5/17 Mixed

Question 1

Good pasture syndrome

Answer 1

Renal failure and pulmonary hemorrhage in patinets with anti-GBM antibodies
Hypertension, hematuria, moderate proteinuria = nephritic syndrome
Linear deposits of ig along the glomerular basement membrane (IgG and C3) –target collagen type IV
Rapidly progressive glomerulonephritis
Glomerular crescents on light microscopy

Question 2

Bacterial joint infection

Answer 2

High synovial fluid leukocyte count (>100,000) and absent crystals on microscopic examination suggest bacterial joint infection
Septic arthritis requires antibiotic treatment to prevent joint destruction, osteomyelitis, and sepsis
Often due to gonococcus in young age group

Question 3

Which nerve is at risk of injury during thyroidectomy

Answer 3

External branch of the superior laryngeal nerve
Due to proximity to superior thyroid artery and vein
Innervates the cricothyroid muscle

Question 4

Cirrhosis

Answer 4

Diffuse hepatic fibrosis with replacement of the normal lobular architecture by fibrous-lined parenchymal nodules
Chronic viral hepatitis, alcohol, hemochromatosis, and nonalcoholic fatty liver disease are the most common causes of cirrhosis in the US
Can lead to portal hypertension, which can cause gastroesophageal varices (prone to rupture, massive GI hemorrhage, death)

Question 5

Telomerase and telomeres

Answer 5

Telomerase is a reverse transcriptase that lengthens telomeres by adding TTAGGG repeats to the 3’ end of chromosomes
Stem cells have long telomeres due to high telomerase activity, allowing them to proliferate indefinitely in a controlled manner
Ex. epidermal basal cells

Question 6

Tuberculoid leprosy

Answer 6

Least severe form
Mycobacterium leprae
Limited by intact CMI response (Th1 mediated)
Milk skin plaques develop, associated with hypopigmentation, hair follicle loss, focally decreased sensation

Question 7

MOA of myasthenia gravis

Answer 7

Autoantibodies against postsynaptic nicotinic Ach receptors results in blockade of active site, receptor internalization/degradation, and damage to the motor end plate due to complement fixation
Decreased numbers of functional Ach receptors at NMJ
Reduces end-plate potential (threshold potential is not reached, muscle cells do not depolarize)

Question 8

Cannulation of the femoral vein

Answer 8

Should occur approximately 1 cm below the inguinal ligament and just medial to the femoral artery pulsation
NAVL

Question 9

Cavernous hemangioma

Answer 9

Most common benign liver tumor
Adults 30-50
Cavernous, blood-filled vascular spaces of variable size lined by single epithelial layer
DO NOT BIOPSY: procedure can cause fatal hemorrhage and is of low diagnostic yield

Question 10

Principle site of uric acid precipitation?

Answer 10

Uric acid is soluble at physiologic pH but can precipitate in normally acidic environment of the distal tubules/collecting ducts
Tumor lysis syndrome occurs when tumors with a high cell turnover are treated with chemotherapy > causes intracellular ions (K, P, uric acid) to be release into serum
Prevention includes urine alkalinization and hydration

Question 11

Fractures of the orbital floor

Answer 11

Commonly result from direct frontal trauma to the orbit
Infraorbital nerve runs along the orbital floor before exiting the skull just inferior to the orbit
Damage can result in paresthesia of the upper cheek, upper lip, upper gingiva
Inferior rectus muscle can become entrapped, limiting superior gaze

Question 12

Hypocalcemia

Answer 12

Signs: muscle cramps, perioral paresthesias, hypotension, laryngospasm, Chvostek sign (facial muscle contraction elicited by tapping on facial nerve anterior to the ear), Trousseau sign (carpopedal spasm triggered by prolonged inflation of a blood pressure cuff around the arm)
Most common cause = injury to parathyroid glands during thyroid surgery

Question 13

Dobutamine

Answer 13

B-adrenergic agonist (B1> B2> a1)
Rx: refractory heart failure associated with severe LV systolic dysfunction and cardiogenic shock
+ inotropic effect (increased contractility), + chronotropic effect (increased heart rate), increase myocardial O2 consumption, vasodilation

Question 14

Inflammatory breast cancer

Answer 14

Peau d’ orange (erythematous rash, itchy, firm/coarse skin texture)
Breast edema
Cancer obstructs lympathetic drainage

Question 15

Etanercept

Answer 15

Tumor necrosis factor-alpha (TNF-a) inhibitor
Added to methotrexate to treat moderate to severe RA
Fusion protein linking a soluble TNF-a receptor to the Fc component of human Ig.
Reduces the biological activity of TNF-a by acting as a decoy receptor

Question 16

Suffix of a biological agent

Answer 16

Monoclonal antibody (-mab)
Receptor molecule (-cept)
Kinase inhibition (-nib)

Question 17

Spleen

Answer 17

Most common intra-abdominal organ injured during blunt trauma
Of mesodermal origin (dorsal mesentery)
Supplied by the splenic artery (a branch of the major foregut vessel, the celiac trunk)

Question 18

Case-control study

Answer 18

Used to compare the exposure of people with the disease (cases) to the exposure of people without the disease (controls). The main measure of association is the exposure odds ratio.

Question 19

Adjustable gastric banding

Answer 19

to encircle the upper stomach, the gastric band must pass through the lesser omentum

Question 20

Beta blockers in the treatment of hyperthyroidism

Answer 20

Reduces heart rate and feelings of anxiety/agitation

Decreases the peripheral conversion of T4 to T3 by inhibiting iodothyronine deiodinase

Question 21

The common and proximal carotid arteries derive from which aortic arch?

Answer 21

Third

Question 22

Food borne botulism

Answer 22

Diplopia, dysphagia, dysphonia
Electrodiagnostic studies reveal normal nerve conduction velocity but decreased compound muscle action potential (CMAP), repetitive nerve stimulation leads to facilitation of CMAP

Question 23

Orchiopexy

Answer 23

Surgical repair of an undescended testicle lodged in the inguinal canal
Reduce testis through the superficial inguinal ring and fix it in the scrotum
The superficial and deep inguinal rings are physiologic openings in the external abdominal oblique aponeurosis and the transversalis fascia, respectively.

Question 24

Huntington disease pathogenesis

Answer 24

Hypo-acetylated histones bind tightly to DNA and prevent transcription of genes in their associated regions
Alteration of gene expression in Huntington disease occurs in part due to deacetylation of histones
This prevents the transcription of certain genes that encode for neurotrophic factors, contributing to neuronal cell death

Question 25

Toxic megacolon

Answer 25

Complication of ulcerative colitis Abdominal pain/distension, blood diarrhea, fever, signs of shock Plain abd x-ray is preferred diagnostic imaging study Barium contrast studies and colonoscopy are contraindicated due to the risk of perforation

Question 26

Alpha-1 antitrypsin deficiency

Answer 26

Serum protein, inhibits neutrophil elastase, reduces tissue damage caused by inflammation Histologically- reddish-pink, periodic acid-Schiff positive granules of unsecreted, polymerized AAT in the periporal hepatocytes

Question 27

Photoaging (wrinkles)

Answer 27

Product of excess exposure to ultraviolet A wavelengths and is characterized by epidermal atrophy with flattening of rete ridges Decreases collagen fibril production and increased degradation of collagen and elastin in the dermis

Question 28

Odds ratio (OR)

Answer 28

Measure of association between an exposure and an outcome | In an standard contingency table, OR=ad/bc

Question 29

Sarcoidosis

Answer 29

Hilar adenopathy, pulmonary disease, constiutional symptoms | NON-CASEATING GRANULOMAS (distinguishes sarcoidosis from tuberculosis infection)

Question 30

G6PD deficiency inheritance

Answer 30

X-linked recessive inheritance

Question 31

Glucagonoma

Answer 31

``` Rare tumor of alpha-cells Necrolytic migratory erythema Hyperglycemia Normocytic normochormic anemia Elevated levels of glucagon in the serum ```

Question 32

Arteriovenous concentration gradient (inhaled anesthetics)

Answer 32

Reflects the overall tissue solubility of an anesthetic. Anesthetics with high tissue solubility are characterized by large arteriovenous concentration gradients and slower onsets of action

Question 33

Amiodarone

Answer 33

Class III antiarrhythmic drug Superventricular and ventricular arrhythmias Block potassium channels, inhibit the outward K currents, prolong repolarization and total action potential duration APD is ~ QT interval unlike other drugs that cause QT prolongation, amiodarone has a VERY LOW RISK of inducing TORSADES DE POINTES

Question 34

Direct hernias

Answer 34

Caused by weakness of the transversalis fascia in Hesselbach's triangle Medial to the inferior epigastric vessels, protrude through the external inguinal ring, covered by external spermatic fascia

Question 35

IgA protease

Answer 35

Produced by N. meningitidis, N. gonorrhoeae, S, pneumo, H. flu Cleaves secretory IgA at its hinge region, rendering it ineffective Secretory IgA exists on mucosal surfaces and in secretions and acts to bind and inhibit the action of pili as well as other cell surface Ag that normally mediate mucosal adherence and subsequent penetration

Question 36

Attack rate

Answer 36

Ratio of the number of people who contract an illness divided by the number of people who are at risk of contracting that illness

Question 37

Most common causes of death in patients with tricyclic antidepressant overdose

Answer 37

Cardiac arrhythmias and refractory hypotension Inhibition of fast Na channels in cardiac myocytes (and the His-Purkinje system) is thought to be the major underlying cellular event

Question 38

Third heart sound (S3)

Answer 38

Occurs during early diastole and is best heard with the bell of the stethoscope over the cardiac apex while the patient is in the left lateral decubitus position at end expiration Can be normal in healthy young adult Considered abnormal in patients >40 and suggests ventricular enlargement (rapid passive ventricular filling)

Question 39

Lateral ankle sprain

Answer 39

Due to inversion of a plantar-flexed foot and most commonly involves the anterior talofibular ligament Stronger forces can cause joint instability by injuring additional ligaments

Question 40

Retroperitoneal hematomas

Answer 40

Abdominal and pelvic trauma | Pancreatic injury is a frequent cause

Question 41

Following IV administration, a highly lipophilic drug (anesthetics) will...

Answer 41

Be rapidly distributed to organs with high blood flow (brain, liver, kidneys, lungs) The drug is then slowly redistributed to tissues with relatively low blood flow (skeletal muscle, fat, bone) This accounts for the short duration of action of many commonly used anesthetics, such as propofol

Question 42

Carcinoid tumors

Answer 42

If confined to the intestine- do not cause carcinoid syndrome (secretory products are metabolized by the liver before entering systemic circulation Intestinal carcinoids that metastasize to the liver and extraintestinal (bronchial) carcinoids release vasoactive substances that avoid first pass metabolism resulting in carcinoid syndrome (flushing, diarrhea, bronchospasm)

Question 43

E. coli

Answer 43

Lactose fermenting, INDOLE POSITIVE gram-negative rods that are important cause of UTI in women

Question 44

Precursor proteins or peptides responsible for localized amyloidosis (confined to a single, specific organ)

Answer 44

Cardiac atria: atrial natriuretic peptide Thyroid gland: calcitonin Pancreatic islets: islet amyloid protein (amylin) Cerebrum/cerebral blood vessels: B-amyloid protein Pituitary gland: prolactin Immune globulin light chains cause multi-organ amyloid deposition in primary systemic amyloidosis

Question 45

Annular pancreas

Answer 45

Pancreatic tissue encircling the descending duodenum Caused by failure of the ventral pancreatic bud to properly migrate and fuse with the dorsal bud during the seventh and eighth week of fetal development Usually asymptomatic but may present with duodenal obstruction or pancreatitis

Question 46

Risks of secondhand smoke exposure

Answer 46

``` Prematurity, low birth weight Sudden infant death syndrome Middle ear disease (otitis media) Asthma Respiratory tract infections ```

Question 47

Duchenne Muscular dystrophy

Answer 47

Can occur due to nonsense mutations in the dystrophin gene | Nonsense mutations introduce premature stop codons (UAA, UAG, UGA)

Question 48

Ion channels

Answer 48

When a specific ion channel opens, the respective ions will flow across the membrane in a direction that brings the resting membrane potential closer to that ion's equilibtrium potential

Question 49

Vesicoureteral reflux

Answer 49

Retrograde urine flow from bladder into the ureter Hydrostatic pressure of refluxing urine along with infections due to ascending bacteria cause inflammation Compound papillae in upper and lower poles of kidney are most susceptible to reflux induced damage which appears as dilated calyces with overlying renal cortical scarring can lead to hypertension