1. Explain what happens to the brain when a stroke occurs.
When a stroke occurs, brain is noit getting enough blood supply and therefore is shortened of oxygen supply.
2. Briefly explain the differences between the three different types of strokes.
Ischemic stroke occurs when arteries are clogged by blood clots that lad to head. This type of stroke divides in embolic and thrombotic. Embolic stroke occurs when a blood clot form somewhere in the body, break off and travel to the head where they block brain's blood vessels. Thrombotic stroke occurs when a clot forms in the artery supping blood to the brain.
3. Identify some of the most common risk factors - in other words, who is most likely to have a stroke?
Old people, people with hich cholesterol and high blood pressure. And people who eat unhealthy things that makes them fat and clogs their arteries. also stress increases stroke chances along with genetics.
4. What disabilities can result from a stroke?
Paralyzation, death, unability to speak...Depending on what part of the brain is damaged during the stoke.
5. What is brain plasticity and what does it mean in terms of recovering from a stroke?
Brain plasticity is the ability of brain to change. This change occurs due to learning something new or a damage to the brain. While it was thought that brain doesn't form/destroy the pathways, it is possible even in adulthood. Stroke may change some pathways in brain as a result, slightly changing its functions.
Notes from video:
atroke every 45 seconds in america
stroke- brain attack when blood supply is damaged, results in death of cells and brain damage, skills controlled by that area are lost (speech, movement, memory)
effects on person dependson what area was afflicted and how much damage was done
ischemis stroke- 83% of cases, occur when artyeries are clogged by blood clots that lead to tyhe head- resultsin issufiecient oxygen supply to that part of the brain
divides into embolic and thrombolic
embolic when blood clot formss somewhere in the body and breaks of and travels to the head and blocks brain's blood vesels
thrombatic forms clot in artery suppling bloodto tye brain
hemorragic strokes- 75% of cases, more dangerous, when aa blood vessel in brain ruptures and bleeds into the brain causing pressure on brain tissue
intercerebral or subarachnoid
intercerebral occurse when bleeding occurs in thebrain itself, high blood pressure is the main cause
subarachnoid hemmorage occurs when blood spills to the spinal fluid around the brain causing it to be surrounded by conaminated fluid
Source:
https://www.youtube.com/watch?feature=player_embedded&v=fKrXCly1kK0
http://www.brainandnerves.com/uk/blood-vessels-of-the-brain/stroke/
Thursday, February 21, 2013
Monday, February 4, 2013
Biology and Technology
Definition:
CT: computed tomography, uses x-rays and powerful computers to create cross section pictures of body
PET: positron emission tomography, uses a radioactive substance called tracer to look for diseases and shows how well tissues in body work
FMRI: functional magnetic resonance imaging, measures brain activity by monitoring changes in blood
How does each work?
CT: X-ray machine "scans" body, depending of which part is being scanned because radiation isn't healthy and is limited as much as possible by special covers. For some examinations a contrast dye is give to patient through IV, rectum or orally, depending on the examination, to make some parts to be clearer on the x-ray which can be in form of a photograph.
PET: The patient is given tracer, usually given through IV, asked not to eat 4-6 before the test. After the traces is absorbed, the patient is laid on a table and put into a special tube. The tracer goes through various organs through the blood system and is visible on monitors in 3-D which help diagnose the patient. This method
FMRI: Measures the amount of oxygen in blood. The neural activity in brain requires oxygen. fMRI uses strong electromagnet to see which part of brain is working based on how much oxygen is being used. This happens in a tube machine in which the patient lays motionlessly.
What is able to be learned through the use of each?
CT: Studying blood vessels, blood clots, broken bones, infections, stroke and bleeding in brain
PET: Brain function, cancer, heart problems, brain disorders
FMRI: Which part of brain is functioning
How can each be used to explain human behavior?
CT: May help unusual behavior by diagnosing patient as having a stroke. Another example is hydrocephalus ( build up of fluid in brain)common in old people and infants. The symptoms may be above all vomiting, irritability and sleeplessness.
PET: Helps to diagnose brain damage, dementia or tell the difference between Parkinson's or other movement disease. For example, PET may show the spiral way of how the brain cells die, which is symptom of Alzheimer's disease
FMRI: Scientists are able to go as far as "read mind" of a person by showing him/her a picture while in the machine, scanning which part of the brain is activated when the person thinks of this object/how to use it/ how to hold it/ his or her experience with it, and record this data. So far, people had very similar results for the same objects.
Sources:
http://www.nlm.nih.gov/medlineplus/ency/article/007342.htm
http://psychcentral.com/lib/2007/what-is-functional-magnetic-resonance-imaging-fmri/
CT: computed tomography, uses x-rays and powerful computers to create cross section pictures of body
PET: positron emission tomography, uses a radioactive substance called tracer to look for diseases and shows how well tissues in body work
FMRI: functional magnetic resonance imaging, measures brain activity by monitoring changes in blood
How does each work?
CT: X-ray machine "scans" body, depending of which part is being scanned because radiation isn't healthy and is limited as much as possible by special covers. For some examinations a contrast dye is give to patient through IV, rectum or orally, depending on the examination, to make some parts to be clearer on the x-ray which can be in form of a photograph. PET: The patient is given tracer, usually given through IV, asked not to eat 4-6 before the test. After the traces is absorbed, the patient is laid on a table and put into a special tube. The tracer goes through various organs through the blood system and is visible on monitors in 3-D which help diagnose the patient. This method FMRI: Measures the amount of oxygen in blood. The neural activity in brain requires oxygen. fMRI uses strong electromagnet to see which part of brain is working based on how much oxygen is being used. This happens in a tube machine in which the patient lays motionlessly.What is able to be learned through the use of each?
CT: Studying blood vessels, blood clots, broken bones, infections, stroke and bleeding in brain
PET: Brain function, cancer, heart problems, brain disorders
FMRI: Which part of brain is functioning
How can each be used to explain human behavior?
CT: May help unusual behavior by diagnosing patient as having a stroke. Another example is hydrocephalus ( build up of fluid in brain)common in old people and infants. The symptoms may be above all vomiting, irritability and sleeplessness.
PET: Helps to diagnose brain damage, dementia or tell the difference between Parkinson's or other movement disease. For example, PET may show the spiral way of how the brain cells die, which is symptom of Alzheimer's disease
FMRI: Scientists are able to go as far as "read mind" of a person by showing him/her a picture while in the machine, scanning which part of the brain is activated when the person thinks of this object/how to use it/ how to hold it/ his or her experience with it, and record this data. So far, people had very similar results for the same objects.
Sources:
http://www.nlm.nih.gov/medlineplus/ency/article/007342.htm
http://psychcentral.com/lib/2007/what-is-functional-magnetic-resonance-imaging-fmri/
Thursday, January 24, 2013
Nature vs Nurture: The Twin Edition
Twin Studies:
Studies and observations based on genetic information of twins. These studies are mainly used to determine the impact of the environment and genetics on humans.
Adoption Studies:
Studies that observe the nature vs nurture impact on psychological development. The focus falls on children with disorder and whore biological parents have it, too, but adoptive parents do not. This helps to show how the psychological illness develop and whether they are caused and impacted only by genetics or also environment.
Minnesota Study of Twins Reared Apart (MISTRA)
MISTRA is a study done in times when it was widely believed that personalities are 100% molded by the environment. It lasted from 1979 and ended 20 years and it is considered one of the most important psychological studies for past 50 years.
There are different types of twins; monozygotic when an egg splits into two in the womb and the twins have the same genes and dizygotic, when two eggs are fertilized and the twins have about 50% same DNA. MISTRA observed 81 monozygotic twin pairs (MZ) and 56 dizygotic twin pairs (DZA)who were used as controls, to find out which traits are given by the genetics and which are determined by the environment. The result was shocking for the time period; genes have a huge impact on how we develop.
Candidates for research were twins separated before the age of four who lived apart more than 95% of their life. Many times these siblings lived in different states and acknowledged each other existence during the MISTRA research. Some, however, met before while searching for their biological parents or just by coincidence, but this variable was also used as a research and suggests that the quirky similarities between twins weren't modified by their acquaintances.
The studies say that intelligence levels of MZ twins are very similar and that testing them is like "testing the same person twice".
Big surprise were the personality findings where was assumed that personality is formed by the environment. Studies shown that personality is about 50% given by the genes and the environment that person makes for himself, or the "non-shared environment". Many parents think that how they raise their children determines who they will become, but they are wrong. The household, the "shared environment", has some impact but it was shown that twins reared apart and twins who grow up together have very similar yet not identical personalities.
Among traits that are determined mostly by genes are hand coordination becoming better with practice, headache frequencies, dependency on alcohol, intensity of religion (religion is determined by the environment and usually taken over from parents), morning vs evening person, likely hood of gum disease (even with different diets) and spelling abilities.
As far as sexual orientation, men are more more influenced by the genes, while women are more to be influenced by the environment, for example they are more likely to establish relations with women when they are not attractive to men.
Children who grow up together develop subconscious anti-incest mechanism. It wasn't surprising then that the DZA different sex twins were often flirtatious which each other when they met.
Ethical Issues
Most twins separated at birth were not even aware they had a twin. For some, it might have been a traumatic experience to find out they are adopted. Questions like "who are my real parents?" or "Why didn't they keep me?" appeared in their minds. Also, if one twin suffers from some genetic disorder, the other twin is most likely but not for 100% going to have the same condition. This other twin is very likely to spend their life thinking about getting the disease and worrying and in the end may not even get it.
Pros
The science behind twin and personality was cleared, not completely, but significantly. It is known now that personality is very much affected by the genes but not entirely. It is still known to what extent but it leads to more knowledge and maybe even as a semi-solid bases for new studies. If scientist will be able to identify which gene exactly does what or what environmental causes trigger of certain habits and how they can prevent someone, for example from alcoholism, it would significantly improve one's life.
Cons
"Labeling something doesn't explain the process by which it happens" says Evan Balaban, a scientist who transports brain cells from quails to chickens so they sing like quails. Also, there are many genes which interact in many different ways that at this rate it will take a lot of time for science to figure out how it works. Also, if everything was proven to be genetic, the society would attack the environmental causes that would eliminate some people.
Sources:
http://www.reference.md/files/D018/mD018486.html
http://aje.oxfordjournals.org/content/155/7/585.full#sec-11
http://www.psychology-lexicon.com/cms/glossary/glossary-a/1582-adoption-study.html
http://www.amren.com/features/2012/07/science-versus-ideology/
Nature and Nurture: When It Comes to Twins, Sometimes It's Hard To Tell the Twin Apart by Arthur Allen; Washington Post (Sunday, Jan 11, 1998)
Studies and observations based on genetic information of twins. These studies are mainly used to determine the impact of the environment and genetics on humans.
Adoption Studies:
Studies that observe the nature vs nurture impact on psychological development. The focus falls on children with disorder and whore biological parents have it, too, but adoptive parents do not. This helps to show how the psychological illness develop and whether they are caused and impacted only by genetics or also environment.
Minnesota Study of Twins Reared Apart (MISTRA)
MISTRA is a study done in times when it was widely believed that personalities are 100% molded by the environment. It lasted from 1979 and ended 20 years and it is considered one of the most important psychological studies for past 50 years.
There are different types of twins; monozygotic when an egg splits into two in the womb and the twins have the same genes and dizygotic, when two eggs are fertilized and the twins have about 50% same DNA. MISTRA observed 81 monozygotic twin pairs (MZ) and 56 dizygotic twin pairs (DZA)who were used as controls, to find out which traits are given by the genetics and which are determined by the environment. The result was shocking for the time period; genes have a huge impact on how we develop.
Candidates for research were twins separated before the age of four who lived apart more than 95% of their life. Many times these siblings lived in different states and acknowledged each other existence during the MISTRA research. Some, however, met before while searching for their biological parents or just by coincidence, but this variable was also used as a research and suggests that the quirky similarities between twins weren't modified by their acquaintances.
The studies say that intelligence levels of MZ twins are very similar and that testing them is like "testing the same person twice".
Big surprise were the personality findings where was assumed that personality is formed by the environment. Studies shown that personality is about 50% given by the genes and the environment that person makes for himself, or the "non-shared environment". Many parents think that how they raise their children determines who they will become, but they are wrong. The household, the "shared environment", has some impact but it was shown that twins reared apart and twins who grow up together have very similar yet not identical personalities.
Among traits that are determined mostly by genes are hand coordination becoming better with practice, headache frequencies, dependency on alcohol, intensity of religion (religion is determined by the environment and usually taken over from parents), morning vs evening person, likely hood of gum disease (even with different diets) and spelling abilities.
As far as sexual orientation, men are more more influenced by the genes, while women are more to be influenced by the environment, for example they are more likely to establish relations with women when they are not attractive to men.
Children who grow up together develop subconscious anti-incest mechanism. It wasn't surprising then that the DZA different sex twins were often flirtatious which each other when they met.
Ethical Issues
Most twins separated at birth were not even aware they had a twin. For some, it might have been a traumatic experience to find out they are adopted. Questions like "who are my real parents?" or "Why didn't they keep me?" appeared in their minds. Also, if one twin suffers from some genetic disorder, the other twin is most likely but not for 100% going to have the same condition. This other twin is very likely to spend their life thinking about getting the disease and worrying and in the end may not even get it.
Pros
The science behind twin and personality was cleared, not completely, but significantly. It is known now that personality is very much affected by the genes but not entirely. It is still known to what extent but it leads to more knowledge and maybe even as a semi-solid bases for new studies. If scientist will be able to identify which gene exactly does what or what environmental causes trigger of certain habits and how they can prevent someone, for example from alcoholism, it would significantly improve one's life.
Cons
"Labeling something doesn't explain the process by which it happens" says Evan Balaban, a scientist who transports brain cells from quails to chickens so they sing like quails. Also, there are many genes which interact in many different ways that at this rate it will take a lot of time for science to figure out how it works. Also, if everything was proven to be genetic, the society would attack the environmental causes that would eliminate some people.
Sources:
http://www.reference.md/files/D018/mD018486.html
http://aje.oxfordjournals.org/content/155/7/585.full#sec-11
http://www.psychology-lexicon.com/cms/glossary/glossary-a/1582-adoption-study.html
http://www.amren.com/features/2012/07/science-versus-ideology/
Nature and Nurture: When It Comes to Twins, Sometimes It's Hard To Tell the Twin Apart by Arthur Allen; Washington Post (Sunday, Jan 11, 1998)
Tuesday, January 8, 2013
Sperry and Gazzaniga: The Split Brain Study
1. What does it mean for a person's brain to be "split"?
A person can live with his brain literally split in two. Human brain has two sections, the left one responsible for rational, analytical, quantitative and logical thinking and the right one responsible for imaginative, conceptual and intuitive. If these two hemispheres are separated, the patient will survive only with some notable differences. The person wasn't able to learn with the two hemispheres simultaneously.
2. What was the reason why this procedure was performed on patients?
These two hemispheres are connected together by a little bundle of nerves called corpus callosum that used to be cut in 1960' to treat a kind of epilepsy.
3. Explain one of the tests Sperry and Gazzaniga performed on these split brain patients.
a) A person with split brain would be shown a picture, for example a fork, and then asked what it is.
b) Person would be given an object and asked what it was.
4. What were the results of this test?
a) The person would not be able to say what the picture is, yet would be able to write it on the paper and be aware that he wrote something.
b) If a person would be given an object, for example a toothbrush, to hand that is taken care of by hemisphere also responsible for visual things, person would understand what he is holding but wouldn't be able to say what it is, just show brushing motion.
5. What is the reason that these results occurred?
Since the brain is split, the two hemispheres do not communicate with each other. It is almost as if the people had two brains and you can talk only to one at a time.
6. What is the corpus callosum and what role does it serve in your brain?
Corpus callosum is a bundle of nerves that connects the two hemispheres of brain and allows communication between them which allows simultaneous work and understanding.
Sources:
http://www.openzine.com/aspx/ReadMore.aspx?ID=122859&lid=78&IssueID=19000&zineID=0&divid=317
http://www.macalester.edu/academics/psychology/whathap/ubnrp/split_brain/pioneers.html
A person can live with his brain literally split in two. Human brain has two sections, the left one responsible for rational, analytical, quantitative and logical thinking and the right one responsible for imaginative, conceptual and intuitive. If these two hemispheres are separated, the patient will survive only with some notable differences. The person wasn't able to learn with the two hemispheres simultaneously.
2. What was the reason why this procedure was performed on patients?
These two hemispheres are connected together by a little bundle of nerves called corpus callosum that used to be cut in 1960' to treat a kind of epilepsy.
3. Explain one of the tests Sperry and Gazzaniga performed on these split brain patients.
a) A person with split brain would be shown a picture, for example a fork, and then asked what it is.
b) Person would be given an object and asked what it was.
4. What were the results of this test?
a) The person would not be able to say what the picture is, yet would be able to write it on the paper and be aware that he wrote something.
b) If a person would be given an object, for example a toothbrush, to hand that is taken care of by hemisphere also responsible for visual things, person would understand what he is holding but wouldn't be able to say what it is, just show brushing motion.
5. What is the reason that these results occurred?
Since the brain is split, the two hemispheres do not communicate with each other. It is almost as if the people had two brains and you can talk only to one at a time.
6. What is the corpus callosum and what role does it serve in your brain?
Corpus callosum is a bundle of nerves that connects the two hemispheres of brain and allows communication between them which allows simultaneous work and understanding.
Sources:
http://www.openzine.com/aspx/ReadMore.aspx?ID=122859&lid=78&IssueID=19000&zineID=0&divid=317
http://www.macalester.edu/academics/psychology/whathap/ubnrp/split_brain/pioneers.html
Subscribe to:
Comments (Atom)