THE BBB...
The blood-brain barrier is a semi-permeable wall, that runs along the sides of the blood vessels in the brain, in the sense that it allows some materials to cross such as oxygen and carbon dioxide and keeps harmful ones away. You can think of it as your personal Border Customs Agent telling you what you can and cannot pass through the "border" (aka brain).
The BBB works by tightly joining endothelial cells to one another so almost nothing can get through. There are several molecules and chemicals that can pass through.
- Small uncharged molecules
- These include the essential elements, oxygen and carbon dioxide. Water is able to cross through the walls of the endothelial cells that make up the BBB through protein channels.
- Lipid soluble molecules
- This refers to the molecules that are able to dissolved in fats such as Vitamins A and D as well as psychoactive drugs. Ex., antidepressants, sleeping aids, and even drugs like heroin.
- Some chemicals
- These are transported to the brain by active transport and include chemicals such as glucose (fuel), certain hormones, and amino acids among a few others.
The BBB is needed to keep the brain protected from harmful and toxic substances that can cause damage. Since neurons are hardly ever repaired or replaced the brain needs a "gatekeeper" controlling the entrance to viruses, harmful chemicals, and bacteria.
THE BBB AND HEROIN
Heroin crosses through the blood brain barrier approximately 100 times faster than morphine! The reason is because it is highly soluble in lipids and therefore passes easily as mentioned above. As it passes through the BBB it is turned into morphine and the user then feels this intense "euphoric" feeling pass through them. A heroin overdose is caused by the chemicals in the drug altering the brain's neurons oppositely. What do I mean by oppositely? Although you may know it is wrong and your brain is "telling" you not to do it, the pleasure centers in your body are telling you "YES!!" With each use tolerance builds and leads the user to need more. Excess use of heroin stops many automatic process including breathing and beating (heart) which eventually may lead to death.
Below is a video describing the death of the actor, Philip Seymour Hoffman as explained by a drug addiction expert.
Hopefully I have enlightened you, dear reader, on the blood-brain barrier and how important it is for our health.
References
Kalat, James. Biological Psychology:Eleventh Edition
http://news.nationalgeographic.com/news/2014/02/140204-philip-seymour-hoffman-actor-heroin-overdose/
http://www.howitworksdaily.com/science/the-blood-brain-barrier-explained/
http://faculty.washington.edu/chudler/hero.html
Hello Alejandra. You have definitely enlightened me with your post. It is amazing how fast heroin can pass thorough the blood brain barrier. If heroin is much faster than morphine, imagine the damage it can make? In the short clip it is mentioned that heroin is a very dangerous and addicting drug. It is also one of the most powerful drugs that cause euphoria. Euphoria is the feeling of excitement, happiness, and well-being. Once an individual gets hooked on it, they want to continue to feel that feeling and it becomes very hard to control. I think that we need to get this information out there. Let people know how dangerous it is to do heroin or any type of drug. The consequences of doing drugs are devastating and sometimes even fatal.
ReplyDeleteI enjoyed reading this blog, I liked how you incorporated Philip Seymour and how his tragic death relates to the topic. I liked how you explained BBB, by stating, "The blood-brain barrier is a semi-permeable wall, that runs along the sides of the blood vessels in the brain, in the sense that it allows some materials to cross such as oxygen and carbon dioxide and keeps harmful ones away. You can think of it as your personal Border Customs Agent telling you what you can and cannot pass through the "border" (aka brain)." and how you further shows what is does.
ReplyDeleteI really liked how you used relevant examples in order to make your topic much more real. I liked phillip seymour hoffman as an actor, so I enjoyed how you used him to tie into your subtopic of heroin and how it is so destructive because of its permeability in regards to the blood brain barrier. Overall a very good read, really informative!
ReplyDeleteHey!
ReplyDeleteI love how you made your post not only informative but kept it interesting as well. I'm actually a visual learner so the fact that you added the video and the images, really helps me understand those concepts a lot better. I think that we all know that any sort of drugs are bad for us (In this case you talked about heroin) but it isn't until you learn exactly what makes it so dangerous to our body that you see the reality of things.