1. Blood & Circulatory System

2. Blood – The River of Life
About 8% of body weight
Only fluid tissue in the body
Functions:
Transports oxygen, carbon dioxide, nutrients, wastes, hormones, & enzymes
Helps regulate pH, body temperature, & water content of cells
Prevents excess fluid loss through clotting
Protects against toxins and microbes
Contains erythrocytes (RBCs), leucocytes (WBCs) & thrombocytes (platelets)

3. Blood Major component of the circulatory system
Composed of cells, fluid, & cell fragments
Component
Characteristic
Red Blood Cells (44%)
Transports oxygen and CO2, lacks a nucleus; contain hemoglobin (binds oxygen) produced by red bone marrow
White Blood Cells (1%)
Large; contain a nucleus; defend the body against disease. Live only a few hours/days
Platelets
Cell fragments needed for blood clotting – removed from the blood by the spleen
Plasma (55%)
Fluid; contains proteins, transports RBC & WBC, platelets, nutrients, enzymes, hormones, gases, & salts (91.5% water & 8.5% solutes)

5. Hematopoisesis Blood Cell Formation Hemocytoblast
Controlled by hormones
Occurs in red bone marrow
Hemocytoblast
Type of blood stem cell
Produces:
Lymphoid Stem Cells – lymphocytes
Myeloid Stem Cells – all other formed elements in the blood

6. Hematopoisesis

7. Hemostasis Prevention of blood loss Three phases
Vascular spasms
Smooth muscle of blood vessel contracts to stop bleeding
Platelet plug formation
Platelets begin to clump
Coagulation or blood clotting
Involves coagulation factors
Normally…blood clots in 3-6 minutes

8. Disorders of Hemostasis
Undesirable Clotting
(Thrombus)
Can lead to heart attack or
strokes
Bleeding Disorders
Thrombocytopenia
Spontaneous bleeding
Insufficient number of circulating platelets
Hemophilia
Lack of clotting factors (proteins needed for normal blood clotting)

9. Blood Types Three Blood Type Antigens: A, B, & O
An antigen is a blood protein found on a blood cell surface.
Four Blood Types: A, B, AB, O
Type A
Antigen A present
Type B
Antigen B present
Type AB
Antigens A & B
Universal recipient
Type O
Neither A nor B antigens
Universal donor

10. Blood Type - Antibodies
Antibodies are produced by the body in reaction to foreign proteins being present
Individuals will not produce antibodies for proteins on their own red blood cells, but do produce antibodies for foreign proteins.

12. Rh Factor
1937 – Rh factor in blood was demonstrated leading to the discovery of many other blood groups
Presence of Rh Factor – Rh positive
Absences of Rh Factor – Rh negative
Mixing of different blood types can have serious consequences
Rh incompatibility rarely causes complications in a first pregnancy
But Rh antibodies that develop during later pregnancies can be dangerous to mother and child.
can result in severe anemia, jaundice, brain damage, heart failure or death

14. Blood Disorders Anemia Polycythemia Infectious Mononucleosis – viral
Decreased erythrocyte count (RBCs)
Decrease in oxygen in the blood
Polycythemia
Abnormal increase in the number of erythrocytes (RBCs) – thickens blood
Infectious Mononucleosis – viral
Elevated white cell count
Leukemia (type of Cancer)
Uncontrolled production of white blood cells that interferes with normal clotting & vital body activities