Human Brain and Behaviour
24 September, 2012
- The kind of things that go wrong in the brain
- Vascular supply of the brain; you can get a blockage of the vascular supply or blood flow
- There is various things that can cause a blockage
- First type is cerebral vascular accident. Something has happened in the blood supply of the
brain. We refer to this as a stroke or CVA. This generally refers to a severe interruption of the
blood supply to the brain. When you lose blood supply it results ischemia. Ischemia simply says
that the brain is not receiving enough oxygen and glucose. The lack of oxygen is the result of a
stroke, the blockage of blood. If it is severe enough it then leads to an infarct. It is an area of the
brain that is dying or pretty much dead. A CVA can be slow or fast, but in the vast majority it
happens fast. The larger the artery is blocked the larger the area is destroyed.
- The second type encephalo malacia, refers to the situation where the blood supply lost happens
very slowly. It can happen over years, and results in the softening of tissue. It is like a delicate
fruit, like a banana where it gets brown for a few days, but its not really dead in the inside.
- The Third kind of problem is transient ischemic attack. This is temporary, very short lived. It is
not permanent, can be here for minutes and hours and then gone. Its most often seen in things
like migraine headaches. You get a constriction of the muscles and blood vessels. The brain
doesn’t die or anything but its is not getting enough oxygen or glucose to focus properly. Most
occurs in vision.
What actually causes these things? (What causes a stroke?)
- Thrombosis- it is a locally formed acclusion (blockage). Right where it is that is where it is
formed. It is a bloodclots in the brain. When people are sentery and not moving it can form a lot
of clots. If you are older this is more likely to occur if you are travelling for a long period of time,
this can create clots.
- Embolism- is a blockage that is formed elsewhere in the body, breaks off from there migrates
and floats around the arteries and then stops in the brain. If this lodges in the brain
- Oterios Glorosis- it is a cholesterol build up that slowly closes the arteries.
The next major thing that can happen in the brain, is intead of being blocked it can burst
- Cerebral Hemridge- it is a massive bleeding, when a blood vessel burst and theres a massive
bleeding in the brain itself. It depends on where it occurs and to what part of the brain to
determine whether it is fatal. It refers to a bleeding inside the brain. If there is bleeding inside
the brain it will damage the brain, and once its dead it is dead. - Sub Dural Hematoma – this is bleeding outside of the brain. This is bleeding between the brain
and the skull. Why is this a problem, because it creates a great deal of pressure on the brain. The
treatment is simple, all you have to do is go in the brain, open it up and get rid of the blood, and
stop the blood. If it is caught in time the person can live a normal life.
- Angoima- collection of a mass of blood vessels. Usually enlarged and abnormal. These are things
that people are born with. Birth marks, are discoloration of skin, these are abnormal collection
of vessels that come together. It can be torted an twisted, they are more prone to strokes,
because they are more likely to burst.
- Aneurism- vascular dialation. It is an expanded blood vessel, that is called by localized problems
and elasticity. This could lead to a stroke if the blood vessels burst. It is caused by weakening of
the blood vessel. The blood vessel loses its strength and receives all this pressure when it finally
bursts. It is really just the swelling, it doesn’t have to burst.
Closed Head Injury- Term used when someone has a blow to the head, and it doesn’t actua