Uworld: 5-5

Front 1

What are the three types of RNA polymerases?

Functions?

Back 1

I: forms ribosomal RNA in nucleolus; always active--loosely regulated

II: synthesizes mRNA; tightly regulated

III: transcribes DNA to form small RNA molecules such as tRNA, snRNPs (snurps); few regulatory factors

Front 2

Genetic predisposition for Alzheimer's:
Early vs Late Onset

Back 2

Early: Amyloid precursor protein (APP) and presenilin gene mutations promote beta-amyloid

Late-onset familial AD: apolipoprotein E-4 (ApoE4)-->senile plaques

Front 3

Familial hypercholesterolemia:
Pathophys

Back 3

Defective LDL receptors-->dec'd hepatic LDL uptake and severe elevation in total cholesterol and LDL levels

Front 4

Buspirone:
Indications
MOA

Back 4

Generalized ANXIETY disorder

5HT1a agonist

Front 5

Fluoxetine:
MOA

Back 5

SSRI

Front 6

Opioid tolerance:
Mechanism

Back 6

Chronic tolerance involves inc'd adenylyl cyclase activity OR inc'd NO levels

Front 7

Morphine tolerance:
Mechanism

Back 7

Glutamate binds, activates NMDA receptors-->inc'd phosphorylation of opioid receptors-->inc'd NO levels-->morphine tolerance

Front 8

Ketamine:
MOA

Back 8

NMDA receptor antagonist--blocks actions of glutamate and blocks morphine otlerance

Front 9

Chronic dry cough
Low-grade fever, malaise
CXR shows pulmonary infiltrates severe in appearance (more so than would be expected from symptoms)

Diagnosis
Growth requirements on agar

Back 9

Mycoplasma pneumoniae

Requires cholesterol for growth on agar

Front 10

Currant jelly sputum

Back 10

Klebsiella pneumoniae

Front 11

Chocolate agar

Back 11

H influenzae (supplemented with factor X (hematin) and V (NAD+))

Front 12

Most common in southwest US and northern Mexico

Back 12

Coccidoides immitis

Front 13

Ground glass infiltrates on CXR

Back 13

Pneumocytsis jiroveci

Front 14

Label muscle groups.

Back 14

Front 15

Psoas:
Action

Back 15

Flex thigh

Front 16

Erector Spinae:
Action

Back 16

Extend spine

Front 17

What activities/events can lower glucose levels in a diabetic?

Back 17

Exercise

Front 18

What activities/events can elevate glucose levels in a diabetic?

Back 18

Infection
Pain
Sleep deprivation
Stress


ALL INC GLUCOSE LEVELS (via catechols)

Front 19

Why is glucagon used in type 1 DM?

Back 19

Glucagon can increase production of glucose from the liver in times of hypoglycemia.

Done via inc'd glycogenolysis (breakdown of glycogen) and inc'd gluconeogenesis (production of glucose from non-carb source)

Note: Glucagon stimulates insulin secretion from pancreas, but pts w/DM I have diminished beta cells.

Front 20

With defective immunoglobulin isotype switching, what immunoglobulin will be overproduced?

Back 20

IgM

Front 21

These cells require insuline for glucose uptake.

Back 21

Muscle cells
Adipocytes

Note: Without insulin, receptor is in cytoplasm. With insulin, receptor integrates into cell membrane (receptor = GLUT4 transporter)

Front 22

Precipitating factors for isolated atrial fibrillation in healthy patients.

Specific EKG findings.

Back 22

Binge alcohol consumption
Inc'd sympathetic tone
Pericarditis

Absent P waves (no coordinated atrial contractions)
Irregular QRS complexes

Front 23

RBF vs RPF:
Equations

Include equation for clearance.

Back 23

Renal Blood Flow = PAH clearance/(1-HCT)

Renal Plasma Flow = PAH clearance

Clearance = (Ux x V)/Px

Front 24

Describe the reactions that require tetrahydrobiopterin.

Back 24

Note: tetrahydrobiopterin = BH4

Front 25

Where is aqueous humor produced?

Describe its path.

How does narrow-angle glaucoma arise?

Back 25

Formed by epithelial cells of ciliary body

Excreted into posterior chamber and transferred through pupil into anterior chamber

Passes through trabecular meshwork of anterior chamber ANGLE into Schlemm's canal

Schlemm's canal drains into espiscleral and conjunctival veins

When the anterior chamber narrows, the trabecular meshwork is obstructed and results in narrow-angle glaucoma. Manifests acutely with HA and eye pain.

Front 26

How does timolol treat glaucoma?

Back 26

Timolol and other non-selective beta-blockers diminish secretions of aqueous humor by ciliary epithelium.

Front 27

How does acetazolamide treat glaucoma?

Back 27

Decreases aqueous humor secretion by ciliary epithelium.

Front 28

How does latanoprost treat glaucoma?

Back 28

PG agonist-->increases outflow of aqueous humor and thus decreases intraocular pressure

Front 29

How is glycogen degradation coupled with skeletal muscle contraction?

Back 29

Increased calcium in cytosol-->activates phosphorylase kinase
-->phosphorylates (activates) muscle phosphporylase
-->breaks down glycogen for use by muscle

Front 30

What are the direct and indirect effects of alpha-1 receptors?

Back 30

Direct effects:
-Contraction of vascular smooth muscle
-Inc'd cardiac contractility
-Mydriasis (via contraction of pupillary dilator muscle)

Indirect effects:
-Inc'd systemic BP due to inc'd vasoconstriction stimulates baroreceptors in carotid sinus and aortic arch-->inc'd vagal influence on heart
Causes decreased heart rate (REFLEX BRADYCARDIA), dec'd conductance in AV node

Note: indirect vagal influence overwhelms direct cardiac effects of alpha-1 receptor

Front 31

What are the direct effects of alpha-2 receptors?

Back 31

CNS mediated decrease in BP

Dec'd aqueous humor fluid production from ciliary body

Inhibition of adrenergic and cholinergic NT release

Front 32

This microbe produces dextrans from glucose.

Back 32

Viridans streptococci (mutans, sanguis)

Producing dextrans from glucose assists in colonization of host organisms.

Front 33

What drugs are associated with agranulocytosis?

How would you monitor this?

Back 33

C^3:
Clozapine
Colchicine
Carbemazapine

Requires periodic CBC with differential.

Front 34

Clozapine:
Use
MOA
AE

Back 34

Antipsychotic, used in schizophrenia

Blocks D4 receptors (unlike most antipsychotics, which act on D2 receptors)--less likely to cause pseudoparkinsonism, tardive dyskinesia, hyperprolactinemia

AGRANULOCYTOSIS; need CBC
SEIZURES

Front 35

Ptosis
Down and out gaze
Normal light and accommodation reflexes

Diagnosis
Pathophys

Back 35

Diabetic mononeuropathy of CN III

Due to ISCHEMIC nerve damage, only somatic nerve fibers affected. Parasymp fibers oc CNIII retain function.

Front 36

What nerve is responsible for pupillary response to light and accommodation?

Back 36

CN III (parasymp fibers)

Front 37

Risperidone:
Use
MOA
AE

Back 37

Anti-psychotic used for schizophrenia

D2 receptor antagonist

AE: hyperprolactinemia-->inhibition of GnRH release-->amenorrhea (via PL)

Front 38

First step of suspected child abuse.

Back 38

Contact child protection services IMMEDIATELY.

Do not confront parents, do not call for a consult.

Front 39

Paroxysmal Nocturnal Hemoglobinuria:
Pathophys
Effects

Back 39

Deficiency of CD55 and CD59-->disallows inactivation of complement

Results in thrombosis:
-Recurrent venous thrombosis
-Budd-Chiari Syndrome

Also results in hemolytic anemia!
Also associated with pancytopenia since it is a stem cell disorder.

Front 40

72 year-old male
Headaches
Visual deterioration
Resolves with prednisone

Diagnosis
Pathophys

Back 40

Temporal cell arteritis (Giant cell arteritis); because it is GIANT CELL, must be granulomatous inflammation of temporal artery

Also presents with facial pain, jaw claudication

Front 41

Describe the metabolism of fructose. How does this differ in essential fructosuria?

Back 41

Essential fructosuria = fructokinase deficiency

Front 42

What antigens are produced by HBV?

How do they differ in terms of structure/function?
Which indicate high infectivity?

Back 42

HBcAg = nucleocapsid core; resides within hepatocytes and assembles virion. Marker of high infectivity.

HBeAg = nucleocapsid core; marker of high infectivity. Resides within hepatocyte, assemblres virion.

HBsAg = noninfective envelope that forms spheres and tubules. Infected hepatocytes may secrete this (often a lot more than amount of HBcAg produced).

Front 43

Blowing holosystolic murmur best heard at apex
High-grade fever
Dyspnea
Fatigue
Erythematous macules on sole of foot

Diagnosis
Pathophys

Back 43

Mitral regurgitation secondary to bacterial endocarditis

Lesions on foot = Janeway lesions; are the result of septic embolization from infected cardiac valve vegetations

Front 44

Epithelium of ovary

Back 44

Simple cuboidal

Front 45

Epithelium of fallopian tube

Back 45

Simple columnar

Front 46

List 4 direct dopamine agonists.

Which dopamine receptor do they bind?

Back 46

Bromocriptine
Pergolide
Pramipexole
Ropinerole

All act on D2 receptor

Front 47

What are fatty streaks?
How are they formed?
When do they become apparent?

Back 47

Fatty streaks are the earliest lesion of atherosclerosis

Composed of intimal, lipid-filled foam cells, derived from macs that have engulfed lipoproteins

May progress to atherosclerotic plaques later in life, but do not predict occurrence or location of atheromatous plaques later in life

Present in all individuals after age 10

Front 48

Burning sensation in a dermatomeal distribution
Followed by erythematous rash 2-3 days later
Transforms into vesicles

Diagnosis
Histologic features of vesicle

Back 48

Herpes Zoster

Vesicle will feature intranuclear inclusions in keratinocytes and multinucleated giant cells

Front 49

Clathrin:
Role

Back 49

Mediates endocytosis