Download [ingestion] ohol t sm is ingestion.

MODULE TWO // ALCOHOL METABOLISM
[ingestion]
The human body needs to process substances that enter the body.
Useful ingredients are either transformed into heat and energy or
built into living tissues needed for growth and repair. Useless
stances are changed into a useful form or else
minated as a waste product.
Alcohol is an
xcellent source of calories or units of heat
d energy, yielding more calories per
gram than sweets starches and
proteins, but less than fats.
The
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st
in g
poi
nt
1
in
th
f
e
p r o c ess o
a lc
Ingestion occurs when you take
a sip of alcohol. Alcohol is one
of the few foods that is already
simple enough to be absorbed
at once; its molecules are small
enough and its chemical pattern
simple enough to be used for
fuel almost immediately after
o h ol m
swallowing.
bol
eta
ism
i s i n g e stio n
.
mouth
MODULE TWO // ALCOHOL METABOLISM
[absorption]
A small amount of alcohol is
absorbed by the tiny blood vessels
in the
mouth, but the majority of
the absorption process transpires in
stomach and small
intestines. Alcohol mixes with
the contents of the stomach,
the
mouth
where up to 20% of alcohol is
absorbed into the bloodstream
stomach
through the mucous membrane of
the
stomach;
the remaining
alcohol is absorbed by the
intestines.
The
small intestines
small
small intestines
are
only mildly affected by alcohol.
The absorption of alcohol through
2
the mucous membranes occurs so
rapidly
that
the
alcohol
concentration in this organ is never
very high.
Alcohol causes the stomach to
release chemical substances which
stimulate the flow of the acidic
gastric juices. If only a small quantity
of alcohol is consumed, appetite
may actually increase because the
flow
of
digestive
enzymes
is
increased. However, large quantities
of alcohol result in over acidity,
irritating
the
stomach.
lining
of
the
MODULE TWO // ALCOHOL METABOLISM
3
[circulation]
When alcohol reaches the brain cells, a
person feels "buzzed".
The effects of
alcohol on the brain is what causes
drunkeness. If the circulation of alcohol
through
the
circumvent
the
bloodstream
brain,
could
intoxication
would not occur.
Once absorbed, alcohol travels through
the bloodstream and into the organs and
body tissue.
The body tries to dilute the
alcohol by equalizing the concentration of
water to alcohol throughout. Organs and
tissues that are rich in blood or water, like
the brain or kidney are affected more
quickly than soft tissues like bone and
muscle, which has less water available to
dilute the alcohol.
veins
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capillaries
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Al c
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A l c o h o l Alco
arteries
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Alcohol is absorbed into the bloodstream through
the mucus membranes of the small instestines
For about fifteen minutes after two or three drinks, your blood pressure,
pulse rate and total flow of blood increases by about five percent. The
pulse rate may also increase immediately after strong drinks are
consumed, this is due in part by the reflex action of the irritated tissues of
the throat and esophagus. Blood pressure drops shortly afterwards due to
the depressant nature of alcohol. Physiological affects of alcohol on the
heart are caused by impairment of the central nervous system and not by
the direct relationship of alcohol concentration in the heart.
MODULE TWO // ALCOHOL METABOLISM
[oxidation]
Alcohol is a toxin.
As soon as it is absorbed by the bloodstream, the
body works to remove it. At most, 5% of alcohol consumed is dispelled
through sweat, breath and urine before being metabolized.
The
remaining alcohol must be chemically broken down into carbon dioxide
and water.
This process is called oxidation. Alcohol undergoes three
successive changes before it can be used fuel.
liver
step 2
a second enzyme,
step 1
named aldehyde
an enzyme named
dehydrogenase
acohol dehydrogenase
breaks toxic
breaks down alcohol
acetaldehyde
into acetaldehydre
into acetic
step 3
unlike the first two steps,
m
e
acid
en
zy
which primarily take place
in the liver, any cell or
e
ym
enz
organ can convert the
acetic acid into carbon
dioxide and water.
Illustration showing the metabolism of alcohol.
Once alcohol reaches the liver, it begins to
dedicate almost all of its function to breaking down
alcohol
into
a
usable
source.
Alcohol
dehydrogenase, an enzyme found primarily in the
liver converts the alcohol in to acetaldehyde.
Acetaldehyde is actually more toxic than alcohol,
but is converted into acetic acid by another
enzyme,
aldehyde
instaneously.
dehydrogenase,
almost
This prevents acetaldehyde from
accumulating in the body.
The final step of metabolism can take place in
almost any cell or organ. The breakdown of Acetic
acid into carbon dioxide and water releases heat
or energy to be used by the cells as calories.
4
MODULE TWO // ALCOHOL METABOLISM
[summary]
Alcohol moves through the body in a predictable manner. After being
ingested, alcohol is rapidly absorbed by the stomach and small intestine.
Once in the bloodstream, alcohol travels to the organs, including the liver,
where the breakdown of alcohol begins.
A
When an alcoholic beverage is consumed it
passes down the esophagus through the
stomach and into the small
intestine.
A
B
Alcohol is initally absorbed into the
bloodstream through the mucous
membrane, although the majority of alcohol
enters the bloodstream through the walls of the
small intestine, where it is rapidly absorbed
into the blood and distributed throughout the body.
C
Traveling via the bloodstream, alcohol reaches
the brain in less than a minute. It is the effects of
alcohol in brain cells that cause intoxicity.
D
The liver is responsible for the metabolism and
elimination, of 95% of ingested alcohol from
the body.The remainder of the alcohol is eliminated
through excretion of alcohol in breath,
urine, sweat, feces, and saliva.
D
C
key sites for alcohol breakdown
S
aldehyde
dehydogenase
alcohol
dehydrogenase
Acetaldehyde Acetic Acid
Alcohol
water &
carbon dioxide
There are three steps of oxidation, or the process by
which carbon dioxide and water result. The first step
consists
of
an
enzyme
called
alcohol
dehydrogenase acting on the alcohol to produce
acetaldehyde.
down
by
Acetaldehyde is rapidly broken
another
enzyme
called
aldehyde
dehydrogenase, into acetic acid. Acetic acid can
be broken down by any of the cells or organs in the
body, resulting in carbon dioxide and water.
MODULE TWO // ALCOHOL METABOLISM
[questions]
Fact Query
The __________________ absorbs nearly 80% of the alcohol into the
bloodstream.
The majority of alcohol metabolism occurs in the _______________.
Drunkeness is caused by alcohol's effect on _________ cells.
Process Query
What are the four main steps of alcohol metabolims? Describe
the process in your own words, or by labeling a
illustration/diagram.
1
alcohol
dehydrogenase
Alcohol
2
3
aldehyde
dehydogenase
Acetaldehyde
Acetic Acid
water &
carbon dioxide
Concept Query
Acetaldehyde is a -toxic substance which causes nausea,
flushed skin and heart palpitations. As previously discussed,
the enzyme aldehyde dehydogenase quickly binds to
acetaldehyde and converts it into a non-toxic form, acetic
acid. One treatment for alcoholics is the prescription of a drug
which inhibits the ability of aldehyde dehydrogenase. What
do you think happens when someone taking an aldehyde
dehyrogenase inhibitor drinks alcohol? Why?
4
MODULE TWO // FACTORS IN TOXICATION
[rate of oxidation]
As long as the alcohol remains inside of the digestive tract, its effects
cannot be felt, nor can it be used for fuel. But since alcohol is ready for
use when swallowed it begins almost as once to circulate throughout the
body via the bloodstream. You previously learned that the process of
metabolism breaks down alcohol into carbon dioxide and water. The liver
can metabolize alcohol at a steady rate of about ¾ ounce of alcohol per
hour. This means that if more that one drink is consumed in an hour, the
alcohol circulates in the bloodstream until the liver can metabolize it. The
more alcohol consumed, the more potent the concentration of alcohol
that passes through the brain and other organs. Unlike the oxidation of
carbohydrates and fats, this process is constant and continuous, and it
continues until the last drop of alcohol leaves the body even if the cells
are not in need of the heat and energy produced. Also unlike
carbohydrates and fats, alcohol cannot be stored. It must be utilized as
soon as it is oxidized by the liver.
Sorry, we are currently
at capacity.
wahoo! we get
to go through
the bloodstream
again!
Please Come Again Later!
now entering
liver
MODULE TWO // FACTORS IN TOXICATION
[rate of oxidationcont.]
There are several factors that greatly contribute to how you are affected
by alcohol
1.
Quantity - how much you drink
2.
Speed - how fast you drink
3.
beverage type - what kind of drink you drink
4.
Body - how much you weigh, how healthy you are
5.
Food - how much you have eaten
6.
Attitude and Environment - how you think and feel
to the brain!
Brain
MODULE TWO // FACTORS IN TOXICATION
[quantity]
It should be of no surprise that the amount of alcohol consumed is most
important influence of how alcohol affects your body. The more alcohol
ingested, the longer the period required for absorption, and thus the
stronger the affects of alcohol. It is important to emphasize that it is the
amount of alcohol in the drink, not the number of drinks that dictates how
m
One 1.5 ounce of hard liquor, one 12 ounce can of
beer and one 5 ounce glass of wine contain about
the same amount of alcohol (10 15 gramsl) despite
having different volumes.
[speed]
Sipping a drink slowly over a period of time alleviates the amount of
alcohol absorbed into the bloodstream at once.
This prevents the
concentration of alcohol from becoming significantly high, mitigating the
physiological effects of alcohol in the bloodstream and organs. Gulping
a drink quickly sends more alcohol into the body, making it more
probable that the liver will not be able to process the alcohol
immediately.
The extraneous alcohol must then circulate
through the body, including to the brain,
until the
liver
can
metabolize it.
MODULE TWO // FACTORS IN TOXICATION
[type of beverage]
Different beverages with the same alcoholic content, but different
composition, produce different absorption rates. This is because the ratio
of alcohol to fluid concentration in wine and beer is higher than distilled
spirits. Beer contains a very low percent
once (however, it is not served in 1.5 oun
liquor). This dilution of alcohol by wate
rate of absorption in the stomach.
M
milks, tomato juice, or melted butter a
absorption.
Contrastingly, drinking mixed drinks
carbonation will increase the speed at w
alcohol is allowed into the small intes
and absorbed. The carbon dioxide in
soda quickly opens the pyloric valve, w
separates the stomach and small inte
Once inside the small intestine, the alc
quickly absorbed into the bloodstream
factor is actually more related to the c
the stomach, than the actual type
consumed.
The liver cannot distinguis
sources of alcohol, nor does it matter w
beverage was drunk once the alcohol
bloodstream.
f
l
h l
fl id
MODULE TWO // FACTORS IN TOXICATION
[body size & gender]
The amount of blood and water in your body is
proportional to your weight.
This means the
drinking the same amount of alcohol will
produce different alcohol to fluid ratios in
people of different weight. A lighter person has
less water to dilute the alcohol, and therefore
will have a higher concentration of alcohol in his or
her body than a heavier person who drank an
identical amount of alcohol.
A person's fixed rate of oxidation effects the amount of alcohol that can
be disposed.
This is determined by the quantity and activity of the
alcohol enzyme (alcohol dehydrogenase) in his liver cells. Thus, a larger
liver is more likely to oxidize alcohol faster. It has also been suggested
that women have less of the gastric form of the enzyme alcohol
dehydrogenase. The deficit of gastric alcohol dehydogenase forces the
body to process alcohol in the liver.
MODULE TWO // FACTORS IN TOXICATION
Additionally, women and men have different relative amounts of
body fat and water. The ratio of fat to water in
women is higher than the fat to water ratio in
men. This means that women's bodies have
less water to dilute alcohol. Since alcohol is
not very fat soluble, the decreased amount
of water in a female's body means that
she has a higher alcohol to water ratio,
and will thus become intoxicated faster than
a male counterpart of the same weight.
A women's menstrual cycle also significantly
influences the rate of absorption and metabolism
of alcohol.
During the premenstrual phase of
her cycle, alcohol is absorbed more rapidly
than
any
other
phase
of
the
cycle,
Healthy, alert people are likely to be less
influenced by alcohol than people with fatigue or
an illness. Both prescription and non-prescription
drugs may also drastically change the way
alcohol effects a person. Alcohol consumed in
combination with some drugs can cause sedative
effects double or triple that of drinking alcohol
alone.
[gender & health]
producing higher blood alcohol levels.
MODULE TWO // FACTORS IN TOXICATION
[food in stomach]
In an empty stomach, the only fluid available for diluting the alcohol are
those contained in or secreted by the stomach itself.
A person who
drinks on an empty stomach has a higher alcohol concentration in his
stomach than one who drinks the same mount on a partially or entirely
full stomach.
[attitude & environment]
In addition to having physiological effects on the body, drinking affects
people psychologically.
In social settings, a person may feel more
confident in consuming more alcohol in a shorter period of time in a
drinking game, than that same person would consume sitting in front of
the TV while watching a game.
Additionally, it has been suggested that psychological influences may
greatly impact the effect of alcohol. In studies done with young people
and alcohol, the mood and attitude of individuals have contributed to
the perception of intoxication, and resulted in behaviors that reflect that
of a person who has consumed more alcohol than actuality. It has been
argued that in light drinking situations, psychological factors are usually
even more influential than the alcohol.
MODULE TWO // FACTORS IN TOXICATION
[summary]
The effects of alcohol can vary drastically between two people, even if
they drink the same amount of alcohol. Factors that influence the speed
at which alcohol is absorbed into the bloodstream make up the majority
of tips for reducing the effects of alcohol. Psychological and social factors
Six factors influence how alcohol affects your body:
also seem to play a role in the level of intoxication.
1.
Quantity
2.
Speed
3.
beverage type
4.
Body
5.
Food
Attitude
& Environment
6.
The speed at which alcoholic drinks are consumed plays a large role in
intoxication. If alcohol is consumed faster than its rate of oxidation in the
liver, the alcohol is forced to continue to circulate in the bloodstream until
it can be metabolized. The higher the ratio of water to alcohol in drinks,
the more diluted the alcohol will be in the stomach. Food factors such as
how much was eaten before drinking, what was eaten, and how long
ago, can inhibit the immediate absorption of alcohol through the
stomach walls.
Biological factors such as gender and weight also
influence the concentration of water to alcohol in the body. The social
context in which the alcohol is consumed, psychological expectations
and thoughts about drinking have also been suggested to play a role in
the in toxicity levels caused by drinking alcohol.
MODULE TWO // FACTORS IN TOXICATION
[questions]
Fact Query
The most influential factor of intoxication is _______________.
One shot of hard liquor has the same amount of alcohol as _______
beer(s).
Given that two people of the same weight and gender drink the
same amount of alcohol, a person with a(n) empty/full stomach will
become intoxicated faster than a person with a(n) empty/full
stomach.
Concept Query
Many college students believe that using a straw will help them
"feel the buzz" faster. Using what you know about the main
factors of intoxication, describe a situation in which this
statement is true. Describe a situation when this statement is
false.