Blood Circulation to the Brain
The brain is a unique organ in the body. The blood circulation in the brain
is more complex, more regulated, and less understood than the circulation in any
other tissue. The large arteries carrying blood to the brain are the internal
carotids and the vertebral arteries. The condition of these arteries determines
how much blood flow is available to the brain. The smaller cerebral (pial)
arteries respond to changing demands from blood supply from cerebral tissues.
This auto regulation tries to maintain stable cerebral blood flow even with
unstable cerebral perfusion pressure.
Brain circulation responds in complex ways to a large number of stimuli.
Failure of autoregulation may be one of the most common sources of brain
dysfunction especially in people with high blood pressure on medications.
Brain activity regulates brain circulation by controlling cardiac output and
blood pressure. Emotions, especially anger, are strong events that act on the
cardiovascular system; heart rate increases and blood pressure rises, often
dramatically. Cognitive tasks increase blood flow and metabolic rate in the
regions of the brain that process the task. Changes in localized blood flow are
the basis of functional imaging studies that reveal the modules in the brain
that are active during task processing.
Cerebral microvessels have a unique feature, the blood-brain barrier, which
protects sensitive brain cells from disturbing elements circulating in the
blood. Endothelial cells line blood vessel. Their behavior regulates
permeability. In the brain, tight intercellular junctions limit endothelial
permeability. A variety of chemical signals to and from endothelia cells control
blood vessel transactions with glial cells and neurons. Cerebral vessels have
nerves supplies -sympathetic, parasympathetic, and sensory nerve fibers.
Gaseous transmitters such as nitric oxide (NO) dilate small blood vessels and
participate in the regulation of blood flow
Syncope (fainting) is an expression of reduced cerebral blood flow. Prolonged
standing, emotional arousal, blood pressure drugs, cardiac arrhythmias, and
autonomic nervous system failure are common causes of syncope. Blood tends to
pool in the legs with prolonged standing. Muscle activity is required to pump
venous blood uphill back to the heart. With reduced venous return, cardiac
output drops and humans faint. A common symptom, the feeling of
lightheadedness is an expression of reduced blood flow to the brain. Since
cerebral arterial disease increases with age, decreasing symptoms of limited
blood flow become more common such as lightheadedness, fainting, personality
changes and deteriorating cognitive ability.
Some of the disturbances will be regional with selectively compromised
functions. Other disturbances will be global. The use of medications to reduce
blood pressure may have adverse effects because lowering blood pressure can
decrease cerebral perfusion in patients with chronic vascular brain pathology;
they may develop focal hypoxia and even ischemia in poorly perfused regions of
Stroke is the leading cause of disability in the U.S. and Canada
Stroke is the leading cause of permanent disability in the
U.S. and Canada, second leading cause of dementia and the third leading cause of
adult death. Stroke is the third leading cause of death and a major source of
disability in the US where 700,000 people have a stroke and 158,000 die from
stroke. From 1993 to 2003, the stroke death rate fell 18.5%, but the actual
number of stroke deaths declined only 0.7%, according to 2006 statistics.
The main event of a heart attack is the occlusion by a
sudden blood clot of one or more blood vessels supplying the heart muscle. A
similar occlusion of blood vessels supplying the brain will result in the death
of brain tissue or cerebral infarction. Another cause of stroke is hemorrhage
from a ruptured blood vessel. Yet another stroke mechanism is the occlusion of a
brain artery by a clot that traveled to the brain from another body location,
usually the heart; embolism is most likely to occur in people with atrial
fibrillation and mechanical heart valves.
Neurologists say doctors and the public should give stroke
victims the same urgent treatment given to heart attack victims. The
clot-dissolving drug TPA (tissue plasminogen activator), when used in the first
three hours after a stroke, can restore blood flow in the brains of some
patients. Some hospitals have better
tools for dealing with strokes, but require the stroke patient to seek treatment
quickly. The message in the media is to act fast on the warning signs of a
stroke - stokes are now described as "brain attacks" to encourage the same sense
of urgency attributed to heart attacks. Symptoms include weakness or numbness, especially on one side of the
body; blurred vision, usually in one eye; slurred speech; dizziness; and
The hope for dramatic rescue of stroke victims with TPA is
somewhat tarnished by the impractical requirement of getting the right treatment
right away. One major problem is that some strokes are caused by bleeding into
the brain and TPA would make this worse. Before getting TPA, patients must be
checked to ensure they are not bleeding in the brain. If you were planning to
have a stroke, you have to set up an ideal circumstance in order to be rescued.
You would have to recognize that you were having a stroke almost immediately;
you would have to get to a well-equipped hospital promptly; the emergency room
would have to be set up to make the diagnosis promptly, get a high quality CAT
scan done and interpreted by an expert and then you would have to satisfy
several criteria for treatment - the first is that the CAT scan shows that there
is no bleeding associated with the stroke symptoms.
We share the conviction with a growing number of experts in the field that
simple, safe home remedies especially diet revision and exercise can substantially reduce this destructive disease and save untold
suffering and billions of health-care dollars. Smoking must stop. Diabetes,
high blood pressure, and high blood cholesterqol must be controlled to prevent stroke and, again, diet
revision with weight loss and increased daily exercise can work wonders. Drugs
are only required if risk factors are not controlled by changes in diet and
Well-known risk factors are
- high blood pressure
- high alcohol intake
- excess body fat
- physical inactivity.
- Diet Revision -- Alpha Nutrition Program
- Exercise and Weight Loss
- Reduce blood pressure
In the US Nurses study, a 14-year follow up involving
71,768 women aged 38 to 63 years identified stoke incidence with two dietary
1. A "prudent" diet characterized by higher intakes of
fruits, vegetables, legumes, fish, and whole grains that protected against
Follow the Alpha Nutrition Program.
2 "Western" diet characterized by higher intakes of red and
processed meats, refined grains, sweets, and desserts that increased stroke
Bazzano et found an inverse relationship between dietary
intake of folate and subsequent risk of stroke and CVD. They suggested that:
“increasing dietary intake of folate from food sources may be an important
approach to the prevention of CVD in the US population.“ This study included
9764 US men and women aged 25 to 74 years who participated in the National
Health and Nutrition Examination Survey I USA. Over an average of 19 years of
follow-up, 926 incident stroke events and 3758 incident CVD events were
Here are some key insights from epidemiological studies on
the effect of drinking alcoholic beverages: A small intake of alcoholic
beverages may protect against stroke, but five drinks a day or more triples the
stroke risk. (A drink is a 1.5-ounce shot of liquor, 12-ounces of beer or four
ounces of wine.) Those who consumed
less than one drink per month had a 62 percent lower risk of stroke than
non-drinkers did, while those who consumed up to two drinks a day had a 45
percent lower risk. Smokers have double the risk of stroke than non-smokers,
while former smokers were at 50-percent increased risk. Your risk of stroke
almost doubles if you have a parent who has had a stroke. People who consume
fruits and veggies at least three times a week have a lower risk of stroke.
Increased meat consumption doubles the risk.
Exercise is good for the brain. A physically active life tends to be more
productive with better mental health. The risk of stroke may be reduced by
up to 40% with regular exercise alone.
Regular exercise may delay the onset of dementia. Larson stated” “We learned
that a modest amount of exercise would reduce a person's risk of dementia by
about 40%." His group followed 1,750 adults, 65 years or older. At 2-year
intervals, participants reported their patterns of exercise, including walking,
hiking, aerobics, calisthenics, swimming, water aerobics, weight training, and
stretching: 158 developed dementia including 107 participants who were diagnosed
as having Alzheimer Disease (AD). The rate of dementia was 13.0 per 1,000 person
years for participants who exercised at least 3 times per week vs 19.7 per 1,000
person years for participants who exercised fewer than 3 times per week.
The Alpha Nutrition Program can be recommended, along with Alpha DMX,
exercise and relaxation as a rational strategy of preventing and managing
Go to Brain Center
- You are viewing the Brain Mind Center at Alpha Online, a Division of
Environmed Research, founded in 1984 at Vancouver, BC, Canada. Online Since
1995. Alpha Nutrition is a trademark and a division of Environmed Research Inc. Understanding the human brain is essential to become a well-informed, modern
citizen. Stephen Gislason MD, the author of
the Human Brain, is a physician-writer who is good at making complex subjects more
understandable. This is a book with important ideas, so be prepared to read
and then keep the book as reference.
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Further reading: Neuroscience Notes, Intelligence and
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