the blood-brain barrier is effective against, what
The blood-brain barrier is a selectively permeable membrane that separates the bloodstream from the brain and spinal cord. It is highly effective in protecting the brain from various substances that may be present in the bloodstream. Here are some examples of what the blood-brain barrier is effective against:
1. Pathogens: The blood-brain barrier prevents the entry of most bacteria, viruses, and fungi into the brain. This helps protect the central nervous system from infections.
2. Toxins: The blood-brain barrier blocks the passage of many harmful substances, such as certain drugs, toxins, and heavy metals, from reaching the brain. This reduces the risk of neurotoxicity and damage to the delicate neural tissue.
3. Large molecules: The blood-brain barrier limits the entry of large molecules, including proteins and antibodies, into the brain. This selective permeability helps maintain the proper balance of substances within the brain's environment.
4. Most water-soluble substances: The blood-brain barrier is effective at preventing the movement of water-soluble substances between the bloodstream and the brain. This characteristic ensures the maintenance of a stable internal environment, known as homeostasis, within the brain.
To determine the specific substances the blood-brain barrier is effective against, scientists and researchers employ various techniques, including in vitro studies, animal models, and imaging techniques. These methods allow them to test the permeability and selectivity of the blood-brain barrier for specific substances or identify drugs that can bypass the barrier for therapeutic purposes.
The blood-brain barrier (BBB) is a specialized barrier that separates circulating blood from the brain and protects it by controlling and restricting the entry of substances into the brain tissue. The BBB is effective against various substances, including:
1. Large molecules: Molecules that are too large to pass through the BBB, such as most proteins, are prevented from entering the brain.
2. Microorganisms: The BBB acts as a defense mechanism against pathogens, preventing bacteria, viruses, and other microorganisms from invading the brain.
3. Toxins: Many toxins, such as certain drugs or environmental chemicals, are unable to cross the BBB, limiting their potential harm to the brain.
4. Foreign substances: Substances that are foreign to the brain, such as certain chemicals or foreign particles, are restricted from entering the brain tissue.
5. Neurotransmitters regulation: The BBB plays a role in regulating the transport of neurotransmitters, maintaining the delicate balance of chemical signaling within the brain.
It is important to note that while the BBB is effective against many substances, it is not impermeable and certain molecules, drugs, and diseases can bypass or alter the barrier's integrity.
Bacteria and large hydrophilic molecules.
See:
http://en.wikipedia.org/wiki/Blood-brain_barrier