Toxic substances in the blood are detected at the ______ which in ...

[geoffrey]

Toxic substances in the blood are detected at the ______ which in turn triggers vomiting.
 
  A) cerebellum
  B) blood-brain barrier
  C) hypothamus
  D) amygdala
  E) area postrema

Question 2

The presence of a barrier between the blood stream and the brain is suggested by the observation that
 
  A) all cells of the body are stained by a dye injected into the bloodstream.
  B) injection of dye into the bloodstream stains all cells but those of the brain and spinal cord.
  C) the gut is stained by a dye injected into the brain ventricles.
  D) injection of dye into the ventricles stains all cells of the body.
  E) most chemicals rapidly reach the brain after oral ingestion..

[Carissamariew]

Answer to Question 1

Answer: E

Answer to Question 2

Answer: B
Rationale: The presence of a barrier between the blood stream and the brain is suggested by the observation that injection of dye into the bloodstream stains all cells but those of the brain and spinal cord.