Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Review / Wrong Answers > 5/19 UWorld > Flashcards

5/19 UWorld Flashcards

1
Q

Describe how ethylene glycol affects the kidneys

A
  • Ethylene glycol (anti-freeze) is absorbed from the GI tract and metabolized into glycolic acid (toxic to renal tubules - acute tubular necrosis) and oxalic acid (calcium oxalate cyrstals)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the function of the protein produced by Staph Aureus

A

Protein A is a component of Staph cell wall

It binds antibodies at Fc region, preventing complement from binding, and thus preventing opsinization and phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the defect causing mitochondrial myopathy

A

o Maternal inheritance only from mitochondrial DNA

o Without properly functioning mitochondria, cells cannot use oxidative phosphorylation to produce ATP

o Brain and skeletal muscle will be affected first due to high metabolic demand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Classic presentation and hallmark finding in mitochondrial myopathy

A

o Presentation:

§ Myopathy (muscle weakness, myalgia)

§ Lactic acidosis (due to impaired aerobic glycolysis)

§ Nervous system dysfunction (neuropathy, seizures)

§ ***Muscle biopsy shows ragged red fibers (due to accumulation of diseased mitochondria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the funciton of IFN-a and IFN-b

A
  • Secreted by virally-infected cells
  • Act locally on uninfected cells to prime them for viral defense
  • Bind to receptors in infected and neighboring cells, causing transcription of antiviral enzymes capable of halting protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe how the enzymes transcribed by IFN-a and IFN-b to halt protein transcription only work on infected cells and not uninfected cells

A

These enzymes are only active in the presence of double stranded RNA, which forms in infected cells as a result of viral replication

So normal protein synthesis can still occur in uninfected cells and is selectively inhibited in virally infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the MOA of statins

A
  • Statins inhibit HMG CoA reductase, and thus prevent endogenous cholesterol production
  • In response to decreased hepatic cholesterol synthesis, hepatocytes will increase LDL receptor expression on their surface, thus clearing LDL from circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

MOA of Cholestyramine

A

Sketchy - Cho”lobster”amine

  • Is a bile acid resin that bind bile acids in the intestinal lumen and prevent recycling of bile acids back to the liver
  • The bind to bile acids and then bring them to the colon to be excreted
  • Because there is a decrease in bile acids, the liver must promote synthesis of new bile acids (derived from cholesterol), depleting the liver cholesterol stores
  • Liver will compensate by upregulating expression of LDL receptors, thus drawing LDL out of circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

MOA of Ezetimibe

A

Sketchy = Z-shaped eel

Binds cholesterol in the GI tract, preventing their absorption (vs. Cholestyramine which binds bile acids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

MOA of fibrates

A

Sketchy = Gemfibrozil jellyfish

  • Decreases serum VLDL (35-50%) and decreased triglycerides by activating PPAR-alpha at liver and peripheral tissues
  • When activated, PPAR-alpha upregulates LPL at extra-hepatic sites
  • This means increased hydrolysis of chylomicron and VLDL TG’s at peripheral tissues – aka decreased serum TGs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

MOA of niacin

A

Sketchy = Lock Niacin monster

  • Mechanism of action:
    • Unknown
    • Raises HDL (30%)
      • Most effective drug for increasing serum HDL
      • Decreases HDL cholesterol transfer and delaying HDL clearance
    • Decreases VLDL, and thus decreased TG
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

MOA of fish oil

A
  • Lowers TG by decreasing production of VLDL and Apo-B
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  • What is the drug of choice for anaerobic bacteria above the diaphragm vs. below the diaphragm
A
  • Above = Clindamycin
  • Below = Metronidazole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are Nissl substances and where are they found

A

Nissl substances are found within RER of neurons

Seen in cell bodies and dendrites

Not in axons - axons do not contain RER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the histopathologic changes seen in acute neuronal injury (red neuron)

A
  • Due to transient severe insult that leads to cell death
  • Histopathologic changes:
    • Shrinkage of cell body
    • Pyknosis of the nucleus
    • Loss of Nissl substance
    • Eosinophilic cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the histopathologic changes seen in axonal regeneration

A
  • Enlargement of cell body
  • Eccentric nucleus
  • Enlargement of the nucleolus
  • Dispersion of Nissl substance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the histopatholic changes seen in neuronal atrophy

A
  • Due to progressive degenerative disease
  • Histopathologic changes:
    • Loss of neurons and functional groups of neurons
    • Reactive gliosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Review rule of 4’s

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the cause and effect of reperfusion injury

A
  • Occurs when blood flow is returned to an ischemic area, causing increased killing of cells
  • Due to:
    • Oxygen free radical generation
    • Severe, irreversible mitochondrial damage described as “mitochondrial permeability transition”
    • Inflammation, which attracts neutrophils that cause additional injury
    • Activation of complement pathway
  • Leads to cell membrane damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a common cause of isolated systolic HTN

A

Age-related increased arterial stiffening leading to decreased compliance of aorta and other major arteries

21
Q

What apolipoprotein increases risk for Alzheimer’s and which decreases risk

A

ApoE2 decreases risk

ApoE4 increases risk

22
Q

In what tumor do you see pseudopallisading cell arrangement

A

Glioblastoma multiforme

Tumor surrounding central necrosis

THINK:

  • Pseudopallisading looks like a star = astrocyte
  • Central area is necrotic/dead so this must be an old people tumor – astocyte tumor of adults = glioblastoma multiforme
23
Q

What CNS tumor do you see fried egg apperance?

A

Oligendroglioma

24
Q

What CNS tumor do you see Rosenthal fibers?

A

Pilocytic astrocytoma

Rosenthal fibers = eosinophilic corkscrew fibers

THINK: Chris Rossman putting the star (astrocytes) on the top of a child’s (tumor of children) christmas tree, so it has a swirly base (corkscrew fibers)

25
Q

What CNS tumor do you see Homer Wright rosettes

A

Medulloblastoma

Homer Wright rosettes (small blue cells wraped around pink areas of neuritic processses)

  • THINK: Homer Simpson is dumb like a kid (tumor of children); it seems like he lost actual brain cell, neurons (tumor of neurons)
26
Q

In what CNS tumor do you see perivascular pseudorosettes?

A

Ependymoma

Perivascular pseudorosettes - tumor cells surrounding vessel

THINK: Ependymoma = tumor surrounding ventricles; ventricles are open spaces containing body fluids; pseudorosettes is surrounding a vessel which contains body fluids

27
Q

Describe the pathophysiology of exophthalmos in Graves disease

A
  • Lymphocytes infiltrate the orbital tissues and secrete cytokines that stimulate fibroblasts to secrete increasing amounts of glycosaminoglycan ground substance such as hyaluronic acid. This increased hyaluronic acid draws water into the orbit resulting in extraocular muscle edema. Combined with interstitial edema, this process pushes the globe outward (proptosis). A sensation of grittiness and excessive tearing occur because the lids are now unable to completely cover the proptotic globe. Desiccation and keratitis may result
28
Q

What is the treatment for exophthalmos in Graves disease

A
  • Treated with glucocorticoids
  • Antithyroid drugs to do not have a direct effect on ophthalmopathy
29
Q

What are the most common viral causes of meningitis

A
  • Enterovirus (most common) – Coxsackievirus, Echovirus, Poliovirus
  • Arbovirus
  • Herpes simplex virus type 2
30
Q

What are the most common bacterial causes of meningitis

A
  • Adults:
    • Strep pneumoniae
    • Neisseria meningitides
  • Neonates:
    • Group B strep
    • Gram negative bacilli
31
Q

Differentiate between CSF in bacterial vs. viral meningitis (glucose, protein, WBC)

A
  • Viral:
    • WBC < 500
    • Lymphocytic predominance
    • Glucose normal or slightly slow
    • Protein < 150 (less elevated that in bacterial)
    • No organisms on gram stain and culture
  • Bacterial:
    • WBC > 1000
    • Neutrophlic predominance
    • Glucose < 46
    • Protein > 250
    • Gram stain positive
32
Q

What characteristic of viruses allows them to undergo rapid genetic shift?

A

Segmentation

33
Q

What are the segmented viruses?

A
  • There are 4 segmented viruses - BOAR
    • Bunyavirus (3 segments)
    • Orthomyxo (8 segments)
    • Arenavirus (2 segments)
    • Rheovirus (11 segments)
34
Q

What are the watershed areas of the colon

A

Splenic flexure (b/w SMA and IMA)

Rectosigmoid junction (b/w sigmoid artery and superior rectal)

35
Q

Describe the pathway (enzymes and substrates) of catecholamine synthesis

A
36
Q

What part of the catecholamine synthesis pathway is affected by cortisol?

A

Norepinephrine to Epinephrine via Phenylethanolamine-N-methyltransferase (PNMT)

37
Q

How does pregnancy effect levels of thyroid hormone

A

Pregnancy cause increased thryoxine-binding globulin (TBG) –> high total thyroid hormone levels but low free hormone

Patient will be euthyroid with normal TSH

38
Q

What are the cartilage, muscle, and nerve derivates of the branchial arches?

A
  • 1st arch
    • Cartilage:
      • Maxillary process, mandibular process, incus, malleus
    • Muscles:
      • Muscles of mastication, mylohyoid, tensor tympani, tensor veli palatine
    • Nerves:
      • CN V2 and V3
  • 2nd arch
    • Cartilage:
      • Stapes, styloid, stylohyoid
    • Muscles:
      • Muscles of facial expression
      • Stapedius, stylohyoid
    • Nerves:
      • CN VII
  • 3rd arch
    • Cartilage:
      • Greater horn of hyoid
    • Muscles:
      • Stylopharyngeus
    • Nerves:
      • CN IX
  • 4th-6th
    • Cartilage
      • Arytenoids, cricoid, thyroid
    • Muscles:
      • 4th à Cricothyroid, most pharyngeal constrictors, levator veli palatini
      • 6th à All laryngeal muscles except cricothyroid
    • Nerves:
      • 4th à CN X superior laryngeal branch (swallowing)
      • 6th à CN X recurrent laryngeal branch (speaking)
39
Q

What is the difference between proteins produced by free ribosomes vs. proteins produced by ribosomes attached to RER

A

Free ribosomes - translate proteins found in the cytosol

Attached ribosomes - translate proteins meant for the cell membrane and meant to be excreted into extracellular space

40
Q

What medication can be used for acute treatment of agitation and psychosis associated with delirium

A

Haloperidol

41
Q

What is the cause of “wet, wacky, wobbly”

A
  • Normal pressure hydrocephalus
    • Ventricular dilation with normal ICP
    • Occurs in the elderly
    • Triad - “Wet, wacky, wobbly”
      • Urinary incontinence - wet
      • Dementia - wacky
      • Ataxia - wobbly
        • Magnetic gait – feet appear stuck on floor
42
Q

What are the complications/presentation seen in congenital hydrocephalus

A
  • Macrocephaly
  • Bulging fontanelle
  • Poor feeding
  • Developmental delay
  • Spasticity and hyperreflexia (due to UMN injury caused by stretching of periventricular pyramidal tracts)
  • Seizures
43
Q

What antibody will differ the most between patients given IM inactivated polio vaccine vs. oral live attenuated polio vaccine

A

Duodenal luminal IgA (aka mucosal IgA)

44
Q

Presentation of serotonin syndrome

A

§ Autonomic instability (hyperthermia, hypertension, tachycardia)

§ Altered mental status (agitation, confusion)

§ Neuromuscular irritability (tremor, hyperreflexia, myoclonus)

§ GI symptoms

45
Q

Antibiotic associated with serotonin syndrome

A

Linezolid

MOA - inihibits 50S ribosomal subunit

Also has MAOI action

46
Q

Lesions to what brain lobe affect personality?

A

Frontal lobe

47
Q

Differences between lesions in the right vs. left frontal lobe

A
  • Frontal lobe
    • Deficits in executive functioning, concentration, orientation, judgment, personality
    • Left sided lesions – associated with apathy and depression
    • Right sided lesions – associated with disinhibited behavior
48
Q

Lesion to what brain lobe will cause hemispatial neglect?

A

Non-dominant parietal cortex (usually R-side)

49
Q

What are the effects of a lesion to the dominant parietal lobe?

A
  • Gerstmann syndrome = agraphia (inability to write), acalculia (inability to calculate), finger agnosia (inability to distinguish fingers), left-right disorientation

Review / Wrong Answers (140 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions