Random USMLE Facts volume 6-6

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

Random USMLE Facts volume 6-6:

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

What histological changes take place after ischemic neuronal injury?

• 12-48 hours: "red neurons."
• 24-72 hours: necrosis and neutrophilic infiltration.
• 3-5 days: macrophage infiltration and phagocytosis.
• 1-2 weeks: reactive gliosis; liquefactive necrosis.
• More than 2 weeks: glial scar.

Which anticancer drug causes tingling?

Vincristine.

What are metanephrines?

Metanephrines are catecholamine metabolites - released in pheochromocytoma.

What do neural crest cells that migrate to the intestine give rise to?

Neural crest cells that migrate to the intestine give rise to ganglion cells of the submucosal (Meissner) and myenteric (Auerbach) plexi of the bowel wall. This migration is interrupted in Hirschsprung disease and the rectum is mostly affected. Infants with Hirschsprung disease display bilious vomiting and abdominal distention.

What are some findings in polymyalgia rheumatica?

Bilateral stiffness of the shoulder and pelvic girdle muscles, fever, weight loss, and increased ESR.

What are some findings in polymyositis?

Symmetric proximal muscle weakness; inflammation, necrosis and regeneration of muscle fibers. Furthermore, there is overexpression of MHC class I proteins on the sarcolemma leading to infiltration with CD8+ T lymphocytes and myocyte damage.

What molecular event takes place in hypersensitivity type I reaction (anaphylaxis)?

Cell surface-bound IgE bridging by antigen.

PABA-containing sun screens protect against what radiation?

UV-B radiation.

Avobenzone protects against what radiation?

UV-AI and UV-AII.

Zinc oxide-containing sunscreens protect against what radiation?

UV-B, UV-AI and UV-AII.

What is the blood supply of the stomach?

• Proximal lesser curvature: left gastric artery.
• Distal lesser curvature: right gastric artery.
• Proximal greater curvature: left gastroepipolic artery.
• Distal greater curvature: right gastroepiploic artery.
• Proximal greater curvature above splenic artery: short gastric arteries.

What is IGF-1?

Insulin-like growth factor released mainly from the liver, and also from the hypothalamus in response to growth hormone (GH).

Where is the loudest heart sound heart in aortic stenosis?

Right after the aortic valve opens.

What is the relation between blood oxygen content and vascular resistance in the lungs?

Arterial/arteriolar resistance increases as blood oxygen content decreases. This ensures blood flow from under-ventilated regions to well-ventilated regions.

What are some findings in leukemia?

See: Notes on White Blood Cell Disorders

During losartan administration, what happens to bradykinin values?

No change. It should be noted that losartan binds to angiotensin 1 receptors. Because losartan doesn't affect ACE activity, ACE can continue inhibit bradykinin levels. "Brad hates going to ACE hardware."

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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