Functions of Blood

Transport of:
 Gases,
nutrients, waste products
 Processed molecules
 Regulatory molecules

Regulation of pH and osmosis

Maintenance of body temperature

Protection against foreign substances

Clot formation
Composition of Blood

Plasma—55%

Formed elements—45%
 Red
blood cells (RBC)—
erythrocytes
 White blood cells
(WBC)—leukocytes
 Platelets—thrombocytes
Composition of Blood
Formed Elements

Red blood cells (erythrocytes)

White blood cells (leukocytes)
 Granulocytes
Neutrophils
 Eosinophils
 Basophils

 Agranulocytes
Lymphocytes
 Monocytes


Platelets (thrombocytes)
Production of Formed Elements


Hematopoiesis or hemopoiesis: Process
of blood cell production
Stem cells: All formed elements
derived from single population
Hematopoiesis
Concept Check
What are the functions of blood?
-transportation, regulation of pH, maintain body
temperature, protection, & clot formation
What types of things does it transport?
-gases, nutrients, waste products, molecules
What are the three types of cells in blood?
-erythrocytes, leukocytes, platelets
What is most blood made out of?
-plasma
What is the process of blood cell formation called?
-hematopoesis
Erythrocytes—RBC



Mature RBC
 Contain no nucleus
 Contain no organelles
 Is a biconcave, disk shape
 Average life span is 120 days
Filled with hemoglobin—protein that can carry up to
4 atoms of oxygen
 Anemia—lack of iron in hemoglobin
CO2 –transported in plasma and RBC
Leukocytes


Protect body against
microorganisms &
remove dead cells &
debris
Movements
 Ameboid-pseudopodia
 Diapedesis-
move
through the walls of
blood vessels
 Chemotaxis- move
toward chemicals

Types
 Neutrophils:
Small
phagocytic cells
 Eosinophils:
Reduce
inflammation
 Basophils:
Release
histamine and
increase
inflammatory
response
 Lymphocytes:
Immunity
 Monocytes:
Largest
WBCs; become
macrophages
Leukocytes—WBC


WBCs are outnumbered by RBCs 700:1
Differential WBC count will show any
abnormal number of WBCs.
 Leukopenia—decreased
# of WBCs
 Leukocytosis—increased # of WBCs
Platelets- Thrombocytes

Average life span is 7-10 days

Function: coagulation
 AKA

blood clotting
Hemostasis—stoppage of blood flow
 Platelets
will stick to damaged lining of the
vessel to form a platelet plug
 Proteins released to attract more platelets
 Substances released to cause vasoconstriction
Thrombocytes

Cell fragments
pinched off from
megakaryocytes in
red bone marrow
Concept Check
What are some characteristics of RBCs?
-no nucleus or organelles, bioconcave disk shaped,
contain hemoglobin
What are some characteristics of WBCs?
-outnumbered by RBCs, live only a few days
Why are there so many different kinds of WBCs?
-each have different functions
What is the function of a thrombocyte?
-coagulation (clot blood)
Blood Grouping



Determined by antigens (agglutinogens) on
surface of RBCs
Antibodies (agglutinins) can bind to RBC
antigens, resulting in agglutination
(clumping) or hemolysis (rupture) of RBCs
Groups
 ABO
and Rh
 Most common blood type: O+
 Most rare blood type: AB-
ABO Blood Groups
Blood Types
Type
Antigen
present
Antibody
present
Can
Receive
Can
Donate
To
Genotype
A
Antigen
A
Antibody
B
A, O
A, AB
IAIA, IAi,
AA, AO
Antigen B Antibody
A
B, O
B, AB
IBIB, IBi,
BB, BO
B
AB
Antigen
A&B
None
A, B, AB,
O
AB
IAIB,
AB
O
None
Antibody
A&B
O
A, B, AB,
O
ii,
OO
Rh Blood Group

First studied in rhesus monkeys

Types
 Rh
positive: Have these antigens present on
surface of RBCs
 Rh negative: Do not have these antigens
present

Hemolytic disease of the newborn (HDN)
 Mother
produces anti-Rh antibodies that
cross placenta and cause agglutination and
hemolysis of fetal RBCs
Erythroblastosis Fetalis
Plasma

90 % water

10% solutes
 6-8%
proteins—used
in blood clotting &
antibody dispersal
 2% other stuff
Plasma

Liquid part of blood
 Pale

yellow made up of 90% water, 10% other
Colloid: Liquid containing suspended
substances that don’t settle out
 Albumin:
Important in regulation of water
movement between tissues and blood
 Globulins: Immune system or transport
molecules
 Fibrinogen: Responsible for formation of blood
clots
Hemostasis

Arrest of bleeding

Events preventing excessive blood loss
 Vascular
spasm: Vasoconstriction of damaged
blood vessels
 Platelet plug formation
 Coagulation or blood clotting
Fibrinolysis

Clot dissolved by
activity of
plasmin, an
enzyme which
hydrolyzes fibrin
Coagulation—Blood Clotting

Uses the proteins in the plasma
 prothrombin
(protein)—converted into
thrombin (enzyme) by thromboplastin
released in platelets
 Soluble
fibrinogen (protein)—converted
into strands of insoluble fibrin by thrombin
 Fibrin
makes a mesh of fibers that trap
RBCs and platelets to cause the clot.
Anticoagulants (antithrombins)


Act against thrombin
to prevent
production of fibrin
Heparin—natural
anticoagulant (blood
thinner)
Concept Check
What is the difference between clotting and
clumping?
-clotting is natural; clumping is not & can cause
problems
Why are there so many steps to clot the blood?
-bc they are needed to work together to perform
their functions; preventing excessive blood loss
What is the use of an anticoagulant?
-blood thinner
What are the steps of hemostasis?
-vasoconstriction, platelet plug formation,
coagulation
Diagnostic Blood Tests

Type and crossmatch

Complete blood count
 Red
blood count
 Hemoglobin measurement
 Hematocrit measurement



White blood count
Differential white blood
count
Clotting
Hematocrit

Volume of blood
(RBC & WBC) in a
given sample
Blood Disorders 


Erythrocytosis: RBC
overabundance

Anemia: Deficiency of
hemoglobin






Hemophilia-clotting absent
Thrombocytopenia-# of
platelets reduced; chronic
bleeding
Leukemia-cancer of bone
marrow; abnormal production
of 1 or more WBC types
Iron-deficiency
Pernicious-inadequate
 Septicemia-blood poisoning;
vitamin B12
spread of microorganisms &
Hemorrhagic-loss of blood
toxins by blood
(ulcer, trauma)
 Malaria-caused by a protozoan
Hemolytic-RBCs rupture;
destroyed
(plasmodium) by a mosquito
Sickle-cell-hereditary;
abnormal hemoglobin; shape  Infectious mononucleosis-virus
that infects lymphocytes (B
cells)

Hepatitis-infection of the
liver by virus