The Presence of a Barrier Between the Blood Stream and the Brain

question 93

Multiple Choice

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..

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Definitions:

Catalyzed

A process in which the rate of a chemical reaction is increased by the presence of a catalyst, which remains unchanged by the reaction.

Heterogeneously Catalyzed

A reaction process aided by a catalyst that exists in a different phase than the reactants, usually solids catalyzing reactions in liquids or gases.

Solid Catalyst

A solid catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process, and it maintains its solid physical state during the reaction.

Reactants

Starting materials in a chemical reaction, which are expended in the creation of the final substances.