Blood Brain Barrier- Layers of the protection for the brain

What is the primary function of the Blood-Brain Barrier (BBB)?

The BBB maintains a constant internal environment for the brain by regulating what substances can enter from the blood.

Why is the Blood-Brain Barrier important for neurons?

It protects neurons by separating them from harmful blood-borne substances.

How permeable are the brain's capillaries compared to the rest of the body?

They are the least permeable capillaries in the body, restricting most substances from entering the brain.

What type of cellular structures contribute to the BBB's restricted permeability?

Tight junctions in the capillary walls prevent most substances from passing between cells.

What essential substances are allowed to pass through the Blood-Brain Barrier?

Water, glucose, and essential amino acids.

Why does the brain need glucose, and why can it pass through the BBB?

Glucose is the main energy source for brain cells, and it passes through because the BBB selectively allows it.

How does water enter the brain despite the Blood-Brain Barrier?

Water is allowed through the BBB to maintain hydration and cellular function in the brain.

Why are essential amino acids allowed through the Blood-Brain Barrier?

Essential amino acids are needed for protein synthesis and brain cell function, so they are selectively allowed through the BBB.

What types of substances does the Blood-Brain Barrier (BBB) prevent from entering brain tissue?

Metabolic waste and most drugs.

What property of brain capillaries is primarily responsible for the protection provided by the BBB?

The impermeability of brain capillaries.

Which types of molecules can easily diffuse through the Blood-Brain Barrier despite its selectivity?

Fats, gases, and other fat-soluble molecules.

Name three substances that are able to pass through the Blood-Brain Barrier.

Alcohol, nicotine, and anesthetics.

Why is the Blood-Brain Barrier unable to block fat-soluble molecules?

Fat-soluble molecules can diffuse through all plasma membranes, including those in the BBB.

How does the Blood-Brain Barrier affect drug delivery to the brain?

Most drugs are blocked from entering brain tissue, making drug delivery to the brain more challenging.

What role does the impermeability of brain capillaries play in the Blood-Brain Barrier?

It prevents many harmful substances, like metabolic waste, from reaching brain tissue.