Transcript Transport - TeacherWeb

Human Circulation
(Transport)
© Lisa Michalek
Transport
• After digestion is completed, nutrients go into the
blood stream and are transported to the cells of the
body.
• In the cells, nutrients are chemically combined with
oxygen and energy is released.
• Transport is the process of absorption and
circulation of materials throughout the body.
Transport
• Absorption involves the passage of materials into
and out of the bloodstream.
• Circulation is the distribution of materials to all
parts of the body.
• The transport system is also called the circulatory
system.
• The circulatory system is made up of the heart,
blood vessels, blood, lymph and lymph vessels.
Circulation
• Blood flows in a circle
throughout the body
and is used over and
over.
• Blood moves in a
continuous pathway of
blood vessels.
• This system provides
the body cells with
needed substances and
carries away cellular
excretions.
The Heart
• The heart is a muscular,
four-chambered organ.
• The heart pumps blood
through blood vessels
adjusting the rate and flow
and pressure to changing
body requirements.
Blood Vessels
• Blood vessels are tubes that transport blood to and
away from body parts.
• The three major types of blood vessels are:
– arteries,
– veins,
– capillaries.
Arteries
• Arteries are blood vessels that carry blood away
from the heart.
• Because they are very muscular and elastic, they
help pump blood through the body.
• To do this, they expand and then snap back to
normal size.
– This expansion and snapping back of the arterial walls is
called the pulse.
• Blood in the arteries is under pressure from the
pumping action of the heart.
– This pressure is called blood pressure.
Capillaries
• The capillaries are the smallest blood vessels.
• They are one-celled, microscopic blood vessels that
connect arteries to veins.
• Exchanges of oxygen and carbon dioxide, between
the blood and body parts takes place through the
capillary walls.
• This exchange takes place by diffusion.
Veins
• Veins are blood vessels that
transport blood under low pressure
from the capillaries back to the heart.
• Veins have valves that prevent the
backflow of blood.
• Atherosclerosis (ath-er-o-skler-O-sis) is a disease in
which plaque (plak) builds up inside your arteries.
Arteries are blood vessels that carry oxygen-rich blood to
your heart and other parts of your body.
• Plaque is made up of fat, cholesterol, calcium, and other
substances found in the blood. Over time, plaque hardens
and narrows your arteries. This limits the flow of oxygenrich blood to your organs and other parts of your body.
• Atherosclerosis can lead to serious problems, including
heart attack, stroke, or even death.
Composition of Blood
• Blood is the liquid that transports materials
throughout the body within the blood vessels.
• Plasma, red blood cells, white blood cells, and
platelets make up the blood.
• Plasma is the straw colored, non-living part of
blood.
– Plasma is 90% water.
– Plasma transports blood cells, end products of digestion,
hormones, cellular excretions, and antibodies throughout
the body.
– Plasma also helps to regulate body temperature.
Red Blood Cells
• Red Blood Cells are shaped like round plates that
are indented in the center.
– Mature Red Blood Cells do not have a nucleus.
• Blood appears to be red because red blood cells
contain the iron-rich pigment hemoglobin.
– Hemoglobin carries oxygen from the lungs to the body
cells.
Platelets
• Platelets are smaller than either
red or while blood cells and do
not contain a nucleus.
• They live only 2 to 4 days and are
very numerous.
• Platelets are involved in the
clotting of blood.
White Blood Cells
• White blood cells fight infections and are part of the
body’s defense or immune system.
• They are irregular in shape and have no color.
• White blood cells are larger than red blood cells and
have a nucleus.
• There are fewer white cells than red cells unless they
are fighting infection, when they increase in number.
White Blood Cells
• There are several different types
of white blood cells.
• Some, called phagocytes, aid in fighting disease
by engulfing (ingesting) bacteria,
viruses, and other foreign organisms.
– Phagocytes engulf bacteria the
same way amoebas engulf food.
• Other white blood cells (lymphocytes)
produce proteins known as antibodies.
– Antibodies are produced when foreign particles,
antigens enter the body.
– Some common antigens are bacteria and foreign tissue.
Lymph and Lymph Vessels
• Lymph comes from the portion of the blood plasma that
diffuses out of the capillaries.
• This fluid is also called intercellular fluid or tissue fluid.
• This intercellular fluid helps transport dissolved materials
between capillaries and cells.
• Excess intercellular fluid enters lymph vessels and is
circulated through these vessels as lymph.
• Lymph vessels transport the lymph to veins where it enters
the blood and becomes part of the plasma again.
Lymph and Lymph Vessels
• The lymph system also helps protect
the body against infection.
• The armpits, neck, and groin contain
groups of tiny bean-shaped organs
called lymph nodes.
– Lymph tissue is also located in the
tonsils, adenoids, spleen, thymus
gland, digestive tract, and bone marrow.
• These structures filter out bacteria and
viruses from lymph.
• Lymph tissue also produces a type of
white blood cell that helps the body
fight disease.
Immunity
• The ability of the body to resist certain
disease-causing organisms (pathogens) is
known as immunity.
• To resist disease the body has certain body defenses.
– One body defense is the presence of barriers such as skin,
nose hairs, and mucus coated linings in the digestive and
respiratory tracts.
– Another defense is hydrochloric acid in the stomach.
– A third defense is the ability of white blood cells to
engulf bacteria.
– The body’s final defense is the production of antibodies
to fight foreign substances that enter the body. These
antibodies are carried by the blood.
Immunity
• Immune reactions occur
between antibodies and antigens
when the body defends itself
against invading organisms.
• Along with antibody
production, there are other
types of immune responses
such as skin graft rejection
and organ transplant rejection.
Antigen (invader)
Antibodies (defender)
Active Immunity
• Active immunity occurs when the
body makes its own antibodies to a
particular antigen.
• This can occur as a result of having
a particular disease and recovering
from it or by having a vaccination
to a particular disease.
• If you had chicken pox,
you now have active immunity
against this disease.
Antigen (invader)
Antibodies (defender)
Vaccinations
• A vaccination consists of an injection of a dead or
weakened form of a disease-causing microorganism.
• This organism can no longer cause the disease, but can still
stimulate antibody production by white blood cells.
• This type of immunity lasts a long time.
• Diphtheria-Tetanus (DPT),
Oral Polio, Measles Mumps
and Rubella (MMR)
are immunizations required for
public school attendance.
Passive Immunity
• Passive immunity is a temporary immunity to a disease
produced by the injection of antibodies into the body.
• The antibodies can be produced by another person or
by an animal.
• Passive immunity lasts for only a short time.
• It is used to increase the body’s
defense temporarily against a
particular disease.
• For example, people who have
been exposed to hepatitis are given
injections of antibodies to hepatitis.
Blood Typing and Transfusions
• There are three blood types known as A, B, and O.
• The typing of blood in the ABO blood group system
is based on the presence or absence of antigens on
the surface of the red blood cells.
• Blood type is important when giving transfusions.
• If the blood types of the donor and receiver are not
agreeable, an antigen-antibody reaction occurs.
• This reaction results in the clumping of blood.
• When this happens, the blood cells clog the
capillaries and cause death.
Transport System Disorders
• High Blood Pressure occurs when the blood
pressure in the arteries is increased.
– This can be caused by stress, diet, heredity,
cigarette smoking, and aging.
– High blood pressure can damage the lining of the
arteries and weaken the heart muscle.
– Some ways of controlling high
blood pressure are by decreasing stress,
loosing weight, and taking medication.
Transport System Disorders
• Arthrosclerosis is the buildup of plaque
on artery walls.
• The buildup of plaque will cause a
decrease in blood flow through the artery
to vital organs.
• In some cases, this plaque buildup will
occur in coronary arteries. The blockage
stops the flow of blood to some of the
heart muscle.
• The heart muscle is then usually damaged
from lack of oxygen. This is called a heart
attack.
Transport System Disorders
• Leukemia is a form of cancer in which
the bone marrow makes too many nonworking white blood cells.
– The large numbers of white cells crowd out
developing red blood cells and platelets.
• Sickle Cell Anemia is red blood cell disorder,
where instead of being like normal round cells,
affected blood becomes hard, sticky and
shaped like sickles, which clog blood flow and
break apart.
– All forms of sickle cell disease are inherited and
present in African Americans, Arabs, Greeks,
Italians, Latin Americans and Native Americans.
Sickle Cell Anemia
Transport System Disorders
• AIDS
– The acquired immune deficiency syndrome is a
disease caused by a virus that scientists call HIV
(human immunodeficiency virus).
– The virus destroys the body’s immune system, making
it unable to fight off even small infections.
– The disease is transmitted by body
secretions during sexual contact or
by direct exposure to blood.