Lecture three –psyb65
Things that can go wrong:
Blockage of blood flow:
Cerebral vascular accidents: CVA –can also refer to a stroke. Something has happened in
the blood supply in the brain. It refers to a severe interruption in the blood supply of the
brain. Ischemia: not getting enough oxygen or glucose. Ischemia is the result of a blockage.
Ex. If someone suffocates themselves, their brains can become ischemic. Usually caused by a
stroke but can be caused by other things. This can lead to infarct. Infarct: area of the brain
that is dead. Dead or dying tissue. Ex. A person had a CVA which resulted in ischemia, and
you can see an infarct on the MRI. CVA- can be slow or fast. But it usually happens fast. The
larger the artery that is blocked, the larger the part of the brain that will be destroyed.
Encephalo Malacia: this refers to a situation where the blood supply loss is really slow. This
occurs over years. The softening of a brain tissue. Area of deteriorating tissue. Not all the
neurons are dead, but there is a lot of damage. Most often called by a blockage in the
TIA: Transient ischemic attack- it is transient (temporary), ischemic (not enough oxygen).
Most often seen in things like migraines. A constriction of the muscles that surround the
blood vessels. Most common symptom is vision problems.
What actually causes these things?
Thrombosis: a locally formed exclusion (local blockage) it happens on the spot. Ex. Blood clot.
Embolism: Blockage that is formed elsewhere in the body. Breaks off from there and migrates
through the blood supply, arteries and lodges in the brain. Can cause a stroke.
Arteriosclerosis caused by the buildup of (cholesterol) fatty plaques in the artery. Can also break
off and travel to the brain.
Strokes are generally caused by things traveling and lodging somewhere.
The next worse thing that can happen is the blood supply bursting
Cerebral hemorrhage: a massive bleeding. A blood vessel bursts and you get a massive bleeding
to the brain itself. A bleeding inside the brain.
Subdural hematoma: blood vessels bleeding outside the brain. Between the Dura and the brain.
It creates a great deal of pressure on the brain. Subdural hematoma White side is accumulated blood. Bleeding between the brain and the skull
puts a lot of pressure on the brain. There should be a ventricle on each side, there is a little bit
but everything has been squeezed over to the other side. All the cerebral spinal fluid has been
pushed to the ventricles on the other side. The black side is the cerebral ventricles (lateral
ventricle) Treatment: if caught on time, you can take the blood out and you stop the bleeding. If
caught on time, the person will be perfectly healthy.
Angioma: A collection or a mass of blood vessels that are usually enlarged and are abnormal.
These are things that people are born with. These can be very fragile by their very nature. More
prone to strokes, more prone to bursting.
Aneurysm: vascular dilation. It is an expanded blood vessel caused by localized problems in
elasticity. Can lead to a stroke if the blood vessel bursts. Ex. Balloon animals. If it’s long and
straight it is normal, but if you twist it, it will bloom. Caused by this weakening in the blood
vessels. The blood vessels lose its strength. Swelling doesn’t have to burst.
Closed head injuries (caused by a blow to the head that does not actually break into the brain itself)
The problem is that the brain swell; happens when tissue is damaged. You’re essentially bruising
If it is very minor we refer to it as a concussion (confusion, memory loss) the brain is swollen
The problem with closed head injuries is that the skull does not allow the brain to swell so the
brain starts compressing itself, putting pressure on itself. Causing a concussion
If it becomes more extreme, the only place it can go is the opening at the back of the skull
(foramen magnum) it is the only exit point. If it gets bad enough, it will compress the base of the
brain where the vital life processes are, causing death. Contracoup- even though the damage is on the right, you have to check the left to see if it caused any
damage because the brain is like a soft boiled egg inside the skull, if it gets hit on one side, it will cause
damage and ricochet back and cause damage on the other side. “contracoup effect”
Brain Tumor – Cancer- tumors of the brain. Brain Tumors are caused by cancer which is tissue that is
growing quite independently of the surrounding tissue. There are a number of different types.
Glioma- just under half of all brain tumors (45%). They are from Glia cells (helper cells). They
have tremendous range. Benign- they are not going to spread to malignant to highly malignant.
Meningioma- Cancer of the meninges, they are usually benign. They are not life threatening but