Scanners and treating brain injury Flashcards
why is brain surgery not painful
there are no pain receptors in the brain
what do CT scans do
fire x-ray radiation at the brain from several angles
what do CT scans produce
3D image of brain
what do CT scans show
the structure of the brain but not the function
how can seeing the structure of the brain help figure out the function
differences (disease or damage) in brain structure can be linked to the way people think or act, suggesting the function of that part of the brain
who are CT scans not recommended for
children and pregnant women as it exposes the patient to higher doses of radiation than a normal x ray
how do PET scans work
radioactive glucose is injected into the blood before the scan to show which parts of the brain are active when being scanned
why do areas where the glucose builds up (or have greater blood flow) appear brightly on the scan
more active cells take in more glucose for respiration
more active cells give out gamma rays from the radioactive atoms
why are PET scans useful
for studying disorders that change brain activity as it shows parts of the brain that are unusually inactive or active
identifying tumours - use more blood than normal tissue
why is it hard to repair damage in the nervous system
neurones in the CNS don’t readily repair themselves (no adult stem cells that differentiate into neurones in the spinal cord) so neurones cannot be made to repair damage
why else is it hard to treat problems in the nervous system
it is easily damaged and could be damaged further leading to permanent damage
drugs given to treat diseases cannot always reach the brain because of the membrane that surrounds it
why are tumours hard to remove
they are buried deep in the brain or spinal cord
what is chemotherapy
injecting drugs that kill actively dividing cells
why does chemotherapy sometimes not work
blood-brain barrier which is a natural filter that only allows certain substances from the blood into the brain
