniotic always Monozygotic twins arise from fertilization of a single oocyte. Twinning may occur at different stages resulting in different patterns. Most common is monochorionic/diamniotic (occurs during the end of the first week)

Hyperviscosity syndrome

Didence diplopia, tinnitus, headache, dilater/segmented fundoscopic findings, neuropathy, evidence of infiltrative disease (hepatosplenomegaly, anemia, thrombocytopenia) All could suggest Waldenstrom macroglobulinemia

Why in most tissues does ischemic injury result in coagulative necrosis?

Digestive enzymes denature BEFORE they can significantly disrupt tissue integrity.

Color vision alterations

Digoxin toxicity Causes life-threatening arrhythmias Nonspecific GI and neuro symptoms

Cavernous hemangioma

Dilated vascular spaces with thin-walled endothelial cells - present as soft blue compressible masses up to a few cm in size. Associated with VHL when present on the brain and viscera.

Features of decidualized endometrium

Dilated, coiled endometrial glands and vascularized edematous stroma These changes occur during the luteal phase under the influence of progesterone This would be found on an ectopic pregnancy. 334

What is the antidote for arsenic poisoning?

Dimercaprol - it is a chelating agent. Its sulfhydryl group combines with arsenic to displace arsenic from binding m other sulfhydryl groups. 841

Anticoagulant that increases PT and PTT, but not thrombin time? Which anticoagulants prolong thrombin time?

Direct factor Xa inhibitors (apixaban and rivaroxaban) prolong PT and PTT without affecting thrombin time. Heparin and direct thrombin inhibitors prolong thrombin time.

Stimulus control for insomnia

Dissociating the bedroom from any stimulating activities that do not involve sleep (TV, reading, eating). Leaving the bedroom if unable to fall asleep within 20 minutes

Schizophrenform disorder

Distinguished from schizophrenia by a sx duration of >1 month but <6 months.

How does a noncompetitive inhibitor change Km and Vmax?

Doesn't change Km - decreases Vmax

How to calculate initial drug concentration using dose and Volume distribution

Dose/Volume distribution Volume distribution refers to how well the drug distributes into tissues compared t plasma; the higher the Vd, the greater the drug distribution into the tissues.

Syphilis treatment in patient with severe penicillin allergy

Doxycycline x 14days 3256

How do cells undergoing apoptosis still perform translation even when initation factors are being degraded by caspases?

During apoptosis, ribosomes are capable of binding to a unique sequence of mRNA called the internal ribosome entry site (IRES) which allows translation to begin in the middle of the mRNA sequence (even when initiation factors that normally recognize the Kozak sequence are being degraded).

What are the embryologic derivatives of the kidney (what forms the collecting system vs glomeruli, Bowman's space, PCT, etc.)?

During kidney development, the ureteric bud branches off of the caudal mesonephric duct (mesonephric duct will become male internal reproductive organs - vas deferens and epididymis). The ureteric bud then penetrates into the sacral intermediate mesoderm and induces the formation of the metanephric mesoderm. These two structures talk to each other and induce the development of the kidney. The ureteric bud forms the collecting system of the kidneys (collecting tubules and ducts, major and minor calyces, renal pelvis, and the ureters). The metanephric mesoderm (or metanephric blastema) forms the glomeruli, Bowman's space, proximal tubules, loop of Henle, and distal tubules.

Primary ciliary dyskinesia

Dynein arm defect

Dystonia, akathisia, athetosis

Dystonia - sustained muscle contraction resulting in twisting, repetitive movements, or abnormal postures. Torticollis is a focal dystonia of the sternocleidomastoid. Akithesia - sensation of restlessness that causes the pt to move frequently Athetosis - slow writhing movements that typically affect the hands and feet. Characteristic of Huntington's. Chorea - brief, irregular, unintentional muscle contractions. Movements tend to flow from one to another but are not repetitive or rhythmic. Also characteristic of Huntington's.

What compensatory change does the heart undergo in chronic aortic regurgitation

Eccentric hypertrophy of the left ventricle Increases in volume --> eccentric hypertrophy Increases in pressure --> concentric hypertrophy An eccentric hypertrophy leads to an increase in total stroke volume to maintain cardiac output.

What's the difference between efficacy and potency?

Efficacy refers to a drug's maximum achievable biological effect (Emax) while potency refers to the dose at which a drug exhibits a given effect (ED50) Higher potency means that the drugs has a higher affinity for the target (or can access the target more effectively). Higher efficacy refers to a higher ceiling of biological effect. 1707

Exam findings of constrictive pericarditis

Elevated JVP Prominent y descent Abdominojugular reflux Kussmaul's sign (increase or lack of decrease in JVP with inspiration) Pericardial knock Pericardial calcifications on CXR Caused by thickened pericardium that limits diastolic filling. Etiologies include idiopathic, viral pericarditis, cardiac surgery or radiation, TB pericarditis. Sx: Fatigue and DOE, peripheral edema

Triad of acute liver failure

Elevated aminotransferases Hepatic encephalopathy Synthetic dysfunction (INR > 1.5)

What contributes to acanthosis nigricans in DM2?

Elevated serum fatty acids - In the absence of insulin, triglycerides are broken down into fatty acids and promote insulin resistance by inhibiting insulin-dependent glucose uptake and increasing hepatic gluconeogensis.

Treatment of myasthenic crisis

Endotracheal intubation and plasmapheresis (or IVIG). Hold home acetylcholinesterase inhibitors as they promote oral secretions and can increase the risk of aspiration.

Dysostosis multiplex

Enlarged skull, abnormally shaped ribs and vertebrae) = Gargoylism Associated with Hurler syndrome = mucopolysaccharaidosis --> accumulation of heparan sulfate Corneal clouding

What converts trypsinogen -->Trypsin

Enterokinase/Enteropeptidase

Tryptase

Enzyme released by mast cells during anaphylaxis

Difference between ephelides (freckles) and solar lentigines?

Ephelides are caused by increased melanin while solar lentigines are caused by increased melanocytes

Site of aqueous humor production

Epithelial cells of the ciliary body (site of action of beta blockers like timolol as well as alpha agonists like brimonidine)

From which cells does renal cell carcinoma arise?

Epithelium of the proximal renal tubules - it is the most common renal neoplasm (accounts for 70% of kidney tumors) Renal oncocytomas are a rare tumor of the collecting duct cells. Transitional cell tumors are responsible for 90% of tumors involving the renal pelvis.

Treatment of Botulism?

Equine serum heptavalent botulinum antitoxin Symptoms often begin with bilateral cranial neuropathies (blurred vision from fixed pupillary dilation) diplopia, facial weakness, dysarthria, dysphagia.

What is the difference between a gastric erosion and a gastric ulcer?

Erosions are limited to the mucosa (the deepest they can go is the muscularis mucosa - they cannot touch the submucosa)

How does estrogen activity affect free T3, free T4, total T3, and total T4.

Estrogen activity raises circulating thyroxine binding globulin which is the primary (70%) serum carrier for thyroid hormone. An increase in TBG causes a transient decrease in free T3 and T4 levels. This is sensed by the pituitary --> release of TSH --> increased production of T4 --> normalization of free T3 and T4 with increased total T3 and T4 (with the extra fraction bound to TBG).

How does low estrogen cause osteoporosis?

Estrogens normally release osteoprotegerin which serves as a decoy receptor for RANK-L, just like denosumab. Without estrogens, you have less OPG, and therefore more RANKL available to osteoclasts promoting bone resorption. Estrogen also decreases expression of RANK on osteoclast precursors.

Impact of exercise on heart rate, EDV, EDP, and ESV

Exercise causes an increase in cardiac output. This is accomplished by increasing heart rate and preload, while decreasing afterload. Heart rate is up End diastolic volume is increased (increased preload) End systolic volume is decreased (increased SV) End diastolic pressure is unchanged because the increased CO cancels the hypotensive effect or vasodilation in exercising muscles. 6691 (UW2)

Predisposing factors for vitamin A deficiency

Exocrine pancreatic insufficiency (CF) Biliary disease (PBC) Cholestatic liver disease/biliary obstruction Intestinal malabsorption (Crohn, bariatric surgery) Causes night blindness, severe eye dryness and corneal ulceration, hyperkeratosis, growth retardation.

What nerve is at risk during ligation of the superior thyroid artery during thyroidectomy? What does it innervate and what are the consequences?

External branch of the superior laryngeal nerve It only innervates the cricothyroid (everything else is innervated by the the recurrent laryngeal nerves)

Lymph drainage of the superior portion of the bladder (dome)

External iliac nodes Inferior bladder --> internal iliac nodes

Gardner syndrome

FAP + osseous and soft tissue tumors, congenital hypertrophy of retinal pigment epithelium, impacted/supernumerary teeth

Turcot Syndrome

FAP/Lynch syndrome + malignant CNS tumor (glioma, medulloblastoma) Turcot = turban

Equation for Filtration fraction

FF = GFR/RPF Approximately = 0.2

Equation for Filtration fraction and Renal Plasma flow

FF = GFR/RPF Don't confuse RBF with RPF! RPF = RBF*(1-Hct)

Filtration Fraction

FF = GFR/RPF (renal plasma flow) The fraction of plasma flowing through the glomeruli that is filtered across the glomerular capillaries into Bowman's space. GFR can be calculated from Cr clearance and RPF can be calculated from PAH clearance (para-Aminohippuric acid) Urine concentration*Urine flow/Plasma concentration

Lung volume at which pulmonary vascular resistance is lowest

FRC Increased lung volumes increase PVR due to the longitudinal stretching of alveolar capillaries by the expanding alveoli. Decreased lung volumes also increase PVR due to decreased radial traction from adjacent tissues on the large extra-alveolar vessels. 1620

What is the relationship between specificity and false positive rate?

False positive rate = 1 - specificity

What nerve can become compressed by a retroperitoneal hematoma? What are the associated motor and sensory symptoms?

Femoral nerve Weakness on leg extension and thigh flexion - patient may report difficulty climbing stairs or "buckling knees". Diminished patellar reflex Sensory loss on anterior and medial thigh and medial leg

Enzymes inhibited by lead poisoning

Ferrochelatase and ALA dehydratase Results in anemia, ALA accumulation, elevated zine protoporphyrin levels Q1454

Why type of necrosis is associated with diabetes?

Fibrinoid

What components of the extracellular matrix do integrins bind to?

Fibronectin, laminins, and collagen The intracellular domains interact with actin (microfilaments) and keratin (intermediate filaments) 1872

Histopathologic features of the spleen in chronic SCD

Fibrosis and atrophy Microvascular occlusion nearly alway affects the spleen due to trapping of sickle cells by the rigid splenic cords. Auto infarction begins in early childhood and can precipitate splenic sequestration crisis in infants. However, repeated infarction eventually lead to significant scarring, fibrosis, and atrophy of the spleen, which would likely be present in this adult patient Splenic congestion occurs during a splenic sequestration crisis (marked hemoglobin decrease, rapidly enlarging spleen), Which develops due to vaso-occlusion within the cords of Bill Roth and splenic pooling of erythrocytes. However, repeated infarction leads to functional asplenia and auto splenectomy by late childhood/adolescence.

Mechanism of abnormality in holoprosencephaly?

Field defect - an initial embryonic disturbance leads to multiple malformations by disrupting the development of adjacent tissues and structures within a particular region. This is due to incomplete division of the forebrain. Seen in Trisomy 13 + maternal alcohol use Deformations are fetal structural anomalies that occur due to extrinsic mechanical forces. Developmental dysplasia of the hip from uterine constraint on the fetus in breech position.

Through which muscles does the median nerve course?

Flexor digitorum superficialis and flexor digitorum profundus. Courses between the humeral and ulnar head of the pronator teres muscle and then runs between the FDS and FDP muscles before crossing the wrist within the carpal tunnel According to Kaplan: a median nerve block should be administered between the tendons of the palmaris longus and flexor carpi radialis. 1749

How do you make the diagnosis of chronic lymphocytic leukemia CLL?

Flow cytometry (demonstrating clonal mature B cells) Generally don't need lymph node biopsy. It would be useful in diagnosing lymphomas.

What is the formula for Flow rate? Calculate the flow rate (L/min) through an aorta with cross-sectional area of 2cm and mean velocity blood flow of 20cm/sec

Flow rate = Area * Velocity = (2cm^2)(20cm/sec) = 40 ml/sec = 2400 ml/min = 2.4 L/min

Dengue Fever

Flu-like febrile illness with marked myalgias and joint pains. Retro-orbital pain. Maculopapular rash Thrombocytopenia, increased vascular permeability, spontanesous bleeding, positive tourniquet test. Supportive care Secondary infection with a different viral serotype can cause a more severe illness possibly due to antibody-dependent enhancement of infection, enhanced immune complex formation, and/or accelerated T-lymphocyte responses.

What substances will be increased and decreased in small bowel bacterial overgrowth following gastric bypass surgery?

Folic acid/folate and vitamin K will be increased. Enteric bacteria produce vitamin K and folate. All other fat soluble vitamins, B12, and iron will be decreased.

How do the clinical presentations of diffuse large B cell and follicular lymphoma differ?

Follicular lymphoma has an indolent course of waxing and waning painless lymphadenopathy. DLBC lymphoma presents with a RAPIDLY enlarging nodal (neck, abdomen, mediastinum) or extranodal symptomatic mass. B symptoms can be seen.

What stage of collagen synthesis is most often disrupted in osteogenesis imperfecta?

Formation of procollagen (cannot form the triple helix within the RER

Describe the pathogenesis of fragile X syndrome

Fragile X is caused by a trinucleotide (CGG) repeat expansion in the FMR1 gene (greater than 200 repeats) on the long arm of chromosome X which results in DNA hypermethylation and inactivation of the gene.

MOA of cell injury in carbon tetrachloride poisoning?

Free radical formation by lipid peroxidation

Cause of Trochanteric Bursitis

Friction of the tendons of the gluteus medius and tensor fascia lata over the greater trochanter of the femur. Pain is localized to the lateral hip and is worsened by direct pressure.

What sugars must be removed from the diet in aldolase B deficiency?

Fructose and sucrose (fructose and glucose) Fructose-1-phosphate accumulates and depletes intracellular phosphate inhibiting the activation of hepatic phosphorylase and gluconeogenesis --> life-threatening hypoglycemia.

Deficiency of what neurotransmitter causes Huntington's?

GABA Bilateral atrophy of the caudate nucleus and putamen (striatum) leads to dilation of the frontal horns.

Maculopapular rash, nausea, vomiting, abdominal pain, and bloody diarrhea one week after liver transplant. What cells mediate this response?

GVHD Graft T cells become sensitized against the MHC antigens of the recipient and subsequently attack the host's tissues.

Pathogenesis of acute calculous cholecystitis?

Gallstone obstruction of cystic duct --> hydrolysis of luminal lecithins to lysolecithins which disrupts the protective mucosal layer --> bile salt irritation of the luminal epithelium --> prostaglandin release with transmural inflammation --> gallbladder hypomotility --> increased intraluminal pressure causing ischemia --> bacterial invasion

What connects osteocytes to each other?

Gap junctions 1159

Artery that is eroded most frequently from posterior duodenal ulcers

Gastroduodenal

What is Fanconi syndrome? What are some causes?

Generalized resorptive defect in PCT - YOU LOSE EVERYTHING Associated with increased excretion of nearly all amino acids, glucose, HCO3-, and PO43-. May result in metabolic acidosis (proximal renal tubular acidosis). Causes include hereditary defects (eg, Wilson disease, tyrosinemia, glycogen storage disease, cystinosis), ischemia, multiple myeloma, nephrotoxins/drugs (eg, ifosfamide, cisplatin, tenofovir, expired tetracyclines), lead poisoning.

Where do germ cells originate and migrate? Melanocytes?

Germ cells originate in the yolk sac and migrate to the gonadal ridge. Melanocytes begin in the neural crest and migrate to the epidermis.

What type of mutation should be considered when multiple offspring develop a disease that is not present in the parents?

Germline mosaicism This is much more likely than multiple independent somatic mutations

What must you consider when you obtain abnormal values on a maternal serum quadruple screen?

Gestational dating errors - especially with a history of irregular periods. These tests depend on accurate dating. For example, AFP increases with gestational age, thus obtaining a low AFP may in fact be due to miscalculating the gestational age as opposed to aneuploidy. AFP is high in neural tube defects (open spina bifida, anencephaly), ventral wall defects (omphalocele/gastroschisis), and multiple gestations.

Painful bluish lesion under the nail? What is the function of the cell of origin?

Glomangioma - benign glomus tumor A glomangioma is a neoplasm of the modified smooth muscle cells of a glomus body. Glomus bodies normally participate in thermoregulation by shunting blood away from the skin in cold temperatures and towards the skin in hot temperatures.

Which nerve supplies parasympathetic innervation to the parotid gland? How about the other submandibular and sublingual glands?

Glossopharyngeal CN IX for parotid Facial VII for others - however it courses through the parotid gland

When do you switch from IV insulin to subcutaneous when managing DKA/HHS? Management of DKA/HHS

Glucose < 200 Gap < 12 Bicarb > 15 Able to tolerate po Overlap SQ and IV for 1-2 hours

Describe the pathogenesis of cataracts in diabetes

Glucose enters cell --> converted to sorbitol by aldose reductase --> normally would be converted to fructose by sorbitol dehydrogenase, however, this is a slow enzyme so in DM, sorbitol accumulates --> osmotic and oxidative damage --> development of hydropic lens fibers that degenerate eventually resulting in lens opacification and cataract formation. This pathway also contributes to the development of diabetic retinopathy, neuropathy, and nephropathy. Galactitol buildup is responsible for the cataract in galactosemia

What reaction is catalyzed by G6PD?

Glucose-6-Phosphate --> 6-phosphogluconate (generating NADPH)

Amino acid most important in maximizing acid excretion in metabolic acidosis

Glutamine It is used to generate NH3 and bicarb

During DKA, which enzyme is responsible for producing a gluconeogenic precursor that is subsequently converted to glucose in the liver?

Glycerol kinase Glycerol produced by the degradation of TGs in adipose tissue can by used by glycerol kinase in the liver and kidney to synthesize glucose during gluconeogenesis. 1889

Most common AA in collagen?

Glycine

Which enzymes are responsible for maintaining euglycemia in the first 12-18 hours of starvation? How about after 12-18 hours of starvation?

Glycogenolysis maintains euglycemia in the first 12-18 hours. The first step is breakage of 1-4 glycosidic linkage to form glucose-1-phosphate via the enzyme glycogen phosphorylase (deficient in McArdle). Glucose-1-phosphate can then be converted into glucose-6-phosphate and then glucose. After 12-18 hours gluconeogenesis is the mechanisms by which euglycemia is maintained. Gluconeogenesis involves the biotin-dependent conversion of pyruvate --> oxaloacetate (via pyruvate carboxylase) Oxaloacetate is then converted to malate which is able to be shuttled out of the mitochondria and converted back into oxaloacetate. Next oxaloactetate --> PEP (via PEPCK). Gluconeogenesis continues up bypassing irreversible steps with fructose 1,6 bisphosphatase (bypasses PFK-1) and glucose-6-phosphatase (bypasses hexokinase). Glucose-6-phosphatase is deficient in Von Gierke

Best way to reduce the risk of fractures in an elderly woman?

Go for a walk outside daily

Linear deposits of C3 and IgG along the glomerular basement membrane

Goodpasture syndrome

Is enterococcus gram positive or gram negative?

Gram positive

What are the walls of a pancreatic pseudocyst composed of?

Granulation tissue and fibrosis - this is in contrast to a true cyst, who's walls are comprised of epithelium.

Ingestion of a solution containing 13C-labeled urea followed by blowing into a tube and detecting the labeled carbon on breath samples. What is this testing for?

H. Pylori

What gene is mutated in hand-foot-genital syndrome - distal limb defects including hypoplastic first digits and GU malformations.

HOXA13 This gene encodes transcription factors that guide the pattern of embryo development along the rostro-caudal, limb, and genital axes.

What STIs produce a painful initial lesion?

HSV and Haemophilus ducreyi (chancroid) Ducreyi can present with multiple deep ulcers, with a base that is gray to yellow. Organisms often clump in long parallel strands = school of fish Granuloma inguinale is NOT painful and typically does not present with lymphadenopathy despite its names. It can present with extensive and progressive ulcerative lesions. the base may have granulation-like tissue. Deep staining gram-negative intracytoplasmic cysts (Donovan bodies)

Difference between CMV retinitis and HSV retinitis in advanced HIV?

HSV retinitis is painful and typically proceeded by keratitis and conjunctivitis. It is typically referred to as acute retinal necrosis syndrome. VZV can also cause this.

Intranuclear acidophilic inclusions vs. intranuclear basophilic inclusions

HSV vs. CMV

Gram-negative rods in a "school of fish" chain associated with purulent ulcers with ragged borders and suppurative lymphadenopathy

Haemophilus ducreyi

Hematologic malignancy associated with middle-aged men, characterized by bone marrow failure and infiltration into the RES causing massive splenomegaly and a "dry tap".

Hairy cell leukemia

Disease, associated symptoms, and treatment associated with excessive amounts of neutral amino acids in the urine.

Hartnup disease Presents like a niacin deficiency since niacin is dependent on tryptophan - thus the 3 D's are diarrhea, dermatitis, and dementia. Treat with niacin and high protein diet.

What factors affect oxygen content of the blood?

Hb, SaO2, PaO2

Hemoglobin type associated with beta tetramer

HbH Associated with 3 allele deletion on alpha-globin gene. Not a problem until after birth (in contrast to Hb Barts, in which there are 4 deletions --> no alpha, so gamma tetramers form --> incompatible with life --> hydrops fetalis

Does vasoconstriction cause heat retention or heat loss?

Heat retention - you are conserving heat.

Target of inactivated Influenza vaccine

Hemagglutinin Inactivated vaccines predominantly generate a humoral immune response instead of cell-mediated. In contrast, live-attenuated viral vaccines can generate both.

Where is hepcidin synthesized

Hepatic parenchymal cells "Hep" - as in hepatic

Ligaments of the lesser omentum

Hepatogastric and hepatoduodenal Must pass through the lesser omentum in a gastric banding surgery. Hepatic artery, common bile duct, portal vein, lymphatics and hepatic plexus lie between these 2 layers of the lesser omentum

Mutation in the the transthyretin gene

Hereditary form of cardiac amyloidosis

Afferent limb of the carotid sinus

Hering nerve - glossopharyngeal nerve (9) Efferent is through the vagus. The vagus is also the afferent for the aortic arch baroreceptors

What type of virus obtains its lipid bilayer envelope from the host cell's nuclear membrane (as opposed to the host cell's plasma membrane, which is typically the rule)

Herpes viruses

What gastric abnormality is frequently found with Mallory-Weiss syndrome?

Hiatal hernia in about 50% of patients UW says 10% of all upper GI bleeds are from MW syndrome

TSH, T4, and T3 levels in Hashmoto's

High TSH, low T4, normal T3 Normal T3 because it has a short half-life and conversion of T4 --> T3 in the peripheral tissues can be variable.

Drug used to treat proptosis in Graves

High dose glucocorticoids Remember this is an inflammatory infiltrate (Th1 cells release cytokines --> stimulate retro-orbital fibroblasts to produce excessive glycosaminoglycans) Antithyroid drugs do not have a direct effect on ophthalmopathy

Radioactive iodine uptake in graves disease vs painless (silent) thyroiditis?

High in graves, low in silent Note that silent thyroiditis is the self-limited hyperthyroid phase of Hashimoto's

Leukocyte alkaline phosphatase levels in CML and leukemoid reaction?

High or normal in leuekemoid reaction - very low in CML

Serum finding that defines 21-hydroxylase deficiency

High serum level of 17-hydroxyprogesterone

What are homeobox genes?

Highly conserved DNA sequence (usually ~180 nucleotides) that encodes DNA-binding transcription factors that play an important role in the segmental organization of the embryo along the cranio-caudal axis. Defects --> severe skeletal malformations

What is most important in making the diagnosis of tetanus

History and physical There is no serum toxin assay available for tetanospasmin

What visual changes could occur with MCA stroke

Homonymous hemianopsia - they supply the optic radiations (Meyer's loop = the lower optic radiations within the temporal lobe ---- Upper optic radiations pass through the parietal lobe) PCA stroke can also cause this via damage to the occipital cortex Anterior choroidal artery stroke can also cause it due to damage to the optic tract and LGN

Enzyme that drives the breakdown of stored triglycerides into free fatty acids and glycerol during times of starvation

Hormone-sensitive lipase

What hormone mediates the rise in serum glucose during pregnancy

Human placental lactogen Secreted by the syncytiotrophoblast Causes insulin resistance to ensure that the growing fetus has enough glucose. Also stimulates pancreatic beta cell insulin production. 8330

Large oxyphilic cells filled with granular cytoplasm that surround residual follicles in Hashimoto's thyroiditis

Hurthle cell

Side effect of erythropoietin (EPO) therapy

Hypertension

Bifid carotid upstroke with brisk upstroke ("spike and dome")

Hypertrophic obstructive cardiomyopathy - dynamic LV outflow tract obstruction.

Abdominal abnormality associated with exposure to macrolides

Hypertrophic pyloric stenosis

Beta thalassemia

Hypochromic, microcytic anemia due to decreased beta globin chain synthesis. Unpaired alpha chains precipitate within red cells and cause membrane damage. leading to ineffective erythropoiesis and extravascular hemolysis.

What mediates the symptoms of hypoglycemia? What medication can blunt these symptoms and therefore should be prescribed with caution in diabetics?

Hypoglycemia is combated by several mechanisms: glucagon, sympathetic activity (epinephrine limits glucose use by insulin-sensitive tissues and stimulates hepatic glycogenolysis and gluconeogenesis by binding to beta 2 receptors), growth hormone, and cortisol Symptoms are divided into two categories: 1) Neurogenic - caused by increased sympathoadrenal activation and mediated by NE/E/ACh. NE/E cause tremulousness, palpitations, anxiety/arousal while ACh causes sweating, hunger, and paresthesias. 2) Neuroglycopenic - behavioral changes, confusion, visual disturbances, stupor, and seizures caused by decreased brain activity in an attempt to diminish glucose utilization Beta blockers blunt the sympathetic adrenergic symptoms of hypoglycemia and are therefore risky in diabetic patients. If one must be used, it is best to use a beta 1 selective agents or beta blockers with partial agonist activity (pindolol, acebutalol) so that the symptoms of hypoglycemia can still be detected.

Elevated CK with chronic fatigability and mild weight gain. No chest pain, dyspnea, palpitation or lower extremity edema.

Hypothyroidism Measure TSH to rule it out. Also present was a localized lump raised from the surface of the skeletal muscle following percussion of the muscle with a reflex hammer. Q765

Clinical features of debranching enzyme deficiency that distinguishes it from Von Gierke

Hypotonia Ketoacidosis Cytosolic accumulation of glycogen with abnormally short outer chains (dextrins)

Layers of the spermatic cord

ICE tie Internal spermatic fascia - transversalis fascia Cremasteric muscle and fascia - internal oblique External spermatic fascia - external oblique p.354

Which cytokine is produced exclusively by lymphocytes?

IL-2 IL-2 functions to stimulate the growth and differentiation of T cells, B cells, NK cells, and macrophages.

How is severe hypoglycemia with loss of consciousness treated in a medical and nonmedical setting? MOA?

IV glucose (50% dextrose ampule) in medical Intramuscular glucagon in nonmedical Increases hepatic glucose production

Initial treatment of severe or symptomatic hypercalcemia (>14mg/dl)?

IVF and calcitonin Bisphosphonates after initial treatment The patients are usually volume down from polyuria and decreased oral intake --> need to replete intravascular volume and correct hypercalcemia rapidly with calcitonin.

Different management of exertional vs. non-exertional heat stroke

Ice-water immersion for exertional Evaporative cooling (sparing lukewarm water while fans blow air on the pt's skin) for non-exertional Ice-water immersion is associated with increased mortality in non-exertional

What type of antibody class is used to prevent Rh alloimmunization in Rh negative mothers

IgG anti-D antibodies They opsonize Rh+ fetal erythrocytes, promoting clearance by maternal reticuloendothelial macrophages and preventing maternal sensitization. Routinely administered at 28 weeks and immediately post-partum They don't cause significant transplacental fetal hemolysis because the quantity of anti-Rh administered is very small compared to that produced in a typical immunologic reaction.

Location of the largest number of goblet cells in the intestine

Ileum

What causes the liver to turn black in Dubin Johnson syndrome

Impaired excretion of epinephrine metabolites accumulate as dense pigments in lysosomes producing the black appearance. DJ syndrome is a benign autosomal recessive mutation in the canalicular membrane transport protein causing a defect in hepatic excretion of bilirubin glucoronides.

How is the transmembrane chloride channel affected in the most common CFTR mutation?

Impaired post-translational processing (improper folding and glycosylation). It is then targeted for proteasomal degradation This is a 3-base pair deletion in the CFTR gene at AA position 508 (F508) This mutation actually produces a functional protein with normal chloride ion conduction - it just can't make it to the membrane due to impaired post-translational processing.

Primary amenorrhea and palpable mass anterior to the rectum

Imperforate hymen Cyclic abdominal or pelbic pain due to the accumulation of menstrual blood in the vagina and uterus (hematocolpos)

How does atrial fibrillation impact the P waves, QRS complex, and R-R interval on EKG? What determines the rate of ventricular contraction during Afib?

In A fib there is chaotic electrical activity in the atria (usually due to increased excitability in the pulmonary veins) that can be transmitted to the ventricles through the AV node. Thus it is the duration of the AV node's refractory period that determines the ventricular rate. QRS is narrow, P waves are absent, and R-R intervals are irregularly irregular. 1977

In a healthy patient what structures are primarily responsible for controlling respiratory rate and what are they responding to? How does this change in COPD?

In healthy individuals, the major determinant of respiratory rate is pCO2, which is sensed by central chemoreceptors. Central chemoreceptors are relatively unresponsive to changes in pO2, since the BBB is relatively impermeable to H+, and thus peripheral blood pH and pO2 do not play a major role in mediating respiratory rate in the central chemoreceptors. However peripheral chemoreceptors (the carotid body and aortic body) are more responsive to pO2, and send their afferents to the medulla to mediate changes in RR in response to low pO2. Pulmonary stretch receptors (myelinated and unmyelinated C fibers) in the lungs and airways regulate the duration and of inspiration depending on the degree of lung distension. In COPD, patients chronically retain pCO2, and thus pO2 becomes a more important driver of RR (hypoxemia instead of hypercapnia). In these patients, it is changes sensed by the PERIPHERAL chemoreceptors that will alter RR. For example, breathing rate with slow dramatically when administering supplemental O2. 1583

How to distinguish primary from secondary adrenal insufficiency

In primary, ACTH will be high --> hyperpigmentation Also you will have hypoaldosteronism --> hyperkalemia, hyponatremia (mild), acidosis Aldosterone is controlled by RAAS, so in central AI, aldosterone function is preserved l

What is the best indicator of the severity of mitral regurgitation?

In severe mitral regurgitation, there is a large volume of blood regurgitating back into the LA, and then into the LV during diastole. The excessive volume that is pushed into the LV during diastole produces an S3 heart sound, which is the best indicator of MR severity. The intensity of the holosystolic murmur does not correlate well since larger regurgitant orifices present with softer murmurs.

Role of CFTR in moving Cl in sweat glands, respiratory epithelia, and intestinal epithelia

In sweat glands in reabsorbs Cl, in the respiratory and intestinal epithelial it push CL into the lumen

Where does axon regeneration occur?

In the PNS - not in the CNS due to the persistence of myelin debris, secretion of neuronal inhibitory factors, the development of dense glial scar, and the slowed recruitment of microglia due to the BBB.

Where in the nephron is mannitol most active?

In the descending limb of Henle Not the PCT - this is where CA inhibitors are active Actually it is really both - one image showed descending limb as primary site although I think PCT would be more correct.

What are the ABGs in aspirin toxicity?

In the first 12 hours, respiratory alkalosis After 12 hours, mixed respiratory alkalosis and anion gap metabolic acidosis (pH will appear normal indicating this is not compensation since compensatory responses can never get you to a completely normal pH)

Embryological cause of Patent foramen ovale

Incomplete fusion of atrial septum primum and secundum ASD results from aplasia of the septum primum or septum secundum (most common in general population) during development. This is a much rarer cause of paradoxical embolism Remember A goes with A (ASD with aplasia) 202

Effect of restrictive lung diseases on elastic recoil

Increased Decreased lung compliance

DLCO in asthma?

Increased - this is due to increased pulmonary capillary blood volumes This is in contrast to other obstructive diseases like emphysema which has a decreased DLCO

Describe the pathogenesis of PCOS

Increased LH stimulates Theca cells to make more androstenedione --> converted into estrone in peripheral adipocytes --> estrone causes negative feedback inhibiting the release of FSH from the pituitary --> Granulosa cells degenerate --> follicle cannot mature --> multiple degenerative follicles Infertility Oligomenorrhea Hirsutism DM 2 Increased risk of endometrial carcinoma

Mechanism of spider angiomata in liver disease

Increased adrenal synthesis of androstenedione --> estrone --> estradiol --> increased sex hormone-binding globulin --> decreased free testosterone (also liver is less capable of metabolizing estrogen so there is more estrogen already) -->arteriolar dilation.

What causes asterixis is liver disease? What will BUN levels be in liver disease?

Increased ammonia (NH3) NOT increased BUN! The increase in NH3 is often preceded by a trigger such as increased load of nitrogenous substances absorbed in the gut secondary to GI bleed. Other causes include drugs (sedatives, narcotics), hypovolemia, electrolyte changes, infections, and portosystemic shunts (TIPS). BUN will usually be low in liver disease since you have inadequate processing of nitrogenous wastes into urea. Colonic bacterial digestion of lactulose creates an acidic environment in the gut which traps NH3 and NH4+, promoting nitrogen excretion (not dissimilar from trapping protons on NH4+ when the kidney is correcting an acidosis). The asterixis is thought to be caused by increased GABA activity, and decreased glutamate activity. 102

What prevents the development of clinically apparent edema in early COPD?

Increased lymphatic drainage. As hydrostatic pressure increases (due to cor pulmonale), transudate can leak out of capillaries and into the interstitium causing a rise in interstitial pressure. Early on, this rise in interstitial pressure can be compensated for by increasing lymphatic drainage - over time this compensation is overcome and peripheral edema develops. 1578

What is responsible for the lethargy and confusion induced by high-flow oxygen in a patient with COPD

Increased physiologic dead space Normally in COPD, the pulmonary vasculature is constricted due to hypoxia. When high-flow oxygen is administered, this is reversed causing an increase in physiologic dead space as poorly ventilated alveoli are perfused (V/Q mismatch), Also increased PaO2 decreases Hb's affinity for CO2 resulting in dissociation of bound CO2 and increased blood PCO2 (Haldane effect). Peripheral chemoreceptors in the carotid and aortic bodies also fire less frequently in response to the elevated PaO2 resulting in decreased RR. 12141

Role of IP3

Increases Ca release from the ER to activate protein kinase C Phenylephrine binds to GPCR, Gq alpha subunit activates phospholipase C which turns PIP2 --> IP3 and DAG DAG activates protein kinase C directly, IP3 binds to an intracellular receptor to increase Ca release from the ER and further activate PKC

What is the impact of dobutamine on PCWP?

Increases in contractility cause a decrease in filling pressures --> decreased PCWP

How does nephrotic syndrome impact aldosterone?

Increases its release Increased permeability of glomerular capillary wall --> loss of proteins in the urine --> drop in oncotic pressure --> intravascular fluid moves into interstitium --> RAAS activated by low intravascular volume --> aldosterone and ADH released.

Arterial supply below the pectinate line

Inferior rectal artery (from internal pudendal artery)

Nerve that innervates external hemorrhoids

Inferior rectal branch of the pudendal nerve Somatic = painful

Venous drainage below the pectinate line

Inferior rectal vein --> internal pudendal vein --> internal iliac vein --> common iliac vein --> IVC

Cells involved in RA

Infiltrating CD4+ T cells secrete cytokines that promote inflammatory synovitis. They also stimulate C cells to produce Rf and anti-CCP antibodies that contribute to chronic inflammation and joint destruction.

Erythematous, itchy breast rash that has worsened over the course of a few weeks.

Inflammatory breast cancer --> Peau d'orange rash This is caused by cancerous cells obstructing lymphatic drainage due to spread to the dermal lymphatic spaces.

Histologic/clinical/pathophysiological features of abetalipoproteinemia?

Inherited inability to synthesize apolipoprotein B due to AR loss of function mutation in the MTP gene (microsomal triglyceride transfer protein - chaperone protein necessary for proper folding of apoB and also participates in the transfer of lipids to newly formed chylomicrons and VLDV particles) Lipids absorbed in the small intestine cannot be transported into the blood and accumulate in the intestinal epithelium, resulting in enterocytes with clear or foamy cytoplasm

Entacapone

Inhibits COMT increasing the bioavailability of levodopa by inhibiting peripheral methylation. This produces more stable plasma concentrations and prolongs the therapeutic effect in PD

MOA of amatoxin (mushroom toxin)

Inhibits RNA polymerase II --> decreased mRNA synthesis --> apoptosis

Shoulder droop

Injury to trapezius Accessory nerve is vulnerable to injury in lymph node dissections and penetrating trauma at the posterior triangle of the neck Impaired abduction of the arm above the horizontal (due to weakness in rotating the glenoid upward) ad winging of the scapula may also be present.

Detail the path of insulin from mRNA to release

Insulin mRNA is first translated in the cytosol creating preproinsulin. The preproinsulin has an N-terminal peptide signal sequence that is recognized by signal recognition particle (SRP) as it is being translated - upon SRP binding, translation is halted and the preproinsulin is transported to the RER. In the RER the signal peptide is cleaved --> proinsulin. Proinsulin is then sent to the golgi where it is packaged into a secretory granule. Within the secretory granule proinsulin is cleaved into insulin and C-peptide. When glucose enters the beta islet cell, glucokinase converts glucose to G6P ultimately leading to an increased ratio of ATP/ADP which causes closure of K+ channels. This leads to a depolarization and opening of VG-Ca2+ channels resulting in influx of Ca2+ and subsequent release of insulin and C-peptide.

Another name for somatomedin C?

Insulin-like growth factor

What cells release interferons alpha and beta? What is their MOA and how does it differ from that of interferon gamma?

Interferons alpha and beta are released by most human cells in response to viral infection. They bind to type I interferon receptors which results in transcription of antiviral enzymes that halt protein synthesis only in the presence of ds-RNA (providing selectivity for virally infected cells). They also induce MHC class I expression on all cells and stimulate the activity of NK and cytotoxic T cells. Interferon gamma is released by T cells and NK cells and promotes Th1 differentiation, increases expression class II MHC molecules, and improves intracellular killing by macrophages. 1468

What lymph nodes would you want to biopsy in a patient that has rectosigmoid cancer above the dentate line?

Internal iliac (distally) and inferior mesenteric (proximally)

Lymphatic drainage of the anus above the pectinate line

Internal iliac lymph nodes Below the pectinate line drains to the superficial inguinal lymph node: Most cutaneous lymph from the umbilicus down including the external genitalia and anus (below the dentate line). Malignancy around the orifice of the anal canal would drain here. Exceptions include the glans penis and posterior calf (popliteal lymph nodes) which bypass the superficial nodes to drain to deep inguinal lymph nodes.

What vessels can be bilaterally ligated in severe postpartum hemorrhage?

Internal iliacs All the pelvic organs have sufficient collaterals to maintain function/fertility Uterus receives its collateral from the ovarian artery

Nerve that is damaged from food being lodged in the piriform recess

Internal laryngeal nerve - a branch of the superior laryngeal nerve (X) It mediates the afferent limb of the cough reflex (does not contain motor component unlike the recurrent and external laryngeal nerves)

Action of latissimus dorsi on the arm

Internal rotation Also extension and adduction Innervated by the thoracodorsal nerve

Aschoff body

Interstitial myocardial granulomas Found in carditis due to acute rheumatic fever. Aschoff bodies contain plump macrophages with abundant cytoplasm and centra, slender ribbons of chromatin (Anitschkow, or caterpillar cells)

Crypts of Lierberkuhn

Intestinal layer that contains stem cells tat replace enterocytes/goblet cells and Paneth cells that secrete defensins, lysozyme, and TNF

Mallory bodies

Intracytoplasmic eosinophilic inclusions of damaged keratin filaments (intermediate filaments)

Appearance of babesia on blood smear

Intraerythroctic organisms (ring inclusions) Could also show maltese cross.

Intracranial hemorrhage in a 1 month old that was born at home without medical assistance. How could this have been prevented?

Intramuscular vitamin K injection at birth. Newborns are vitamin K deficient due to the lack of colonic bacteria that normally synthesize vitamin K as well as poor transplacental transfer and low content in breast milk. There is also insufficient utilization by the immature liver. As a result, infants are more prone to bleeding if they do not receive exogenous vitamin K.

What kind of blood transfusion do you give in SCID?

Irradiated packed RBCs

How does a neuron respond to ischemia vs. axonal injury

Ischemia will produce a red neuron Axonal injury produces chromatolysis - enlarged cell body

Most common cause of CN III palsy (down and out)?

Ischemic neuropathy from poorly controlled DM. Remember this is differentiated by the absence of changes in pupillary response due to the sparing of the peripheral parasympathetics that ride on the oculomotor nerve.

What bony landmark is used in a pudendal nerve block?

Ischial spine

Describe the histologic features of a lung hamartoma

Islands of mature (or disorganized) hyaline cartilage, fat, smooth muscle, and clefts lined by respiratory epithelium. Alveolar growth pattern without invasion is a description of bronchioalveolar carcinoma, a variant of adenocarcinoma which almost always arises at the lung periphery and has a characteristic distribution along the alveolar septae without vascular or stromal invasion. It appears as a peripheral mass or as a pneumonia-like consolidation.

What is the mechanism of peripheral neuropathy in isoniazid deficiency?

Isoniazid is structurally similar to B6 meaning that it promotes its excretion and also competes for it in many reactions including the synthesis of GABA from glutamate. This causes a frank B6 deficiency that results in the peripheral neuropathy. Isoniazid is not directly toxic to nerves (like vincristine and paclitaxel).

Where does CN V emerge>

It arises at the level of the middle cerebellar peduncle at the lateral aspect of the mid-pons. Infarcts involving the anterior portion of the medial pons can produce dysarthria and contralateral ataxic hemiparesis. 2125

What does thiolase do?

It catalyzes the first step of cholesterol formation: condensation of 2 molecules of Acetyl-CoA to form acetoacetyl-CoA. Also called acetyl-CoA acetyl transferase.

How does exercise impact systemic vascular resistance?

It decreases it Sympathetic discharge causes contraction of arterioles in all tissues except the actively working muscles. While this causes a rise in systolic blood pressure, there is only a minor rise in MAP because of the overall decrease in systemic vascular resistance caused by the substantial arteriolar vasodilation in active skeletal muscles (the result of adenosine, potassium, ATP, CO2, and lactate) Exercise Physiology 1622

How does left heart failure influence lung compliance

It decreases it. In left heart failure there is reduced contractility of the heart leading to an increased end diastolic pressure (blood is backing up) --> this increased pressure is transmitted back to the pulmonary vasculature, causing a transudation of fluid from the pulmonary capillaries into the lung interstitium. This increases resistance to movement, decreasing lung compliance such that normal inspiratory effort is not sufficient to adequately distend the lungs. Edematous fluid dilutes surfactant, increasing surface tension - reducing compliance and making alveoli more prone to collapse.

How does pulmonary capillary wedge pressure change during ARDS?

It doesn't - it is usually normal. ARDS results in increased pulmonary capillary permeability leading to decreased lung compliance, increased work of breathing, and worsened V/Q mismatching. PCWP is usually normal. 486

What happens if when you add normal plasma to ristocetin in Bernard-Soulier syndrome?

It doesn't correct since the problem is not vWF, but GpIb receptor. Ristocetin activates Gp1b receptors on platelets and makes them available for vWF binding. Adding normal plasma will correct (improve platelet aggregation) in vWF disease.

How does TTP impact PT and PTT

It doesn't! These will be normal. This distinguishes it from DIC

How is dead space affected in ARDS?

It increases Alveolar filling with proteinacious material and cellular debris causes ineffective gas exchange and right to left shunting Widespread pulmonary inflammation also causes redistribution of blood away from well-ventilated alveoli, leading to increased alveolar dead space and hypercapnia.

How does preload change in CHF?

It increases Due to decreasing CO, RAAS is activating leading to increased Na/H20 retention and relative volume expansion increasing preload. Afterload is increased by the increase in angiotensin II (vasoconstriction increases peripheral vascular resistance) Afterload is also increased by the increase in sympathetic output caused by baroreceptors sensing decreased perfusion. Epi and NE cause an increase in PVR, further increasing afterload and worsening the vicious cycle. 843

Why doesn't acetaminophen have anti-inflammatory effects?

It inhibits COX enzymes primarily in the CNS with only weak inhibition in the peripheral tissues.

What is the metyrapone test? What does it block?

It is a test of the HPA axis. Metyrapone inhibits 11-beta hydroxylase which prevents the formation of cortisol. In an intact HPA axis, this will lead to an increase in ACTH as well as 11-deoxycortisol and its metabolite 17-hydroxycorticosteroid.

What is Osgood-Schlatter disease? What is the site of insertion of the muscle involved in this disease?

It is an overuse injury of the secondary ossification center (apophysis) of the tibial tubercle. It occurs with repetitive quadriceps contraction and presents as pain and swelling at the tibial tubercle, which is the site of insertion of the patellar ligament (which ultimately connects to rectus femoris) 11819

How is preload affected by heart failure, renal failure, and IV fluids?

It is increased - these are all states of fluid overload.

How is PTT affected in antiphospholipid syndrome

It is paradoxically increased despite being a hypercoagulable state

At what step of the TCA cycle is GTP synthesized? Where is it used in gluconeogenesis?

It is synthesized in the conversion of Succinyl-CoA into Succinate by succinyl-CoA synthetase. In gluconeogenesis, it is used to convert Oxaloacetate --> PEP by PEPCK

What is the attributable risk percent in the exposed? How do you calculate it from relative risk?

It is the excess risk in the exposed population that can be attributed to the risk factor. = (1-RR)/RR * 100

How does silicosis predispose to TB infections?

It is thought that silica particles disrupt macrophage phagolysosomes causing them to release particles and viable mycobacteria, impairing the immune system's ability to control the infection (also causing alveolar and interstitial lung injury from released enzymes). Scarred areas of lung are actually less accessible to TB, and thus fibrosis alone does not predispose to TB (however cavitary TB lesions can predispose to fungal pneumonia)

Why is insulin modified in the short-acting post-prandial drug forms?

It prevents polymerization, allowing for more rapid action (normal insulin polymerizes and causes a delay in reabsorption)

Why does isosorbide dinitrate oral formulation require a much higher does than sublingual nitroglycerin?

It undergoes extensive first pass metabolism

How will succinyl choline impact train-of-four stimulation at onset and 30 minutes later? How does this compare to a non-depolarizing agent.

It will exhibit an equal reduction of all 4 twitches during phase I. Then progressive reduction of the 4 twitches in phase II (which is identical to a non-depolarizing agent) 1212

Contrast the pathogenesis and clinical features of Janeway lesions and Osler nodes.

Janeway lesions are painless, macular, erythematous lesions typically located on the palms and soles of patients with infective endocarditis. They are caused by microemboli from septic valvular vegetations. Osler nodes are tender, violaceous nodules typically located in the pulp of the fingers and toes. They are caused by immune-complex deposition in the skin.

Hoarseness and difficulty swallowing, loss of gag reflex, deviated uvula, left shoulder droop and reduced shrug. Where is the lesion?

Jugular Foramen syndrome CNs 9, 10, and 11 affected.

Conn's syndrome effect on Na+, K+, Bicarb, and clinical volume status.

K+ will be low since aldosterone is up. Similarly, bicarb will be high (you are losing H+ which promotes bicarb production and increased activity of the basolateral bicarb/Cl- exchanger --> metabolic alkalosis) Despite increased Na retention in the renal tubule, the resulting hypertension induces pressure natriuresis and the release of ANP which prevents elevated Na levels and the development of peripheral edema. Thus this patient is euvolemic with normal Na levels due to aldosterone escape. 929

Most common tumor in HIV-positive individuals?

Kaposi Sarcoma Presents as MULTIPLE blue-violet or brownish dermal plaques that appear on the feet and legs before spreading proximally.

What dietary substances should be provided to patients with pyruvate dehydrogenase deficiency?

Ketogenic amino acids - Lysine and Leucine You want to avoid anything that will increase the production of pyruvate since all pyruvate will be shunted towards lactate --> lactic acidosis 998

What is the most common site of epistaxis? What feeds these arteries?

Kiesselbach plexus is the most common site - it is on the anterior nasal septum and fed by the sphenopalatine, ethmoidal, and superior labial arteries (anastomoses). Posterior epistaxis is usually much more serious and involves the sphenopalatine arteries.

Location of Zenker's diverticulum

Killian triangle = between the thyropharyngeal and cricopharyngeal parts of the inferior pharyngeal constrictor. Caused by esophageal dysmotility --> mucosal herniation at Killian triangle

Formula for loading dose?

LD = Vd * target dose * kg of patient Don't forget to multiply by kg of the patient!

Familial hypercholesterolemia

LDL receptor, ApoB-100 defects Elevated LDL Premature atherosclerosis, tendon xnhtomas, xanthelasmas

Protein defect, elevated lipoproteins, and major manifestations of Familial chylomicronemia

LPL or ApoC-2 defects (ApoC2 activates) Chylomicrons elevated Acute pancreatitis, lipidemia retinalis, eruptive xanthomas

Where is surfactant stored in type II pneumocytes

Lamellar bodies

What disease and substance is associated with basophilic stippling?

Lead poisoning. The substance is aggregates of rRNA.

What would clinical signs would a lesion in the left lateral hemisphere of the cerebellum cause?

Left dysdiadochokinesia

Difference in right and left sided frontal cortex lesions?

Left-sided lesions associated with apathy while right-sided lesions associated with disinhibition.

What is a proliferation of abnormal melanocytes along the basal epidermal layer?

Lentigo maligna - subtype of melanoma in situ Lentigo maligna melanoma is most often found in the head and neck (see the image below). Approximately 10-30% of all cutaneous melanoma arise in this region.

What ligament contributes to spinal stenosis?

Ligamentum flavum. It can become hypertrophied in degenerative arthritis of the spine resulting in narrowing of the spinal canal.

What is the immediate effect of ligand binding to a receptor tyrosine kinase? Name 4 examples of the receptors.

Ligand binding results in receptor dimerization. This dimerization enables the autophosphorylation of intracellular domains which results in a conformational change exposing each subunit's catalytic domain. Phosphorylation of tyrosine residues on target proteins follows. Insulin, EGF, PDGF, and VEGF are ligands with tyrosine kinase receptors. This is in contrast to the JAK-STAT pathway in which ligand binding which results in the activation of STATs which enter the nucleus and promote gene transcription.

What bacterial factor in E. coli is responsible for causing sepsis?

Lipid A - the toxic component of LPS that causes activation of macrophages and widespread release of IL-1 and TNF alpha.

Abdominal pain diagnosed as a rare vascular tumor associated with arsenic or polyvinyl chloride exposure. Cell marker CD31 positive? What is the lesion and what is this marker?

Liver angiosarcoma - malignancy of endothelial blood cells. CD31 is the marker for PECAM1, the molecule responsible for leukocyte extravasation.

Dosage calculations for loading dose and maintenence dose

Loading dose = (Target dose * Volume distribution)/F Maintenence = Target * Clearance * Time (dosage interval)

How can you rapidly distinguish between an acute and chronic respiratory acidosis?

Look at the bicarb If it is >30 it likely chronic If it is <30 it is likely acute Chronic respiratory alkalosis can be distinguised by bicarb <18

Diuretic class most likely to cause hypokalemia? What is the MOA of this hypokalemia?

Loops All diuretics (except K+ sparing) cause K+ loss by increasing the volume delivered to the collecting duct, where aldosterone then attempts to reclaim the additional volume at the expense of K+.

What genetic change mediates the diffuse involvement of signet-ring (diffuse) adenocarcinoma?

Loss of E-cadherin - similar to Invasive Lobular Carcinoma

Attrition Bias

Loss to follow-up occurs disproportionately between the exposed and unexposed groups A form of selection bias = systematic differences between groups in terms of treatment response or prognosis.

What will aldosterone levels be in 17 hydroxylase deficiency?

Low - aldosterone is regulated by RAAS - since this patient will be very hypertensive because of the excess weak mineralocorticoids, RAAS will be turned way down, and thus aldosterone will be low.

Maternal serum markers of Down syndrome

Low alpha-fetoprotein and estriol High B-HCG and Inhibin

How does salivary gland flow rate impact Na, Cl, HCO3, and K+ concentrations?

Low flow rates increase the time that saliva is in contact with ductal epithelial cells generating saliva with lower concentration of sodium, and chloride but higher concentrations of K+. High flow rates reduce ductal epithelial contact, leaving saliva composition similar to the initial acinar cell secretion. Epithelial cells add K+ and remove Na+, Cl-, and HCO3-. The more time you spend with them (i.e. the slower the rate), the more K+ and the less Na, Cl, HCO3. Think of the epithelial cells as concerned mothers trying to remove basic salty snacks (Na, Cl, and bicarb) and replace them with healthy bananas (K+). If the kid (saliva) runs out the door too fast (fast flow), he will not get a banana and hang and make off with the basic salty snacks. In the pancreas, high flow is associated with high bicarb and low Cl- (remember you want to neutralize the contents of the intestine).

pH, bicarb, and pCÓ in DKA

Low pH Low bicarb low PaCÓ

CD16

Low-affinity Fc receptor found on the surface of neutrophils, NK cells, and macrophages

HCG in ectopic pregnancy?

Lower than expected

Bone that is dislocated with a fall onto an outstretched hand

Lunate - more medial bone articulating with the radius. Often the scaphoid will also be fractured

What are the histopathologic findings in primary biliary cholangitis? What other pathologic process exhibits this pattern?

Lymphocytic infiltrates with the destruction of small and mid-sized intrahepatic bile ducts, necrosis and micronodular regeneration of periportal tissues. Granulomas and bile staining of hepatocyte are common. This is similar to the pattern seen in GVHD

What cell is primarily responsible for the uptake of shigella?

M cell (Microfold cell) Shigella exhibits specificity for the microfold cells at the base of mucosal villi within a Peyer patch region of the ileal mucosa. M cells sample gut lumen contents and . transfer antigens to their basal lamina within endosomes where macrophages and lymphocytes can mount an immunne response. Shigella passes through M cells via endocytosis and subsequently lyses the endosome, multiplies, and spreads laterally into other epithelial cells. Shigella sonnei is the most common in the West

What causes a decrease in CO with no impact on venous return?

MI or negative inotropic drug 1624

What is the defect in the most common form of cystic fibrosis?

MISFOLDED PROTEIN Protein is retained in the RER and not transported to the cell membrane

Difference between Waldenstrom and Multiple myeloma?

MM produces monoclonal IgG and IgA while Waldenstrom produces IgM M is an upside down W as in Waldenstrom

Most sensitive test for assessing vertebral osteomyelitis

MRI of the spine

Sequence of Fever

Macrophages release IL-1 and TNF These cytokines increase COX activity in the perivascular cells of the hypothalamus PGE2 is created and changes the temperature set point

What must you look out for in a patient with dermatomyositis

Malignancy Especially lung, colorectal, and ovarian cancers. On muscle biopsy you will see perimysial infiltrates, perifascicular atrophy, and patchy necrosis. Associated with CD4+ cell infiltrate

Cystic medial necrosis of the aortic wall

Marfan or Ehlers-Danlos

Genetic change in a patient with neonatal hypotonia, extreme hyperphagia, progressive obesity, hypogonadism, and small hands and feet with normal FISH.

Maternal uniparental disomy (both chromosome 15s are inherited from mother). This is the less common form of Prader-Willi syndrome (more commonly arises from a microdeletion on the paternal chromosome 15 - material 15 is imprinted - however this microdeletion would have been detected on FISH).

Supplies the middle meningeal artery and may be injured in a pterion fracture (meeting of the frontal, parietal, termporal, and sphenoid bones)

Maxillary artery (branch of the external carotid). Enters the skull at the foramen spinosum and courses intracranially deep to the pterion. Skull fractures at the pterion can cause laceration of this vessel leading to an epidural gematoma.

Nests or sheets of polygonal or spindle-shaped cells with extracellular amyloid deposits on thyroid biopsy?

Medullary carcinoma Arrow points to amyloid deposits derived from calcitonin secreted by the parafollicular C cells. It is a neuroendocrine tumor associated with MEN2

Name the three genetic causes of Down syndrome in order of frequency.

Meiotic nondisjunction - 95% of cases - failure of homologous chromosomes or sister chromatids to separate during meiosis resulting in the inheritance of 3 copies of chromosome 21. Nondisjunction during meiosis is almost always of maternal origin. Unbalanced translocation - 2-3% - 46 chromosomes however there is extra genetic material attached to one chromosome. Mosaicism - <2% - affected individuals have 2 distinct cell lines as a result of nondisjunction during mitosis. The proportion of these aberrant cells determines phenotypic severity.

Most common site of urethral injury from a pelvic fracture

Membranous segment (just after the prostate), at the bulbomembranous junction. The bulbous urethral segment is reinforced by the surrounding corpus spongiosum but is susceptible to crushing injuries (straddle injury)

Thoracic malignancy with numerous long slender microvilli and abundant tonofilaments

Mesothelioma

What enzyme is upregulated in cancer cells that enables penetration of the basement membrane? What enzymes are involved in adhering to the basement membrane and detaching from neighboring cells?

Metalloproteinases enable cancer cells to penetrate through the BM. Physiologically they play a role in tissue remodeling. Laminins are upregulated to facilitate BM binding E-cadherins are downregulated to facilitate detachment from neighboring cells.

What phase is a secondary oocyte frozen in until fertilization?

Metaphase of meiosis II

Antiemetics with dopamine antagonist activity

Metoclopramide Promethazine - also H1 and M blockade Prochlorperazine

Histopathological features of HIV-associated dementia

Microglial nodules, groups of activated macrophages/microglial cells formed around small areas of necrosis that may fuse to form multinucleated giant cells.

Histologic findings of Reye syndrome?

Microvesicular steatosis - no necrosis or inflammation is present. We think it is caused by an inborn metabolic error that renders the individual more sensitive to the toxic effects of salicylates.

Which cytoskeletal element comprises microvilli?

Microvilli are microfilaments that contain a core of actin microfilaments

What distinguishes arginase deficiency from other Urea cycle disorders?

Mild or no hyperammonemia

What gives brown fat its color?

Mitochondria - the ECT and phosphorylation are uncoupled in the mitochondria of brown adipose tissue - this means that no ATP is generated, however energy is released by electron transport in form of heat (this is facilitated by the protein thermogenin)

Location of small circular DNA molecules that resemble a bacterial chromosome and code for proteins, transfer RNA, and ribosomal RNA?

Mitochondria! Mitochondrial DNA exists as a small circular chromosome and codes for about 14 proteins including the ribosomal and tRNA needed for mitochondrial protein synthesis.

Developmental delay with a family history of hearing loss in mother and delayed speech in older sister. Uncle had stroke-like episodes at age 25. Physical exam shows ophthalmoplegia and hypotonia. Lactic acidosis. Diagnosis and association?

Mitochondrial myopathy

Ragged red fibers on muscle biopsy

Mitochondrial myopathy

Murmur associated with hypertrophic cardiomyopathy?

Mitral regurgitation - holosystolic murmur heart heart best at the apex and radiates to the axilla.

Most common cardiac abnormality associated with Fragile X?

Mitral valve prolapse and aortic root dilation (likely related to the connective tissue disorder aspect)

Most common predisposing condition for infective endocarditis in the developed world and developing nations?

Mitral valve prolapse with regurgitation in developed world Rheumatic heart disease in developing nations. RHD is a late (10-20 years) complication of rheumatic fever.

Describe the pathogenesis of pulmonary hypertension in scleroderma.

Monoclonal T cells release cytokines (especially TGF-B) which leads to the proliferation of fibroblasts --> fibroblasts lay down excessive collagen all throughout the body --> one of the earliest tissues damaged by this collagen is small arterioles --> intimal thickening of pulmonary arterioles occurs from this collagen deposition --> increased pulmonary pressures --> PAH --> cor pulmonale with signs of RHF (edema). There will also be an accentuated S2 (the case whenever there is elevated pulmonary artery pressure) Diffuse Scleroderma is associated anti-topoisomerase I CREST is associated with anti-centromere

Hallmark of Atypical depression

Mood reactivity - being able to experience improved mood in response to positive events (albeit briefly) Other features include hypersomnia and hyperphagia, leaden paralysis, rejection sensitivity. CBT and SSRIs are first line but MAOIs can be considered in treatment refractory individuals.

Cherry hemangioma

Most common benign vascular tumor in adults. Small, bright red papular lesions AKA senile hemangiomas typically appear in third or fourth decade of life. Always superficial on the skin

Fragile X Syndrome

Most common inherited cause of ID. Caused by a loss-of-function mutation in the FMR1 gene on the long arm of chromosome X. Macroorchidism, long narrow face, prominent forehead, and chin. Developmental delay and neuropsychiatric features in childhood. Can have hyperlaxity of hand joints! (not Ehlers-Danlos)

Regions that drain to the superficial inguinal lymph nodes

Most cutaneous lymph from the umbilicus down including the external genitalia and anus (below the dentate line). Malignancy around the orifice of the anal canal would drain here. Exceptions include the glans penis and posterior calf (popliteal lymph nodes) which bypass the superficial nodes to drain to deep inguinal lymph nodes.

Inheritance of hereditary spherocytosis

Mostly AD

How would smoke exposure for 1 week impact: mucus production and secretion activity of airway cilia alveolar macrophage function

Mucus production goes up Ciliary function goes down Macrophage function goes down

Teenager presenting with primary amenorrhea with fully developed secondary sexual characteristics. Pelvic US shows a shortened vaginal canal and rudimentary uterus.

Mullerian aplasia (Mayer-Rokitansky-Kuster-Hauser) Variable uterine development and no upper vagina - cannot menstruate, however they have normal ovaries and thus secrete estrogen and develop secondary sexual characteristics. This can be distinguished from AIS by the presence of body hair. In AIS, the genotype is XY, but there will be female phenotype with no uterus or ovaries and cryptorchid testes. They develop breasts due to peripheral aromatization of testosterone to estrogen.

MDR1

Multidrug resistant gene - encodes P-glycoprotein, a transmembrane protein that functions as an ATP-dependent efflux pump that allows tumor cells to pump out chemotherapy. We use this protein in the BBB, as well as intestinal and renal epithelium to eliminate foreign compounds from the body. Verapamil, diltizazem, and ketoconazole have been shown to reduce its action.

Appearance of HSV gingivostomatitis ulcer (primary infection) on Tzanck smear

Multinucleated giant cells

29 year old with decreased vision and pain that is aggravated by eye movement. Several months later she develops an intention tremor of the left arm. Diagnosis?

Multiple sclerosis

When do you prophylax against GBS meningitis

Must be within 4 weeks of delivery 30 weeks would be too early Penicillin first line, ampicillin acceptable alternative.

Cell that kills other cells that have downregulated MHC class I

NK cells Tumor cells and virally infected cells downregulate MHC class I

Pathophysiology of Crohn disease?

NOD2 codes for an intracellular microbial receptor that normally activates the NF-kB pathway. Defective NOD2 results in inhibition of the NF-kB pathway --> impaired innate barrier function of the intestinal mucosa --> chronic exaggerated response by the adaptive immune system --> chronic GI inflammation

First line treatment of reactive arthritis?

NSAIDs

In primary adrenal insufficiency, what will be the levels of Na, K, Bicarb, and chloride?

Na+ will be low K+ will be high Bicarb will be low Chloride will be high (to preserve electroneutrality given the low bicarb caused by the retention of H+) Do not confuse this with Conn's! In Conn's everything will be the opposite except Na+ is usually normal since ADH is still intact and pressure natriuresis prevents elevated Na+

Why are asplenic patients prone to infections by encapsulated organisms

Nearly 50% of the bodies immunoglobulins are synthesis by splenic B-cells. Splenic opsonizing antibody is particularly important in the clearance of encapsulated species as the capsule allows them to resist innate phagocytosis. Complement is primarily made in the liver

Features of acute humoral rejection

Necrotizing vasculitis with a neutrophilic infiltrate Also C4d deposition This is in contrast to the more common acute cellular rejection which is marked by lymphocytic interstitial infiltrate and endotheliitis. This is due to sensitization of host T lymphocytes against donor MHC antigens. Prevention is attempted with calcineurin inhibitors and treatment includes systemic corticosteroids. 546

What will grow on a medium containing vancomycin, colistin, nystatin, and trimethoprim?

Neisseria This is Thayer Martin agar - chocolate agar.

Spread of Neisseria vs. Haemophilus to the meninges

Neisseria goes: pharynx --> blood --> choroid plexus --> meninges Haemophilus goes: pharynx --> lymphatics --> meninges

How do you calculate the excretion rate of a substance?

Net excretion is equal to the total filtration rate minus the reabsorption rate. The total filtration rate can be calculated as the GFR * plasma concentration Thus: Net excretion = Filtration rate - Reabsorption rate = (GFR)(Plasma concentration) - Reabsorption rate Inulin clearance can be used to estimate GFR

MOTEL PASS

Neural Crest Derivatives Melanocytes Odontoblasts Tracheal cartilage Enterochromaffin cells Laryngeal cartilage Parafollicular C cells of the thyroid Adrenal medulla and all ganglia Schwann cells Spiral membrane

Embryologic derivative of cutaneous neurofibromas

Neural crest These are nerve sheath neoplasms predominantly comprised of Schwann cells.

S-100 positive

Neural crest tumors Schwannoma and melanoma Schwannomas present with a biphasic pattern of cellularity Also found in disorders of Langerhans cells (Birbeck granules) even though they are of mesodermal origin 1304

Effect of VPA on pregnancy

Neural tube defects Decreases levels of folic acid and increases the risk of neural tube defects 507

Birth defect associated with elevated acetylcholinesterase?

Neural tube defects (spina bifida, anencephaly, etc.)

Cells responsible for centriacinar emphysema

Neutrophils Oxidative injury --> activation of resident alveolar macrophages --> inflammatory recruitment of neutrophils --> release of proteases (elastase, cathepsins, matrix metalloproteinases) --> impaired function of alpha-1 antitrypsin --> acinar wall destruction and irreversible airspace dilation distal to the terminal bronchioles.

What is the impact of nitrates on end-diastolic left ventricular volume?

Nitrates cause venodilation --> decreases preload --> decrease LV EDV This reduces myocardial oxygen demand by decreasing systolic wall stress

Is there any proofreading of the AA-tRNA pairing after AA-tRNA synthetase has formed the bond?

No - if the bond is formed (and not excised by synthetase proofreading activity) it will be incorrectly incorporated onto the growing polypeptide chain.

How will vasectomy affect ejaculate volume, ability to maintain erection, and fertility?

No impact on ejaculate volume of ability to maintain erection, however the man can produce viable sperm in the ejaculate for up to 3 months (or at least 20 ejaculations) since the sperm distal to the transection.

Effect of hemolysis on serum iron

No significant effect

How does diastolic HF ipacy LV EF, LV EDV, and LV end-diastolic pressure

Normal ejection fraction, normal volume, increased ED pressure Diastolic HF is caused by decreased ventricular compliance 186

What will the liver enzymes be of a neonate born to a mother with HBsAg, HBeAg, and anti-HBc.

Normal, however the neonate is most likely infected and has a 90% of progressing to chronic infection if vaccine and immunoglobulin are not administered within 12 hours of delivery. The damage to the liver is mediated by cellular immunity and since neonate's do not have a robust immunity, liver enzymes will be normal. HBeAg is likely high in this infant.

Most common cause of viral gastroenteritis in developed countries?

Norovirus Vaccines against rotavirus have caused its incidence to fall.

Cardiac catheterization curve for AR

Note the high peaking LV and aortic pressures during systole, ls of dicrotic notch, and steep diastolic decline in aortic pressure (causing a wide pulse pressure)

What type of receptor does thyroid hormone bind to?

Nuclear/retinoid X binding to DNA

Define odds and the odds ratio

Odds is the probability of an event occurring divided by the probability of the event not occurring. An odds ratio is typically used in case-control studies: It describes the odds of developing a disease given an exposure / odds of developing the disease when not exposed OR = ad/bc

Another name for vitelline duct

Omphalomesenteric duct

Where are the leads placed in a biventricular pacemaker?

One in the RA, one in the RV, and one in the LV. In order to get to the LV, the lead must be passed through the coronary sinus, which resides in the atrioventricular groove on the posterior aspect of the heart.

How does anemia impact PaO2, SaO2, and oxygen content

Only oxygen content is decreased.

What mediates the upstroke in cardiac pacemaker cells

Opening of VG L-type Ca channels

Fundoscopic findings in open-angle glaucoma?

Optic disc cupping due to optic disc atrophy

What travels through the optic canal?

Optic nerve Ophthalmic artery Central retinal vein

Describe the changes in bone in osteoporosis, hyperparathyroidism, vitamin D deficiency, and osteopetrosis

Osteoporosis - trabecular thinning with fewer interconnections Hyperparathyroidism - subperiosteal resorption with cystic degeneration Vitamin D deficiency - unmineralized osteoid resulting in low mineral density Osteopetrosis - persistence of unmineralized spongiosa in the medullary canals (normally replaced by bone marrow) 629

What ventilatory settings do you change to improve oxygenation?

Oxygenation can be improved by either increased FiO2, or increasing PEEP. If FiO2 is already high (>60%) or the patient is experiencing ARDS, first increase PEEP to help prevent the collapse of alveoli and improve oxygenation. Ventilation is improved by changing RR or tidal volume.

Where are P bodies located and what do they do?

P bodies are located in the cytoplasm and are involved in mRNA regulation and turnover. mRNA that has just left the nucleus may associate with P bodies in yet another regulatory step of gene expression.

Why does the PAH extraction ratio ([arterial plasma]- [venous plasma]/ [arterial plasma]) decrease when its plasma concentration is increased above a certain level.

PAH is both secreted and reabsorbed and effectively estimates renal plasma flow (RPF). Between filtration and secretion, there is nearly 100% excretion of PAH which is why it estimates RPF. Excretion is defined as filtration+secretion - reabsorption. Since the process of PAH is mediated by a carrier enzyme-mediated process, the secretion can be saturated and thus the extraction ratio can be decreased. In contrast, filtration is not an enzyme dependent process, so excretion cannot be saturated.

What mediates the gingival hyperplasia from phenytoin toxicity?

PDGF Macrophages are exposed to increased levels and stimulate proliferation of gingival cells and alveolar bone.

What histologic feature would be expected in a patient with DM2?

Pancreatic islet amyloid deposition - Islet amyloid polypeptide (amylin) is one factor thought to be responsible for beta cell dysfunction. Amylin is stored in insulin secretory granules and o-secreted with insulin from beta cells. Deposits of amylin are universally seen in the pancreatic islets of patients with type 2 DM. Amylin may play a causative role in beta cell apoptosis and defective insulin secretion, however this is controversial.

FNA of thyroid nodule reveals clusters of overlapping cells with large nuclei containing sparse, finely dispersed chromatin. Numerous intranuclear inclusion bodies and grooves are also seen. Diagnosis?

Papillary carcinoma Orphan annie eye inclusion

Empty appearing nuclei with a thin rim of peripheral chromatin on thyroid biopsy?

Papillary carcinoma - most common thyroid carcinoma. Also associated with psammoma bodies. Increased risk with RET and BRAF mutations and childhood irradiation.

Dizziness, dysarthria, and bilateral limb ataxia in a patient with a 50-pack year smoking history. Autopsy reveals purkinje cell degeneration. What is the etiology?

Paraneoplastic cerebellar degeneration caused by the formation of antibodies that cross-react with purkinje cells - Anti-Yo, Anti-Hu, Anti-P/Q

Location of ADH synthesis

Paraventricular and supraoptic nuclei of the hypothalamus. Damage to the hypothalamus --> permanent DI Damage to the posterior pituitary --> transient DI

Describe the sequence of replication of HBV

Partially double stranded circular DNA --> repaired dsDNA --> serves as template for transcription into intermediate +single stranded RNA --> serves as template for viral proteins and reverse transription --> single-stranded DNA intermediate --> converted back into partially double-stranded DNA.

Why would a patient with severe aortic stenosis who develops Atrial fibrillation experience hypotension and pulmonary edema?

Patients with chronic severe aortic stenosis typically have hypertrophied left ventricles to compensate for the elevated afterload (pressure against which the ventricle must pump). This hypertrophied LV is less compliant, and thus the atrial kick becomes an essential part of diastolic filling. During A fib, this atrial kick is lost, causing a sudden drop in preload, upon which the LV was dependent - this results in acute hypotension (can no longer pump blood out) as well as a back up of blood into the LA and then pulmonary vasculature --> pulmonary edema

What structure is incised in a vertical, midline episiotomy? How about a medial lateral episiotomy?

Perineal body Transverse perineal muscle

What is the relationship between cortisol and epinephrine?

Permissive Cortisol exerts a permissive effect by increasing vascular and bronchial smooth muscle reactivity (upregulates alpha receptors) and increases glucose release by the liver in response to glucagon. 551

Where do very long chain fatty acids and fatty acids with branch points at odd-numbered carbons undergo oxidation?

Peroxisomes Normally fatty acids are oxidized in the mitochondria, but these types need to be oxidized in peroxisomes.

Straw-colored discharge from the umbilicus

Persistence of allantois remnant (normally obliterated --> median umbilical ligament) Patent urachus (connects bladder to umbilicus) If purulent discharge, think urachal sinus Urachal cyst would be obliteration on both sides.

Pigmented mucocutaenous macules

Peutz-Jeghers syndrome - autosomal dominant Hamartomatous polyps in the GI tract.

Round/Oval intracytoplasmic inclusions seen on silver stain in patients with dementia.

Pick bodies seen in FTD

Most common benign brain tumor in children? Most common malignant tumor? How can they be differentiated on imaging? What are there histologic features?

Pilocytic astrocytoma (pictured) is the most common benign brain tumor of children. It is a low-grade glioma that presents most frequently in the cerebellum. It can be distinguished from medulloblastoma (most common malignant brain tumor in children) by the presence of both solid and cystic components. Microscopically pilocytic astrocytomas are GFAP positive with hairlike processes and Rosenthal fibers (eosinophilic intracytoplasmic inclusions). Medulloblastomas are only solid and tend to compress the 4th ventricle causing hydrocephalus. They are comprised of small cells with hyperchromatic nuclei that form Homer Wright rosettes (groupings of cells surrounding the neuropil)

Appearance of actinomyces on histology (sulfur granules in particular)

Pink/purple on H&E Don't expect to necessarily be able to see the branching filaments (this image is low power)

What occupies the most space in the greater sciatic foramen?

Piriformis. It passes through the greater sciatic foramen and is involved in external hip rotation. Muscle injury or hypertrophy can compress the sciatic nerve causing a sciatica-like syndrome (piriformis syndrome).

What proliferative stimulus plays a major role in the cellular components of atherosclerotic plaque formation?

Platelet derived growth factor PDGF After endothelial injury, it is released by locally adherent platelets, damaged endothelial cells, and infiltrating macrophages. It promotes the migration of smooth muscle cells from the media into the intima and increases their proliferation. Platelets also release TGF-beta which is chemotactic for SMCs and promotes the production of interstitial collagen. Formation of atheroma

Thin curvilinear areas of lucency that parallel the bowel wall lumen

Pneumatosis intestinalis (air in the bowel wall) Think necrotizing enterocolitis

Consequence of anterior duodenal ulcer

Pneumoperitoneum

Genetic alteration in beta thalassemia

Point mutation in splice sites and promoter sequences --> decreased beta globin synthesis.

Familial hypertriglyceridemia

Polygenic Elevated VLDL Associated with coronary disease, pancreatitis, and diabetes.

What is the function of a major virulence factor of H. flu?

Polyribosylribitol is a polysaccharide capsule that binds to factor H, a host protein that circulates and prevents complement deposition on host cells. By binding factor H, H. Flu can evade normal complement deposition and phagocytosis.

Best test for lactose intolerance

Positive hydrogen breath test Stool pH is acidic due to fermentation products Increased stool osmotic gap and positive stool test for reducing substances (sugars)

What lung segments would a supine patient be most likely to aspirate into?

Posterior segments of the upper right lobe or Superior segments of the right lower lobe NOT apical segment of right upper lobe.

Pelvic pressure and constipation that have worsened over the last year. Easier to defecate while pushing the vaginal canal with her fingers to get stool out but still an uncomfortable sensation of incomplete evacuation. No heavy flow or menstrual pain or dyspareunia. Irregularly enlarged uterus and normal rectal tone. Diagnosis?

Posterior subserosal uterine leiomyoma (fibroid)

Location of the descending aorta relative to the esophagus and LA

Posterior to both - esophagus is in between them

Define and calculate the power of a study

Power is defined as the ability of a study to detect a difference between groups when such a difference truly exists. Power is related to type II error (beta) which is the probability of concluding there is no difference between groups when one truly exists. Power = 1-type II error rate Type I error describe the probability of seeing a difference when there is no difference in reality. It is generally compared to the p-value. 1204

Type of bursitis associated with repetitive kneeling?

Prepatellar bursitis (housemaid's knee) Popliteal cysts are caused by swelling of the gastrocnemius or semimembranous bursa often from osteoarthritis or inflammatory joint disease.

Potter sequence

Presents as pulmonary hypoplasia with facial and lower limb deformities. Renal anomaly (most often bilateral agenesis, but also posterior urethral valves or ARPKD) --> oligohydramnios --> compression of the face and lower extremities --> lack of normal alveolar distention by aspirated amniotic fluid.

Itchy middle aged woman with anti-mitochondrial antibody

Primary biliary cholangitis Autoimmune reaction --> lymphocytic infiltrate + granulomas --> destruction of intralobular bile ducts Increased IgM Associated with other autoimmune disorders

Concentric onion skin bile duct fibrosis --> alternating strictures and dilation with "beading" of intra- and extrahepatic bile ducts

Primary sclerosing cholangitis Middle-aged men with IBD Associated with UC, p-ANCA+, Increased IgM Can lead to secondary biliary cholangitis, increased risk of cholangiocarcinoma and gallbladder cancer.

How does progesterone promote the formation of gallstones

Progesterone inhibits bile acid secretion and slows gallbladder emptying

What component of combined oral contraceptives is responsible for preventing pregnancy? What is the MOA? What does the other component do?

Progestins mediate pregnancy prevention in all hormone-containing contraceptives. They inhibit the release of gonadotropes (FSH and LH) from the anterior pituitary, preventing the LH surge and thus preventing ovulation. Combined oral contraceptives contain estrogen to improve the bleeding profile. 879

What causes motor fluctuations in individuals taking levo-dopa (on/off phenomenon)

Progressive nigrostriatal degeneration leading to decreased therapeutic window for levodopa.

What do the crescents in RPGN consist of?

Proliferated glomerular parietal cells, monocytes, and macrophages that have migrated into Bowman's space as well as abundant fibrin between the cellular layers of the crescents.

What is POMC cleaved into?

Proopiomelanocortin 1) Beta-endorphins 2) MSH 3) ACTH

Oogonia arrest in which phase until ovulation?

Prophase of meiosis I

MOA of bortezomib?

Proteasome inhibitor used in the treatment of MM and Mantle cell lymphoma. Inhibition of proteasomes leads to the accumulation of toxic intracellular and proapoptotic proteins increasing cellular apoptosis.

32 year old patient with a history of DVT and a normal PTT that does not change when activated protein C is added. How should it change normally and what does this patient have.

Protein C is an anticoagulant that degrades factor V and factor VIII - thus you would expect PTT to prolong after administration. If it doesn't prolong, consider factor V leiden

Enzyme and sequence responsible for insulin promoting glycogen synthesis

Protein phosphatase Insulin binds to its receptor --> tyrosine kinase is activated --> MAPK pathway promotes mitogenic functions while PI3K stimulates metabolic functions such as GLUT4 translocation to the membrane, fat synthesis, and glycogen synthesis. Glycogen synthesis occurs via activation of protein phosphatase --> dephosphorylates (activates) glycogen synthase --> glycogen synthesis occurs

Where do proteins accumulate in I-cell disease? What is the pathogenesis.

Proteins accumulate within lysosomes. There is a deficiency in a Golgi body phosphotransferase that prevents the normal phosphorylation of mannose residues on lysosome-bound proteins. These proteins are erroneously exported into the cytoplasm, and lysosomal proteins accumulate (without the normal degradative enzymes) producing the characteristic inclusion bodies seen in I-cell disease. Patients present with failure to thrive and cognitive deficits in the first year with coarse facial features, corneal clouding and limited joint mobility. It is typically fatal in childhood.

What will happen in a COP II mutation?

Proteins will not be able to be trafficked to the Golgi and thus you will have a dilated RER.

Seborrheic Dermatitis

Pruritic, erythematous plaques with a greasy scale that predominantly affects the scalp and face. Dandruff may also be present. Can be associated with PD and HIV. Malassezia species may play a role in its pathogenesis and topical antifungals (keto, selenium sulfide) are effective in treating the condition.

Histologic features of GBM

Pseudopalisading tumor cells around areas of necrosis. New vessel formation small round cells, bizarre giant cells, large number of mitoses.

Young obese woman with daily headache that worsens with bending and bilaterally symmetric papilledema and transient visual disturbances. What causes the papilledema/

Pseudotumor cerebri The papilledema is caused by elevated ICP, which compresses the optic nerves resulting in impaired axoplasmic flow and optic disc edema

What irreversible change may occur if ASD is not corrected?

Pulmonary vascular sclerosis Increased blood flow into the pulmonary artery causes the muscular pulmonary arteries to develop laminated medial hypertrophy that can increase pulmonary vascular resistance above SVR to the point that the direction of the shunt switches (Eisenmenger) Over time the pulmonary vascular sclerosis becomes irreversible and closure of the cardiac septal defect can not be tolerated by the right ventricle. RV hypertrophy and RA dilation may also occur but these are no considered irreversible. If the pulmonary hypertension is corrected the right heart can revert to a more normal morphology.

How do you differentiate CN 3 compression from and aneurysm vs. diabetic neuropathy?

Pupil involvement (blown pupil) will only occur with an aneurysm (parasympathetic ride on the outside) whereas diabetic neuropathy will present with diplopia, ptosis, and down and out eye. If the pupil is blown - suspect compression.

Fastest conduction speed in cardiac tissue

Purkinje Park at venture avenue Purkinje, atrial muscle, ventricular muscle, AV node

First line medication for nausea and vomiting in pregnancy?

Pyridoxine (B6)

Oxygen-induced CO2 retention in COPD

Question 4718

Provide the sequence of pressures one would expect in a healthy heart undergoing cardiac catheterization

RA = 5 RV = 25/5 PA = 25/10 LA (PCWP) = 10 LV wouldn't be obtained through cardiac catheterization but would be 130/10 and aortic pressure would be 130/90

What are the two mechanisms of compensation in CHF that lead to a viscious cycle?

RAAS and increased sympathetic tone

Nests of epithelial cells with abundant clear cytoplasm

RCC (Clear-cell type)

Mutation associated with Hirschsprung disease

RET

Formula for renal perfusion fraction RPF

RPF = PAH Clearance = (PAH urine concentration)(urine flow rate)/(PAH plasma concentration) Renal blood flow = RPF/(1-hct) 1556

Crescent formation seen on light microscopy

RPGN

Impact of repairing a VSD on chamber pressures?

RV pressure decrease LV pressure increase LA pressure decrease

What accounts for the rapid onset but short duration of action of highly lipophilic drugs such as propofol or thiopental?

Rapid redistribution to poorly perfused tissues (skeletal muscle and adipose tissue) Initially, the drug is rapidly distributed to well-perfused organs such as the brain, liver, lungs, and kidneys, but then it is rapidly redistributed to tissues with lower blood flow. This makes them useful as anesthetic agents.

Linear deposits of immunoglobulin along the glomerular basement membrane on immunofluorescent microscopy

Rapidly progressive glomerulonephritis Anti-GBM antibodies react with collagen type IV causing RPGN with glomerular crescent formation on light microscopy.

Why does rapidly squatting alleviate the hypoxia associated with tetrology of Fallot?

Rapidly squatting causes an increase in SVR (you are clamping down on your vessels to maintain perfusion to the brain and other organs). This increase in SVR causes a greater return of blood to the RA and RV and thus a greater fraction of blood enters the pulmonary circulation for oxygenation, reducing the R-->L shunting of normal tetralogy of Fallot.

Outline the regulation of Rb in cell cycle progression. What modification renders it inactive?

Rb is a tumor suppressor protein that regulates the transition of G1 --> S phase. It is active (inhibiting cell cycle progression) when it is hypophosphorylated. Phosphorylation inactivates it. Growth factors activate cyclins which in turn activate cyclin dependent kinases which phosphorylate Rb and enable the progression from G1-->S p27 is a protein that inhibits CDKs, thus serving as a check before G1-->S phase can progress. p53 induces p21 which inhibits CDKs, preventing the phosphorylation of Rb - thus Rb remains hypophosphorylated and continues to prevent cell cycle progression. Remember that phosphorylation INACTIVATES Rb --> cell cycle progresses

Describe loss of heterozygosity in the context of heriditary retinoblastoma

Rb is a tumor supressor gene meaning that according to the 2-hit hypothesis, you will need to inactivate both copies of the gene in order to progress to malignancy. Individuals with hereditary Rb are born with a germline defect in one of their RB1 genes. An additional somatic mutation causes "loss of heterozygosity" and enables progression to malignancy. 6607

Two most important factors for osteoclast differentiation

Receptor for activated nuclear factor kappa-B ligand (RANK-L) and macrophage colony stimulating factor (M-CSF) Osteoclasts are hematopoietic in origin (think of them like macrophages) and are multinucleated Osteoblasts are mesenchymal in origin and stimulated by TGF-beta and FGF

Mutation in hemochromatosis

Recessive mutation in HFE gene (C282Y > H63D), chromosome 6, associated with HLA-A Abnormal iron sensing and increased intestinal absorption Triad of cirrhosis, DM, skin pigmentation (bronze diabetes) Causes restrictive cardiomyopathy (classically) or dilated cardiomyopathy (reversible), hypogonadism, arthropathy (Ca pyrophosphate deposition, esp in MCP joint). HCC is a common cause of death. Tx: phlebotomy, chelation with deferasirox, deferoxamine, oral deferiprone.

Describe the difference between recombination and reassortment

Recombination is the exchange of genetic material that occurs through the crossing of two double-stranded DNA molecules (homologous regions exchanged). Reassortment is the exchange of genome segments in segmented viruses that infect the same host cell (i.e. genetic shift in influenza)

Clinical signs of primary ciliary dyskinesia?

Recurrent sinopulmonary infections due to impaired mucociliary clearance. Recurrent otitis media. Bronchiectasis Situs inversus Infertility NOT cleft palate - this is due to a failure of fusion of the maxillary and medial nasal processes during development.

Hairy Cell Leukemia causes splenomegaly in which part of the spleen?

Red pulp TRAP+ - tartrate-resistant acid phosphatase + Trapped in the red pulp Trapped and can't get into LNs. Tx with cladribine (ADA inhibitor - adenosine kills neoplastic B cells).

What is pulsus alternans?

Refers to the beat-to-beat variation in pulse amplitude due to a change in systolic BP; it is most commonly seen in patients with severe LV dysfunction.

How is blood flow to the right ventricle affect by systole and diastole

Relatively no effect - its pressures are much lower than the left ventricle's, and thus the increase in systemic blood pressure during systole is able to compensate fo the rise in RV wall pressure This is not the case for the LV, where the rise in wall pressure during systole is large enough to cause a drop in blood flow. The subendocardium experiences the greatest rise in pressure which is why it is most prone to ischemia (also most distal from the feeding vessels)

Why do patients with carcinoid syndrome present with ascites/edema

Release of 5HT from mets tumor evades hepatic metabolism --> travels to heart and stimulates fibroblast growth and fibrogenesis --> pathognomonic plaque-like deposits of fibrous on endocardium --> tricuspid regurgitation, pulmonic valvulopathy, RHF --> ascites and peripheral edema The left side of the heart is spared because 5HT is metabolized by endothelial MAO in the pulmonary vasculature.

What does inhibin do? Where is it released from and go to?

Released by sertoli cells --> inhibits FSH release from the anterior pituitary

What is the role of I kappa beta ni the nuclear factor-kappa B (NF-kB) signal transduction pathway from IL-1 binding to IL-6 induction?

Releases NF-kB after undergoing phosphorylation

What are Howell-Jolly bodies

Remnants of RBC nuclei They are normally removed by the spleen so their presence indicates functional asplenia.

Where are the cells that secrete erythropoietin?

Renal cortex

How will ACE inhibitor therapy impact renin levels?

Renin levels will increase. ACE normally inhibits renin release via negative feedback - less ACE --> less negative feedback --> more renin

Mechanism of asplenia in SCD

Repeated infarcts

Reaction Formation

Responding in a manner opposite to one's actual feelings

What portion of the heart would be obscured by a right middle lobe infiltrate? What structure forms the right border of the heart?

Right atrium for both.

Right-sided face and arm swelling and engorgment of subcutaneous veins on the same side of the neck. Which vein is mot likely obstructed?

Right brachiocephalic vein It is formed by the union of the right subclavian and the right internal jugular. The external jugular drains into the subclavian. SVC syndrome would cause these symptoms on both sides of the face. Don't forget that the right brachiocephalic also drains the right lymphatic duct which drains lymph from the right upper extremity, the right face and neck, the right hemithorax and the RUQ of the abdomen.

Difference between rubella and measles exanthems?

Rubeolla (measles) tends to darken and coalesce while rubella does not. Post-auricular lymphadenopathy is more characteristic of rubella.

How does SIADH affect urine Na+ concentration, urine osmolality, serum osmolality, serum sodium, and clinical volume status?

SIADH causes an inappropriate retention of water --> transient, subclinical hypervolemia. RAAS is then turned down and ANP and BNP are secretes resulting in natiuresis and a return to euvolemic volume status. The serum osmolality is down (too much water), and the serum Na+ is down (loss from ANP/BNP). The urine osmolality is inappropriately concentrated for the body's hyponatremic state (usually >100 mOsm/kg) with more sodium excretion than would be expected. If the urine osom is low (<100), it suggests that this is primary polydypsia 226

Muscles of the rotator cuff? Which one is most frequently injured? Which one is tested in the "empty-can" test?

SITS Supraspinatus, infraspinatus, teres minor, subscapularis Supraspinatus is tested with the empty can test and is the muscle most frequently injured due to impingement between the acromion and the head of the humerus.

Most significant SE associated with Lamotrigine

SJS/TEN Discontinue use immediately if a skin rash appears because a benign rash (occurs in up to 10% of patients) cannot be easily distinguished from SJS/TEN. SJS < 10% body surface TEN > 30% body surface Characterized by flu-like symptoms followed by widespread mucocutaneous epidermal necrosis.

Drainage of the superior rectal vein

SRV --> IMV --> splenic vein --> portal vein Portosystemic anastomosis between the super rectal vein and the middle and inferior rectal veins.

What is the antidote for nitroprusside toxicity?

Same as cyanide toxicity: 1) Hydroxocobalamin - directly binds CN helping excretion 2) Sodium thiosulfate - donates sulfur to rhodanese which is the enzyme responsible for metabolizing CN but is saturated during toxicity 3) Sodium nitrite - forms methemoglobin which CN binds to avidly to form cyanmethemoglobin.

Hypercalcemia and elevated serum ACE levels

Sarcoidosis

Peripheral smear findings in scleroderma renal crisis?

Schistocytes SRC pathophys: Increased vascular permeability --> activation of coag cascade --> increased renin Activated coag cascade --> microangiopathic hemolytic anemia/DIC --> schistocytes

Age at which precocious puberty is dx in girls?

Secondary sexual characteristics at <7 years

What cells in the pancreas are stimulated by secretin? How about CCK?

Secretin stimulates the ductal cells while CCK stimulates the acinar cells.

Splitting

Seeing others as all good or all bad

Features of disseminated HSV

Seen primarily in immunocompromised patients - presents with diffuse vesicles on an erythematous base. Erythema multiforme does not define disseminated HSV, but rather represents a systemic response (CD8+ mediated) to local infection.

Major cause of M&M associated with theophylline intoxication

Seizures followed by tachyarrhythmias

What causes dot- or flame-shaped hemorrhages on fundoscopic exam. Blurry vision for the last 2 weeks and a shadow deelped suddenly across the visual field of his right eye. Patchy loss of vision

Severe hypertension in retinal precapillary arterioles causes endothelial disruption, leakage of plasma in the arteriolar wall and fibrinous necrosis. The necrotic vessels can bleed into the nerve fiber layer, which can bee seen as the hemorrhagic lesions.

What is verotoxin?

Shiga-like toxin (EHEC)

Which steps of collagen synthesis occur in the ER?

Signal sequence cleavage Hydroxylation of lysine and proline residues Glycosylation Triple helix formation (hydrogen bonds) The pre-collagen molecule is then moved into the extracellular space where a procollagen peptidase (deficient in some forms of Ehlers-Danlos) cleaves terminal propeptides from the procollagen. Finally covalent crosslinking occurs via lysyl oxidase. 1245

Epithelial cell type of the ovary?

Simple cuboidal (the only cuboidal epithelium of the female GU tract)

What type of RNA virus can be infectious on its own

Single-stranded positive sense RNA viruses - they do not require anything other than host cell machinery to work

What is acrochorda?

Skin tags

Impact of a large arteriovenous concentration gradient of an inhaled anesthetic on onset of action

Slow onset of action The arteriovenous concentration gradient is the difference between the arterial and venous concentration of blood. If tissue solubility is high, a large amount of has is taken up from the arterial blood which results in a low venous concentration. As a result, saturation of the blood requires further absorption of anesthetic (i.e. slower saturation) in order to replace that which is absorbed by the peripheral tissues --> slower onset of action.

What afferents are unmyelinated? What efferents are unmyelinated?

Slow pain, heat sensation, and olfaction are unmyelinated. All efferents are myelinated except for post-ganglionic autonomic neurons.

What site is primarily damaged in chronic rejection in lung transplantation? What is primarily damaged in acute rejection? How is this unique to lung transplantation?

Small bronchioles are the primary site of inflammation and fibrosis in chronic rejection. This is called bronchiolitis obliterans. This inflammation and fibrosis of bronchiole walls leads to narrowing and obstruction of the affected bronchioli --> dyspnea, nonproductive cough, and wheezing. This is in contrast to chronic rejection in renal transplantation in which vascular obliteration underlies the pathology. In acute rejection, it is primarily the vasculature (pulmonary and bronchiole vessels) that is damaged by perivascular infiltration with lymphocytes, macrophages, and plasma cells. Alveolar walls and pleura are NOT affected in chronic rejection

Impact of smoking on gastric pH and H. pylori infection rates?

Smoking increases gastric acidity, reducing H. pylori infection rate.

Blood cells lacking a zone of central pallor

Spherocytosis Autosomal dominant due to membrane defect (most often spectrin and ankyrin scaffolding proteins) Also will see they are 2/3 the size of normal RBCs and more densely hemoglobinized at the periphery 889

Fever, malaise, and maculopapular rash that includes the palms and soles. Patient serum is mixed with cardiolipin, lecithin, and cholesterol, and extensive flocculation is observed. What is the next step?

Spirochetal antibodies - FTA-ABS The first test described the rapid plasma reagin test RPR which is a non-specific treponemal serologic test.

Drainage of the Inferior mesenteric vein

Splenic vein --> portal vein

What dermatologic term is used to describe the changes associated with acute allergic contact dermatitis?

Spongiosis - an accumulation of edema fluid in the intercellular spaces of the epidermis. The intercellular bridges become more distinct in an edematous background leading to the "spongy" appearance. Acanthosis is a thickening of the stratum spinosum and hyperkeratosis is a thickening of the stratum corneum - they are associated with raised scaly plaques. Hypergranulosis is increased thickness of the stratum granulosum of the epidermis and is seen in lichen planus. 1115

Histologic features of acute viral hepatitis?

Spotty necrosis with ballooning degeneration (hepatocyte swelling with wispy/clear cytoplasm), Councilman bodies (eosinophilic apoptotic hepatocytes) and mononuclear cell infiltrates.

Intercellular bridges and keratin pearls

Squamous cell carcinoma

Five most important catalase positive organisms?

Staph A Burkholderia Serratia Nocardia Aspergillus

Equation for the steady state concentration of a drug infusion?

Steady state = Dosing rate / Clearance

Failure of rostral fold closure

Sternal defects (ectopia cordis)

In sickle cell newborns, what are you protecting against with daily penicillin?

Strep pneumo - not neisseria

Organism most often responsible for secondary bacterial pneumonia

Strep pneumo > Staph A > Haemophilus

Difference between sublimation and displacement

Sublimation is a mature defense mechanism in which the individual channels unacceptable thoughts or impulses into a socially acceptable behavior (anger towards stepfather is channeled into competitive boxing) Displacement is transferring feelings associated with one situation or person to another (anger towards stepfather is taken out on teammates)

Which type of salivary gland yields the highest percentage of mucous?

Sublingual Parotid is primarily serous Submandibular is a mix

What enzyme would be impaired in a Vitamin B2 deficiency?

Succinate dehydrogenase In the TCA cycle it converts succinate to fumarate It is also an electron acceptor as complex II in the ETC

Most sensitive screening test for malabsorptive disorder

Sudan III stain

Lymphatic drainage of the scrotum

Superficial inguinal nodes Testes go to the para-aortic

Enzyme most important in neutralizing ROS

Superoxide dismutase Ó-->Ó`-->H202 (via superoxide dismutase) H202--> H20 via catalase or glutathione peroxidase

Treatment of febrile seizures

Supportive care only This is in contrast to heat stroke fever in which you would want to manage with rapid external cooling

Embryologic derivative of anterior pituitary

Surface ectoderm Lens and cornea, inner ear, sensory organs, olfactory epithelium, nasal and oral epithelial lining, epidermis, salivary, sweat and mammary glands.

What mechanism is responsible for restoring a normal body temperature after running a marathon?

Sweating

Sudden changes in voice pitch and volume following bacterial infection

Sydenham chorea

Murmur associated with HCM?

Systolic ejection murmur best heard at the left lower sternal border. Handgrip will impede the forward flow of blood and decrease murmur intensity.

What cells mediate defense against mucocutaneous and disseminated candida infections?

T cells (Th) for superficial infections Neutrophils for disseminated infections

At what levels of the spinal cord will you see lateral horns?

T1-L2 - these are the levels of the sympathetic chain

Vertebral level that the celiac trunk comes of the aorta

T12 L1 is SMA L3 is IMA

What factor is responsible for the excessive collagen formation of keloids

TGF-B - promotes the differentiation of fibroblasts into myofibroblasts and should diminish on completion of wound repair. In keloids it is produced excessively without regulation.

What is the mechanism of neonatal hyperthyroidism in a mother with Graves' disease?

TSH receptor antibodies can cross the placenta --> hyperthyroidism

Path of fructose into blood

Taken up by enterocytes by facilitated diffusion via GLUT5 --> pushed into blood via GLUT2

Path of glucose/galactose into blood

Taken up into enterocytes via SGLT1 (Na+-dependent) --> pushed into blood via GLUT2

How do you distinguish Tay-Sachs from Niemann-Pick on physical exam?

Tay-Sachs does not have hepatosplenomegaly

Marker of ALL

TdT+ A DNA polymerase CD10+ will also be present on B-cell ALL. t(12:21) most common --> good px Down syndrome after age 5

What brain lesion produces visual agnosia (inability to recognize an object)?

Temporo-occipital association cortex

Penetrating stab wound just above the clavicle between the midclavicular and lateral sternal lines in a patient with BP = 88/60 and HR 115. What is damaged and what is the diagnosis?

Tension pneumothorax from penetration of the pleura. Don't forget that the lung apices extend above the level of the clavicle and first rib through the superior thoracic aperture!

Describe the pathogenesis of calcium oxalate stone formation in Crohn disease.

Terminal ileum involvement results in decreased bile acid absorption --> fat malabsorption --> more fat binds with Calcium in the gut --> less calcium available to bind with Oxalate in the large intestine --> less oxalate excretion --> stone formation

Loss of infectivity in a virus after exposure to ether suggests what?

That it is enveloped. Ether and other organic solvents dissolve the lipid bilayer that makes up the outer viral envelope.

Which segments of the sarcomere lengthen and shorten with relaxation and contraction respectively. Identify them on EM.

The I band and the H band. The I band is the area that contains the Z line and only the thin actin filaments. The H band is the inverse of the I band in that it only contains the thick myosin filaments. The A band is Always constant in length.

What is the Kozak sequence? How is it different from the Shine-Delgarno sequence?

The Kozak sequence is a sequence of DNA that helps initiate 5' cap-dependent translation in eukaryotes (enabling the small ribosomal subunit to bind the 5' cap of mRNA), whereas the Shine-Delgarno sequence is the sequence used in prokaryotes for the same purpose.

Function of the musculocutaneous nerve? Which levels does it arise from? How is it commonly injured?

The Musculocutaneous nerve innervates the major forearm flexors (biceps brachii, brachialis) and coracobrachialis (flexes and adducts the arm) and provides sensory innervation to the lateral forearm. It is derived from the upper trunk of the brachial plexus (C5-C7) and can be injured by trauma or strenuous upper extremity exercise (i.e. pitching)

What segment of the glomerulus is responsible for the majority of water reabsorption

The PCT! It is reabsorbed passively with the reabsorption of solutes. 60% of water reabsorption occurs in the PCT, 20% in the descending limbs, and up to 20% in the collecting ducts depending on the body's osmolar status.

What will be the results of a Weber and Rinne tests for an individual with conductive hearing loss in their right ear?

The Rinne test will show that the patient reports not hearing the tuning fork in their right ear after the buzzing sensation on their mastoid process has stopped. This is a negative (abnormal) Rinne test on the right indicating conductive hearing loss (BC > AC) The Weber test will demonstrate lateralization to the AFFECTED ear - they will report hearing the buzzing greatest on the right since the conduction deficit masks the ambient noise in the room allowing the vibration to be better heard. 8589

Most common site of traumatic aortic rupture

The aortic isthmus (just distal to the arch) It is tethered by the ligamentum arteriosum making it relatively fixed and immobile compared to the adacent descending aorta.

What is the significance of the arcuate line?

The arcuate line is a horizontal line located below the umbilicus that demarcates the transition from the superior two-sheathed rectus abdominis from the inferior rectus which only has an anterior sheath. This asymmetry makes the inferior epigastric arteries susceptible to injury - they must be carefully identified and ligated if a transverse incision is going to be performed during C-section.

What region of the hypothalamus is responsible for secretion of DA, GHRH, and GnRH?

The arcuate nucleus

How do you calculate bioavailability of a substance? What would this value look like on a graph of plasma concentration vs. time after administration?

The bioavailability refers to the fraction of the drug that reaches the systemic circulation unchanged. It is = 1 for IV route. To calculate the bioavailability you can generate a plot of plasma concentration vs. time after administration. Dividing the area under the curve of the non IV administration by the area under the curve of the IV route will give you the F. If the doses were not equivalent use the following: F = (AUC oral)(dose IV)/(AUC IV)(dose oral)

What embryologic derivative gives rise to the superior vena cava?

The cardinal veins In utero, they drain into the sinus venosus, which receives all venous drainage during embryologic development. 2023

What's the difference between the pneumococcal conjugate and polysaccharide vaccine?

The conjugate contains nontoxic diptheria protein conjugated to the polysaccharides that enables the activation of T cells and thus higher and longer-lasting antibody levels, less mucosal carriage and memory cell formation. 11872

What causes reactive arthritis?

The deposition of immune complexes, usually from GU or GI infections. Type III

Location of the MLF? Where is the lesion when there is a right gaze palsy?

The dorsal pons In a right gaze palsy the right eye correctly abducts but the left eye does not adduct due to damage of the highly myelinated fibers of the MLF in the left dorsal pons.

what artery gives rise to the inferior epigastric artery? What gives rise to the medial circumflex?

The external iliac right before it dives under the inguinal ligament to become the common femoral. The only other branch of the external iliac is te deep circumflex. Medial circumflex comes off the deep femoral

What vessels are anterior to the ureter? What vessels are posterior to the ureter?

The gonadal vessels and the uterine artery are anterior to the ureter (water under the bridge) The common/external/internal iliac are posterior to the ureter (it is the internal iliac in the true pelvis)

What nerve would you stimulate to improve OSA?

The hypoglossal The lingual nerve is a SENSORY nerve of the mandibular branch of the trigeminal.

What nerve supplies sensory innervation to external hemorrhoids?

The inferior rectal nerve - a branch of the pudendal

What nerve can be damaged in patient with an orbital floor fracture (say from a baseball pitch)? What would the deficit be?

The infraorbital nerve - a branch of the maxillary nerve (V2) can be damaged as it exits the infraorbital foramen just below the orbit. It would produce numbness on the upper cheek, upper lip, and upper gingiva. The inferior rectus muscle could also become entrapped resulting in impaired vertical gaze.

What structure is compromised in ovarian torsion?

The infundibulopelvic ligament (suspensory ligament of the ovary) It carries the ovarian vessels and nerve plexus and can rotate on itself. Typically this occurs when there is a large ovarian mass (cyst, neoplasm, ectopic) and will present with sudden-onset unilateral pelvic pain and nausea and sometimes vomiting and fever. Pelvic US is first-line in dx. The round ligament maintains anteflexion of the uterus and it runs through the inguinal ring to the labia majora.

What ligament must be ligated to prevent heavy bleeding in an oophorectomy? How about in a hysterectomy?

The infundibulopelvic ligament/suspensory ligament of the ovary must be ligated in oophorectomy because it contains the ovarian artery, vein lymphatics, and nerves. The ureter lies medial to the IP ligament. The cardinal ligament/transverse cervical ligament must be ligated in a hysterectomy because it contains the uterine artery.

At what location do you insert the needle for a nerve block of the rectus femoris?

The inguinal crease is the location to anesthetize the femoral nerve (not the femoral ring lies more medially and contains the lymphatics)

What area is targeted for radiofrequency ablation in atrial flutter?

The isthmus between the inferior vena cava and the tricuspid annulus.

Most common location of a saccular berry aneurysm? How does it present?

The junction of anterior communicating artery and anterior cerebral artery - presents with optic chiasm compression --> bitemporal hemianopsia

Define length constant and time constant in the setting of neurotransmission? How are they affected in MS?

The length constant is the distance at which the originating potential decreases to 37% of its original amplitude. The longer the length constant, the better the insulation. MS decreases length constant. The time constant is the amount of time it takes for a change in membrane potential to reach 63% of the new value. A low time potential = a well-insulated neuron. MS increases the time constant.

Effect of solubility on the onset of a gas anesthetic

The lower the solubility, the faster the blood will saturate leading to a fast rise in partial pressure. Increased pressure speeds brain saturation, decreasing onset time. Low solubility = fast onset Low solubility = low blood/gas partition coefficient

Which structure is derived from the ventral pancreatic primordium?

The main pancreatic duct (as well as the uncinate process and the inferior/posterior portion of the pancreatic head) The dorsal pancreatic bud form the majority of pancreatic tissue (body, tail, and most of the head) Failure of the pancreatic buds to fuse --> pancreas divisum

Injury to which vessels in a femoral neck fracture put the femoral head at greatest risk for osteonecrosis

The medial circumflex artery

Lymphatic drainage of the medial foot vs the lateral foot

The medial foot drains to the superficial inguinal nodes whereas the lateral foot drains first to the popliteal lymph nodes, and then to the superficial inguinal nodes.

Most common site of osteomyelitis in children (within the bone)? Most common site of osetomyelitis in adults (within the body)

The metaphysis of long bones is the most common site of hematogenous osteomyelitis in children (also the most common location of osteosarcoma). This is because there is slower blood flow and capillary fenestrae in this region. The most common location of osteomyelitis in adults is the vertebral body (also the location of Pott disease)

Where do the maxillary sinuses drain

The middle nasal meatus. This superior drainage makes them particularly prone to congestion in rhinosinusitis.

What maneuvers increase the murmur associated with HCM?

The murmur is caused by LV outflow obstruction. The greater LV chamber size, the less the mitral valve pushes against the interventricular septum and thus the less the obstruction/murmur. Thus to increase the murmur intensity you need to DECREASE LV chamber size (i.e. end diastolic volume). This can be accomplished with maneuvers that DECREASE afterload (less to push against so more blood gets out), and DECREASE preload (less blood coming in). Examples include SUDDEN STANDING, VALSALVA, and NITROGLYCERIN administration. To decrease the intensity of the murmur you want to make the chamber bigger and thus increase preload and afterload (hand grip, squatting, passive leg raise)

Site of rRNA transcription

The nucleolus - also the site of ribosomal subunit assembly. RNA polymerase I is responsible for transcribing rRNA.

What is ischemic preconditioning?

The phenomenon in which brief repetitive episodes of myocardial ischemia (i.e. angina) followed by reperfusion protect the myocardium from subsequent prolonged episodes of ischemia (delay cell death after complete coronary occlusion)

What artery supplies the posteromedial papillary muscle and anterolateral papillary muscle. What are the branches of?

The posterior descending artery supplies the posteromedial papillary muscle and is most often a branch of the RCA (right dominant, or left circumflex in left dominant). The anterolateral papillary muscle is supplied by the LAD and the left circumflex making it less prone to rupture. Rupture typically happens 3-5 days post-MI.

Heteroplasmy

The presence of both normal and mutated mtDNA, resulting in variable expression in mitochondrically inherited disease. Q596

What nerve is most likely to be injured in a supracondylar humeral fracture with anterolateral displacement of the proximal fracture fragment?

The radial nerve The median nerve (and possibly brachial artery) would be injured if there was anteromedial displacement.

Most common cause of DIC in pregnancy? What causes it? What are some other causes?

The release of tissue factor into maternal circulation from the placenta is the most common cause. This is typically due to placental abruption which may occur in the setting hypertension. An amniotic embolus is another cause however it occurs in the setting of fever and low blood pressure. Sepsis is another cause

What artery supplies the gastric fundus? Where does it come from?

The short gastric artery which is a branch of the splenic artery from the celiac artery. In contrast to much of the gastric vasculature, there are poor anastomoses to the fundus/area supplied by the gastric artery, and thus it is vulnerable to ischemic injury following splenic artery blockage (for example a mass extending posteriorly from the greater curvature.

What causes the superior displacement of the medial fragment of the clavicle in a clavicle fracture?

The sternocleidomastoid. The weight of the arm and pec major cause inferior displacement of the lateral fragment. 1702

What do the superior, middle, and inferior meatuses drain?

The superior meatus drains the sphenoidal and posterior ethmoidal sinus The middle meatus drains the maxillary, frontal, and anterior ethmoidal sinus - it is the most common site of nasal polyps The inferior meatus drains the nasolacrimal duct

Through which muscle does the median nerve traverse?

The two heads of pronator teres

Define transference

The unconscious shifting of emotions associated with a significant individual from one's past to a person in the present.

Describe how airway resistance changes throughout the respiratory tract. Where is it lowest?

The upper airway (nasal passages, mouth, larynx, pharynx_ account for ~50% of the resistance, however resistance increases in the medium-sized bronchi due to highly turbulent airflow. The summated cross-sectional area of small bronchi and bronchioles causes a drop in resistance allowing low-resistance laminar airflow to predominate in airways <2mm in diameter.

What is the venous drainage of internal hemorrhoids? How about external hemorrhoids?

The venous component of internal hemorrhoids drains into the superior and middle rectal veins which drain to the inferior mesenteric and internal iliac veins respectively. External hemorrhoids drain via the inferior rectal vein --> internal pudendal vein --> internal iliac REMEMBER that external hemorrhoids go with PUDENDAL since they are painful - internal thus must go with IMV or internal iliac.

From which segment of the brachial plexus does the median nerve arise? How about the ulnar nerve? How could these be injured?

They both arise from the lower trunk of the brachial plexus (C8 and T1) and could be injured in a sudden upward jerking of the arm (grabbing a branch when falling out of a tree). This would result in paralysis of all the intrinsic hand muscles (Klumpke's palsy) producing a total claw hand deformity due to the relaWhtive sparing of the extrinsic flexors and extensors of the hand.

What is the mechanism of action of insulin resistance caused by TNF-alpha, catecholamines, glucagon, and corticosteroids?

They can promote the phosphorylation of serine/threonine residues on the insulin receptor (and downstream target insulin receptor substrate IRS-1) which inhibits the tyrosine phosphorylation that normally takes place after the binding of insulin. 1326

How do opioids impact blood pressure

They cause hypotension by release of histamine

MOA of alcohol disinfectant?

They disrupt the lipids of the cell membrane and cause denaturation of proteins.

Impact of ANP and BNP on GFR

They increase GFR by promoting afferent arterioral vasodilation and efferent constriction --> increased natriuresis

Why do calcium channel blockers create edema?

They preferentially dilate precapillary vessels (arterioles) which causes an increase in hydrostatic pressure and resulting extravasation of fluid. Anti-RAAS drugs (ACEis) can prevent this by causing postcapillary venodilation which normalizes the increased hydrostatic pressure.

What is the impact of calcium channel blockers on slow-response cardiac tissues?

They prolong phase 4 spontaneous depolarization by blocking L-type Calcium channels (T-type channels are responsible for the beginning of phase 4 but L-type also open) 1973

What is the impact of ACE inhibitors on renin?

They will increase renin production via loss of normal negative feedback from AT II Angiotensin I will also go up for this reason. Can also think about it as everything behind ACE backing up.

What drug factors decrease Vd? What would be considered a low Vd?

Think of volume of distribution as how easily a drug escapes from plasma. The more the drug leaves the plasma, the greater the volume of distribution since you would need a greater dose to achieve a target plasma concentration: Vd = dose administered / plasma concentration of drug Drugs that are trapped within the plasma have low Vds (it doesn't take much drug to reach your target plasma concentration). Thus factors that decrease Vd include: larger molecular weight, hydrophilicity, high plasma protein binding (albumin binding), high charge. A low Vd would be 3-5 L

Biopsy of a large mass surrounding the small intestine reveals uniform, round, medium-sized tumor cells with basophilic cytoplasm and proliferation fraction (Ki-6) > 99%. What infectious agent is associated with the development of this mass?

This is Burkitt lymphoma - associated with EBV

Patient presents with weakness on extension of the fingers and thumb. Sensation is preserved in the upper limbs and triceps reflex is 2+ bilaterally. What is the site of injury?

This is a radial nerve injury within the supinator canal. At this level, there is preservation of the branches that perform wrist extension and sensory innervation to the posterior arm and hand producing an isolated deficit in finger extension. This can happen with repeated supination (screwdriver, mechanic). Injury to the radial nerve in the mid-humerus would produce a wrist drop and sensory loss with sparing of the triceps reflex. Injury to the radial nerve at the axilla (crutch palsy) will produce a deficit in all of the above including an absent triceps reflex.

Underlying injury when a child's (<4yo) arm is pulled down rapidly when holding their hand?

This is a radial subluxation. The sudden increase in axial traction on the proximal radius causes the annular ligament to tear from its periosteal attachment the radial neck. It then slides into the radiohumeral joint and becomes trapped. Less common after age 5 since the annular ligament becomes thicker and stronger.

What changes to the heart would be expected to produce left atrial enlargement, an increase in left ventricular myocardial mass, and an increase in left ventricular wall thickness?

This is concentric cardiac hypertrophy which could be caused by chronic hypertension of aortic stenosis. Eccentric cardiomyopathy is caused by volume overload. In mitral insufficiency, there is regurgitation of blood back into the LA during systole which results in the LV seeing move blood during diastole --> LV dilation = eccentric cardiac hypertrophy

Macrocephaly, full anterior fontanelle and CT scan demonstrating significant dilation of the lateral ventricles in a 6-month-old. What are the most likely complications of this disorder?

This is congenital hydrocephalus Seizures, hypertonicity (UMN damage from stretching of the periventricular pyramidal tracts), and developmental delays. Causes include: Structural malformations - aqueductal stenosis, Dander Walker syndrome, Chiari malformation Infections: toxo and CMB Neoplasm Intraventricular bleeding from unstable germinal matrix

Vertigo/nystagmus, ipsilateral cerebellar signs, loss of pain/temperature sensation in the ipsilateral face and contralateral body, bulbar weakness, and ipsilateral Horner syndrome. What vessel is involved?

This is lateral medullary syndrome (Wallenberg) It involves PICA - or more proximally the vertebral artery. It can occur in the setting of cervical spine trauma with dissection of the vertebral artery. Traumatic dissections of intracranial vessels are rare.

Post-menopausal bleeding, endometrial hyperplasia, firm yellow ovarian mass, and small cuboidal cells in sheets with gland-like structures containing acidophilic material. What is likely to be elevated in the serum?

This is likely a granulosa cell tumor and thus estrogen would be elevated (causing the endometrial hyperplasia)

What structure is most likely involved in a baseball player experiencing right arm numbness and fluctuating tingling and number involving the right shoulder, arm and hand.

This is thoracic outlet syndrome, usually caused by injury to the scalenes which can compress the lower roots of the brachial plexus. The subclavian artery or vein could also be involved. Other etiologies are an anomalous cervical rib, scalene muscle abnormalities, or injury.

A large kidney mass that is composed of fat, smooth muscle, and blood vessels is removed from a patient? What else what you expect this patient to have.

This is tuberous sclerosis and the mass was a. renal angiomyolipoma. Tuberous sclerosis is an AD disease caused by a mutation on chromosome 16 resulting in brain hamartomas, angiofibromas, ash-leaf spots (hypopigmented skin lesions), rhabdomyosarcomas, mitral regurgitation, mental retardation, and seizures. There are also shagreen patches (pictured, connective tissue hamartoma with orange peel or leathery texture) and an increased risk of subependymal giant cell astrocytomas and ungual fibromas.

What is the most common cause of retinal artery occlusion?

Thromboembolic complication of atherosclerosis n the internal carotid artery --> ophthalmic artery --> central retinal artery --> acute, painless, monocular vision loss.

Common consequence of homocystinuria

Thromboembolic events - homocysteine is prothrombotic

What type of mass is myasthenia gravis associated with? What is its embryologic origin?

Thymoma or thymic hyperplasia Thymus is derived from the 3rd pharyngeal pouch (as are the inferior parathyroid glands) 1st pouch --> epithelium of the middle ear and auditory tube 2nd pouch --> palatine tonsil crypts 3rd pouch --> thymus and inferior PT glands 4th pouch --> superior PT glands and ultimobranchial body

Receptors located inside of the nucleus

Thyroid hormone, vitamin A, vitamin D

Time required for lyme disease to be transferred with tick bite

Tick must be attached for at least 36 hours No ppx if <36 hours

Latent period

Time elapsed from initial exposure to clinical manifestation of disease

What are the two most common causes of ring-enhancing lesions on brain MRI in a patient with HIV?

Toxoplasmosis Primary CNS lymphoma - this is almost alway caused by EBV infection and the tumor is a diffuse large-cell non-Hodgkin B Cell lymphoma. The abnormal cells are B cells, not T-cells as in normal EBV infections.

What is the difference between transformation, transduction, and conjugation?

Transformation refers to a bacteria taking up naked DNA in the environment and incorporating it into its chromosomal DNA. Transduction refers to the process in which a bacteriophage (i.e. a virus) inadvertently packages host bacterial DNA into one of its daughter virions. This daughter can then transfer DNA to the subsequent bacterial host, potentially resulting in the transfer of antibiotic resistance genes. Conjugation is the process by which one bacteria that is F+ passes DNA to another bacteria via a conjugative pilus. This pilus is transferring F+ genes (on a plasmid), not chromosomal DNA. Chromosomal DNA could be moved to a plasmid for subsequent conjugation via transposons.

Which structure is incised to relieve carpal tunnel syndrome

Transverse carpal ligament (flexor retinaculum) Carpal tunnel contains the tendons of the flexor digitorum profundus and superficialis, flexor pollicis longus, and the median nerve.

First management step with uncomplicated cystitis?

Treat with antibiotics: 1) Bactrim 3 days 2) Nitrofurantoin 5 days 3) Fosfomycin single dose No need for urine cultures with uncomplicated

Felty Syndrome

Triad of splenomegaly, inflammatory arthritis, and neutropenia typically in the setting of diagnosed RA. Often associated with necrotizing skin lesions

EKG findings of WPW syndrome

Triad: Short PR interval Widened QRS Delta waves

Pear shaped organisms on wet mount

Trichomonas vaginitis

MOA of abortive migraine therapy

Triptans are 5-HT 1B and 1D receptor agonists that directly counter the pathophysiologic mechanism of migraines by inhibiting the release of basoactive peptides, prooting vasoconstriction, and blocking pain pathways in the brainstem.

Presentation and associated findings of serum sickness

Type III hypersensitivity reaction to nonhuman proteins characterized by vasculitis and fibrinoid necrosis resulting from tissue deposition of circulating immune complexes. Clinical findings include fever, pruritic skin rash, arthralgias, and low serum C3 and C4.

Features of congenital hypothyroidism

Typically occurs a few months after birth after maternal T4 has dropped. Lethargy, constipation, hypotonia, macroglossia, umbilical hernia, and a large anterior fontanelle Common cause of reversible ID

What clinical signs would be present in a lesion at the cerebellopontine angle?

Typically sensorineural hearing loss and tinnitus due to dysfunction of CN8 by a vestibular schwannoma.

Enzyme deficiency associated with megaloblastic anemia

UMP synthase Orotic aciduria No hyperammonemia (in contrast to ornithine transcarboxylase deficiency)

What type of UV is responsible for sunburn and aging? What is the mechanism for the changes in aging?

UVA for Aging UVB for SunBurn A for aging, B for burn! The changes in aging are due to decreased collagen fibril production, upregulation of metalloproteinases (collagenases), thinning of the epidermis, reduction in subcutaneous fat, blood vessels, and increased crosslinking of collagen. 1860

Most oxygenated vessel in fetal circulation

Umbilical vein

Genetic cause of multiple spontaneous abortions and a newborn with dysmorphic features and numerous organ anomalies?

Unbalanced translocation - consider this whenever there are multiple spontaneous abortions.

Why do calcium channel blockers not affect skeletal muscle?

Unlike cardiac myoctes and smooth muscle cells, skeletal muscle cells are not reliant on an influx of extracellular Calcium to trigger release of calcium from the sarcoplasmic reticulum (CICR) - rather skeletal muscles have L-type calcium channels that directly interact with Ryanodine calcium channels on the SR which enables the release of intracytoplasmic Ca stores in the absence of extracellular Ca influx.

What enzyme converts uric acid --> allantoin?

Urate oxidase - humans don't have it but we can take rasburicase or pegloticase (recombinant form) to mitigate tumor lysis syndrome or hyperuricemia of other etiologies.

Most common cause of unilateral fetal hydronephrosis?

Ureteropelvic junction obstruction due to inadequate canalization. Posterior urethral valves is the most common cause of bilateral fetal hydronephrosis.

What is the underlying dysfunction in stress incontinence?

Urethral sphincter dysfunction In urge incontinence, it is a hyperactive detrusor muscle In overflow incontinence, it is from impaired detrusor contractility. 10962

What renal stones form in the setting of chronic diarrhea?

Uric acid stones You are losing bicarb so you are in a state of relative acidosis - your kidney tries to compensate by excreting H+ and reclaiming bicarb --> urine acidifcation --> uric acid stone formation

Initial treatment of PBC?

Ursodeoxycholic acid UDCA Even in asx patients Glucocorticoids are ineffective

Through which skull foramen do the branches of the trigeminal nerve pass?

V1 - superior orbital fissure (along with CNs 3,4, and 6 - just remember all the nerves in the cavernous sinus) V2 - Foramen rotundum V3 - Foramen ovale Foramen spinosum passes the middle meningeal artery. Remember spinosum.

Leads with ST elevation in distal LAD occlusion

V3 and V4 V1 and V2 would also be involved in a proximal occlusion

How do you prevent neonatal tetanus

Vaccination of pregnant women or women who may become pregnant. The vaccine enables the other to generate IgG against the tetanus toxin - these antibodies can cross the placenta and provide passive immunity to the neonate.

Drug used in the treatent of patients with absence seizures and tonic-clonic seizures

Valproate

Define variable expressivity, genetic heterogeneity, and penetrance.

Variable expressivity refers to a condition in which a genotype has varying phenotypic manifestations (i.e. Marfan syndrome, where some pts may have severe CV disease while others simply have tall habitus despite having the same gene mutation). Genetic heterogeneity refers to a condition in which a single phenotype can be caused by multiple different genotypes (i.e. Osteogenesis imperfect can arise from mutations on several different collagen genes). Penetrance describes the frequency that individuals with a given genotype will express a phenotype. If not all individuals with a genotype express a phenotype, the condition is considered to have incomplete penetrance. 6488

Cause of intestinal atresia of the distal midgut (jejunum, ileum, proximal colon)

Vascular occlusion in utero

Formula for half-life

Vd*0.7/CL

Persistent St-segment elevation after a recent MI and deep Q waves in the same leads

Ventricular Aneurysm

Flaccid paralysis of all four extremities 2 hours after endotracheal intubation of a woman with severe pneumonia and a chronic history of RA. What is the cause of the paralysis?

Vertebral subluxation Patients with RA frequently gave cervical spine disease that can cause joint destreuction with vertebral malalignment. Forceful endotracheal intubation can worsen the subluxation leading to acute compression of the spinal cord and or vertebral arteries with neurologic manifestations.

Most common cause of myocarditis in the general population

Viral infection: Adenovirus, coxsackie B, Parvo

Large mediastinal mass with associated elevations of AFP and beta HCG

Virtually diagnostic of nonseminomatous germ cell tumor (note this is a primary, not metastatic from testicle)

What correlates with the observed growth of mycobacteria in parallel chains (serpentine cords)?

Virulence This growth pattern indicates the presence of cord factor, a virulence factor that inhibits neutrophils, destroys mitochondria and induces the release of tumor necrosis factor. Sulfatides are responsible for inhibiting the fusion of phagosomes and lysosomes, promoting the persistence of Mycobacterium within phagocytes. They do not impact growth pattern.

What vitamin deficiency presents with same findings as Freidrich ataxia?

Vitamin E deficiency - spinocerebellar, dorsal columns, and peripheral nerve damage) B12 could also present this way

Sudden loss of vision and onset of floaters. On exam, loss of fundus details, floating debris and a dark red glow.

Vitreous hemorrhage (typically in the setting of diabetic retinopathy) Central retinal vein occlusion findings include disk swelling, venous dilation and tortuosity, retinal hemorrhages, and cotton wool spots.

What is the impact of fluid resuscitation on systemic vascular resistance in hypovolemic shock. What hemodynamic alteration is responsible for the benefit of fluid infusion?

Volume resuscitation in hypovolemic shock will reduce the systemic vascular resistance by toning down the sympathetic and RAAS that has been activated in the hypovolemic state (vessels are clamped down trying to perfuse organs - if you give fluid, they can relax a little). Fluid resuscitation causes an increase in preload which causes an increase in end-diastolic sarcomere length. This increase in sarcomere length causes an increase in stroke volume and cardiac output as defined by the Frank-Starling mechanism.

3 Major causes of Metabolic Alkalosis

Vomiting/NG tube - low urine Cl Loop/Thiazide diuretic - high urine Cl Mineralocorticoid excess - high urine Cl First two respond to saline, latter does not.

Pathophysiology of WPW syndrome

WPW is due to an accessory depolarization pathway that bypasses the atrioventricular node and directly connects the atria and ventricles EKG triad = shortened PR, widened QRS, delta waves Atrial fibrillation usually begins from rapid electrical impulses originating in the pulmonary veins Atrial flutter is caused by a reentrant current that rotates around the tricuspid annulus

Bilateral wedge-shaped strips of necrosis over the cerebral convexity, parallel and adjacent to the longitudinal cerebral fissure

Watershed infarcts caused by profound cerebral hypoperfusion - also called ischemic-hypoxic encephalopathy.

What is the cause of direct inguinal hernias? What do they protrude through and what are they covered by?

Weakness in the transversalis fascia (not rectus abdominis - contents pass lateral to rectus abdominis) Protrudes only through the external ring and is only covered by the external spermatic fascia (from external oblique) unlike an indirect hernia which contains all three layers (ICE TIE = internal spermatic fascia from transversalis fascia, cremasteric fascia from internal oblique, and external spermatic fascia from external oblique)

Viral encephalitis, fever, rash, and flaccid paralysis

West nile virus

Features of normal pressure hydrocephalus. What is its pathogenesis?

Wet, wobbly, and wacky Urinary incontinence, ataxia, and dementia. May present with classic magnetic gait in which they cannot lift feet from ground. Nystagmus could by present. 2-month history of memory problems, difficult walking, and urinary incontinence. Pathogenesis is decreased CSF resorption by the arachnoid granulations. Brain imaging reveals ventricular enlargement that is out of proportion to sulci enlargement (i.e. hydrocephalus ex vacuo)

How will a patient with a superior gluteal nerve injury present?

While standing, their hip will drop to the contralateral side While walking they will lean to the ipsilateral side It innervates gluteus medius, minimus, and tensor fascia lata Injury to the inferior gluteal nerve results in gluteal maximus palsy with difficulty rising from a chair

Pathogenesis of parasthesias following a massive blood transfusion

Whole blood is often mixed with solutions containing citrate anticoagulant. Citrate can chelate calcium and magnesium --> hypocalcemic signs. Stored RBCs gradually lose their intracellular potassium which can potentially cause hyperkalemia after an infusion.

Histologic and gross findings of inhaled anesthetic-induced hepatotoxicity?

Widespread centrilobular necrosis and inflammation of the portal tracts and parenchyma - indistinguishable from fulminant viral hepatitis. Grossly the liver may appear shrunken and atrophic due to extensive hepatocellular damage. MUST CONSIDER anesthetic-induced (halothane) hepatotoxicity when they mention a surgery outside of the US and a patient presenting with acute hepatitis. Expect elevated liver enzymes and function tests (elevated AST/ALT, PT, PTT)

How will a patient with a psoas abscess present?

With their knee and hip flexed and externally rotated to minimize stretch. Pain is exacerbated by extension of the hip (psoas sign)

Where does isotype switching occur?

Within the germinal centers of lymph nodes. This occurs after a B cell has been activated (via CD40-CD40L) by an activated T cell which releases cytokines to promote gene rearrangement on the heavy chain constant region of the B cell. Somatic hypermutation occurs at the variable region. VDJ (heavy chain) and VJ (light chain) recombination occurs during B cell maturation in the bone marrow and is responsible for the enormous variety of different Ig molecules (in addition to random combination of heavy and light chains, and random addition of nucleotides by TdT. 1614

What muscles are impacted by lateral epicondylitis

Wrist extensors - extensor carpi radialis brevis and extensor digitorum This is tennis elbow - excessive microtrauma of the tendon leads to angiofibroblastic tendinosis (excessive fibroblasts and neovascularization) at the origin of the tendons at the lateral epicondyle Golder's elbow involves the medial epicondyle and impacts the wrist flexors.

Inheritance pattern of G6PD deficiency

X-linked recessive

Klinefelter's effect on hormones

XXY - Primary hypogonadism (low testosterone) Lack of negative feedback from the testicle (Sertoli's normally release inhibin onto the pituitary to reduce FSH, and Leydig's release testosterone onto the hypothalamus and pituitary to reduce GnRH and LH respectively) leads to increased FSH and LH --> increased estrogen --> gynecomastia

Through which physiologic opening must you pull the testes when they are lodged within the inguinal canal?

You must pull them through the opening of the external oblique aponeurosis which forms the superficial inguinal ring. The deep inguinal ring is formed by an opening in the transversalis fascia.

Equation for half life

half life = (0.7)(Vd)/(Cl)

Vesicular rash on palms and soles following chlamydia infection

keratoderma blennorrhagicum This is an extra-articular symptom of reactive arthritis. Don't choose syphilis just because you see palms and soles! Also the syphilis rash is maculopapular or pustular - not vesicular.

What does reverse transcription PCR detect?

mRNA It uses reverse transcription to create a complementary DNA template that is then amplified using normal PCR. This template would only contain exons. It can diagnose CML by identifying an mRNA transcript containing both BCR and ABL exons in affected cells. 12278

Under completely ischemic conditions, when will myocardial contractility cease?

~60 seconds ATP is rapidly depleted from areas of the cell with high metabolic demand resulting in loss of contractility within ~60 seconds Ischemia for more than 30 minutes results in irreversible ischemic injury.