Uworld: 2A

Front 1

Brunner’s Glands:
Function
Location

Back 1

Located in duodenum.

Secrete alkaline mucous into ducts that track upward through the muscularis mucosae and into the crypts of Liberkühn for release into lumen.

Front 2

Crypts of Liberkühn:
Function
Location

Back 2

Located in duodenum and colon.

Release the alkaline mucous produced by Brunner’s glands in duodenum

Release mucus produced by goblet cells in colon

Front 3

Peyer’s Patches:
Location

Back 3

Ileum

Front 4

Glomerulonephritis
Photosensitivity Rash
Arthralgias

Back 4

SLE

Front 5

VRDL in SLE:
Lab values
Effects

Back 5

Lab values show increased antiphospholipid antibody (APLA) against Lupus anticoagulant

Effects:
1) Venous thromboembolism
2) Arterial thromboembolism
3) Increased fetal loss***

Front 6

Lupus anticoagulant:
Diagnostics
Effects

Back 6

Can detect with positive VRDL (*false positive*), prolonged PTT***

Inc’d anticoagulant→hypercoagulable state (uncertain mechanism)→thromboembolism and/or repeated miscarriages

Front 7

Anaplastic cells:
Define anaplasia
Histologic features

Back 7

Anaplasia = neoplastic cells with a complete lack of differentiation

Histologic features:
-Lose cell polarity/tissue architecture—cells coalesce into sheets/islands in disorganized fashion

-Cellular pleomorphism—sig variation in shape/size of cells

-Larger nuclei than those in normal cells (high nucleus-to-cytoplasm ratio)

-Numerous, often abnl mitoses

-GIANT, MULTINUCLEATED TUMOR CELLS

Front 8

Under 1 year-old
Repeated lower respiratory infections
Candida extract injection results in indurated nodule

Back 8

Bruton’s agammaglobulinemia


Positive reaction to candida indicates intact T cell response

Recurrent resp infections due to very low number of mature B cells

Front 9

Bruton’s agammaglobulinemia:
Pathophys

Back 9

X-linked immunodeficiency
Absence of immunoglobulin and B cells due to defect in B cell maturation (remember: B cells produce Ig)

Front 10

No LN germinal centers

Back 10

Bruton’s agammaglobulinemia

Front 11

Paracortical zone of LN:
Contents

Back 11

T cells
APCs

Front 12

Cystic Fibrosis:
Molecular pathophys

Back 12

Mutation in CFTR gene (deltaF508) results in defective post-translational folding and glycosylation

Results in degradation of CFTR membrane protein before it reaches cell surface

Front 13

ANOVA;
Utility

Back 13

Compare means of three or more variables

Front 14

Chi-square test:
Utility

Back 14

Compare proportions of a categorized outcome (“high”, “normal”, “low”, etc)

Front 15

A study compares drug outcome via fibrinogen levels categorized as high and normal.

What statistical test would be appropriate for this study?

Back 15

Chi-square

Front 16

Patent Urachus:
Presentation
Embryologic pathophys

Back 16

Patent urachus presents with urine discharge from umbilicus.

Urachus is remnant of allantois, which connects bladder with yolk sac during fetal development. Failure of urachus to obliterate = patent urachus.

Front 17

Persistent yolk sac:
Presentation

Back 17

Persistent yolk sac (vitelline duct) connects small bowel with skin at umbilicus. Presents w/meconium discharge from umbilicus.

Front 18

Cyanide poisoning:
Pathophys
Presentation
Treatment and MOA

Back 18

Cyanide binds cytochrome a-a3 complex (…)—critical for electron transport during ox-phos. This results in inhibition of aerobic metabolism and death

Presentation: Rapidly-developing cutaneous flushing
Tachypnea
HA
Tachycardia
N/V
Confusion
Weakness

Tx: Nitrites (Fe2+→Fe3+)—form methemoglobin, which can’t bind oxygen, but can avidly bind CN-; thus, sequestering it in blood (keeps poison out of mitochondria)

ALTERNATE TREATMENT: Na+ Thiosulfate—combines w/CN- to form less-toxic thiocyanate, which is excreted in urine.

Front 19

How does methemoglobin differ from hemoglobin?

Back 19

Methemoglobin contains ferric rather than ferrous iron. CN- binds ferric iron more avidly than mitochondrial cytochrome enzymes.

Front 20

This nerve exits through the obturator foramen.

Function?

Back 20

Obturator nerve: adductor compartment of thigh

Damaged during pelvic surgery, especially during LN dissection

Front 21

Adduction of thigh:
Nerve

Back 21

Obturator nerve

Front 22

Abduction of thigh:
Nerve

Back 22

Superior gluteal nerve
Femoral nerve

Front 23

Extension of thigh:
Nerve

Back 23

Inferior gluteal nerve

Front 24

Flexion of thigh:
Nerve

Back 24

Lumbar plexus
Femoral nerve

Front 25

Extension of leg:
Nerve

Back 25

Femoral

Front 26

Glossopharyngeal nerve:
CN Number
Result of injury

Back 26

CN IX
Lose gag reflex, sensation in upper pharynx, POSTERIOR tongue, tonsils, middle ear, loss of taste in POSTERIOR third of tongue

Front 27

Taste sensation in anterior two-thirds of tongue:
Cranial Nerve

Back 27

Facial

Front 28

General sensation of tonsillar lining:
Cranial Nerve

Back 28

Glossopharyngeal

Front 29

Salivary secretion from submandibular and sublingual gland:
Cranial Nerve

Back 29

Facial

Front 30

Protrusion of tongue:
Cranial Nerve

Back 30

Hypoglossal Nerve

Front 31

Minute ventilation:
Formula

Back 31

Tidal volume x Respiratory Rate
INCLUDES DEAD SPACE

Front 32

Urea formation:
Critical step
Effect of defect in this step
Treatment

Back 32

Ornithine transport from cytosol to mitochondria, where it then combines with carbamoyl phosphate to form citrulline.

Defect in this step would lead to inc’d levels of ammonia!-->CNS dysfn

Tx: Protein restriction

Front 33

Nicotinic acid:
MOA
Use
AEs

Back 33

Nicotinic acid aka vit B3/niacin, inhibits VLDL production.

Used to increase HDL levels.

AEs:
Flushing
Hepatotoxicity in high doses
Cholesterol gallstones if acts as bile acid-binding resin (research this)

Front 34

Hypertension
Low plasma renin
Weakness
Paresthesia

Back 34

HTN & low renin→elevated aldosterone
Weakness & parasthesia→hypokalemia (expected in aldosterone excess)

Thus, primary mineralocorticoid excess

Front 35

Excess aldosterone:
Effects

Back 35

Sodium retention
K+ loss
Inc’d urinary H+ excretion (metabolic alkalosis)

Front 36

Why is hypernatremia not seen in hyperaldosteronism?

Back 36

Aldosterone escape—inc’d sodium and Cl- absorption in hyperaldosteronism leads to intravascular hypervolemia.

This promotes releas of atrial natriuretic peptide→diuresis and eventual compensatory sodium loss

Thus, no edema

Front 37

Describe the following lab values for primary aldosterone excess:
Bicarbonate
Potassium
Sodium

Back 37

Bicarb will be elevated—this is a state of metabolic alkalosis

K+ will be decreased—aldosterone promotes K+ excretion

Sodium will be normal—despite retention of Na+, ANP keeps Na+ levels normal

Front 38

Digoxin:
Effects
Use

Back 38

Use for a. fib w/rapid ventricular response (AD w/RVR—HR>100) bc slows conduction through AV node (USED AS SECOND LINE TX)

Slows conduction through inc’d parasympathetic tone via VAGUS STIMULATION

Summary--Digoxin has 2 physiologic effects:
1) Blocks Na-K-ATPase in cardiac myocytes→inc’d intracellular Ca2+
2) Dec’d AV nodal conduction by inc’d Psymp tone

Front 39

Obstructive lung disease:
Effect on lung volumes
Examples of such diseases
Effect on TLC/RV

Back 39

Ex: Asthma, chronic bronchitis, emphysema, bronchiectasis

Obstructive lung dz→air trapping and hyperinflation of lungs:
Inc’d TLC, RV, and RV/TLC
Dec’d FEV1, FEV1/FVC
While TLC will be increased, RV will be decreased by a much greater factor; thus TLC/RV will increase.

Front 40

Pulsus paradoxus is a sign of __________.

Back 40

Cardiac tamponade

Front 41

2 weeks post-mild respiratory illness
Severe weakness, dizziness
Fluid accumulation in pericardial cavity

Back 41

Cardiac tamponade; likely secondary to inflammn caused by virus (possibly same virus that caused upper resp tract infection)

Front 42

What is pulsus paradoxus?

Back 42

Drop in arterial BP during inspiration of over 10 mmHg (decrease of less than 10 mmHg is physiologic)

Clinically: palpate radial pulse and noting it disappears on inspiration

Front 43

When does cardiac tamponade become symptomatic?
Pathophys?
Effects on pre/afterload

Back 43

When pericardial pressure exceeds 10 mmHg, force is sufficient to cause collapse of atria→inc’d systemic venous pressure, reduced ventricular preload, and eventually dec’d cardiac output.

Death results from cardiogenic shock, when Q is insufficient to provide O2 for tissue.

Front 44

Pulsus alternans is a sign of_________.

Back 44

LV dysfn

Front 45

What is pulsus alternans?

Back 45

Beat to beat variation in magnitude of pulse pressure in presence of regular cardiac rhythm.

Front 46

Pulsus parvus et tardus is a sign of _______.

Back 46

Aortic stenosis

Front 47

What is pulsus parvus et tardus?

Back 47

Pulse of low magnitude and delayed peak

Front 48

Multiple sclerosis:
Molecular pathophys
Diagnosis
Presentation

Back 48

Lesions of white matter than result in:
-demyelination (denudation) of axons
-Depletion of oligodendrocytes (produce myelin in CNS)
-Lipid-laden macrophages (they phagocytize myelin breakdown products)
-Astrocytosis (astrocyte proliferation is a reaction to inury)

Dx: Brain MRI

Presentation:
-Dysfnl lateral conjugate gaze (slow adduction of one eye while looking laterally)—due to denudation of MLF (medial longitudinal fasciulus)
-Optic neuritis—dec’d or blurred vision, monocular blindness, central scotoma (whatever that is)
-Sensory loss, arm of leg weakness
-Cerebellar syx (clumsiness, ataxia)

Front 49

Intenuclear ophthalmoplegia:
What is it?
Cause?

Back 49

Dysnl lateral conjugate gaze—have trouble adducting one eye upon lateral gaze

Due to lesion of MLF (as in MS)

Front 50

Pyridoxine:
Role

Back 50

AKA vitamin B6—cofactor for transamination and decarboxylation of amino acids, for gluconeogenesis, etc.

Transamination = amino acid + alpha-keto acid→transfer amino group to alpha-keto acid for it to become amino acid

Ex: oxaloacetate + glutamate→aspartate
Transaminases (aminotransferases) = enzyme, pyridoxine (B6) = cofactor

Front 51

Lecithinase:
Associated bug
MOA

Back 51

Main toxin of C. perfringens
Lecithinase AKA phospholipase C AKA alpha-toxin; splits phospholipid molecules

Front 52

This bug cannot grow on 5% sheep blood agar.

Why not? How can this be changed?

Back 52

Sheep blood agar plates lack nutrients to support growth of H. flu; also have Factor V inactivating enzymes.

Growth of H flu can be achieved by streaking medium w/Staph aureus.

Staph. Aureus lyses RBCs in medium and releases Factor X (hematin) is released. Factor V (NAD+) is also released by staph.

Front 53

Factor V and X AKA

Back 53

Factor V = NAD+
Factor X = Hematin

Front 54

Lactose fermentation:
Associated bug
Gene required

Back 54

E. coli

Lac-operon (inducible and repressible in absence of glucose)—activated by glucose deficit, repressed when glucose available

Front 55

Recurrent infections with Pseudomonas
Chronic diarrhea
Weight loss

Back 55

Cystic fibrosis

Front 56

How does cystic fibrosis result in diarrhea and weight loss?

Treatment?

Back 56

Obstructive fibrosis and progressive exocrine pancreas insufficiency→malabsorption→diarrhea

Tx with pancreatic lipase

Front 57

Sulfasalazine:
MOA
Use

Back 57

Inhibit PG and LK synthesis during inflammn

Use in Crohn’s, UC

Front 58

Octreotide:
MOA
Use

Back 58

SMS analogue that decreases gut motility, blood flow, pancreatic secretion

Use in VIPoma

Front 59

This nerve is most commonly affected in leg injuries.

Back 59

Common peroneal (fibular) nerve—superficial and courses laterally around neck of fibula

Front 60

Fibular nerve:
Location
Functions
Effect of lesion
Examples of trauma

Back 60

Located at neck of fibula

Eversion of foot
Dorsiflexion of feet and toes
Sensation of feet

Lesion→foot drop and foot inversion

Ex: Lateral blow to knee and tightly applied plaster casts/devices

Front 61

Foot drop

Back 61

Fibular nerve (common peroneal)

Front 62

Unopposed inversion of foot

Back 62

Lesion to fibular nerve (Common peroneal)

Front 63

Unopposed eversion of foot

Back 63

Injury to tibial nerve

Front 64

Dorsiflexion of foot

Back 64

Injury to tibial nerve

Front 65

Tibial Nerve:
Function

Back 65

Inversion and plantarflexion of feet

Front 66

Long-term hemodynamic compensatory response to aortic regurgitation.

Back 66

Inc’d LV preload (end-diastolic volume)
ECCENTRIC LV hypertrophy

Front 67

When is concentric hypertrophy seen in the LV?

Back 67

In times of pressure overload, such as aortic stenosis and systemic HTN.

Front 68

When is eccentric hypertrophy seen in the LV?

Back 68

In times of volume overload, such as in aortic regurgitation.

Front 69

Patient undergoing elective surgery:
Drug to prevent venous thrombosis
MOA

Back 69

Heparin—increases effect of Anti-Thrombin III (by binding it)

Front 70

Argatroban:
MOA
Use

Back 70

Directly bind thrombin active site and inhibit its activity

Use in HIT

Front 71

Ticlopidine:
MOA
Use

Back 71

Inhibit ADP mediated platelet aggregation; useful in tx of unstable angina and non-Q wave MI (…)

Front 72

This drug inhibits arachidonate product formation.

Back 72

ASA

Arachidonate = arachidonic acid

Front 73

Pelvic inflammatory disease:
Presentation
Causes
Effect on pregnancy

Back 73

Fever
Rebound abdominal tenderness
Vaginal discharge

N. gonorrhoeae or Chlamydia

50% of patients with PID have ectopic pregnancy

Front 74

Back 74

COPD:
Low, flattened diaphragm
Hyperinflated lungs

Front 75

Back 75

Severe obsructive dz—COPD (inc’d RV at end-expiration, dec’d tidal volume)

Front 76

Back 76

Pulmonary fibrosis—dec’d lung volume and compliance (RESTRICTIVE PATTERN)—dec’d tidal volume and residual volume

Front 77

Slow growing mass
Oral trauma
Yellow pus

Back 77

actinomyces israeli

Front 78

Actinomyces:
Gram -/+
Location
Effects
Treatment

Back 78

Gram +
Oral flora
Chronic (slow growing) face and neck abscesses

Tx: Parenteral PCN, surgical debridement

Front 79

Ectopic pregnancy:
Treatment
MOA

Back 79

Methotrexate (<6 weeks gestation of ectopic pregnancy)

MTX competitively inhibits dihydrofolate reductase (DHF), which catalyzes reduction of folic acid to DHF and subsquently reduces DHF to tetrahydrofolate (THF).

MTX inhibition of THF inhibits purine and thymidylate synthesis and results in accumulation of dihydrofolic acid polyglutamate.

Front 80

This drug is structurally similar to folic acid.

Back 80

Methotrexate

Front 81

Why is hydroxyurea used in HbS?
Under what circumstances is it used?

Back 81

Increases Hb F synthesis thus conferring protection against polymerization of sickle cells

Reserved for sickle patients with pain crises

Front 82

Why are Gardos channel blockers used in HbS?

Back 82

Hinder efflux of K+ and H2O from cell, preventing dehydration of RBCs and reducing polymerization of HbS

Front 83

Left supraclavicular LAD

Back 83

Occult gastric cancer (Virchow's node)

Front 84

Subcutaneous mass in periumbilical region

Back 84

Occult gastric cancer
(Sister Mary Joseph Nodule)

Front 85

Poorly differentiated cells in ovary heavily loaded with mucus

Back 85

Krukenberg tumor due to gastric cancer mets

Front 86

Severe chest pain not relieved by rest of nitroglycerin
Diaphoresis
Dyspnea
Lightheadedness

Back 86

Acute transmural MI

Front 87

What are the EKG signs of acute transmural MI? Provide a chronological progression.

Back 87

Peaked T waves = first sign
ST elevation in minutes to hours
Q-waves in involved leads within hours to days

Front 88

Transmural infarction:
Cause

Back 88

Plaque rupture producing a superimposed thrombus that COMPLETELY occludes involved coronary artery

Front 89

When do symptoms of unstable angina become apparent?

Back 89

Upon 75% of coronary artery lumen occlusion

Front 90

What is Prinzmetal's angina?

How does it differ from acute MI?

Back 90

Episodic angina that occurs at rest

Duet o coronary artery vasospasm

Responds promptly to vasodilators such as nitroglycerin

Front 91

Describe the steps of glycolysis in both aerobic and anaerobic conditions.

Back 91

Glucose-->Fructose 1,6-bisphosphate
-->Glyceraldehyde-3-phosphate-->1,3-BPG via glyceraldehyde-3-phosphate dehydrogenase REQUIRES NAD+
-->Pyruvate
-->Acetyl Coa-->TCA

Aerobic: NAD+ regenerated (from NADH) via TCA

In exercising muscle, cell has limited stored of NAD+; instead of pyruvate forming, lactate is made.

Front 92

P50:
What is it?
Effect of left/right shifts?
When do left/right shifts occur?
Physiologic responses to these shifts?

Back 92

P50 = Po2 where Hgb is 50% sat'd
A decreased in P50 means Hgb has increased O2 affinity--this causes less O2 to be released into tissues, and results in hypoxia, then reflex POLYCYTHEMIA
KNown as a LEFT shift (inc'd pH, dec'd 2,3-DPG, dec'd Temp)--THINK LUNGS for LEFT

Right shift:
Inc'd p50 means lower affinity for O2 and will inc tissue delivery;
Causes: Dec'd pH, inc'd 2,3-DPG, inc'd temp (THINK TISSUES)

Front 93

When is hypoxia-induced hemolysis seen?

Back 93

Sickle cell

Front 94

When is oxidant-induced hemolysis seen?

Back 94

G6PD deficiency + oxidant stress (antimalarials, sulfonamides, fava beans)

Front 95

Hereditary spherocytosis:
Associated mutations

Back 95

Mutations in spectrin and ankyrin

Front 96

Marfan Syndrome:
Autosomal Dom/Rec?
Gene defect
Most likely cause of death
Known anatomic abnormalities

Back 96

Autosomal dominant
Defect in fibrillin-1 gene-->lens dislocation, mitral valve prolapse, medial degeneration of the aorta (leading to aortic dilatation and ***dissection***)

Most likely cause of death: aortic disease

Front 97

Hypertension
Low potassium
Depressed renin
Adrenal mass

Back 97

Aldosterone-secreting tumor (adenoma) leading to hyperaldosteronism (Conn's Syndrome)

Front 98

Aldosterone secreting tumor:
Presentation
What is the role of aldosterone?
Treatment

Back 98

HTN, hypokalemia, metabolic alkalosis, depressed renin activity

Aldosterone induces resorption of Na, H2O, and wasting of K+ and H+, leading to hypokalemia and alkalosis.

Inappropriately high aldosterone will inhibit renin activity.

Tx: Aldosterone antagonists! Ex: spironolocatone, eplerenone

Front 99

Sprinolocatone:
Drug Class
AE

Back 99

Aldosterone antagonist
AE: gynecomastia

Front 100

What drugs can be added to antibiotics to help overcome beta-lactamases?

Back 100

Lactamase inhibitors such as tazobactam and clavulanic acid (and sulbactam)

Front 101

Antibiotic for anaerobes

Back 101

i.e., bacteroides!

Piperacillin