BLOOD
Functions of Blood
Transportation
– oxygen and carbon dioxide
– nutrients, hormones,
metabolic wastes
– heat
Regulation
– pH through buffer systems
– body temperature
– osmotic pressure within
cells
Protection
– clot blood
– Fight disease
Components of Blood
Plasma = straw colored
liquid portion
– Water = 92%
– Solutes – electrolytes,
hormones, gases, etc. = 8%
Formed Elements =
Blood Cells
– Erythrocytes
– Leukocytes
– Thrombocytes
Plasma and Serum
Plasmapheresis:
separates plasma
from blood cells
Serum --when
blood clotting
factors are
removed
Hematopoiesis
Production of blood
cells
occurs in red bone
marrow
From stem cells called
Hemocytoblasts
Erythropoietin
produced in the
kidneys starts new
RBCs (see pg 372)
Erythrocytes (RBC’s)
Carry Hemoglobin -gives whole blood
it’s red color
Have no nucleus
Live about 120 days
Hemoglobin
Heme = iron – contains 4 per globin –gives blood
it’s color
Globin = protein ( carries some CO2)
Leukocytes (WBC’s)
main function
protection from
foreign particles
Two Main Types:
Granulocytes
Agranulocytes
Granulocytes
Neutrophils
– Phagocytes – most
numerous
Eosinophils
– Removes allergens,
reduces inflammation,
increase with virus
Basophils
– promotes inflammation
by secreting histamines
– Heparin to prevent
blood clotting
Agranulocytes
Lymphocytes
– produce antibodies T
and B cells)
Monocytes
– become Macrophages
– Large “large eaters”
Thrombocytes (Platelets)
Clot blood
(hemostasis) and
repair damaged
blood vessels
life span of about
5 to 9 days
Hemostasis
mechanism by which bleeding is stopped
Three Basic Mechanisms
– Vascular Spasms
– Platelet Plug Formation
– Coagulation (Clotting)
Vascular Spasm
contraction of the smooth muscles in the
vascular walls of a damaged blood vessel
reflexes from pain receptors
Platelet Plug Formation
Platelet Adhesion =
platelets contact and stick to
walls of damaged vessels
Platelet Release Reaction =
platelets extend projections
and release content of their
granules
Platelet Aggregation =
platelets gather in area of
wound or injury
forms a Platelet Plug to stop
bleeding
Coagulation (Clotting)
Several steps needed
for process to work
Intrinsic (within blood)
Extrinsic (within
tissues)
forms a Clot = a
network of
fibrinogen(protein
fibers) changes to
fibrin
Coagulation
Fibrinogen changed
to fibrin
Thrombus and Embolus
Thrombus:
stationary clot
Embolus: traveling
clot – effects 4
organs – heart,
lungs, brain and
kidneys
Clot may be blood,
gas, fat, wastes, etc.
ABO Blood Typing
each parent contributes antigens (agglutinogens), or
lack of antigens to their offspring
O + O = O blood type
A + O and A + A = A blood type
B + O and B + B = B blood type
A + B = AB blood type
Rh Factor
Presence or absence
of Protein D on
erythrocyte
May effect –
mother’s 2nd
pregnancy
May cause Hemolytic
disease of the
newborn.
THE END OF BLOOD