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Chapter 12
Applied Learning Outcomes
Use the terminology associated with
the blood and lymphatic system
Learn about the following:
• Blood components
• Lymphatic system components
• Immune system function
• Mechanisms of immunization and
vaccination
Understand the aging and pathology
of the lymphatic system
Chapter 12 – The Lymphatic System and the Blood
Overview
Blood is composed of plasma
and formed elements.
Blood transports materials
needed for body
homeostasis.
There are three blood cell
types: RBCs, WBCs, and
platelets.
The lymphatic system
regulates body fluids and the
immune system.
Chapter 12 – The Lymphatic System and the Blood
Overview
Embryos
•lack blood until week 5 of development.
•Have pockets of special cells that start producing blood 2
weeks after the blood vessels form from the mesoderm.
Plasma
•the fluid portion of the blood.
•Cells and other material are transported in
•Composed of 90% water, 7% protein, 1% minerals,
and 2% other materials like gases, chemical signals,
and nutrients.
•Primary gases are oxygen, carbon dioxide, and nitrogen
•Blood proteins assist with healing and immune system
•55% of blood volume is plasma
•45% is formed elements (Blood cells)
Overview
Three categories of blood cells:
1. erytrhocytes (red blood cells) RBC
2. leukocytes (white blood cells) WBC
3. thrombocytes (platelets)
Hematocrit (packed cell volume (PCV)
the percentage of packed RBCs in a unit volume of
whole blood
Measure it by putting whole blood in a tube inside a
centrifuge.
Spin the blood until the RBCs collect as a pellet at the
bottom of the tube.
WBCs and Platelets can be found the same way.
Overview
Lymphatic system
1. made up of tissues that produce, store, and carry
lymphocytes throughout the body.
2. responsible for fighting infection and controlling fluid
levels in tissues.
3. Includes bone marrow, specialized organs, and network of
thin tubes
4. Develops from mesoderm around week 5
5. Its full growth and function are not complete until after
birth
Blood Cells
RBCs contain the protein hemoglobin.
Blood type is another feature of RBCs.
• Classifications are types A, B, and D
• The A and B proteins make up the ABO blood group
system
• The D protein is the Rh factor
The five types of WBCs are neutrophils, lymphocytes,
eosinophils, monocytes, and basophils.
WBCs are categorized as granulocytic or
agranulocytic.
Chapter 12 – The Lymphatic System and the Blood
Red Blood Cells
Lack a nucleus
Immature RBC are called reticulocytes
RBCs live maximum of 120 days
Contain hemoglobin that transports oxygen and carbon dioxide
Women average 4.8 million RBC/ cubic mm of blood
Men average 5.4 million RBC/ cubic mm of blood
Complete blood count (CBC) or Full blood count (FBC)
Series of tests that examine components of the of blood
Also known as a Hemogram
Red Blood Cells
Blood Type:
Way of categorizing RBCs according to variation of proteins
on the cell membrane surface.
The proteins A and B make up the ABO Blood group
system
People with O type blood do not have protein A or B on
their cell membrane surface
The D protein is called the Rh factor. You are Rh+ if you
have the D protein
Rh- people lack the D protein.
Blood Types
Type
Makes
antibodies
A
B
AB
O
accept
give to
against B
A, O
A, AB
against A
B, O
B, AB
no antibodies
A,B, AB,
against any blood and O
against A and B
O
AB
universal
recipient
A,B, AB, universal
&O
donor
Blood Types
Rh+ have protein D on cell membrane.
Rh- lack protein D on cell membrane.
Erythroblastosis fetalis
when a pregnant woman’s body produces an immune
response against Rh positive blood from her
developing fetus.
Only affects Rh- mothers. They are now given a drug called
Rhogam during and after pregnancy. It causes the mother’s
body to destroy any antibodies she has built up against Rhblood.
White Blood Cells
Five types of WBCs:
1. Neutrophils most abundant (40-75%)
2. Lymphocytes (20-50%)
3. Eosinophils (5%)
4. Monocytes (1-5%)
5. Basophils (0.5%)
Differential WBC count evaluates the percentage of each
WBC type.
Important indicator of infectious diseases
Between 4000 to 11,000 WBC/cubic mm
White Blood Cells
Granulocytes (polymorphonuclear WBCs)
•Have granules in cytoplasm
•Produce specialized secretions for fighting infections
•Nucleus is polymorphic (unusual shape)
•Neutrophils, eosinophils, and basophils are examples.
Agranulocytes (mononuclear WBCs)
•Lack visual granules
•Play role in the immune system
•Lymphocytes and monocytes are examples.
•Lymphocytes divided into two types:
•B-lymphocytes and T-lymphocytes
Platelets
•Not true cells
•Cell fragments
•Come from larger cells called Megakaryocytes
•Megakaryocytes are covered with many proteins that
allow platelets to stick to a variety of materials.
•Stickiness helps reduce blood flow to a damaged area
•250,000 to 500,000 platelets /cubic mm of blood
Blood Cell Function
RBCs – transport atmospheric gases throughout the
body: oxygen from the lungs to the cells; carbon
dioxide from the cells to the lungs
WBCs – granulocytes
produce secretions that
kill microorganisms;
lymphocytes are
agranulocytes that
produce the body’s
immune response
Chapter 12 – The Lymphatic System and the Blood
Blood Cell Function
RBCs carry oxygen from the lungs to the body cells
Oxygen attaches to the hemoglobin.
Four oxygen molecules bind to one hemoglobin molecule.
RBCs carry carbon dioxide from body cells to the lungs.
Carried three ways in the blood
1. 10% of the CO2 never enter the RBC- it is transported
as a gas in the blood plasma
2. 22% of CO2 released by tissues is carried by Hemoglobin
3. Rest of CO2 is transported as a bicarbonate ion
RBCs stimulate formation of bicarbonate ions using enzyme
Carbonic anhydrase it converts carbon dioxide and water into
bicarbonate ions.
Important in maintaining blood pH.
Blood Cell Function
WBCS -most of their functions are involved in repairing the
body and fighting infectious disease.
Granulocytes:
contain granules of toxic chemicals that are released to
kill microorganisms and regulate reactions to foreign
materials in the body.
Neutrophils- pass through capillaries into infected tissues
they adhere to injured tissues and use phagocytosis
to engulf bacteria and damaged cells.
can secrete potent antibiotics
Eosinophils- produce secretions that defend against large parasitic
organisms. Secretions kill protista and worms
increase in Eosinophils indicated parasitic infection.
Blood Cell Function
Granulocytes:
contain granules of toxic chemicals that are released to
kill microorganisms and regulate reactions to foreign
materials in the body.
Basophils are least common WBC
they secrete histamine
stimulates the immune response
Overproduction of histamine causes
runny nose, sneezing, and watery eyes
Special basophil- Mast cell are responsible for
inflammation of tissues.
Blood Cell Function
Agranulocytes:
Monocytes- once they leave bone marrow
develop into either:
circulating monocytes
tissue monocytes (macrophages)
Circulating moncytes major role is to detect infectious
agents traveling in the blood
Tissue macrophages remove dead cells and attack
microorganims that are difficult to kill, such as fungi.
Platelets
Involved in the Blood clotting process
Carry out a two-step process:
the platelets adhere to an injured area
followed by the activation of clot formation.
Intact vessels secrete a lipid called prostacyclin which prevents
platelet activation.
Damage to a blood vessel or body tissue produces a reaction
The Clotting cascade:
tissue or blood vessel damaged
1. Release collagen and clotting factors
2. Causes platelets to adhere to damaged tissue and to each other
3. Causes conversion of prothrombin into thrombin.
4. Thrombin converts to a protein called fibrinogen into fibrin
5. Fibrin forms sticky meshwork (beginning of clot)
6. Sticky meshwork forms temporary barrier- prevents blood loss,
7. Impedes passage of microorganisms
8. Scab that forms is an example of a clot
9. Clots not permanent, temporarily patch until it is repaired
10. Plasminogen converted to plasmin-it is an enzyme that dissolves
the clot.
Blood Clotting Cascade
Cut in skin
sticky platelets
clotting factors
(prothrombin, prothrombin activator, calcium)
causes the conversion to
thrombin
+
fibrinogen
fibrin forms a sticky meshwork that
adheres to thrombocytes and other
blood components.
Blood Cell Formation
Chapter 12 – The Lymphatic System and the Blood
Blood Cell Formation
All blood cells in adults are produced in the bone marrow.
In the embryo, the liver is responsible for blood cell formation.
All red and white blood cells are derived from a type of
stem cell called hematopoietic or multipotent stem cell.
Hematopoietic cells can develop into
lymphoid stem cells or myeloid progenitor
Lymphoid progenitor cells give rise to WBCs
Myeloid progenitor cells give rise to platelets, RBCs, WBCs
Blood Cell Formation
Erythropoiesis is the process by which RBCs are formed.
RBCs mature in approximately 7 days and live about 120 days.
Aging RBCs are destroyed in the liver and spleen.
The digestive system then removes the hemoglobin as a yellowish
chemical called bilirubin.
WBCs live from 13 to 20 days.
Immature WBCs are released from bone marrow.
They are called bands or stabs.
Then they are destroyed by the lymphatic system.
Lymphatic
System
• Composed of
lymphatic glands,
lymph nodes, and
lymph vessels
• Immune function
provided by WBCs
• Immunity is either
innate or acquired
• The body has a
primary and a
secondary immune
response
Chapter 12 – The Lymphatic System and the Blood
Lymphatic System
Structural components are
•Lymphatic vessels
•Lymph nodes (lymph glands)
•Spleen
•Thymus
•Tonsils
•WBCs
•Lymph
Lymph vessels are thin ducts that carry lymph.
They drain excess fluid that accumulates in tissue
preventing edema (swelling)
Lymph does a variety of jobs:
•Removal of foreign bacteria and materials
•Transports fat from digestive system
•Moves mature lymphocytes (WBCs) to the blood
Lymphatic System
Lymphatic trunk is a network of lymph vessels that drains regions
of the body.
drains lymph from larger areas of the body
has collections of small swollen regions of lymphatic tissue
Tonsils are one of a pair of clusters of lymphatic tissue, located in
the throat.
Peyer’s patches is another cluster of lymphatic tissue
located in the intestines
Lymphatic System
Lymph nodes are complex collections of lymphatic tissue
covered by connective-tissue capsules.
Four components making them up:
Blood vessels
lymphatic sinuses
lymphocytes
filler tissue (stroma)
Hilum is region of the lymph node where the blood vessel
enters and exit.
Trabeculae is partitions that divide the lymph node into
regions. They contain B and T lymphocytes.
Macrophages are found in the lymphatic sinuses.
Lymphatic System
Spleen is divided into two functional regions:
Red pulp - it is a storage area for RBCs
Also responsible for removing old or damaged
RBCs from circulation.
White pulp - region of lymphatic tissue
contains B and T lymphocytes
Thymus gland located above the heart
larger during childhood begins to shrink during puberty
loses some of its functions as you age.
Immune Response
Is a complex array of anatomical structures and cellular events
that protects the body from foreign chemicals called antigens.
The immune system uses two mechanisms to respond to disease:
Innate immunity
Aquired immunity
Immune Response
Innate immunity
nonspecific immunity
skin, mucus membranes, saliva, stomach acid, tears, fever
Interferons are a group of proteins that cells produce
following a viral infection. They bind to other cells and
inhibit viral replication.
Complements are a group of plasma proteins that can be
activated to destroy microorganisms.
Monocytes (WBCs) travel the body destroying any
material that is not recognized as part of the body.
Natural killer (NK) cells are specialized T-lymphocytes
that secrete proteins that kill tumor cells and
microorganisms.
Immunization and
Vaccination
Natural immunity is the unintentional stimulation
of the immune system. Artificial immunity is the
use of therapy to stimulate the immune system.
Immunization is a medical strategy for enhancing
the body’s natural immune response. Vaccines
are immunizations that produce active immunity.
Active immunity is caused by exposure to
antigens. Passive immunity is produced by
providing the body with antibodies.
Chapter 12 – The Lymphatic System and the Blood
Wellness and Illness over
the Life Span
Anemia is a common ailment of the blood that is actually
a group of various RBC disorders. Most cases of anemia
involve a decrease in the number of RBCs.
Genetic disorders can lead to the production of abnormal
blood cells.
Blood clotting is also subject to a variety of disorders.
WBCs are prone to deficiencies and cancers. Most
deficiencies are due to malnutrition and exposure to
hazardous chemicals.
Disorders of the lymphatic system affect its ability to
drain body fluids and carry out immune functions.
Chapter 12 – The Lymphatic System and the Blood
Wellness and Illness over
the Life Span
• Much of the aging of the blood and
lymphatic system is due to changes in the
digestive and endocrine systems.
• WBC function is likely to become abnormal
with age.
• Immobility and weakening of the skeletal
muscles is another feature of aging.
Chapter 12 – The Lymphatic System and the Blood
Summary
Plasma brings many nutrients to cells and carries
away wastes.
RBCs carry oxygen to cells and remove carbon
dioxide.
WBCs form part of the immune system that
protects the body from disease and assists with
injury repair.
The lymphatic system uses its own components
and cells derived from the blood to prevent and
fight off infections.
Aging brings about changes to the immune
system that make people more susceptible to
infections and less likely to rapidly heal injuries.
Chapter 12 – The Lymphatic System and the Blood