The Filtering System That Prevents Most Substances from Reaching the Brain

question 19

Multiple Choice

The filtering system that prevents most substances from reaching the brain is called the:

• A) glial-brain barrier
• B) blood sheathing system
• C) blood-brain barrier
• D) mescaline-brain filter

---

Definitions:

Hydrophobic

Hydrophobic describes molecules or substances that repel water, unable to mix or dissolve in it, often because of nonpolar characteristics.

RNA Transcription

The process by which DNA is copied into messenger RNA (mRNA) in the cell nucleus, serving as a template for protein synthesis.

Thymine

One of the four nucleobases in the DNA molecule, paired with adenine in DNA strands.

Uracil

A nitrogenous base found in RNA that pairs with adenine and replaces thymine during DNA transcription.