PSY2061 Study Guide - Final Guide: Intracerebral Hemorrhage, Brain Ischemia, Brain Tumor
11 Jun 2018
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Nathaniel Parsons
PSY2061 Learning Objectives Week 7 S1 2018
Brain Damage and Neuroplasticity
Discuss the causes of brain damage
Tumours are a mass of cells that grow independently to the body. 20% of tumours are
meningiomas – tumours that grow between the meninges. The meninges are the three
membrane which cover the CNS. They encapsulate tumours as they grow within their own
membrane. Furthermore, they affect the brain via the pressure that they exert on
surrounding tissue. Additionally, benign tumours can be surgically removed without risk of
further growth in the body.
Most brain tumours are infiltrating, they grow diffusely (to spread) through surrounding
tissue. Malignant tumours are difficult to remove/ destroy completely. Any cancerous tissue
that remains after surgery may continue to grow. Gliomas tumours are infiltrating, rapidly
growing and a common type of tumour.
10% of brain tumours do not originate in the brain, they grow from infiltrating cells that are
carried via the bloodstream. These tumours are called metastatic tumours (metastasis
meaning the transfer between organs).
Cerebrovascular disorders such as stroke have sudden onset causing brain damage. In the
U.S stroke is the 5th leading cause of death and a major cause of neurological dysfunction.
Additionally, stroke is the leading cause of adult disability. This can include but is not limited
to amnesia, (memory), aphasia (language), paralysis and comas. The infarct is the area of
brain tissue affected by stroke. The cells in this area are either dead or dying. Surrounding
the infract area is tissue which can also die or recover, based on a variety of factors.
There are two types of stroke, the first being cerebral haemorrhage. A cerebral haemorrhage
is bleeding in the brain when a blood vessel bursts. The blood damages the surrounding
tissue. Bursting aneurysms (localised swelling of the wall of a blood vessel) are common
causes of intracerebral haemorrhages. Aneurisms can occur at any part of the body and can
be congenital (present at birth) or the result of exposure to vascular poisons or infection.
Additionally, cerebral ischemia occurs when there is a disruption of blood supply to the brain.
There are three major causes of cerebral ischemia. The first is thrombosis where a thrombus
clogs the blood vessel. A thrombus can be a blood clot, fat, oil, air bubble, tumour cells or a
combination of the above. Secondly, embolism is when a plug called an embolus is
transferred from a larger blood vessel to a smaller blood vessel, causing it to clog. Thirdly,
Arteriosclerosis occurs when the walls of the blood cells thicken and the channels narrow –
usually from fat deposits. Eventually the channels can become blocked, leading to the
blocking of blood vessels. Glutamate plays an important role in cerebral ischemia induced
brain injury. After blood doesn’t reach the brain excessive ions (Na2+ and Ca2+) are released
which is toxic and can kill post synaptic neurons.
Contusions are closed head injuries which involve damage to the cerebral cortex system.
Contusions produce internal haemorrhaging which results in hematoma – clotted blood in
organs or tissue (bruising). Blood can accumulate and cause damage to nearby brain tissue.
A concussion is damage which causes an altered state of consciousness. However, there is
no evidence of contusion or structural brain damage. Concussions can create long-term
brain damage.
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Document Summary
Tumours are a mass of cells that grow independently to the body. 20% of tumours are meningiomas tumours that grow between the meninges. The meninges are the three membrane which cover the cns. They encapsulate tumours as they grow within their own membrane. Furthermore, they affect the brain via the pressure that they exert on surrounding tissue. Additionally, benign tumours can be surgically removed without risk of further growth in the body. Most brain tumours are infiltrating, they grow diffusely (to spread) through surrounding tissue. Malignant tumours are difficult to remove/ destroy completely. Any cancerous tissue that remains after surgery may continue to grow. Gliomas tumours are infiltrating, rapidly growing and a common type of tumour. 10% of brain tumours do not originate in the brain, they grow from infiltrating cells that are carried via the bloodstream. These tumours are called metastatic tumours (metastasis meaning the transfer between organs). Cerebrovascular disorders such as stroke have sudden onset causing brain damage.
