Random USMLE Facts volume 1-6

Rahul's Noteblog Notes on USMLE facts, Exam Tips, and USMLE Lab Values Random USMLE Facts volume 1-6

Random USMLE Facts volume 1-6:

USMLE Facts 1	USMLE Facts 2	USMLE Facts 3	USMLE Facts 4	USMLE Facts 5
USMLE Facts 6	USMLE Facts 7	USMLE Facts 8	USMLE Facts 9	USMLE Facts 10

Under normal circumstances, pO₂ of inspired air is 160 mmHg. However, this value decreases to 150 mmHg in trachea. Why?

This happens due to the additional partial pressure of water vapor in the area. After inspired air enters the alveoli, pO₂ drops and pCO₂ rises. Thus, alveolar air reaches a state of equilibrium with pO₂ and pCO₂ values in the blood. The faster the speed of blood flow in capillaries, the faster the rate of equilibrium. The rate of diffusion of O₂ and CO₂ across the alveolar membrane is perfusion limited. Thus, if there is decreased perfusion (blood flow), equilibrium may occur slowly or not at all.

Which anti-arrhythmic drug causes mild bradycardia and QT prolongation on EKG recording? And why?

Sotalol, because it is the only class 3 anti-arrhythmic drug with beta-adrenergic blocking abilities and class 3 effects (prolongation of QT interval).

What happens do the brain during COPD?

Hypercapnia (high pCO₂) occurs during COPD. Hypercapnia causes cerebral vasodilatation via a decrease in cerebral vascular resistance.

For some drugs, why is rectal administration more effective than oral administration?

Because rectal administration bypasses the first-pass metabolism. There is more drug in the blood, and more blood flows to the liver.

What happens during Mullerian agenesis?

Fully developed secondary sexual characteristics with a shortened vaginal canal and rudimentary uterus.

How can reoccurrence of genital herpes be prevented?

Daily oral valacyclovir, acyclovir, or famciclovir after first episode.

Explain a Monospot test? What is it used to identify?

If the patient's serum fails to agglutinate sheep erythrocytes, the monospot test is negative. Monospot tests are used to identify CMV, HHV-6, and toxoplasmosis.

What do neutrophils do during ascending urinary tract infection?

Infiltrate the renal interstitium.

What is isotretinoin used for? What test must be performed before isotretinoin administration?

Treatment of acne. Perform serum beta-HCG level test (pregnancy test).

What type of vaccination is used against B. pertussis and V. cholera?

Heat-killed vaccination.

What type of vaccination is used against B. burgdorferi?

Recombinant bacterial outer surface protein vaccination.

What type of vaccination is used against C. diphtheria and C. tetani?

Inactivated toxoid vaccination

What type of vaccination is BCG?

Live-attenuated organisms.

What happens to T lymphocytes when lymphocytes isolated show mutated and functionally defective FAS gene product? In what autoimmune disorder is mutated FAS seen in?

Clonal deletion of activated T lymphocytes. Mutated FAS is seen in SLE.

What should be administered during adrenal crisis?

Corticosteroids.

What is bronchiolitis obliterans?

Disease caused due to chronic rejection of a lung transplant.

Give examples of ergot compounds and name a few side-effects following their usage:

Bromocriptine and pergolide; they can cause Raynaud phenomenon, erythromelalgia, and retroperitoneal or pulmonary fibrosis. These may be used to treat Parkinson's disease.

USMLE Facts 1	USMLE Facts 2	USMLE Facts 3	USMLE Facts 4	USMLE Facts 5
USMLE Facts 6	USMLE Facts 7	USMLE Facts 8	USMLE Facts 9	USMLE Facts 10

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