CHAPTER 11

Human Blood
 Human Blood
• General Description
- River of life

- Specialized connective tissue

- Thick, heterogeneous liquid that has solid and liquid components

- White cells constitute has an average density of approximately

1060 kg/m3

- average adult has a blood volume of 5 liters

- In one microliter of blood contains 4.7-6.1 million RBC for MALE and 4.2-
5.4 million RBC for FEMALE

Hematocrit - portion of blood occupied by RBCs (45%)

- Sticky, opaque fluid with a characteristic of
metallic taste

- Heavier than water

- More viscous than water

– 4,000-11,000 WBC that are part of the immune

system which “destroy and remove” old and
aberrant cells and cellular debris as well  as attack
infectious agents known as pathogens

– 200,000-500,000 thrombocytes are responsible for

blood clotting known as “COAGULATION”
Functions of  Blood
 
• TRANSPORT
            - oxygen, nutrients,
carbon dioxide, hormones, heat
and wastes
     
• REGULATION
            - pH, body
temperature and water  content
 
• PROTECTION
- against blood loss through
clotting and against diseases
through phagocyctic    WBCs
and antibodies
 
 Blood Composition

  1. Plasma
2. Formed elements (RBCs,
WBCs, platelets)
 Blood Liquid (Plasma)
- Liquid portion of the blood

- Over 100 different substances are dissolved in this straw-colored

fluid examples are nutrients, metal ions (salts)
respiratory gases, hormones, plasma proteins and various wastes
and products of cell metabolism.
- 55% of the whole blood
- straw-yellow in color

• Made up of:
• - 91.5%-92% water
• - 7%-8% blood plasma proteins
• - 1.5% other solutes
Components:
A. Water (90%) - acts as “solvent” and “transport”
nutrients

B. Plasma proteins- most abundant solutes in plasma.

Albumin - promotes “water retention”
Globulin - acts as “carrier molecule” to
transport liquid and fat soluble
in the blood (alpha & beta globulins)
-used as antibodies (gamma globulins)
Fibrinogen - for “blood clotting”

Serum plasma - minus fibrinogen and other clotting

factors
C. Plasma Electrolytes - inorganic molecules that
separate into ions when dissolved in water
Cations - positively charged (Na+,K+,Ca+,Mg+)
Anions - negatively charged (Cl,I)

D. Nutrients and Waste products

Nutrients - glucose, amino acid,
phospholipids, triglyceride, etc.
Metabolic waste - lactic acid, urea

E. Gases and buffers - principal gases

dissolved in plasma
 pH of the Blood
• - normal pH of the blood is 7.40
(normal range is 7.35-7.45) weak alkaline
solution

• - below 7.35 is too acidic and above & .45

is too alkaline
 Blood Cells Life
 Hematopoiesis - Blood cell formation
that occurs in the red “bone
marrow” or “myeloid tissue”

-Each type of  blood cell is

produced in different no. in
response to changing body needs
and different stimuli after they
mature they are discharged into
blood vessels surrounding the
area.

• Erythropoiesis -  production of RED

BLOOD CELLS
 
• Myelopoiesis- production of WHITE BLOOD CELLS and platelets
 
-All formed elements arise from common type of stem cell
 
- Healthy erythrocytes have a plasma life of 120 days before
they are degraded by the spleen

- Lifespan of WBCs ranges from 13-20 days after which time

they are destroyed in the lymphatic system

• Bands/Stabs – “immature cells” released into the circulation

• Phagocytosis – “cell eating”

  - Platelets are fragments of a cell. They have a lifespan of 10
days. 
 Transport of Gases
• - 98.5% of oxygen combined with
hemoglobin
• - 1.5% of oxygen dissolved in blood
liquids

• - ARTERIES carries oxygenated blood

away from the heart and deliver it to
the body via arterioles and capillaries
where the oxygen is consumed.
Afterwards venules  and VEINS carry
deoxygenated blood back to the heart

• - hemoglobin in the blood leaving the

lungs is about 98%-99% saturated with
oxygen
• - deoxygenated blood returning to the
lungs is 75% saturated
• - A fetus, receiving oxygen via the placenta , is exposed to much lower
pressures. This is about  21% of the level found  in an adult’s lungs and so
fetuses produce another form of  hemoglobin with a much higher affinity
for oxygen known as hemoglobin F in order to function

• - In carbon dioxide transport, when blood flows through capillaries,

carbon dioxide diffuses from the tissues into the blood. Some carbon
dioxide dissolved in the blood. Some carbon dioxide reacts with
hemoglobin and other proteins to form carbamino compounds. The
remaining carbon dioxide is converted to bicarbonate and hydrogen ions
through the action of RBC carbonic anhydrase. Most carbon dioxide is
transported through the blood in the form of bicarbonate ions.
• -CO2, the “main cellular waste product is carried in blood mainly”
dissolved in plasma, in equilibrium with bicarbonate and carbonic acid.
86%-90% of C02 in the body  is converted into carbonic acid , which
can quickly turn into bicarbonate, the chemical equilibrium being
impt. In the pH buffering of plasma, Blood pH is kept in a narrow
range bet. 7.35-7.45.

• - In the Hydrogen ions transport, some oxyhemoglobin loses oxygen

and becomes deoxyhemoglobin. Deoxyhemoglobin binds most of 
the hydrogen than does oxyhemoglobin.
 Color of the Blood
Hemoglobin - is the principal
determinant of the color of the 
blood in human.

Deoxygenated blood - is a “darker

shade of red”; present in veins.

Carbon monoxide poisoning -

is “bright red.”

Cyanide poisoning - increase

redness of blood.

Sulfhemoglobinemia -  arterial
hemoglobin is partially
oxygenated and “appear dark red
with a bluish hue” known as
“cyanosis.”
 Red Blood Cells
(Erythrocytes)
Main Functions
- transports O2 throughout body, and picks up CO2
- Hemoglobin = molecule which combines with O2 to
transport it
Oxyhemoglobin - plenty of oxygen, bright red
Deoxyhemoglobin - not carrying much O2, "bluish red"
 Red blood cells
• (Erythrocytes)
Shape are “biconcave discs”

• 5 million per cubic millimeter (RBCC = red blood

cell count, amount of blood cells in a cubic
millimeter)

• lacking nuclei, they will not divide. The production

of RBC at a rate of 2 million per second is called
“Erythropoiesis”

• Blood cells live for about 120 days, then are

phagocytized by the liver and spleen

• In the EMBRYO, liver is the main site of the

production of the RBC’s.

• The developing cells that has left before or after the

bone marrow, they are called “Reticulocytes” and
comprise about 1% of circulating RBC.

• a typical erythrocyte contains about 270 million

hemoglobin molecules, w/each carrying heme
group.
White Blood Cells
(Leukocytes)
Derived from Greek “Leukos” means
“white” and “kytos” means “cell”
 White Blood Cells (Leukocytes)
• General function - defend the
body against disease-causing
agents (microorganisms)

• Are cells of the immune system

• They are called the “defenders and

fighters” of the body.

• The WBC has different types:

Granulocytes
– Neutrophil
– Eosinophil
– Basophil

Agranulocytes
- Monocytes
- Lymphocytes
 Granulocytes (granular cytoplasm/
polymerphonuclear leukocytes)
1. Neutrophil
– very active in phagocyting bacteria and are present in large
amount in the pus of wounds, most common, 60% WBC
– Defend against bacterial or fungal infection and other very small
inflammatory processes.
– “1st responders to microbial infection”

2. Eosinophil
– “Parasitic infections and allergic reactions.”
– attack parasites, control allergic reaction; 2% WBC
– produces Heparin (prevents blood clots) and Histamines
(causes inflammatory reaction); less then 1% WBC

3. Basophil
– Chiefly responsible for “Allergic response and antigen response” by releasing
histamine causing inflammation.
– Inflammatory Reaction = blood vessels dilate, fluid accumulation and swelling, attraction of
WBCs. At the site of an infection, dead and damage leukocytes, bacteria and body cells
accumulate = pus
– A bi-or tri-lobed nucleus but is hard to see due to the granules covering it.
– Characterized by their large blue granules.
 Agranulocytes (lacking granular cytoplasm/
mononuclear leukocytes)
1. Lymphocytes
– More common in the lymphatic system

– Has deeply staining nucleus and has

small amount of cytoplasm.

– Defense against the attack of

pathogenic micro-organisms
• (Very Bad For People)
Virus, Bacteria, Fungi,& Protista.
• Yield antibodies and arrange them
on their membrane; 30%
• types of lymphocytes:
– B-cells
– T-cells
– CD8+cytotoxic T cells
– yo T cells
– Natural killer cells
2. Monocyte
– precursors of macrophages, phagocytes; 6%
– Share the “vacuum cleaner” (phagocytosis) function
of neutrophils
– Much longer lived and they have an additional role:
presents pieces of pathogens to T cells so that the
pathogens may be recognized again & killed
– Eventually leaves the bloodstream & becomes tissue
macrophages
– Able to replace its lysosomal contents unlike the
neutrophil.
– Has kidney-shaped nucleus & typically agranulated.
– Also possesses abundant cytoplasm.

3. Macrophage
– Monocytes undergo phagocytosis and
are then known as macrophages.
– Against FUNGI
BLOOD TYPE
ABO system
- is the most important blood
group system in human blood
transfusion

Blood type
- are inherited and represent
contributions from both parents.
 HiSTORY
• ABO blood type were discovered in 1900
by Dr. Karl Landsteiner at the
University of Vienna

• He wondered why some patients died as

a result of blood transfusions and why
some were saved
UNIVERSAL DONOR :

TYPE “O”
UNIVERSAL RECIPIENT :

TYPE “AB”
 ANTIGEN
An antigen is a molecule
recognized by the
immune system.

->> Originally the

term came from
“antibody generator.”

->> Characteristic of
the blood
 Group AB Anti-B Group A

B
A

B
B

B
 Group O No Antibodies Group ABO

B B
O A
O A AB
O B
O O
B
A A
O O O
O A
AB
O
A AB
O
 ERYTHROBLASTOSIS
FETALIS
Refers to “2 potentially disabling/fatal blood disorders” in infants:
*Rh incompatibility
*ABO incompatibility
Either maybe apparent before birth
Can cause fetal DEATH in some cases.

The disorder is caused by incompatibility between a mother's blood

and her unborn baby's blood. Because of the incompatibility, the
mother's immune system may launch an immune response against
the baby's red blood cells. As a result, the baby's blood cells are
destroyed, and the baby may suffer severe anemia (deficiency in
red blood cells), brain damage, or death.
Description
• How the genes are paired determines the
person's blood type.

• RBC carry several types of proteins:

– Antigens – A,B, and O antigens are used to classify
a person’s blood as type A, B, AB, or O.

• Each parent passes one A, B, or O antigen

gene to their child.

• How the genes are paired determines the

person's blood type.
• A person who inherits an A antigen gene from each parent has
type A blood

• receiving two B antigen genes corresponds with type B blood

• inheriting A and B antigen genes means a person has type AB

blood.

• If the O antigen gene is inherited from both parents, the child

has type O blood

• And if the pairing of A and O antigen genes corresponds with

type A blood.

• Same as the A, the B antigen gene is matched with the O antigen

gene, the person has type B blood.
Rh factor – another RBC antigen that plays a role in
describing a person’s blood type.
• If (+)Rh factor - at least ONE copy of Rh factor is
inherited.
• If ( - )Rhfactor - NO copies of Rh factor is inherited.
• The presence of blood type A,B, and O antigens + the
presence/absence of Rh factor determine’s a person’s
specific blood type, such as: A(+), B(+), and so on.

A person's blood type has NO EFFECT on health.

• However, an individual's immune system considers only
that person's specific blood type, or a close match,
acceptable.
• If a radically different blood type is introduced into the
bloodstream, the immune system produces antibodies,
proteins that specifically attack and destroy any cell
carrying the foreign antigen.
Immunit
y
• Our immune system protects us from foreign
substances which include pathogens,
allergens, tissue and organs grafts or even
transfused blood components. Our immune
systems also identifies and destroys
abnormal cells(i.e. tumor and virally infected
cells). The immune systems has two
branches: innate and adaptive. Like soldiers,
our immune is divided in line of defense. Our
first and second line fall under the innate
branch, while our third falls under the
adaptive branch.
Definition of Terms:

• Antigens (short for antibody-generating)

can be any molecule that elicits
antibody production. Antigen are usually
proteins or other molecules (e.g. sugars
and lipids) complex with proteins (i.e.
glycoproteins and lippoproteins). An
epitope or antigenic determinant is a
specific region in antigen where the
corresponding antibody can bind.
Antibodies (immunoglobulin) are glycoprotein,
each Y-shaped unit made of four peptide
linked together by disulfide bonds. Two
fragments are presents: Fragment of antigen
binding (Fab) and Fragment crystallizable (fc).
Paratopes are antibody equivalent of epitopes.
Opsonization refers to the enhancement of
phagocytosis. Cytokines are chemical
regulators of the immune system
manufactured by leokocytes.
 Antibody type Characteristics:
IgG Gamma Predominate in the secondary immune response
(Y) Can cross the placenta

IgG Alpha Present in bodily secretions

(α) Divalent(2 antibody molecules; 4 antigen binding
sites)joined
by J chain

IgG Mu (µ) Predominate in the primary immune response

Pentavelant; most efficient in agglutination and
complement fixation
Act as B cell receptors

IgG Epsilon Binds to Fc on the surface of basophils and mast cells;

(є) Participate in type 1 hypersensivity

IgG Delta Present in small quantities

(ō) Acts as B cell receptors
• Innate
– Otherwise known as natural or non-
specific, this branch of the immune
system is present at birth and the response
is the same regardless of what kind and
how many times a pathogen has been
encountered. It is divided into first and
second lines of defense.
• First line of defense
The first line of defense can be categorized as:
– physical
– mechanical
– chemical.

• Intact skin and mucus membranes are relatively

impermeable to pathogens. Constant beating of the cilia
lining the trachea, coughing and sneezing causes
expulsion of pathogens, thus preventing them from
entering the respiratory tract. Bodily secretions such as:
sweat, tears, saliva, mucus and colostrum contain IgA,
lactic and fatty acids; and lysozyme (an enzymethat
degrades bacterial cell walls)which are chemical
inhibitors of pathogens. The very low pH of the stomach
and vagina inhibits most pathogens except amoebic cyst
forms and Helicobacter pylori
( bacteria that causes stomach ulcers).
• b. Second line defense
This line of defense has both the ff.
components:
– cellular
– Humoral

The word “humoral” pertains to non- cellular

elements such as antibodies in blood or other
body fluids. Phagocytes such as machrophages,
monocytes , and neutrophils engulf and digest
pathogens and cell debris. The events in
phagocytis are summarized in Table 2.
monocytes travel the blood stream and
become macrophages upon reaching tisues
where they will remain.
• The complement system makes up the humoral
component of the 2nd line of the defense. The
complement system is a series of plasma
proteins which ultimate purpose is cytolysis.
Other complement proteins serve as:
• Anaphylatoxins which mediate the inflammation.
• Opsonins which enhance phagocytosis.
• Chemotactic factors.

Complement proteins are labeled with the capital letter “C”

and numbered from 1 to 9 (C1 to C9). Complement activation
begins with C1 binding to the Fc portion of antibody bound to
antigen on pathogen surface. Ultimately, membrane attack
complex(MAC) is formed on pathogen plasma membrane
resulting in its destruction.
Inflammation
- is a non- specific defensive response
to injury and infection. Its purpose is to
destroy and prevent the spread of pathogens,
and aid in healing of the afflicted tissue. Upon
injury, tissues release inflammatory mediators
or anaphylatox8ins such as histamines,
eukotrienes and prostaglandins. This causes
vasolidation and increased capillary
permeability. Increased blood flow would allow
more leukocytes, oxygen and nutrients to
reach the afflicted tissues. During
inflammation, leucocytes migrate to the site
of injury (chemotaxis), line up along the
pheriphery of blood vessels(margination) and
then squeeze through gaps in the endothelial
cell lining of the blood vessels(diapedesis) to
reach the afflicted area.
Fever or pyrexia
- prevents pathogen growth and multiplication by
elevating body temperature and depleting plasma iron
which is needed by the pathogen. Pathogen is engulfed
by phagocyte causing release of the cytokin,IL-1. once
released, IL-1 stimulates the hypothalamus(i.e., the
body’s thermostat/temperature regulator) to release
prostaglandins are metabolized, elevating the
hypothalamic thermostat. To compensate, the brain,
through peripheral nerves, signals blood vessels to
constrict. The decrease in blood vessel diameter
conserves heat until body temperature is equal to
hypothalamic thermostat.
 Table 2. Events in Phagocytosis
Event Description
Chemotaxis Phagocytes are attracted to the site of infection
by chemotactic agents.
Attachment Phagocyte attaches to pathogen.
Indigestion Pseudopodia surround the pathogen, and it is
taken into the phagocyte. Pathogen is enclosed in
a phagosome.
Digestion Lysosome attaches to phagosome forming a
phagolysome. Pathogen is broken down and
dissolved by digestive enzymes and other
mechanisms(i.e. nitric oxide, superoxide anion
and hydrogen peroxide).
Exocytosis Remnants of the pathogen are excreted.
 Table 3. Cardinal signs of
Inflammation
Event Description
Dolor Pain due to release of prostalglandins
Rubor Redness due to increased blood flow
Calor Heat due to increased blood flow
Tumor Swelling due to increased blood flow
Funtiolaesa Loss of function
• B. Adaptive
- This branch constitutes the third
line of defense and is also known as acquired
or specific. It is absent at birth (hence the
name “acquired “) and specific immune
responses are mounted against different
pathogens. Upon second encounter with the
same pathogen, an improved immune response
is mounted. It is also comprised of cellular
and humoral components.
• a. Cell mediated immune response
- Virally infected or tumor cells
display molecules recognized by receptors on
the surface of T cytotoxic lymphocytes. Once
recognized, T cytotic lymphocytes release
prforinis (an enzyme that perforates cell walls
causing lysis) and granzymes. Granzymes are
serine proteases that activate capases and
nucleases signaling apoptosis(i.e.,programmed
cell death).
• b. Humoral Immune Response
- Approximately 1 billion
different b cells with antibody receptors (IgM
or IgD) for specific antigens circulate the blood
stream. Once a B cell with the appropriate
receptor encounters the corresponding antigen,
it divides into clones(i.e., T cell- independent
activation). Some of the clones differentiate
into plasma cells which secrete antibodies
that target the antigen that activated the
parent B cell. The remainder of the clones
become dormant b memory cels which await
second encounter with the same antigen B
cells can also be activated byT helper cells
(i.e., T cell dependent activation).
Thank
you!
(^__^)