UWorld_2.13

Question 1

Support/anchoring for actin filaments in muscle sarcomere

Answer 1

• Z-line
  
  • lies in center of “lucent” I band

Question 2

Characteristics of craniopharyngioma

Answer 2

• calcified cystic tumors
• arise from remnants of Rathke’s pouch (<== embryonic precursor of anterior pituitary)
• common present
  
  • H/A
  • growth failure
  • bitemporal hemianopsion=

Question 3

Presentation of congenital hypothyroidism

Answer 3

• hypotonia
• “hoarse cry” @ birth
• poor feeding
• jaundice
• macroglossia
• constipation and umbilical hernia
• increased incidence of heart defects: ASD, VSD

Question 4

Common nerve block during childbirth + anotomic placement

Answer 4

• pudendal nerve block <== often used if woman has progressed too far in labor to receive epidural anesthesia
  
  • pudendal = S2-S4
  • sensory info from perineum and genitals + motor innervation of spincter urethrae and external anal sphincter
• administration
  
  • palapte ischial spines intravaginally
  • administer anesthetic @ that region

Question 5

Nerves that innervate periuneum/genitals

Answer 5

• pudendal
• genitofemoral
• ilioinguinal

Question 6

Endorphins/opiods molecular precursor and related molecules

Answer 6

• proopiomelanocortin (POMC) ==>
  
  • beta-endorphins (opiods)
  • ACTH
  • MSH (melanocyte-stimulating hormone)

Question 7

Toxins produced by Bordetella pertussis

Answer 7

• pertussis toxin = disinhibits adenylate cyclase through G_i ADP-ribosylations
  
  • ==> increased cAMP levels ==> edema and phagocyte dysfxn
• adenylate cyclase toxin = acts as adenylate cyclase
  
  • ==> increased cAMP levels ==> edema and phagocyte dysfxn