Blood
Blood - Introduction
 Connective Tissue inside blood vessels
Blood - Introduction
 Composed of plasma and formed
elements (rbc, wbc, and platelets)
Blood - Plasma
 Plasma is obtained by centrifuging the
blood
Blood - Serum
 Serum is obtained by letting the blood
clot in a test tube.
Blood - Serum
 Fluid that lacks clotting factors such as
fibrinogen
Interstitial Fluid
• Fluid outside the vascular system that
bathes body cells
Functions of blood
 Transports oxygen, carbon dioxide,
nutrients, heat, wastes, and hormones
Functions of blood
 Regulates pH, body temperature, and
water content of cells
Functions of blood
 Prevents blood loss through clotting
Functions of blood
 Combats toxins and microbes through
certain phagocytic white blood cells and
plasma proteins
Physical Characteristics of Blood
 viscosity greater than that of water
Physical Characteristics of Blood
 Temperature 38 degrees C (100.4)
Physical Characteristics of Blood
 ph of 7.35 to 7.45
Physical Characteristics of Blood
 8% of body weight
Physical Characteristics of Blood
 Volume = 4 to 6 liters
Components of Blood
 Blood consists of
1. 55% plasma
2. 45% Formed elements
Plasma
 Consists of 91.5% water and 8.5%
solutes
Plasma
 Principal solutes include proteins
(albumins, globulins, fibrinogen),
nutrients, enzymes, hormones, respiratory
gases, electrolytes, and waste products
such as urea and bilirubin
Plasma
 Albumin is a transport protein for
steroids
Plasma
 Gamma globulins are antibodies
 Alpa and Beta globulins transport iron
and fats
Plasma
 Fibrinogen has a role in clotting
Formed Elements
 Composed of;
1. Erythrocytes (RBCs)
2. Leukocytes (WBCs)
3. Thrombocytes (platelets)
Formed Elements
 Hematocrit – percentage of total blood
volume occupied by red blood cells
Formed Elements
 Normal hematocrit for;
1. Male – 42-52%
2. Female – 37-48%
Anemia
 A significant drop in hematocrit
Anemia
•
1.
2.
3.
4.
5.
Symptoms include;
Headaches
Weakness
A feeling like your heart is pounding
Fatigue
Shortness of breath
Agglutination
• This process involves antibodies joining
red cells together and form clumps
Formation of Blood Cells
• All blood cells are formed from
pluripotent hematopoietic stem
cells
Formation of Blood Cells
• Pluripotent stem cells divide into
myeloid stem cells and lymphoid
stem cells
Formation of Blood Cells
•
1.
2.
3.
Myeloid stem cells give rise to;
RBCs
Plateletes
All WBCs except for lymphocytes
Formation of Blood Cells
• Lymphoid stem cells give rise to
lymphoctyes
Formation of Blood Cells
• In order to become mature lymphocytes,
the precursor cells leave the marrow and
go to the thymus, lymph nodes, and
spleen
Red Blood Cells
• Contain the oxygen-carrying protein
hemoglobin
Red Blood Cells
• Lack nuclei
Red Blood Cells
• Each cell contains 280 million hemoglobin
molecules
Red Blood Cells
• Live 120 days
• Splenic macrophages remove them from
circulation
Red Blood Cells
• Produce about 2 million red cells/second
Red Blood Cells
• Hemoglobin’s function is to carry oxygen
and carbon dioxide
Red Blood Cells
• Hemoglobin is composed of four
polypeptide subunits (two alpha and two
beta)
Red Blood Cells
• Each polypeptide chain contains a central,
iron-containig heme group that combines
with oxygen
Red Blood Cells
• Hemoglobin picks up CO2 in the tissues,
which it releases in the lungs
Red Blood Cells
• 23% of CO2 is hemoglobin-bound
Red Blood Cells
• 70% of CO2 is dissolved in the plasma as
bicarbonate
Red Blood Cells
• 7% is dissolved in the plasma as CO2
Red Blood Cells
• Hemoglobin picks up O2 in the lungs and
releases it in body tissues
Red Blood Cells
• 97% of O2 is carried by hemoglobin
Red Blood Cells
• 3% of O2 is dissolved in the plasma
RBC Life Cycle
• RBCs undergo phagocytosis by
macrophages
RBC Life Cycle
• Hemoglobin is recycled
RBC Life Cycle
• The amino acids of hemoglobin are reused
for protein synthesis
RBC Life Cycle
• The iron portion of the heme group is
carried in the blood by transferrin and
delivered to muscles or the marrow to be
incorporated into new red cells
RBC Life Cycle
• The rest of the heme group is converted
into bilirubin and excreted into bile
RBC Life Cycle
• Bile is stored and concentrated into the
gall bladder
RBC Life Cycle
• After fatty meals it is secreted into the
small intestine
RBC Life Cycle
• Bilirubin is then converted into
urobilinogen
RBC Life Cycle
• Some urobilinogen is reabsorbed into the
blood stream, and the pigment is secreted
into the urine as urobilin.
RBC Life Cycle
• The rest of the urobilinogen in the
intestines is coverted into stercobilin,
which colors the stool brown
White Blood Cells
• Leukocytes
White Blood Cells
• Nucleated and doesn’t contain hemoglobin
White Blood Cells
• Two types;
1. Granular (neutrophils, eosinophils,
basophils)
2. Agranular (lymphocytes and monocytes)
White Blood Cells
• Monocytes differentiate into macrophages
White Blood Cells
• WBCs contain surface proteins called
major histocompatibility
antigens (MHC)
• Unique for each person except for
identical siblings
White Blood Cells
• Live for a few hours or a few days
White Blood Cells
• 5000 – 10000 leukocytes/mm3
White Blood Cells
• Leukocytosis – increase in the number of
WBCs
White Blood Cells
• Leukopenia – abnormally low number of
WBCs
White Blood Cells
• Neutropenia – low neutrophil count
White Blood Cells
• General function of WBCs is to combat
inflammation and infection
Neutrophils
• Kill bacteria by phagocytosis
Neutrophils
• Neutrophil count is elevated during
bacterial infections
Eosinophils
• Secrete histaminase to combat the effects
of histamine in allergic reactions
Eosinophils
• Combat parasitic worms
Eosinophils
• Eosinophil count is elevated during
parasitic infections and allergies
Basophils
• Develop into mast cells that liberate
heparin and histamine in allergic reactions
B lymphocytes
• Differentiate into tissue plasma cells that
produce antibodies
T lympocytes
• Destroy foreign invadors directly
Lymphocytes
• Elevated during viral infection
Monocytes
• Main function phagocytosis
Monocyte
• Develops into macrophages
Blood Groups and Blood Types
• The surface of red blood cells contain
genetically determined blood group
antigens, called agglutinogens
Blood Groups and Blood Types
• Blood is categorized into different blood
groups based on the presence or absence
of various agglutinogens
ABO Group
• Agglutinogens (antigens) A and B
determine blood types
ABO Group
• These antigens are located on the surface
of red blood cells
ABO Group
• Plasma contains agglutins (antibodies),
a and b, that react with agglutinogens that
are foreign to the individual
ABO Group
• Type A blood has A antigens on the red
cells.
• Their plasma has anti-B antibodies.
ABO Group
• Type B blood has B antigens on their red
cells and their plasma has anti-A
antibodies
ABO Group
• Type AB blood has A and B antigens on
their red cells and their plasma has no
anti-A or anti-B antibodies
ABO Group
• Type O has neither A nor B antigens on
their red cells.
• Their plasma has anti-A and anti-B
antibodies.
ABO Group
• How can Type O blood be the universal
donor?
ABO Group
• Cell pack transfusion
Rh Blood Types
• In the Rh system, individuals whose
erythrocytes have Rh antigens are
classified as Rh+
Rh Blood Types
• If your are Rh- you do not develop anti-Rh
antibodies.
• You need to be exposed to them.
Hemolytic disease of the newborn
• If a mother is pregnant for her first time,
the circulation of the mother’s blood & the
fetal blood is kept separate in the
placenta.
Hemolytic disease of the newborn
• Mixing occurs during placental separation
at childbirth
Hemolytic disease of the newborn
• A tiny amount of fetal blood gets into the
mother
Hemolytic disease of the newborn
• If the mother is Rh- and the fetus is Rh+,
she will develop anti-D antibodies
Hemolytic disease of the newborn
• During the next pregnancy, if the fetus is
Rh+ and the mother is Rh-, her anti-D
antibodies will cross the placenta into the
fetal bloodstream & cause a hemolytic
anemia
Hemolytic disease of the newborn
• To prevent development of these
antibodies, RhoGam is given around
delivery of the first child to “hide” its Rh
antigens form the mother’s immune
system