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My name is Urkle Olus Oxygen. I'm going to tell you about a hair raising
adventure I had about 157 years ago. Me and my best friend CO2, were in the
Structural Bases of Life Research Centre working on a Cray supercomputer, trying to
figure out why those huge monstrous humans need us to live. The computer had been
working for weeks and it still didn't have the answer. Then CO2 had one of the scariest
ideas I have ever heard in my entire life. He suggested to boldly do what no Oxygen or
CO2 molecule had done before, to make a record and map the path and make a report
on why the human race needs us to live. I suggested that his idea could be tested on
someone else, but he insisted that his brain wave was one that only we could execute
because of our experience. I know that I personally have travelled through
1,204,621,057 humans but it was always accidental. I would be travelling on my way
when all of a sudden the Nitrogen, Oxygen, Argon, Water Vapour, Carbon Dioxide,
Neon, Helium, Krypton, Hydrogen, Xenon, and Ozone gasses (all are commonly
known as AIR) started to move towards this black hole. Of course we all started
screaming and then we closed our eyes till we came out of the black hole again. But
this time CO2 and I would keep our eyes open and write down the horrendous
experience we had. But this experience I was about to have, took some school work. I
had to learn how to write, spell, and to go into depth on the anatomy of the human
body. After 16 years in school I graduated with first class honers and my title was a
"hyper supergenitic counter clockwise Oxygen atom."
Since I am telling you about what happened to me, I think I should go into depth
about myself. If you are not a moron, you would know that my atomic number is 8 and
my weight is 15.9994 and I make up about 20% of , I forgot the name.........OH!!
Earth's atmosphere. My boiling point or the temperature in which I turn into gas is 182.962. Pretty chilly hey. If you are a person who likes science you could tell me
that liquid oxygen is magnetic and can be held between the poles of a strong magnet.
Cool!! Anyway, I got a little side tracked.
A few days before I was to go on the mission, I took out life insurance, just in
case what I was about to see gave me a vasospasm, or what we call it, a heart-attack. I
also went to a psychiatrist because I was so nervous that when I tried to stand up my
knees would knock together. The trauma I was experiencing was incredible, so
incredible that it even amazed the leading doctors at that time. There was no cure, the
doctors said that I was "self destructing" my "sub atomic nucleic structure" and if I
didn't get myself under control, I would collapse because of exhaustion. I took dozens
of sleeping pills to get to sleep. In the morning, I had to drink at least three cans of Jolt
(twice the caffeine) to keep me awake. Around lunch time, I would get out the Molson
Canadian Ice (fungus pea) just to keep myself settled down. You could say I was "a
living hell."
Then the day came. It came with such swiftness that it just about knocked me
over, but it came. It was the day that I was to do what no sane oxygen atom had done
before, to keep my eyes open and record what happens to me when I first go into that
"black hole", sorry the nose. You see I got a got a lot smarter since I went to school.
Just befor I go on my trip, I want to talk about the things that I will write down.
I will be writing down notes as I see things happen. I will be writing in the present
tense, not the past. I will be doing that because that is what will be happening. As you
may know, this is the first time in my life that I will be doing this so I might get scared
but please stay with me. When I see things I will expand on what I see because that is
why I went to school. So here we go!!
As I enter the nose I see that the air enters in two streams, because the nostrils
(the two openings in the nose) are divided by the septum ,which is a thin wall of
cartilage (tough tissue) and bones. I see the nostrils contain hairs which aid in filtering
dirt out of the air. This guy had a lot of dirt on the sides of his nostrils so I knew he
didn't pick his nose. From the nostrils I enter the nasal passage, which lies above the
mouth. It was getting a little bit dark so I decided to turn my flashlight on. I saw
above the nasal passage three shelflike bones called turbinates which were covered
with mucus membranes which moisten the air. While looking at those structures, I
observed that these bones help warm the inhaled air also. Looking closely at the
mucus membrane, I see they are covered with microscopic, hairlike projections called
cilia. They were waving back and forth constantly, moving dust, bacteria, and fluids
from the nose to the throat for swallowing. Shifting my gaze to the highest part of the
nasal cavity, I could see the olfactory nerve receptors lying in a small piece of mucus
membrane about as big as a dime. These receptors give the human his sense of smell
by generating nerve impulses in response to chemicals in the air. One thing that really
struck me is that the main thing the nasal passage does is to warm the air and add
moisture to it before it goes any farther.<All these advantages of nasal breathing are
lost in mouth breathing.>
From the nasal cavity, I go into the pharynx, which is a cone-shaped tube that
connects the nose and mouth with the voice box and oesophagus. It looks about 5
inches long and has muscular walls lined with mucus membrane. As I'm going down, I
see a flap of cartilage called the epiglottis which is open. I guess I will be going
through it. Now I begin to see the Larynx, or the "Adam's apple," sometimes called the
voice box because it contains the vocal cords. While I keep observing, I notice that the
larynx is shaped like a box, and it has a supporting structure made up of nine sections
of cartilage. The thyroidcartilage, in front, and the cricoid cartilage, in the back, which
look to me as the most important structures. The thyroid cartilage consists of two
wing-shaped plates that meet to form the projection called the "Adam's apple." These
plates make up the side walls of the larynx. The ring-shaped cricoid cartilage forms
the back wall of the larynx. Now I begin to see the vocal cords, two bands of elastic
tissue that lie along the sides of the glottis wall. These muscles can stretch the cords,
change their shape or bring them close together. When the cords are close together, air
rushing between them produce sound. The shape and stretch in the cords determines
the pitch (highness or lowness) of the voice. The shape of the throat, nose, and mouth
determines the quality of a person's voice.
Now I begin to enter the t-t-trachea. It looks to me like a tube reinforced with
cartilaginous rings to prevent collapse. I look closely and notice that the trachea is
lined with cilia. Cilia look like hair. They are always in constant motion moving back
and forth, and carry dust or dirt taken in with the air upward toward the mouth. The
dust is mixed with mucus and the mucus even traps more particles in the air. I can hear
the swishing of the cilia as they move back and forth. As I am going down they were
getting pretty thick and I was weaving in and out of them. As I was doing that I could
see hundreds of dirt particles stuck to the mucus that the upper hairs had missed. The
farther down I go, the smaller the dirt particles get! At the lower end, the trachea
divides into two branches called bronchi. One extends to each lung. These too have
cilia and mucus in them. One thing I am noticing is that there are more special cells
called alveolar macrophages which are engulfing the particles and carrying them to the
mucus or destroying them. Now the bronchi tube I am in begins to divide into
countless small bronchial tubes and these are dividing into even smaller tubes called
bronchioles. While this is going on I am going to go over the mechanics of breathing.
Inspiration, or the intake of air, occurs when the chest cavity is increased in size and
therefore decreased in pressure. The enlargement of the chest cavity involves the
following movements: (1) The rib muscles contract and pull the ribs upward and
outwards and can be aided with the shoulder muscles. (2) The muscles of the resting,
dome-shaped diaphragm contract. This action straightens and lowers the diaphragm
and increases the size of the chest cavity below. (3) The abdominal muscles relax and
allow compression of the abdominal organs by the diaphragm. The enlargement of the
chest cavity results in decreasing of the air pressure within. In an equalizing
movement, air passes through the trachea and inflates the lungs. Expiration, or the
expelling of air from the lungs, results when the chest cavity is reduced in size. The
action involves the following four movements: (1) The rib muscles relax and allow the
ribs to spring back. (2) The diaphragm relaxes and rises to assume its dome-shaped
position. (3) The compressed abdominal organs push up against the diaphragm. This
action is increased during forced exhalation by contraction of the abdominal muscles.
(4) The elastic lung tissues, stretched while the lugs are full, shrink and force air out.
Now back inside the lungs. The bronchiole I am in ends in a sac called alveoli which
is composed of lung tissue. The walls of the alveoli are very thin, only one cell thick
but they are very elastic. While I am floating around in the alveoli, I make an
inspection. I notice that I can see many minute blood vessels outside the alveoli walls
called capillaries. Now I am beginning to see that I am moving toward the wall of the
alveoli. As I am moving, I can see spaces between the cells so I can squeeze through;
and I do.
I thought that the respitory system was exciting, but the circulatory system is
even better!! Now I am in a fluid called blood. Its main purpose is that it is a
transporting medium for all substances in the body. For example it assists in the
transportation of digested food, cell wastes, water, oxygen, heat, and secretions. Blood
is a fluid tissue. It is a peculiar tissue in that the cells are scattered among the
nonliving substances composing the fluid portion. The average human has about 12
pints of blood, which compose about nine per cent of the body weight. The fluid
portion of the blood is the plasma, and the blood cells are called the solid components,
or the corpuscles.
Blood plasma looks straw-coloured and nine-tenths of it is water. The proteins
in plasma give it the sticky quality. One of them, fibrinogen, is essential in the clotting
of the blood. When fibrinogen is removed from plasma, two other proteins remain.
One is serum albumin, which is necessary to normal blood and tissue relationship
during absorption. The other is serum globulin, which gives rise to antibodies causing
immunity to various diseases. Inorganic minerals, dissolved in water give plasma a salt
content of about 1%, while sea water is approximately 3%. These compounds include
carbonates, chlorides, and phosphates of the elements calcium, sodium, magnesium,
and potassium. They are absolutely essential to the blood and to the normal
functioning of the body tissues. Without calcium compounds, blood will not clot in a
wound. Digested foods are present in plasma in the form of glucose, fatty acids and
glycerin, and amino acids. Nitrogenous wastes, resulting from protein metabolism in
tissues, and urea are also in plasma.
Now I am going to explain the solid components of the blood which I can see all
around me. First I will start with the red blood cells which are shaped liked disks with
both sides concave. The red cells are so small that ten million of them can be spread in
one square inch. They are so numerous that, placed side by side, they would cover an
area of 3,500 square yards. It is estimated that the blood of a normal person contains
25 trillion (25 000 000 000 000) red blood cells, or enough to go around the earth four
times at the equator if they were laid side by side. The red blood cells are produced in
the marrow of the bones. During development, they have nuclei, as do other cells.
Normally, by the time they are ready to be released into the blood stream they have lost
their nuclei. The average life of a red cell is about 20-120 days. Worn-out cells are
filtered out of the blood in the spleen and liver. At the same time, certain compounds
are released into the blood stream and used in the manufacture of new red blood cells.
I'm not sure what role they do in the body but I am sure that I will find out.
The white blood cells which I can see are larger than the red blood cells and
differ from them in three ways: (1) White blood cells have nuclei. (2) White
corpuscles do not contain haemoglobin. (3) Some white cells move much like the
ameba. The white blood cells are less numerous than the red cells, the ratio being
about one white cell to every 600 red cells. White corpuscles are formed in the red
bone marrow and in the lymph glands. Normally there are about 8,000 in one cubic
millimetre of blood as against four and one-half to five million red cells.
The white blood cells that can move about are able to ooze through the capillary
walls into the tissue spaces. Here they engulf solid materials, including bacteria. They
are a important defence of the body against infection. Whenever an infection develops
in the tissues, the white cell count may go from 8,000 to more than 25,000 per cubic
millimetre. White cells collect in the area of an infection and destroy bacteria. the
remains of dead bacteria, white corpuscles, and tissue fluid is pus.
Another solid component of blood is the blood platelets. As I look around me
they look like they are irregularly shaped, colourless bodies, much smaller than the red
cells. Platelets are not capable of moving on their own but float along in the blood
stream. They have an important function in the formation of a blood clot.
Now enough of my babbling. At this moment I am moving toward a red blood
cell. On the red blood cell is a substance called haemoglobin. Haemoglobin is a
conjugated protein, containing four atoms of iron, which forms bonds easily and
permits carbon dioxide and oxygen (that's me!) to transport. I see a molecule of CO2
leave the red cell and I am moving toward it like it is a magnet. I stick to the
haemoglobin which is on the red blood cell. I can't even move and I am scared. I think
I am going to die. I notice that all the red cells are red and not as pale as they used to
be. I also see that I am moving, I am out of the capillary, have passed through the
venules and am in the left pulmonary veins. As I am travelling, I hear a loud thumping
sound, and it is getting louder. I look in my note book and find that I am nearing the
heart. Now I am getting closer and the sound is getting very loud. I feel a suction all
around me. As I come out of the left pulmonary veins, I enter a big space in the heart
called the left atrium. This is where the blood enters from the lungs. Then I pass
through the bicuspid valve into an even larger opening than the atrium and this is
called the left ventricle. The left ventricle is where most of the muscle is on the heart
and it pumps the blood to the entire body. As it compresses, the red blood cell I am
attached to passes out through the aortic semilunar valve into the aorta.
As I am in the aorta, I am going to talk about the heart. The heart, as you know,
is an organ that pumps blood to the body. An adult heart is about 5 inches long and
weighs about 9 ounces. The heart is completely enclosed by a thin sac called the
pericardium. The inside of the pericardium has a smooth lining that discharges a
slippery liquid. The heart beats smoothly and with little friction against the moistened
lining. A muscular wall called the septum divides the heart lengthwise. The heart has
four chambers two of which I have described. An adult's heart beats about 70 times a
minute. The walls of the heart are made of a special kind of muscle. The heart muscle
contracts and relaxes regularly and automatically. A beat is one complete contraction
and relaxation of the heart muscle. One part of the heart's muscle system, the sinoatrial
node, has the job of starting each heartbeat, setting the pace, and causing the
contraction of the heart muscle. It has been called the "pacemaker" of the heart. I
could go on and on about this vital organ but I will stop there.
Right now I am in the aorta which is one of many arteries in the body, but it is
the biggest. As blood comes out of the left ventricle it expands and adds to the
pressure of the blood and helps force it to the body. I refer to this as systolic pressure.
The recoil of the artery wall maintains part of the pressure while the ventricles are at
rest. This is the lowest pressure in the arteries, or diastolic pressure. If the aorta were
cut blood would spurt out in a stream six feet or more. While I am going through the
aorta I pass the openings of the left and right coronary arteries. They are the ones that
supply blood to the heart. Now I am in the aortic arch and it starts to branch off into
separate arteries. The blood cell I am on I guess decides to take me down the thoracic
aorta which is going down through the chest. Then I go down to the abdominal aorta
which splits in to two different arteries. And of all things we get caught in a whirlpool
and I decide to take the time to socialize.
I see another molecule and stop him and ask him his name. He tells me that his
name is Brutus Thorac the 3rd. I ask him how he got to the place and this is his story.
Brutus was in a hamburger and was part of a long chain of sugars called
carbohydrates? As you may know it is part of a long chain of sugars called starch,
which is made up of single hexose molecules and Brutus's chemical formula is
C6H12O6. Anyway he is a molecule and was in a hamburger and then that big black
hole picked him up and put him in the hole. In the hole called the mouth were teeth
that the bread he was in was crushed into little bits. Let me describe the mouth. The
mouth has structures in it called teeth. There are 32 teeth in the mouth. The first two
teeth are the incisors which cut the food. Next is the canine tooth which rip the food.
They are sharpm and pointed. The next are the premolars that crush the food into little
bits. The molars which have a large surface area and are grinding and crushing teeth
too. There is a tooth called a wisdom tooth but it gets usually pulled out. Haa!! The
chief function of the mouth is to prepare the food for digestion. The top of the mouth
is called the hard palate and is a bony structure covered with several membranes. The
soft palate lies just back of the hard palate. It is formed by folded membranes which
extend from the rear portion of the hard palate and fasten along the sides of the tongue.
The tongue lies in the floor of the mouth and extends into the throat. This muscular
organ performs several different functions. 1. It acts as an organ of taste. Scattered
over the surface are tiny projections called papillae. These papillae contain taste buds.
They have nerve endings that are stimulated. The result is that the humans can taste
sweet, bitter, salty, and sour. 2. The tongue aids in chewing by keeping the food
between the teeth. 3. During swallowing, food is worked to the back of the tongue.
When the tongue is jerked downward, food lodges in the pharynx and the food goes
down. 4. The tongue rolling in the mouth keeps the inner surface of the teeth clean. 5.
The tongue is essential in speech. Also in the mouth are the three pairs of salivary
glands that secrete saliva. The names of the three glands are the parotid, sublingual,
and the submaxillary glands. The parotid gland is on top of the mouth. The saliva
helps in the digestion of food and cleaning of the teeth, being alkaline, it neutralizes
acids in the mouth. Saliva also lubercates the food, kill bacteria, and stops the
sensation of thirst. An important enzyme in saliva is called amylase which breaks
down starch into smaller parts called maltose. Saliva contains more than 95% water
and contains mineral salts, lubercating mucus, and the enzyme ptyalin. Ptyalin
converts starch (Brutus) into maltose, a disaccharide.
Now I will get back to Brutus. While he was getting chewed up by the molars
the saliva was breaking him down too. He saw his chain break off ahead of him and he
got scared. When the chain finished breaking off all around him, he was only
connected to a fraction of what once the chain was. He was then a double sugar. And,
mean while, he and his buddies were getting sloshed around by that wicked tongue and
that sticky saliva was everywhere. With all this happening, he was being slowly
moved to the back of the mouth. In the act of swallowing, which is when the food
goes from the mouth to the stomach, he passed through the pharynx (it is where I
passed through too) to the oesophagus. This is a tube which is about a foot in length
and connects the mouth to the stomach. He went down the tube with the aid of layers
of muscle in the wall of the oesophagus. One layer is circular, and squeezes inward.
The other layer is longitudinal, and contracts in a wave which travels downward,
pushing the food ahead of it. Just before he entered the organ called the stomach he
passed the cardiac notch.
Now he entered the stomach which is a somewhat J-shaped. It lies in the upper
left region of the abdominal cavity just below the diaphragm. The stomach wall
contain three layers of smooth muscle, each arranged differently. One layer is
longitudinal, one is circular, and one is angled, or oblique. Contraction of the smooth
muscle fibers of the various layers in different directions causes the twisting,
squeezing, and churning movement of the stomach. The lining of the stomach is thick,
wrinkled membrane. Numerous gastric glands are embedded in the stomach lining.
Each gland is a tiny tube with an opening into the stomach. The walls of each gland
are lined with cells which secrete gastric fluid containing an enzyme and hydrochloric
acid. This secretion passes directly into the stomach. The principal enzyme in gastric
fluid is pepsin. This enzyme acts on protein, splitting the complex molecules into
simpler groups of amino acids, known as peptones and proteoses. The hydrochloric
acid, in addition to providing the proper medium for the action of pepsin, dissolves
insoluble minerals and kills many bacteria which enter the stomach with food. It also
regulates the action of the pylorus, which opens at the completion of the stomach
digestion and allows food to pass to the small intestine.
The food which passes from the stomach to the small intestine contains: 1. fats,
unchanged 2. sugars, unchanged 3. some starches which were not acted upon by the
ptyalin of saliva 4. coagulated milk casein 5. some proteins unchanged by the pepsin of
the gastric fluid 6. peptones and proteoses formed from pepsin acting on protein. Poor
Brutus remained in the stomach for three hours. While he was there he was churned
back and forth in a circular path. This action separates the food particles and mixes
them thoroughly with stomach secretions. At the completion of stomach digestion, the
valve at the intestinal end, the pyloric valve, opens and closes several times sending
Brutus through on the second squirt. Now he was in the duodenum, the upper ten
inches of the small intestine. The duodenum carves upward, then backward and to the
right, beneath the liver. Here is where secretions of the liver and pancreas enter.
Beyond the duodenum is a second much longer region, the jejunum. This portion,
about seven and one-half feet in length, is less coiled than the other regions. The lower
part of the small intestine is the ileum and it is about 15 feet long, coils through the
abdominal cavity before joining the large intestine.
As Brutus entered the duodenum, secretions from the liver entered. The liver is
the largest gland in the body and it weighs about 3 and a half pounds. It is a dark
chocolate colour and lies in the upper right region of the abdominal cavity. Bile is
produced by the liver and is a brownish-green fluid. It passes from the liver in a series
of bile ducts which form a Y. As bile is secreted in the liver, it passes down one
branch of the Y, then travels up the other branch to the gull bladder. Here the bile is
stored and concentrated as part of the water is removed. The base of the Y is the
common bile duct. This tube carries bile from the gull bladder to the upper end of the
small intestine, or duodenum. If the common bile duct becomes clogged by a
gallstone, or a plug of mucus, bile enters the blood stream and causes a yellowing of
the eyes and skin, known as jaundice. The liver performs several vital functions. In
receiving glucose from the blood and changing it to glycogen, it serves as a storehouse
in holding reserve carbohydrates as glycogen. In acting on amino acids and forming
urea, it is an organ of excretion. All these changes involve food after digestion. As a
digestive gland, the liver secretes bile which acts on food in the small intestine. In the
formation of bile, the liver plays a part in using what might otherwise be discarded as
waste. Part of the bile is formed from worn-out haemoglobin that the blood system can
no longer use. Bile has several important functions: l. It is partially a waste substance
containing material from dead red blood corpuscles filtered from the blood stream by
the liver. 2. It increases the digestive action of lipase, an enzyme produced in the
pancreas, by breaking globules of fat into small droplets, in the process called
emulsification. 3. It helps to neutralize the hydrochloric acid from the stomach so that
digestion can take place in the intestine. Actually, bile is not a digestive secretion. In
emulsifying fats, it splits large fat particles into smaller ones, producing a milky liquid
called an emulsion. In this form, pancreatic fluid can act on fats more readily.
The pancreas is a many-lobed, long, whitish gland, quite similar in general
appearance to a salivary gland. It lies behind the stomach and the upper end of the
small intestine, against the back wall of the abdominal cavity. It performs two entirely
different functions. The production of insulin and the digestive secretion, pancreatic
fluid, passes into the small intestine through the pancreatic duct, which leads to a
common opening with the bile duct in the wall of the duodenum. Pancreatic fluid acts
upon all three classes of organic nutrients. This digestive fluid contains the following
three enzymes: l. trypsin; 2. amylase; 3. lipase. Trypsin continues the breakdown of
proteins which began in the stomach, by changing peptones and proteoses to still
simpler amino acid groups called paptids. In addition, it may act upon proteins which
were not simplified during stomach digestion. Peptide are not the final product of
protein digestion. Only one additional step is necessary to form the amino acids which
are used by the body tissues. Amylase duplicates the action of the ptyalin in saliva by
changing starch into maltose. This is how the potatoes you did not chew enough are
changed to sugar. Lipase splits fat into fatty acids and glycerin. This is the only
digestive action on fats which reduces them to the form in which they are absorbed.
The intestinal glands secrete intestinal fluid. The mucous lining of the small intestine
contains many tiny embedded glands that are called intestinal glands. They secrete
intestinal fluid, a highly alkaline substance containing four principal enzymes: 1.
erepsin; 2. maltase; 3. lactase; and 4. sucrase. Erepsin completes protein digestion
by changing peptids, formed by the pancreatic fluid, to amino acids. Maltase splits the
double sugar, maltose, into the simple sugar, glucose,(so Brutus is now a single sugar
called glucose) the final product of carbohydrate digestion. Lactase has a similar
action on lactose, or milk sugar, in changing it to glucose. Sucrase acts on sucrose and
changes it to the simple sugars glucose and fructose. Thus, with the combined action
of bile, pancreatic fluid, and intestinal fluid in the small intestine, all three classes of
foods are completely digested. As simple sugars, fatty acids and glycerin, and amino
acids, they leave the digestive system and enter the blood and lymph.
The duodenum is also where secretions from the pancreas enter, this process is
described above.
For Brutus to be absorbed into the blood stream, another process must occur.
This process occurs in the villi. A magnified portion of the small intestine shows that
its irregular lining gives rise to great numbers of fingerlike projections called villi.
These projections are so numerous that they give a velvety appearance to the intestinal
lining. Within the villi are branching lymph vessels, called lacteals, and blood vessels.
The villi bring blood and lymph close to the digested food and increase the absorption
surface area of the intestine enormously. Absorption is increased further by a constant
swaying motion of the villi through the intestinal content.
Glycerin and fatty acids enter the villi and are carried away by the lymph. They
eventually reach the general circulation and travel to the tissues. Glucose (Brutus) and
amino acids, however, enter the blood vessels of the villi. Brutus, however, does not
get carried by a red blood cell but floats around in the plasma. From the villi they are
carried directly to the liver through the portal vein. This is called portal circulation and
it includes an extensive system of veins which lead from the spleen, stomach, pancreas,
small intestine, and colon. The large veins of the portal circulation unite to form the
portal vein, which enters the liver. In the liver some of the wastes and poisons of the
blood are taken out. Additionally, some substances produced by the liver help the
body fight disease and enable blood to clot. The liver also manufactures various blood
proteins, including albumin, globulins, and fibrinogen. The liver also secretes
cholesterol, a fatty substance. The body uses cholesterol to build cell membranes and
to manufacture certain hormones, including the sex hormones. Hormones are
chemicals that influence various body functions. Liver cells use cholesterol to
manufacture bile salts.
From the liver, Brutus, entered the inferior vena cava which is to the right of the
heart. Then he was pushed and sucked into the right atrium and passed through the
tricuspid valve. From the valve he entered the right ventricle, passed through the
semilunar valves of the pulmonary artery and entered the pulmonary artery. The
pulmonary artery branched off in two directions and Brutus took the left pulmonary
artery. This artery took him to the left lung which has two lobes. Here the blood
looses CO2 and get O2 then Brutus went back to the heart through the left pulmonary
veins. He then entered the left atrium and passed through the bicuspid valve into the
left ventricle. From here he went through the semilunar valves of the aorta and then
was in the aorta. He went by the aortic arch and into the thoracic aorta, then down to
the abdominal aorta where he met me!!
I told him that was some story and that his journey was even worse than mine.
He asked me why I was here and I told him that I was recording everything that
happened to me, I was kind of an experiment. He said that was cool and we said our
good byes and then we went our separate ways.
Now I am out of the whirlpool and going into the left branch of the abdominal
aorta called the common iliac artery. This artery goes down the left leg of the
individual I am inside of. The common iliac branches off and I go into the external
iliac artery. It branches off so I go into the femoral artery. From there I then go into
the post peroneal artery which is just below the left knee. I know I am sounding
complicated but please stay with me. From the post peroneal artery I go into the lateral
plantar artery which is near the heal of the foot. I keep branching off into smaller and
smaller arteries until they aren't arteries anymore. They are than called arterioles which
are small blood vessels that carry blood away from the heart. The arterioles then
branch into capillaries which my red blood cell can barely fit through. Only one blood
cell can go through at a time and they go one after the other.
As I am in the capillary the walls are thin and one-celled. The spaces between
the cells are big enough so I can pass through but not my red blood cell. Since there is
more carbon dioxide where I am than oxygen the carbon dioxide takes my place by the
process of diffusion. I then pass through a membrane and if you don't know what a
membrane is I will tell you. A membrane is a layer of tissue through which the cells
are enclosed in and through which they can obtain their food. The membrane is made
up mainly of protein. The membrane also hold the protein in the blood from getting in.
Now I am in between the cell and in a fluid called tissue fluid. The tissue fluid is
connected to the lymphatic system but this system is another story. While I am here I
will tell you facts about cells. The cell is the basic unit of life. The body of a human
being has more than 10 million million (10,000,000,000,000) cells. Also there are all
different kinds of cells. If you want to know, I am near a group of muscle cells. I will
talk more about the cell in a minute.
Now I am floating around in the tissue fluid and I am getting nearer to one of the
cells. As I get closer I see spaces in the cell wall or membrane. The membrane
encloses the entire cell, the nucleus, and all the organelles. The membrane also hold
the cell together. Most membranes consist of a double layer of fatty substance called
phospholipid. Proteins occur at various points and extend to different depths within
the double layer of phospholipids. Only needed materials can enter the cell and its
parts because of the structure and chemical composition of the membranes.
Now I have squeezed through the cell wall and I am floating around in a
substance called cytoplasm. The cytoplasm is all the cell except the nucleus. Proteins
are made in the cytoplasm, and many of the cell's life activities take place there. Also
in the cytoplasm the sugars are broken down into pyruvic acid, and a small amount of
ATP is produced. Many tiny structures called organelles are located in the cytoplasm.
Each has a particular job to do. These organelles are called mitochondria, lysosomes,
the endoplasmic reticulum, centrioles, and golgi bodies. Mitochondria are the power
producers of the cell. A cell may contain hundreds of mitochondria. These sausageshaped structures produce almost all the energy the cell needs to live and to do its
work. Most of your energy comes from the mitochondria, the power producers of a
cell. The mitochondria are like a power plant which burns fuel to produce the
electricity that runs machines. The food humans eat is the fuel that is "burned" inside
the mitochondria. A product of this burning is a compound called adenosine
triphosphate (ATP). ATP is the "electricity" that runs the cell's activities. It supplies
the energy when a protein is made, a muscle cell contracts, a nerve cell sends, a
message, or a gland cell produces a chemical. An ATP molecule consists of three
substances: (1) adenine, (2) ribose, and (3) three phosphate groups. Chemical bonds
(forces that hold atoms together) link the phosphate groups together like railroad cars.
The bonds that attach the second and third phosphate groups are especially rich in
energy. When they are broken, energy is released. Lysosomes are small, round bodies
containing many different enzymes, which can break down many substances. For
example, lysosomes help white blood cells break down harmful bacteria. Endoplasmic
Reticulum is a complex network of membrane-enclosed spaces in the cytoplasm. The
surfaces of some of the membranes are smooth. Others are bordered by ribosomes-tiny round bodies that contain large amounts of RNA. Ribosomes are the cell's
manufacturing units. The proteins the cell needs in order to grow, repair itself, and
perform hundreds of chemical operations are made on the ribosomes. Centrioles look
like two bundles of rods. They lie near the nucleus, and are important in cell
reproduction. Golgi bodies, also called Golgi complex or golgi apparatus, consist of a
stack of flat, baglike structures that store and eventually release various products from
the cell.
Now as I look around I also see a big dark shape located near the centre of the
cell. It is called the nucleus. The nucleus is the control centre that directs the activities
of the cell. A nuclear membrane surrounds the nucleus and separates it from the
cytoplasm. The nucleus contains two important types of structures, chromosomes and
nucleoli. Chromosomes are long, threadlike bodies that normally are visible only when
the cell is dividing. Chromosomes consist chiefly of two substances--DNA and certain
proteins. Lined up along the chromosomes are the genes, the basic units of heredity.
Genes control the passing on of characteristics from parents to offspring. Each gene
consists of part of a DNA molecule. The DNA that makes up the genes determines
that a dog will give birth to a dog instead of a fish. It determines your height, the
colour of your eyes, the shape of your hands, the texture of your hair, and thousands of
other characteristics. DNA works its wonders chiefly by directing the production of
complicated chemical substances called proteins. The cell's structures are built mostly
of proteins. In addition, certain proteins called enzymes speed up chemical reactions in
the cell. Without enzymes, these reactions would occur very slowly, and the cell could
not function normally. Thus, the kinds of proteins a cell makes largely determine the
nature of the cell. Nucleoli are round bodies that form in certain regions of specific
chromosomes. Each nucleus may contain one or more nucleoli, though some cells
have none at all. Nucleoli help in the formation of ribosomes, the cell's centres of
protein production. Nucleoli are made up of proteins and RNA (ribonucleic acid).
RNA is chemically similar to DNA and plays an important role in making proteins.
Another thing I can see in the cell is a vacuole. A vacuole is like an empty space
where the cell can store wastes and food.
After floating around in the cytoplasm I eventually go into the structure called
mitochondrion. The amino, fatty, and pyruvic acids also entered the mitochondrion. I
see enzymes breaking down these substances further in a series of chemical reactions.
I guess that I must also be present for these reactions to take place. With all these
reactions taking place at the same time, I am very dazed. Suddenly I notice that I am
attached to a carbon atom. WOW!!!! You know what, I think I know the chemical
formula for a cell to produce energy. It is C6H12O6 + O2 = H2O + CO2 + energy. That
is Sugar (Brutus) plus oxygen (me, Urkle Olus Oxygen) equals Water plus Carbon
dioxide plus energy. Energy which is in the form of many molecules of ATP. I can
see the ATP then leave the mitochondria and provide power wherever it is needed in
the cell. For every job that is done, enzymes break the ATP phosphate bonds and
release the energy.
Now that I am a carbon dioxide molecule I am leaving the cell by the process of
diffusion. Diffusion is when substances diffuse from areas of greater concentration to
areas of lesser concentration. What also helps the water move around is the fact that
proteins in the blood can't get through the membrane layer but salt can. The salt draws
the water into the cell and the proteins can draw the water out to the capillaries. The
blood pressure also pushes the water out.
I pass through the cell wall and into the tissue fluid. From there I pass through
another membrane that holds the groups cells together and now I am in the capillary. I
see a oxygen molecule leave a red blood cell and then I (CO2) float over to the red
blood cell and stick to it (I stick to the haemoglobin like before). From the capillary I
go into a venule and then into a vein. First I will tell you what an artery is; then what a
vein is. Arteries have elastic, muscular walls and smooth linings. This is what an
artery is made up of from the inside to the outside, first there is a membrane called the
serous membrane, next there is smooth muscle tissue, and last there is the connective
tissue. Arteries must be elastic to absorb part of the pressure resulting from contraction
of the ventricles. This expansion can be felt in the wrist and in other parts of the body
where arteries are near the surface. It is know as the pulse. The muscles of the artery
walls are controlled by nerves. When these muscles contract, they reduce the size of
the artery and raise the blood pressure. Veins carry dark-red blood; that is, blood
lacking oxygen. Veins aren't much different in what makes them up except that they
are bigger and that they have more valves. In the skin the veins have a bluish colour
due to the fact that the skin contains a yellow pigment which changes the appearance
of the dark-red blood. The walls of the veins are thinner and less firm than those of
arteries, and their internal diameter is proportionally larger. Many of the larger veins
are provided with cuplike valves which prevent the backward flow of blood. Veins
have no pulse wave and the blood pressure within them is much lower than that of
arteries. Blood pressure resulting from heart action is almost completely lost as blood
passes through the capillaries. Blood from the head may return to the heart with the
aid of gravity, but in the body regions below the level of the heart other factors are
required. Venous flow from these regions are aided by the working muscles, the
vacuum created in the chest during inspiration, and, to a small extent, by the sucking
action caused by the contractions of the heart. All this circulation is called the
systemic circulation.
The first major vein that I travel up toward the heart is called the small
saphenous vein and it travels up the heal and the back of the leg. As I go up I pass a
few valves and my vein then goes into the vein called the femoral vein. From the
femoral vein I then enter the common iliac vein and then it goes into the inferior vena
cava. The inferior vena cava is then joined by the superior vena cava before entering
the heart. I then entered the first part of the heart called the right atrium. Now I am in
the right ventricle, but before I entered the right ventricle I first passed through the
tricuspid valve. From there I go through the semilunar valves of the pulmonary artery
and passed into the pulmonary artery. The pulmonary artery then splits into two
arteries and my red blood cell decides to take the left pulmonary artery. This artery
then splits into more arteries and eventually into arterioles and capillaries. In the
capillary we start to slow down as we near the alveoli. When we are right against the
alveoli I (CO2) then fall off the red blood cell and pass through a membrane called the
pleural membrane and enter into the middle of the alveoli. I then see an oxygen
molecule take my place and it is attached to the red blood cell. So now I have just
gone out of the circulatory system and have entered the raspatory system again. Right
now I am in an alveoli that is at the end of a bronchus tube called the lateral basel and
it is in the left lung. The left lung has two lubes and the right has three. Now I enter
the bronchiole and it goes into a bigger tube called bronchial and it enter the bronchi
tube. The bronchi tube is the main tube that enters each lung. As I go up the trachea I
noticed the cilia as I did when I went down. Just before I pass out of the trachea I
notice a structure that I didn't notice when I came in. It is called the epiglottis. The
epiglottis sits at the upper end of the trachea and it is a lid. During swallowing, the end
of the trachea is closed by the epiglottis. At other times it remains open for breathing.
The epiglottis keeps the food from going down the wrong hole.
Now I enter the nasal passage and I once again see the hairs and mucus, but,
there isn't any dirt so I gathered that someone taught him to pick his nose and eat it to
recycle those valuable proteins that his body needs. Who am I to say that it is bad.
Guess what? I can see a light at the end of the tunnel, the nose. Now I am outside in
the nice fresh air and I am heading toward a plant!! This is stupid. I get the feeling
that I am going to see some more reactions take place before a can get back to the
Structural Bases of Life Research Centre. THE END!!!
Information about my non-fiction story.
37592 - Character Count
8223 - Word Count
580 - Line Count
626 - Sentence Count
62
- Paragraph Count
15
- Page Count
4
- Average Word Length
13
- Average Word Per Sentence
43
- Maximum Words Per Sentence
Sources to whom I give credit.
Main Author
Book Title
Publisher and Date
James H. Otto
Modern Biology
Holt, Rinehart and Winston, 1960
Carmine D. Clemente
Anatomy
Lea and Febiger, 1975
Aaron O. Wasserman
Biology
Meredith Corporation, 1973
Mr. Morris
Notes
HSS, 1994
To many
World Book Encyclopedia Scott Fetzer Company, 1986
PS -- I didn't use your text book you gave me because I had a three better ones at
home.
Here is a blonde joke you never heard before.
Jean: Do you think she is a natural blonde or a bleached blonde?
Zona: I think she is a suicide blonde.
Jean: What kind is that?
Zona: Dyed by her own hand.