BLOOD
The
Cardiovascular
System
Blood
transports substances and
maintains homeostasis in the body
Hematophobia
= fear of blood
BLOOD AND BLOOD CELLS
 Blood
is a type of CONNECTIVE
TISSUE
 It has two basic components:
 CELLS (rbc, wbc, platelets) = 45%
 Plasma (water, proteins, amino
acids..etc) = 55%
Hematocrit - volume of blood
cells in a sample, should be
45%. The remaining fluid is
plasma (55%). To determine the
percentages, blood is placed in a
centrifuge
Three Types of Blood Cells
 Red blood cells (erythrocytes)
White blood cells (leukocytes)
Platelets (thrombocytes)

 Biconcave
discs
 5 million per cubic millimeter
 Lack nuclei
 HEMATOPOEISIS – formation of blood
cells (bone marrow)
 Liver & Spleen - phagocytosis
EPO, OR ERYTHROPOIETIN (PRONOUNCED, AHRITH-RO-POY-TIN), IS A HORMONE PRODUCED
BY THE LIVER AND KIDNEYS.

In the first part of a
two-night interview
broadcast,
disgraced cyclist
Lance Armstrong
admitted to Oprah
Winfrey that he
took banned
substances,
including EPO,
during all seven of
his Tour de France
victories.
ERYTHROPOIETIN
 Erythropoietin
(EPO) is a hormone produced
by the kidney that promotes the formation of
red blood cells by the bone marrow.
 The resultant rise in red cells increases the
oxygen-carrying capacity of the blood.
 90% erythropoietin is produced by the
kidneys
 10% erythropoietin is produced by the liver
 Normal levels of erythropoietin range from 4
up to 24 mU/ml (milliunits per milliliter).
MAIN FUNCTIONS OF RED BLOOD CELLS
 Transports
oxygen,
picks up carbon
dioxide
 HEMOGLOBIN molecule that
combines with O2
 IRON is critical to
synthesize
hemoglobin
OXYGEN LEVELS
Oxyhemoglobin =
plenty of oxygen; bright red
 Deoxyhemoglobin =
low in O2, “bluish red”
 The blood on the left is oxygenated, the right is
deoxygenated blood (from a vein)

OXYGENATED
DEOXYGENATED
ELEMENTS CRITICAL TO RBC
PRODUCTION
 Folic
Acid
 Vitamin B12
 Iron
 Too few RBC = anemia
WHITE BLOOD CELLS (LEUKOCYTES)
General function is to protect the body against
disease
 There are FIVE different kinds of WBCs

Granulocytes (granular cytoplasm)
Neutrophils, Eosinophils, Basophils
Agranulocytes (lacking granular cytoplasm)
Monocytes, Lymphocytes
NEUTROPHIL
(NUCLEUS HAS SEVERAL LOBES)
 Active
phagocytes
 60% of WBC
 Present in the pus of
wounds
BASOPHIL
Produces Heparin and Histamines
 Important in Inflammatory Reaction
 1% WBC

EOSINOPHIL
 Mainly
attack parasites
 2% WBC
MONOCYTE
 Larger
cell, horseshoe-shaped nucleus
 Become macrophages
LYMPHOCYTES
Nucleus is dark and takes up almost whole cell;
almost no cytoplasm seen
 Defense against invaders
 Yield Antibodies
 30% WBC

Left: Lymphoctye | Right: Neutrophil
ANIMATION: IMMUNE SYSTEM RESPONSE
PLATELETS (THROMBOCYTES)
 Blood
clots and vessel repair
ERYTHROPOIESIS – DESCRIBES THE
PRODUCTION OF RED BLOOD CELLS
The red bone marrow of essentially all bones
produces RBCs from birth to about five years of
age.
 Between the ages of 5 to 20, the long bones slowly
lose their ability to produce RBCs.
 Above age 20, most RBCs are produced primarily
in the marrow of the vertebrae, the sternum, the
ribs, and the pelvis.

ERYTHROPOIESIS – DESCRIBES THE
PRODUCTION OF RED BLOOD CELLS
LIFE CYCLE OF THE RED BLOOD CELL -120 DAYS

1) Kidneys respond to a lower than normal
oxygen concentration in the blood by releasing
the hormone erythropoietin.
2) Erythropoietin travels to the red bone
marrow and stimulates an increase in the
production of red blood cells (RBCs).
3) The red bone marrow manufactures RBCs
from stem cells that live inside the marrow.
4) RBCs squeeze through blood vessel
membranes to enter the circulation.
5) The heart and lungs work to supply
continuous movement and oxygenation of
RBCs.
6) Damaged or old RBCs are destroyed
primarily by the spleen
PLASMA PROTEINS
 Albumins
– blood pressure
 Globulins (alpha, beta, gamma) –
transport lipids and antibodies for
immunity
 Fibrinogen – important for blood
clotting
MAJOR EVENT IN BLOOD CLOTTING =
Fibrinogen converted to FIBRIN
PLASMA
The liquid portion of blood is 92% water
 Also contains nutrients, gases, vitamins (etc) and
plasma proteins

This machine removes the plasma from the
blood and returns the RBC’s to the donor.
HEMOSTASIS
The process of stopping bleeding
 Involves the coagulation and clotting of the blood
to seal the site of damage

THREE EVENTS IN HEMOSTASIS
 1.
Blood Vessel Spasm

Seratonin = vasoconstrictor
 2. Platelet plug formation
 3. Blood coagulation - conversion of
fibrinogen to fibrin
 *Thrombin is an enzyme that causes
the conversion
HEMOSTASIS
COAGULATION THE THICKENING OF
BLOOD TO FORM A
CLOT (HEMATOMA)
 THROMBUS
– blood
clot (abnormal)
 EMBOLUS – when
the clot moves to
another place.