Download Document

Study Sheet A
THE CIRCULATORY SYSTEM – THE BLOOD
Living cells need a constant supply of food and oxygen. Blood supplies these substances to all cells of the
body. It transports the oxygen from the lungs and food from the digestive system. It also removes waste products by
transporting them to the lungs and to the excretory organs such as the kidneys, liver, and skin. Among the wastes
transported are carbon dioxide, urea, ammonia, and other nitrogenous wastes.
Blood is a liquid composed of blood cells (45%), and a liquid in which the cells float, called plasma (55%).
There are three types of blood cells: red cells, white cells, and platelets.
Red blood cells, known as erythrocytes, are the most numerous. They are manufactured in the marrow of
certain bones. Marrow is a soft connective tissue in the cavities of most bones. Red blood cells contain an iron-rich
substance called hemoglobin. It is the hemoglobin in blood that carries oxygen from the lungs to the body cells and
aids in transporting carbon dioxide back to the lungs. Also, it is the hemoglobin that gives blood its red color. Under
a microscope, red blood cells look like thick discs, concave on both sides. Mature red blood cells contain no nucleus
and therefore cannot multiply, as white blood cells do.
White blood cells, called leukocytes, are somewhat larger and are less numerous than red blood cells. For
every white blood cell, there are 500-1,000 red blood cells. Most white blood cells are produced in the bone marrow,
though one third of them originate in lymph nodes and the spleen. They contain a nucleus, but no hemoglobin, and
are, therefore, colorless. White blood cells are the body’s chief defense against disease. When there is an infection,
they gather, multiply, and engulf the bacteria that have invaded the body.
Platelets are the smallest and most numerous of the blood cells. Without platelets, the blood would not clot.
Platelets gather at the site of a broken blood vessel, and then they disintegrate, releasing a chemical factor that starts
the clotting process. Through a complex series of chemical reactions, threads of a protein called fibrin are formed.
The fibrin forms a mesh at the site of the wound. This fibrin traps blood cells. The resulting clot plugs up the hole in
the blood vessel and prevents further blood loss.
Plasma, the liquid in which the blood cells float, is about 92% water. Plasma contains carbon dioxide,
hormones, antibodies, wastes, and enzymes. Simple sugars, glycerol, amino acids, vitamins, and minerals are also
dissolved in the plasma.
Questions
1.
2.
3.
4.
5.
____________ blood cells carry oxygen around the body.
____________ blood cells are disease fighters.
____________ are blood cells that function in helping the blood to clot.
____________ is the liquid part of the blood.
Red blood cells are manufactured in bone ____________.
Activities
(2)
1. Glue Activity Sheets 1 through 3 together to make your display sheet for the Circulatory System.
2. Locate diagram A on your display sheet. Color the red blood cells red (R), and the plasma yellow (Y). Label a
red blood cell, a white blood cell, platelets, and plasma in the spaces provided on your display sheet.
Copr. Christopher Lee Pub!., 1978, Route 1, Box 582A, Houghton Lake, Mich. 48629
Study Sheet B
THE CIRCULATORY SYSTEM – THE HEART
(3)
The heart is a muscular pump which circulates blood throughout the body. The heart is about the size
of a fist and is divided into four chambers, two above and two below. The two upper and smaller chambers
are called auricles or atria, while the two lower chambers are called ventricles.
The right side of the heart is separated from the left side of the heart by a muscular wall, called the
septum. Valves separate the right auricle from the right ventricle, and the left auricle from the left ventricle.
Valves keep the blood from flowing in the wrong direction.
Oxygen-poor (blue) blood, which comes back to the heart from the body cells, collects in the right
auricle. By the contraction of the right auricle, the blood is forced through a valve into the right ventricle. As
the heavy, muscular, right ventricle contracts, it forces blood out of the heart, through another valve, to the
lungs. In the lungs, carbon dioxide is exchanged for oxygen.
Oxygen-rich (red) blood returns to the heart from the lungs and collects in the left auricle. By the
contraction of the left auricle, the blood is forced through a valve into the left ventricle. From here, the left
ventricle pumps it through another valve to the main arteries of the body. The arteries distribute the blood to
capillaries which, in turn, convey it directly to the body cells. In the cells, the oxygen from the blood is used
for internal respiration. Internal respiration includes those chemical processes by which oxygen is used to
burn or oxidize food, thereby producing energy.
The left ventricle is the most muscular chamber because it has to pump the blood through all the
vessels of the body except those to and from the lungs. The heart is slightly tilted to the left, which explains
why the heartbeat seems to be to the left of center. The number of heartbeats per minute is controlled by the
nervous system.
The process of pumping blood from the heart to the body cells and back again is called the systemic
circulation. The process of pumping blood from the heart to the lungs and back again is called the
pulmonary circulation.
Questions
1.
2.
3.
4.
5.
An upper heart chamber is called an atrium or an ____________.
Each side of the heart is separated from the other side by a wall called the ____________.
The pulmonary circulation is the route from the heart to the ____________ and back again.
What word best describes the function of the heart?
What keeps the blood flowing in the right direction?
Activities
1. Locate Overlay 1 on Activity Sheet 4. Color the shaded portions of Overlay 1 brown (Br). Do not color
over the identifying numbers.
2. On you display sheet, color the two inside chambers on the left side of the heart red (R). Remember
that the right and left are reversed as you look at the picture of the heart. Continue by coloring the
two inside chambers on the right side of the heart blue (B).
3. Color the rest of the heart, the valves, and the septum brown (Br).
(4)
4. Cut out Overlay 1. Then, cut at Slits 1 and 2 as marked on your display sheet. Next, attach Overlay 1
to your display sheet. To attach, slide the tabs through the appropriate slits. Glue the tabs to the
back of your display sheet.
5. Label the right auricle, left auricle, right ventricle, left ventricle, septum, and lung in the spaces
provided on your display sheet.
Copr. Christopher Lee Publ., 1978, Route 1, Box 582A, Houghton Lake, Mich. 48629
Study Sheet C
(5)
THE CIRCULATORY SYSTEM – THE BLOOD VESSELS
Blood circulation in the human takes place in a closed system. In this system, blood, which is
pumped out from the heart is restricted to blood vessels, whereas in an open system, the blood flows freely
into spaces around body tissues. In the human, blood is carried in three main types of vessels. Those
taking blood away from the heart are called arteries; those taking blood toward the heart are called veins.
In other words, arteries distribute the blood; veins collect it. The third type, called capillaries, connects the
arteries to the veins.
Because of the elasticity of their thick, muscular walls, arteries bulge with each heartbeat. We
therefore say that they have a definite pulse. Like the branches of a tree, arteries split into successively
smaller and smaller vessels. The smallest arteries, called arterioles, connect to the capillaries. The
arteries carrying oxygen-poor (blue) blood from the right ventricle to the lungs are the pulmonary arteries.
They are the only arteries that carry oxygen-poor blood. All others carry oxygen-rich (red) blood.
The aorta, which carries blood away from the left ventricle, is the largest blood vessel in the body.
Upon leaving the left ventricle, it starts upward, and then curves back down behind the heart. As it
continues down alongside the backbone, it furnished branches to many different organs. Two branches,
the subclavian arteries, supply blood to the arms. Two other branches, the carotid arteries, carry blood to
the head region. Branches of the aorta called the renal arteries take blood to the kidneys where the liquid
wastes are removed. Another branch enters the liver where solid wastes are removed. Another branch
goes to the spleen where some of the worn-out blood cells are recycled. Still another branch goes to the
small intestine, where food, after being completely digested, is absorbed into the bloodstream. At the lower
end of the body cavity the aorta splits into the two iliac arteries which supply the legs with blood. Two
branches of the aorta, called the coronary arteries, leave the aorta near the heart. Furnishing
nourishment to the heart itself, they form part of the so-called coronary circulation. These two arteries
can be seen near the outside wall of the heart.
Arterioles, the smallest arteries, subdivide into microscopic tubes called capillaries. The walls of
capillaries are only one cell thick. It is through the extremely thin capillary walls that oxygen is exchanged
for carbon dioxide and food is exchanged for waste.
As capillaries begin carrying blood back to the heart, they join together into larger vessels called
venules or small veins. The venules then join together into larger vessels, called veins, which carry blood
back to the heart.
Some veins contain valves for maintaining the flow of blood in one direction. No similar structures are
found in arteries. On the other hand, veins lack a pulse and have thinner walls than arteries.
The veins carrying blood from the lungs back to the left auricle are the pulmonary veins.
(6)
They are the only veins that carry oxygen-rich (red) blood. All the other veins carry oxygen-poor (blue)
blood. The veins carrying blood back to the heart from the head region are the jugular veins. The jugular
veins join with the veins from the arms, the subclavian veins, to enter the right auricle as the superior
vena cava. From the legs, the iliac veins unite to form a large vein heading back to the heart from the head
region. This vein is called the inferior vena cava. Along the way, the inferior vena cava is joined by veins
from other internal organs such as the renal veins from the kidneys and the hepatic vein from the liver.
The inferior vena cava enters the lower part of the right auricle.
Questions
1. Small arteries are called ____________.
2. The only artery that carries oxygen-poor (blue) blood is the ____________ artery.
3. The ____________ is the largest blood vessel in the body.
4. The actual exchange of gases occurs in the tiniest blood vessels, the ____________.
5. Since blood remains within the blood vessels in humans, the system is called a ____________ system.
6. Blood vessels carrying blood towards the heart are called ____________.
7. The ____________ veins carry blood from the head to the heart.
Activities
1. On your display sheet, color the blood vessels leading from the right ventricle to the lungs blue (B).
Remember that right and left are reversed as you look at the picture of the heart. Color the blood vessels
leading from the lungs to the left auricle red (R). Color the vessels (over the whole body) leading away
from the left ventricle red (R), and the vessels (from the whole body) returning to the right auricle blue
(B).
2. Locate Diagram B on your display sheet. Color the body cells yellow (Y) and the arteriole and oxygenrich portion of the capillaries red. Color the venule and the oxygen-poor portion of the capillaries blue
(B). The slash marks indicate where the change between oxygen-rich red blood and oxygen-poor blue
blood takes place. Label the arteriole, a capillary, the venule, and a body cell in the spaces provided on
your display sheet.
3. Locate Diagram C on your display sheet. Color the vein blue (B). Locate Overlay 2 on Activity Sheet 4.
Color Overlay 2 blue.
4. Locate Diagram D on your display sheet. Color the artery red (R). Locate Overlay 3 on Activity Sheet 4.
Color Overlay 3 red (R).
5. Cut out Overlays 2 and 3. Then cut at Slits 3, 4, and 5 on your display sheet. Next, attach Overlays 2
and 3 to your display sheet. To attach, slide the tabs through the appropriate slits. Glue the tabs to the
back of your display sheet.
6. Label the following in the spaces provided on your display sheet:
aorta
iliac vein
carotid artery
subclavian artery
pulmonary artery
jugular vein
subclavian vein
pulmonary veins
spleen
renal artery
superior vena cava
kidney
renal vein
inferior vena cava
liver
iliac artery
coronary artery
Copr. Christopher Lee Publ., 1978, Route 1, Box 582A, Houghton Lake, Mich. 48629
Study Sheet D
(7)
THE CIRCULATORY SYSTEM – BLOOD TYPING
Not all blood is alike. There are four common blood types. They are type A, type B, type AB, and type O. The
differences between them are based on the fact that the blood plasma of some persons has substances in nit which
make the red blood cells of some other persons clump together. This clumping of red blood cells is called
agglutination.
The substance in the plasma that causes agglutination is a protein called an antibody. The substances in the
red blood cells with which the antibody reacts is another protein called an antigen. There are two antigens. One is
called antigen A. People with that type of antigen in their red blood cells are said to have type A blood. The other
antigen is called antigen B. People with antigen B in their red blood cells have type B blood. Some individuals have
both antigens. Their blood type is AB. People with no antigens have type O blood.
People with type A blood have plasma antibodies which react with type B blood antigens, causing agglutination.
They are thus called anti-B (against B) antibodies. People with type B blood have anti-A (against A) antibodies in
their blood plasma. Individuals with type AB blood do not have plasma antibodies. Type AB individuals have both
anti-A and anti-B antibodies. Note that the blood cell antigen and plasma antibody are never the same type in the
same individual. One could not survive if that were so, because all that person’s red blood cells would then be
agglutinated.
Knowing a person’ blood type is most important when one person gives blood to another person. This is called
a blood transfusion. The person who gives the blood is called the donor, and the person who receives the blood is
called the recipient. Agglutination due to incompatible blood types can result in death to the recipient. Remember
that it is the type of red blood cell antigen found in the donor’s red blood cells in combination with the type of
antibody found in the recipient’s blood plasma that causes the difficulty.
The four blood typed can thus be summarized:
Blood type
Type of red
blood cell antigen
Type of
plasma antibody
A
B
A
B
anti-B
anti-A
AB
A&B
none
O
none
anti-A and anti-B
The above table shows that type O people can donate blood to anyone. For this reason, type O people are said
to be universal donors. They AB people can receive blood from anyone, and they are said to be universal receivers.
Most people have type O blood or type A blood. A lesser amount have type B, and the fewest have type AB.
There are other factors that must be considered in blood transfusions. The most prominent of these is the Rh
factor. Approximately 85% of people have a factor in their blood called the Rh factor. They are said to be Rh
positive. Those without this factor are Rh negative and they cannot tolerate Rh positive blood.
Questions
1. A person’s blood type is called type ____________ if he has both antigen A and antigen B.
2. Most people’s blood is Rh ____________.
3. A person who can give blood to anyone is called a ____________ ____________.
(8)
4. ____________ is a process that occurs when two incompatible blood types are mixed, causing clumping of
the blood cells.
5. The giving of blood from one person to another is called a ____________.
6. Antigens are located in the ____________ blood cells.
7. Blood type ____________is the rarest type of blood.
8. What blood type can receive blood from all other blood types?
9. What blood type can donate blood to all other blood types?
Copr. Christopher Lee Publ., 1978, Route 1, Box 582A, Houghton Lake, Mich. 48629