Uworld: 5-12

Front 1

List the derivatives of the pharyngeal pouches.

Back 1

Pharyngeal Pouches:
1: Epithelium of middle air, auditory tube

2: Epithelium of palatine tonsil

3: Thymus, Inferior Parathyroid

4: Superior parathyroid

Front 2

Scapular Winging:
Nerve and Muscle Affected

Back 2

Serratus anterior
Long thoracic N

Front 3

Serratus anterior:
Action

Back 3

Fixes scapula against posterior chest wall

Front 4

Deltoid:
Action
Nerve

Back 4

Flex, extend, abduct arm

Axillary

Front 5

Rhomboid Major:
Action
Nerve

Back 5

Dorsal Scapular

Draws scapula medially

Front 6

Budding cells in esophagus

Back 6

Candida

Front 7

Immune defenses against candida:
Roles of each defense

Back 7

1) Th1 cells--local defense
2) Neutrophils: prevents hematogenous spread (via phagocytosis)

Front 8

What distinct infections would low complement predispose someone to?

Back 8

SHiN bacteria bc can't form MAC

Front 9

Following total ishemia, when do cardiac myocytes cease to contract?

When does irreversible ischemic injury occur?

Back 9

Within 60 seconds

Irreversible ischemia ~30 minutes after

Front 10

First-line treatment for HTN

Back 10

Thiazide diuretics

Front 11

First-line treatment for HTN s/p MI

Back 11

beta-blockers

Front 12

What is the best way to prevent neonatal tetanus?

Back 12

Vaccinate mom while she's pregnant with tetanus toxoid.

She'll produce IgG Ab's which will be transferred to the baby via the placenta!

Front 13

Antithyroid Drugs:
MOA
Examples
How do they differ?
AE

Back 13

Methimazole, PTU:
Prevent oxidation of iodine in thyroid gland (which prevents iodination of tyrosine residues)

PTU decreases peripheral conversion of T4 to T3, has a shorter half-life, and is drug of choice in pregnancy.

MTZ is a TERATOGEN.

AE: AGRANULOCYTOSIS!!!

Front 14

34 year-old female
h/o Hypercalcemia treated with neck surgery
Bitemporal visual field defects

Diagnosis
Pathophys of Syx

Back 14

Hypercalcemia treated with neck surgery likely was a parathryoid adenoma (tumor)

Bitemporal visual defects due to pituitary tumor extending above sella tursica and consequently compressing optic chiasm.

Patient with h/o pituitary and hyperparathyroid tumor should be evaluated for pancreatic tumor because of MEN TYPE 1 SYNDROME

Front 15

Describe the following stages of acute tubular necrosis:
Initiation
Maintenance
Recovery

Back 15

Initiation:
Ischemic injury to renal tubules secondary to hemorrhage, acute MI, sepsis, surgery, etc.

Maintenance (24-36 hours after inciting event): Dec'd urine output, fluid overload, inc'd Cr/BUN, hyperkalemia

Recovery (1-2 weeks after maintenance staget): Gradual increase in urine output leading to high-volume diuresis. Electrolyte abnlts may include dec'd K, Mg, PO4, and Ca due to slowly recovering tubular function.

Front 16

Why is it that human influenza viruses can undergo reassortment when exposed to animal viruses?

How does this lead to pandemic?

Which family of viruses does influenza belong to?

What other virus can undergo this reassortment?

Back 16

Influenza A is an orthomyxovirus and has a segmented genome. Can undergo genetic reassortment with animal orthomyxoviruses which sometimes result in altered viral surface glycoproteins (eg, hemagglutinin). This can lead to pandemic.

Other virus that can do this is Rotavirus because it is also segmented.

Note: Reassortment involves exchange of entire genome segments, a far more dramatic process than point mutations in genetic drift.

Front 17

This region of the hypothalamus produces oxytocin and ADH.

Back 17

Supraoptic and Paraventricular nuclei

Note: oxytocin and ADH are then transported to posterior pituitary for release.

Front 18

This region of the hypothalamus mediates hunger.

Back 18

Lateral nuclei

If lesion lateral nuclei-->starvation ensues (no hunger)

Front 19

This region of the hypothalamus mediates sweating and vasodilation.

Back 19

Anterior nuclei (via PSymp)

If lesion--> hyperthermia

Front 20

This region of the hypothalamus mediates satiety.

Back 20

Ventromedial

If lesion-->hyperphagia and obesity

Front 21

Hepatic encephalopathy:
Pathophys
Treatment
Treatment MOA

Back 21

Hepatic damage-->dec'd ability to detoxify nitrogenous wastes (carry out Ammonia-->Urea)

Inc'd ammonia results in disorientation

Tx: Lactulose--bacterial action on lactulose results in acidic colonic contents-->converts absorbable ammonia into nonabsorbable ammonium ion (an ammonia trap)

Front 22

Von Recklinghausen's Disease:
Presentation

Back 22

AKA Neurofibromatosis type 1

PNS tumor syndrome
Pts develop neurofibromas, optic nerve gliomas, Lisch nodules (pigmented nodules of iris), CAFE AU LAIT SPOTS

Front 23

Neurofibromatosis II:
Presentation

Back 23

B/L CN VIII (vesitbulocochlear) Schwannomas, multiple meningiomas

Front 24

Sturge-Weber Syndrome:
Presentation

Back 24

Cutaneous facial angiomas and leptomeningeal angiomas

Skin involvement overlies ophthalmic (V1) and maxillary (V2) distributions of trigeminal nerve

Also presents with MR, seizures, hemiplegia, TRAM-TRACK radiopacities on skull radiographs

Front 25

Tuberous Sclerosis:
Presentation

Back 25

Kidney/liver/pancreatic cysts
CNS cortical and subependymal hamartomas

Front 26

Oslwer-Weber-Rendu Syndrome:
Presentation

Back 26

Congenital telangectasias
Ruptures may result in epistaxis (rhinitis w/hayfever), GI bleeds, hematuria

NO CYSTS PRESENT

Front 27

von Hippel-Lindau Disease:
Presentation

Back 27

Cappilary hemangioblastomas in retina and/or cerebellum

Congenital cysts and/or neoplasms in kidney, liver, pancreas

INc'd risk RCC (b/l)

Front 28

Enlarged tongue
Jaundice
Hypotonia
Poor feeding
1 month-old

Diagnosis

Back 28

Congenital hypothyroidism

Causes severe, irreversible MR if not treated immediately (need T4 for normal brain dev't and myelination during early life)

Front 29

What are the derivates of the aortic arch?

Back 29

1st--MAXIMAL; maxillary artery

Second = Stapedial and hyoid aa

Third = C is third letter of alphabet-->Carotid artery

4th--4 limbs!--systemic circuln; on left: aortic arch, on right: proximal right subclavian artery

(there is no 5th)

6th arch: pulmonary aa and (on left only) ductus arteriosus

Front 30

Branchial arch derivates

Back 30

1-M's, T's--Mandible, malleus incus, muscles of MASTICATION, mylohyoid

2-S's--Stapes, styloid process, stylohyoid

3-Pharyngeal--stylopharyngeus

4th: cricothyroid
6th: everything in larynx except cricothyroid

Front 31

Branchial pouch derivatives

Back 31

1st: middle ear
2nd: palatine tonsil
3rd: INFERIOR PARATHY, THYMUS TOO
4th: SUPERIOR PARATHY

Note 4th ends up being more superior than 3rd!

Front 32

24-year old female
Infertile
Treated with menotropins following single injection of hCG

Explain drug MOA

Back 32

Menotropin: acts like FSH and leads to formation of dominant ovarian follicle

hCG causes an LH surge

Front 33

5 year-old
Bounding pulse over upper left sternum
Continuous murmur

Diagnosis

Back 33

PDA (CONTINUOUS MURMUR)

Front 34

When do double-stranded DNA breaks occur?

Back 34

After exposure to ionizing radiation: X-rays, gamma-rays

Front 35

Describe the events that occur following UV light damage (and subsequent repair) to skin cells.

Back 35

UV light causes thymine dimer formation

Excision of dimer and surrounding nucleotides by UV-ENDOnuclease (not exo!!)--this is accomplished by nicking strand at thymine dimer

Signals removal and replacement of DNA by POLYMERASE and LIGASE

Front 36

Anastrozole:
MOA
Use

Back 36

Used in malignant breast cancer

Prevents aromatization of Androgens to Estrogen

REMEMBER: Estrogen is the main hormone responsible for the growth and dev't of malignant breast tumors

Aromatase inhibitors suppress estrogen to postmenopausal levels.

Front 37

HER2/neu receptor type

Back 37

Tyrosine kinase

(Trastuzumab!)

Front 38

Congenital deafness due to fetal infection

Back 38

Rubella

Front 39

Congenital malformed teeth due to fetal infection

Back 39

Syphilis

Front 40

Polyarthritis
Rash that began on face and spread downward
Generalized LAD

Diagnosis

Back 40

Rubella

Front 41

Congenital rubella:
Presentation

Back 41

Sensorineural deafness
Cataracts
Cardiac Malformations (PDA)

Front 42

Describe how Fructose-2,6-bisphosphate affects glucose breakdown.

What is its effect on alanine metabolism?

Back 42

Note: Alanine is transaminated to pyruvate during gluconeogenesis!

Front 43

Describe the Calcium-related events for skeletal muscle contraction.

Back 43

Upon release from Sarcoplasmic Reticulum, calcium binds to TROPONIN C on thin filaments.

This shifts the position of TROPOMYOSIN exposing MYOSIN BINDING SITE on ACTIN filament.

Lasts only a fraciton of a second before calcium resequestered within SR by Ca2+-ATPase pump

Front 44

Label

Back 44

A) Globus Pallidus (part of basal ganglia along w/caudate and putamen)

B) Putamen
C) Internal Capsule
D) Caudate (affected in HD)
E) Amygdala (limbic system)

Front 45

What is the effect of organophosphate poisoning on muscle activity?
Pathophys of Organophosphate poisoning
Treatment

Back 45

Organophosphate poisoning irreversibly inhibits cholinesterase.


Inc'd ACh concentration in nicotinic synapses (which are also ACh dependent) leads to muscle fasciculations followed by paralysis.

Atropine will reverse muscarinic symptoms, but has no effect on NICOTINIC receptors.

Use PRALIDOXIME to reverse both muscarinig and nicotinic side effects by restoring cholinesterase from its bond with these substances.

Front 46

MHC I vs MHC II:
Present on which cells?
What does each present?

Back 46

MHC I: present on all nucleated cells; present self-antigen, tumor antigen, or cell antigen in response to viral infection

MHC II: APCs only (DC's, macs, B cells)--bacterial organisms, viral particles, freely circulating antigenic material is endocytosed and presented

Front 47

Describe the process of presenting a bacterial antigen on an APC.

Back 47

Antigen is phagocytosed and is loaded onto MHC II with ACIDIFIED ENDOSOMES.

MHC II protein-antigen complex is then expressed on cell surface for subsequent interaction with T cells

Failure to acidify lysosomes would lead to deficient expression of MHC II bound to foreign antigen and subsequent lack of interaction b/t APCs and T cells

Front 48

Which enzymes in glycolysis are unidirectional?

How is this overcome during gluconeogenesis?

Back 48

Unidirectional:
Hexokinase
PFK
Pyruvate Kinase

Enzymes are bypassed via:
Pyruvate Carboxylase (Pyruvate-->OAA)
(-->Malate to exit mitochondria)
Malate--> OAA
OAA-->Phosphoenolpyruvate via Phosphoenolpyruvate carboxykinase (PEPCK)

Then use Fructose 1,6-bisphosphatase (to bypass PFK)
Glucose-6-phosphatase (to bypass hexokinase)

Front 49

What metabolic processes provide glucose during fasting?

Back 49

Between meals: glycogenolysis (until glycogen depleted) and gluconeogenesis

After 12-18 hours of fasting (when glycogen is depleted):
Gluconeogensis (OAA-->Malate-->Phosphoenolpyruvate-->Glucose)

Front 50

What virus is polycistronic?
What structurally enables this?
What does it require?

Back 50

Echovirus mRNA is polycystronic (contains multiple genes within sema mRNA transcript) and produces polyprotein product.

For individual viral proteins to be generated, polyprotein product must be cleaved by specific viral protease.

Can do this because it's Single Stranded, Positive Sense, and Non-Segmented.

Front 51

Carvedilol:
MOA
Use

Back 51

non-specific blockage of beta-1, beta-2, alpha-1

Use in CHF

Front 52

Describe how Neisseria meningitidis gains access to the CNS.

Back 52

First colonized nasopharynx
INvades mucosa to gain access to the bloodstream
Spreads to choroid plexus through blood
Passess BBB
Initiates inflammatory response

Front 53

C3a:
Effects

Back 53

Component of complement

C3a, 4a, 5a all trigger histamine release from mast cells, resulting in vasodilation and enhanced vasc perm

Front 54

C5a:
Effects

Back 54

Vasodilation, enhanced vasc perm

Recruits and activates NEUTROPHILS

Front 55

5-HETE:
Effects
Associated enzyme

Back 55

5-Lipoxygenase

Neutrophil chemotaxis

Front 56

Leukotriene B4:
Effects
Associated enzyme

Back 56

5-lipoxygenase

Neutrophil chemotaxis

Front 57

Luekotriene C4:
Effects
Associated enzyme

Back 57

Vasoconstriction
Bronchospasm***
Inc'd vasc perm

This is true for LK-C4/D4/E4

Front 58

Lipoxin A4:
Effects
Associated Enzyme

Back 58

Vasodilation
INHIBITION of neutrophil chemotaxis
Stimulates monocyte adhesion

Made by 12-lipoxygenase

Front 59

PGI2:
Effects
Associated Enzyme

Back 59

COX1,2

PGI2 AKA PROSTACYCLIN
Vasodilation
Inhibition of PLT agg

Front 60

Thromboxane:
Effects
Associated Enzyme

Back 60

COX-1,2

Vasoconstriction (CONSTRICT)
Promotes PLT agg (PROMOTES)

Front 61

What is the laboratory cutoff for polycythemia and how would you classify it?

Back 61

Front 62

Diagnose
What is being deposited?
Pathophys

Back 62

Crescent formation consistent with Rapidly Progressive Glomerulonephritis

Slide shows deposition of fibrin

Crescents consist of proliferated glomerular parietal cells, monocytes, macs that have migrated to Bowman's space. As progresses, fibrin becomes sclerotic.

This is sign of severe renal injury. Usually leads to rapid and irreversible loss of renal function.

Front 63

Diagnose
What is being deposited?
Pathophys

Back 63

LInear deposits of C3 and IgG consistent with TYpe 1 Rapidly Progressive GN (i.e., GOODPASTURE SYNDROME)

C4 deposition is NOT found.

Front 64

Ulceration in which segment of the GI tract is LEAST associated with malignancy?

Back 64

Duodenum

Usually due to H pylori or NSAIDs

Front 65

65 year-old male
Progressive weight loss
Jaundice
Anorexia
Palpable gall bladder, non-tender

Diagnosis
Most important environmental risk factor

Back 65

JAUNDICE AND NONTENDER GALLBLADDER IS PANCREATIC CARCINOMA!!!!!!!!!!!!!!

Biggest environmental risk factor is smoking

Front 66

When is general anesthesia achieved?
How is potency of anesthetic defined?

Back 66

General anesthesia achieved when threshold amount of anesthetic accumulates in brain

Potency determined by minimal dose to depress CNS; when brain saturated with anesthetic, partial pressure of gas in brain = partial pressure in other compartments. So use alveolar concentration.

Minimal alveolar concentration is used to measure potency: it refers to concentration of inhaled anesthetic that renders 50% of pts unresponsive to painful stimuli.

Lower MAC-->more potent anesthetic

Front 67

What properties of anesthetics give it a slow onset of action?

Back 67

High blood/gas partition means highly soluble in blood-->slow onset

High blood/lipid partition-->high solubility in tissues-->slow onset of action

Front 68

Episodic HTN

Back 68

Pheochromocytoma

Front 69

Vitiligo:
Pathophys

Back 69

Some sort of autoimmune activity (not really known) leads to COMPLETE LOSS OF EPIDERMAL MELANOCYTES

Front 70

Wilson's Disease:
Treatment

Back 70

Penicillamine (Cu chelator)

Front 71

Lead poisoning:
Treatment

Back 71

Dimercaprol and EDTA (chelators for lead)

Front 72

Hemochromatosis:
Chelating Treatment

Back 72

Deferoxamine (BRONZE DIABETES)

Front 73

Child suddenly dies
Erythroid precursor cells found in liver and spleen

Diagnosis
Pathophys

Back 73

Extramedullary hematopoiesis likely caused by severe chronic hemolytic anemia, such as beta-thalassemia

Front 74

What is the effect of beta-blockers on EKG waveforms? Why?

Back 74

Beta-blockers slow AV conduction and will increase the PR interval.

Remember:
PR interval is the period of time from beginning of atrial depolarization to the beginning of ventricular depolarization. The longer the PR interval, the longer it takes for an electrical stimulus to travel from the SA node to the ventricles via the AV node, bundle of His, and fascicles.

Front 75

What EKG abnormality is associated with increased risk for Torsade de pointes?

What drugs cause this abnormality?

Back 75

Long QT; quinidine, sotalol most frequently associated with long QT