UWorld_1.16

Question 1

Rheumatoid factor?

Answer 1

IgM antibody specific for F_c portion of IgG

Question 2

Mechanism of RA

Answer 2

• Anti-IgG (IgM) Abs bind IgG ==> immune complex formation
• immune complexes ==> deposition @ synovium of joints
• ==> phalangeal joint deformities + deposition @ elbows and lumbosacral ares

Question 3

Thiamine (Vit B₁) deficiency ==>

Answer 3

• Wet beriberi ==> neuropathy + cardiac involvement usually ==> CHF
• Dry beriberi ==> symmetrical peripheral neuropathy @ distal extremities
• Wernicke-Korsacoff ==> confusion, encephalopathy @ alcoholics

Question 4

What causes naseau following chemo?

Answer 4

• trigger of chemoreceptor trigger zone (CTZ)
• location = dorsal medulla @ just below level of 4th ventricle in region called “area postrema”

Question 5

Fxn/stimulus of ventromedial hypothalamic nucleus

Answer 5

• mediates satiety
  
  • destruction ==> hyperphagia
• stimulated by leptin

Question 6

Fxn/stimulus of lateral hypothalamic nucleus

Answer 6

• mediates hunger
  
  • destruction ==> anorexia
• inhibited by leptin

Question 7

Fxn of anterior hypothalamic nucleus

Answer 7

• mediates heat dissipation via parasympathetics
  
  • destruction ==> hyperthermia

Question 8

Fxn of posterior hypothalamic nucleus

Answer 8

• mediates heat conservation via sympathetics
  
  • destruction ==> hypothermia

Question 9

Fxn of arcuate hypothalamic nucleus

Answer 9

• secretion of hormones:
  
  • dopamine (inhibits prolactin)
  • GHRH
  • GnRH

Question 10

Fxn of paraventricular hypothalamic nucleus

Answer 10

• secretion of hormones:
  
  • ADH
  • CRH
  • Oxytocin
  • thyrotropin-releasing hormone

Question 11

Fxn of supraoptic hypothalamic nucleus

Answer 11

• secretion of hormones:
  
  • oxytocin
  • ADH

Question 12

Fxn of suprachiasmatic hypothalamic nucleus

Answer 12

• circadian rhythm
• pineal gland fxn