72. BLOOD BRAIN BARRIER Flashcards
What is the blood-brain barrier (BBB)?
The blood-brain barrier (BBB) is a selective permeability barrier that protects the brain against harmful agents and pathogens while allowing necessary nutrients to pass through.
What forms the blood-brain barrier?
The BBB is formed by the blood-brain vessel endothelial cells, which are held together tightly by tight junctions that restrict the passage of large molecules and pathogens.
What role do astrocitic end-feet play in the BBB?
Astrocitic end-feet cover the blood vessels, playing a supporting role in maintaining the integrity of the BBB.
What molecules can the BBB allow through?
The BBB allows required molecules like glucose, oxygen, and amino acids to pass.
What does the BBB block?
The BBB blocks larger or harmful agents like bacteria and toxins.
Where is the BBB less developed in the brain?
The BBB is less developed in certain areas of the brain, such as the area postrema, which allows for the detection of toxins.
What happens to the BBB during inflammation?
Inflammation (e.g., during meningitis or encephalitis) can damage the BBB, allowing pathogens or immune cells to infiltrate the brain.
What challenge does the BBB pose for drug delivery?
The BBB poses a significant challenge to drug delivery for neurologic conditions, such as Parkinson’s disease or Alzheimer’s disease, and specialized techniques are typically used to bypass it for drug delivery.
