Download The Cardiovascular System - Waterford Public Schools

Heart, Blood, Blood vessels
Characteristics of Blood
Blood Facts:
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Connective tissue
Only fluid tissue
pH= 7.35-8.45
Temp.= 100.4 °F
(37°C)
• 8% of body weight
• 5-6 L of blood
If you don’t
fast before
giving blood
Erythrocytes (Red Blood Cells)
Hemoglobin
Molecule (Hb)
• 25 trillion RBC’s in blood
• 2.5 million made and
destroyed every second
250 million
molecules of
Hb/ cell
Hb makes the
blood red
Each Hb molecule
binds four oxygen
molecules so that
each red blood cell
carries one billion
molecules of oxygen.
• Anucleate
• Biconcave
discs
Blue People of Troublesome Creek
(Kentucky)
Caused by a
mutation in Hb
Fugate family
“Papa Smurf”
Paul Karason died in 2013.
Ingested colloidal silver solution to
treat a skin condition and turned blue
Leukocytes (White Blood Cells)
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5 types
Agranulocytes= no granules
Granulocytes= contain granules
Large, lobed nuclei
Clear, colorless (have to be stained to see them)
Can enter and leave the bloodstream and enter other tissues
Pus= millions of living and dead WBC’s, dead body cells, dead bacteria
Leukemia= blood cancer; 30,000-50,000/drop (normal= 4,000-11,000)
Thrombocytes (Platelets)
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Start the clotting process
Actually cell fragments (original cell Megakaryocyte)
Form platelet plugs at the site of a cut
No nuclei
Smaller than RBC’s
Hemophilia= lack of clotting proteins in plasma, so
the clotting cascade cannot progress
Cell
Lifespan
Erythrocyte
20-120 days
Leukocyte
Few hoursyears
Thrombocytes
5-10 days
ABO Blood Groups
Blood Types
AGGLUTINATION
Why do blood types matter?
Rh (Rhesus)
Factor
Blood Vessels
There are between 60,000 and 100,000 miles of blood vessels in a human body
If you could lay them
end to end the blood
vessels would circle the
earth 4 X’s !!
Arteries---- arterioles-----capillaries----venules-----veins
Arteries
• carry blood away from heart
• where you feel your pulse
• Thicker middle wall of smooth muscle
• high pressure
Veins
• carry blood back to heart from the body
• Some have one way valves to prevent blood from backing up
• thinner walls, less smooth muscle, less connective tissue
• contains 64% of total blood volume
• skeletal muscle helps pump blood back to heart
• lower pressure
Capillaries
• one cell thick- simple squamous epithelium
• allows nutrients , gases, wastes to be exchanged between the blood and
the tissue
• connects the arterioles to the venules
• pressure greater than venules, veins but less than arterioles
Blood Clotting
Blood Clotting
1. Cells are damaged- collagen fibers within are exposed. Platelets “stick” to the damaged
site.
2. Platelets release chemicals to attract more platelets to the site= platelet plug forms
3. Platelets release serotonin= blood vessels spasm and constrict to minimize blood loss
4. Damaged tissues release a chemical called thromboplastin
5. PF3 on surface of platelets + thromboplastin + clotting activators (in the plasma) + Ca2+
combine to produce a prothrombin activator
6. Prothrombin activator converts prothrombin (already in the plasma) to thrombin
(an enzyme)
7. Thrombin combines with fibrinogen (plasma protein) = fibrin (mesh that traps
the RBC’s)
8. Fibrin dries pulling the two ends of the wound closer