Chapter 10 - Brain Damage Flashcards
Another name for tumor
Neoplasm (literally, “new growth”).
Tumor or neoplasm
A mass of cells that grows independently of the rest of the body.
About 20% of tumors found in the human brain are _________ (type of tumor).
Meningiomas
Meningioma
Tumors that grow between the meninges.
All meningiomas are ______ tumors.
Encapsulated
Encapsulated tumor
A tumor that grows within its own membrane.
Particularly easy to identify on a CT scan, and can influence the function of the brain only by the pressure they exert on surrounding tissue.
They are almost always benign tumors.
Benign tumor
A tumor that is surgically removable with little risk of further growth in the body.
Infiltrating tumors
Tumors that grow diffusely through surrounding tissue. As a result, they are usually malignant tumors.
Malignant tumors
Tumors that are difficult to remove or destroy completely, and any cancerous tissue that remains after surgery continues to grow.
Gliomas
Brain tumors that develop from glial cells.
Are infiltrating, rapidly growing, and common.
About ______% of tumors do not originate in the brain, but are grown from infiltrating cells that are carried to the brain by the bloodstream from some other part of the body.
10
Tumors that originate in one part of the body but spread to another are called _______ tumors.
Metastatic
Many metastatic brain tumors originate as cancers of the _____.
Lungs
Stroke
Sudden onset cerebrovascular disorder that causes brain damage. In the United States it is the third leading cause of death, the major cause of neurological dysfunction, and the most common cause of adult disability.
The layer of dead or dying tissue produced by a stroke is called a/n _____.
Infarct
Surrounding the infarct is a dysfunctional area called the ________.
Penumbra.
The tissue in the penumbra may recover or die in the ensuing days. The primary goal of treatment following stroke is to save the penumbra.
There are two major types of strokes:
Those resulting from cerebral hemorrhage
And
Those resulting from cerebral ischemia.
Cerebral hemorrhage
Occurs when a cerebral blood vessel ruptures and blood seeps into the surrounding neural tissue and damages it.
Cerebral ischemia
A disruption of the blood supply to an area of the brain.
Three major causes of cerebral ischemia:
Thrombosis, embolism, and arteriosclerosis.
Contusion
Closed-head injuries that involve damage to the cerebral circulatory system. Produces internal hemorrhaging, which results in a hematoma.
Hematoma
A localized collection of clotted blood in an organ or tissue. A bruise.
Contusions frequently occur on the side of the brain ______ to the side struck by a blow.
Opposite
Contrecoup injuries
Contusions that occur on the side of the brain opposite to the side of a blow.
Toxic psychosis
Chronic insanity produced by a neurotoxin.
Apoptosis (“A-poe-toe-sis”)
Cell death that is actively induced by genetic programs; programmed cell death.
Tumors, cerebrovascular disorders, closed-head injuries, infections, toxins, and genetic factors produce neural damage, in part, by activating _________ programs of ________.
Apoptotic,
Self-destruction.
Necrosis
Passive cell death resulting from injury.
Necrotic cell death is ______- it is typically complete in ______. In contrast, apoptopic cell death is ______, typically requiring ______.
Quick,
A few hours,
Slow,
A day or two.
Many seizures do not take the form of _______; instead, they involve subtle changes of thought, mood, or behavior that are not easily distinguishable from normal ongoing activity.
Convulsions (motor seizures).
In thrombosis, a plug called a _______ is formed and blocks blood flow at the site of its formation.
Thrombus
Thrombosis
The blockage of blood flow by a plug (a thrombus) at the site of its formation.
Embolism
The blockage of blood glow in a smaller blood vessel by a plug (embolus) that was formed in a larger blood vessel and carried by the bloodstream to the smaller one.
Arteriosclerosis
A condition in which blood vessels are blocked by the accumulation of fat deposits on their walls.
Ischemia induced brain damage has two important properties:
- It takes a while to develop. Soon after an episode, there usually is little or no evidence of brain damage. After a day or two substantial neuron loss can often be detected.
- damage does not occur equally in all parts of the brain; particularly susceptible are the neurons in certain areas of the hippocampus.
_______, the brain’s most prevalent excitatory nuerotransmitter, plays a role in ________ damage.
Glutamate,
Stroke-induced
Describe how glutamate damage following a stroke is thought to work.
After a blood vessel becomes blocked, many of the blood-deprived neurons become overactive and release excessive quantities of glutamate. The glutamate in turn overactivates glutamate receptors (NMDA) in the membranes of postsynaptic neurons. As a result, large numbers of Na+ and Ca2+ ions enter the postsynaptic neurons. The excessive internal concentrations of Na+ and Ca2+ ions in postsynaptic neurons affect them in two ways: they trigger the release of excessive amounts of glutamate from neurons, thus spreading the toxic cascade to yet other neurons; and they trigger a sequence of internal reactions and ultimately kill the postsynaptic neurons.
Encephalitis
The inflammation associated with brain infection.
Meningitis
Inflammation of the meninges.
The syndrome of insanity and dementia that results from a syphilitic infection is called _______.
general paresis.
There are two types of viral infections of the nervous system:
Those that have a particular affinity for neural tissue and those that attack neural tissue but have no greater affinity for it than for other tissues.
There are two common types of brain infections:
Bacterial infections and viral infections
When bacteria infect the brain, they often lead to the formation of ________.
cerebral abscesses (pockets of pus in the brain).
Toxic insanity
Chronic insanity produced by a neurotoxin.
Some neurotoxins are _______. For example, the body can produce antibodies that attack particular components of the nervous system.
endogenous
Inherited neuropsychological disorders are rarely associated with dominant genes because dominant genes that disturb neuropsychological function tend to be eliminated from the gene pool (individuals who carry one usually have survival and reproductive disadvantages). In contrast, individuals who inherit _________ do not develop the disorder, and the gene is passed to future generations.
one abnormal recessive gene
Genetic ______ is another major cause of neuropsychological disorders of genetic origin.
accident
________, which occurs in about 0.15% of births, is a disorder of genetic accident.
Down syndrome
Down syndrome occurs in the mother during ovulation, when an extra ________ is created in the egg. Thus, when the egg is fertilized, there are three rather than two.
chromosome 21
The probability of giving birth to a child with Down syndrome increases markedly with _______.
advancing maternal age
The probability goes from 1 in 1,667 at maternal age 20 to 1 in 11 at maternal age 49.
There was great optimism for treating neuropsychological disorder when the human genome was documented at the beginning of this century. There has not been a complete cure for all neuropsychological disorders for two reasons:
First, numerous loci on human chromosomes have been associated with each disease- not just one or two.
Second, about 90% of the chromosomal loci involved in neuropsychological disorders were not conventional protein-coding genes; the loci were in poorly understood sections of the DNA.
Tumors, cerebrovascular disorders, closed-head injuries, infections, toxins, and genetic factors produce neural damage, in part, by activating _______.
apoptotic programs of self-destruction.
Cell death is not an either-or situation: some dying cells display signs of ________.
both necrosis and apoptosis