Transcript Blood and Immunity - Calgary Christian School

Blood and Immunity
https://www.youtube.com/watch?v=Futnu_6NmQo&feature=kp
Why is blood a connective
tissue?
 It plays a role in linking all the cells and
organs in the body
Elements of Blood
 Blood consists of two distinct elements:
 A fluid portion – called plasma
Consists of water, dissolved gases, proteins,
sugars, vitamins, minerals, hormones, and
waste products
 Makes up 55% of blood volume

A
solid portion – called the formed portion
Consists of red blood cells, white blood cells
and platelets
 Makes up 45% of blood volume

Red Blood Cells
 Also known as

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
erythrocytes
Make up 44% of blood
volume
Specialized for oxygen
transport as well as
carbon dioxide transport
Small in size (8
micrometers in
diameter)
Live for approx. 120
days
Red Blood Cells
 RBC’s do not have nuclei
 These cells are packed with
hemoglobin, an iron
containing molecule that
chemically binds with
oxygen


The oxygen is taken to the
tissues that require it and it
diffuses from the
hemoglobin to the cells
Hemoglobin also
transports small amounts
of carbon dioxide from the
tissues
www.nlm.nih.gov
Red Blood Cells
 Anemia occurs if there are too few RBC’s or
the RBC’s do not have enough hemoglobin

This reduces the amount of oxygen traveling
through the body

A person with anemia is usually pale, and feels tired
often
This can be caused by a dietary deficiency in iron
The Role of Red Blood Cells in Anemia

http://www.youtube.com/watch?v=_ZV5140OykE
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Red Blood Cells
 RBC’s are produced in the bone marrow
through a process called
erythropoiesis
http://nlds.sdsu.edu/
White Blood Cells
 Also called leucocytes
 Part of the body’s response to infection
 Make up approx. 1% of total blood
volume
 This
number increases when a person is
fighting an infection
 Have nuclei and appear colorless
White Blood Cells
 WBC’s can be divided into three
categories:
 Granulocytes
 Monocytes
 Lymphocytes
http://www.lymphomation.org/bone-marrow.htm
White Blood Cells
 Granulocytes
 Consist of
neutrophils,
basophils, and
eosinophils
 Found in circulating
blood
 Engulf and destroy
foreign bodies
(phagocytosis)
http://www.dmacc.edu/instructors/rbwollaston/Chapter_11_Blood.htm
White Blood Cells
 Monocytes
 Can
leave the blood stream and become
specialized as macrophages
 Also found in circulating blood to engulf
and destroy foreign bodies
White Blood Cells
 Lymphocytes
 Some
produce proteins called antibodies
that recognize foreign bodies (pathogens)
and allow them to be destroyed

Quite often destroyed by granulocytes and
monocytes
Platelets
 Fragment of cells that form when larger
cells in the bone marrow break apart
 Contain no nuclei
 Last in blood from 2-8 days
 Play a key role in blood clotting
Platelets – and blood clotting
 Injury to a blood vessel starts a cascade of
events

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Substances released by the broken blood vessel
attract platelets
The collecting platelets break apart and release an
enzyme called thromboplastin
As long as there are calcium ions present,
thromboplastin will react with prothrombin (a protein
in the plasma produced by the liver) to produce
thrombin
Thrombin is an enzyme that reacts with fibrinogen
(another plasma protein) to produce fibrin
Fibrin forms a mesh of strands around the injured area
http://www.youtube.com/watch?v=--bZUeb83uU&feature=related
Platelets – and blood clotting
Cascade of enzyme-catalyzed
reactions is triggered by platelets,
blood components and damaged
tissue (thromboplastin)
Ca2+
Prothrombin
Thrombin
Ca2+
Fibrinogen
Fibrin
Fibrin threads wind around the platelet plug in the
damaged area of a blood vessel, providing the framework
for a clot. Trapped RBC’s make the clot appear red.
Plasma
 Blood cells are suspended in plasma
 Plasma is 92% water, 7% blood proteins,
0.1% organic substances and 0.9% inorganic
ions (calcium, magnesium etc.)
 Plays a role in the transport of carbon dioxide
in the blood
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CO2 diffuses into the water portion of blood and
forms carbonic acid inside the cytoplasm of RBC’s
It diffuses out of the RBC’s and into the plasma as
bicarbonate ions
It is then carried from the tissues to the lungs for
gas exchange
Blood Disorders
 Hemophilia
 Results from insufficient clotting proteins in
the blood
 People are in constant danger of bleeding
to death if they injure themselves
 Treated with injections of a substance
called Factor VIII, which is a protein
involved in coagulation what is missing
from their blood
Blood Disorders
 Leukemia
 Cancer of the white blood cells
 Myeloid leukemia
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Too many immature leucocytes and are unable to fight
infection
Crowd out RBC – anemia and fatigue
Lymphoid leukemia
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Cancer of the lymphocytes
Same symptoms of myeloid leukemia
 Treatment includes blood transfusions,
chemotherapy and bone marrow transplants

Bone marrow is usually considered the last resort
because it is a very painful procedure
The Defense System
 The skin (preventing
the entrance of
pathogens)


First line of defense
along with eyelashes,
cilia of respiratory tract,
tears and stomach acid
The outer layer of skin
is a hostile environment
for the survival of
microorganisms

Inhospitable for growth of
pathogens
The Defense System
 Non-specific defenses
 Second line of defense
 Cell-mediated immunity from three types of
WBC’s – macrophages, neutrophils and
monocytes

Use phagocytosis to ingest pathogens
 Also

includes natural killer cells
Target body cells that have become cancerous
or have been infected by viruses
The Defense System
 Specific Defenses (antibody-mediated)
 Third line of defense
 Immunity is developed using antibodies
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Antibodies are proteins that recognize foreign
substances and act to neutralize or destroy them
Each person develops an immune system that is unique
because we are not all exposed to the same diseases
and infections
Antigens are molecules that are found on the surface of
the cells and on pathogens
– Provide an identification system allowing immune response
cells to recognize foreign substances in the body
– Antibodies bind to the antigen receptor
http://www.whfoods.com/genpage.php?tname=faq&dbid
The Defense System
 Specific Defenses (antibody-mediated)
 Immunity
is also due to the function of
lymphocytes in the circulatory system
 Lymphocytes are divided into two groups
depending on where they mature

B lymphocytes (B cells) and T lymphocytes (T
cells)
The Defense System
 Specific Defenses (antibody-mediated)
B
lymphocytes (B cells) mature in the
bone marrow
Different B cells produce different antibodies
 When a B cell becomes activated it produces
memory B cells

– which remain in the blood and trigger another
immune response when necessary
The Defense System
 Specific Defenses (antibody-mediated)
 T lymphocytes (T cells) mature in the thymus
gland (near the heart)
 Responsible for cellular immunity
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Helper T cell recognizes antigens and gives off chemical
signals to stimulate other immune cells
Killer T cells bind with infected cells and destroy them
by puncturing a hole in the cell membrane
Suppressor T cells slow and suppress the process of
other T cells so that normal tissue does not get destroyed
Memory T cells remain in the blood stream and are able
to act quickly if the antigen is encountered again
Immune System Disorders
 Autoimmune Disorder
 When the T cells or antibodies mistakenly attack
the body’s own cells as if they had foreign
antigens
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Ex. Rheumatoid arthritis (inflammation of the lining of the
joints) http://www.youtube.com/watch?v=YVvyfFPnKPA

Ex. AIDS
Ex. Diabetes
Ex. Multiple Sclerosis
http://www.youtube.com/watch?v=qgySDmRRzxY
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Immune System Disorders
 Allergies
 An exaggerated response by the immune system
to a harmless material

Immediate reaction – occurs within seconds of
exposure, antibodies trigger the release of histamines
making the area red and swollen
– Some forms of asthma are immediate allergic responses

Delayed reaction – set off by T cells, reaction is slower
and lasts for a longer period of time
– Allergies to some types of jewelry for example
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Symptoms of food allergies can be immediate or delayed
– Why have the incidences of food allergies increased in
Canada?
– What are some common food allergies?
http://www.youtube.com/watch?v=y3bOgdvV-_M
Blood Types
 The type of ANTIGEN present on the surface
of RBC determines blood type.
 Blood from humans is classified into four
groups, based on the antigens on the surface
of RBC (A, B, AB, or O).
 Blood Typing involves identifying the
antigens in a sample

Three of the most important human antigens are
called A, B, and Rh
Blood Types
 The A-B-O System is based on the A and B
antigen.
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It is a means of classifying blood by the antigens
located on the surface of RBC and the antibodies
circulating in the plasma
 An individual's RBC may carry an A antigen, a B
antigen, both A and B antigens, or no antigen
at all.
 These antigen patterns are called BLOOD TYPES
A, B, AB, O respectively
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AB is known as a Universal Recipient, meaning that
they can receive any type blood
O is known as a Universal Donor, meaning they can
donate blood to anyone
http://www.youtube.com/watch?v=H4qkwW-Fl3E&feature=related
Blood Types
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/Cardiovascular%20System.htm
Blood Types
http://www.donateblood.com.au/page.aspx?IDDataTreeMenu=42&parent=30
 http://www.youtube.com/watch?v=ttjn1j
VACk8
What are Blood Types?
Big Idea: Blood Transfusions
 https://www.youtube.com/watch?v=Fmh
QkZsyPVQ
Blood Types
 Rh System
 An antigen that is sometimes on the surface of
RBC is the Rh FACTOR, named after the rhesus
monkey in which it was first discovered
 Rh-positive (Rh+), means that Rh Antigens are
present
 People who do not have Rh Antigens are called
Rh-negative (Rh-)
 If an Rh- person receives a transfusion of blood
that has Rh+ antigens, Rh- antibodies will react
with the antigen and agglutination (clumping) will
occur
Blood Types
 Rh System
 The most serious problem with Rh incompatibility
occurs during pregnancy
 If the mother is Rh- and the father is Rh+, the child
may inherit the dominant Rh+ allele (gene) from
the father
 If the babies Rh+ blood gets into the mother
during delivery, the mother will develop antibodies
to the Rh Factor
 If a second Rh+ child is conceived later, the
mother's antibodies can cross the placenta and
attack the blood of the fetus
 This condition is called ERYTHROBLASTOSIS
FETALIS http://www.youtube.com/watch?v=YGhTFjwO2Ac
Blood Types
 Rh System
 To prevent this condition, an Rh- mother of an
Rh+ child can by given antibodies to destroy and
Rh+ cells that have entered her bloodstream from
the fetus
 The antibodies, a substance called RHOGAM,
must be administered to the mother within three
days after the birth of her first Rh+ child to remove
from her bloodstream any Rh+ antibodies
 By destroying any Rh+ cells in her bloodstream,
any danger to a second child is prevented
because the mother will not make any antibodies
against the blood cells of the Rh+ fetus
Blood Types
 Rh System
http://www.scienceclarified.com/Qu-Ro/Rh-Factor.html