1. The Human Circulatory System
Components and Functions

2. Components of Blood
Plasma
Red blood cells
White blood cells
Platelets

3. Plasma Makes up 55% of the blood
Contains dissolved ions including; Ca, Mg, Na, HCO3
Wastes and nutrients
Proteins (antibodies, enzymes, hormones, clot factors)
Water (91% H2O)

4. Red Blood Cells Most numerous cells Shaped like bi-concave discs
Produced in the bone marrow
Mature RBC’s do NOT contain a nucleus
Hemoglobin is an iron-containing protein in RBC’s that binds to O2 and assist in its transport

5. RBCs, WBCs & Platelets

6. White Blood Cells Larger than RBC’s
Produced in the bone marrow and lymph nodes
Single or multi-nucleated
Necessary to fight pathogens (ie. bacteria, viruses)

7. Types of White Blood Cells
Phagocytes (engulf foreign pathogens via phagocytosis)
-Macrophage
-neutrophils
-monocytes
Lymphocytes
-B cells (produce antibodies)
-T cells
-T4 helper
-Killer T cells

8. Blood Cell Origin and Differentiation

9. Platelets Assist in the clotting process Fragments, contain no nucleus
Made in bone marrow

10. Blood Clotting
Clotting involves a series of enzyme controlled reactions
Injury to blood vessel-causes platelets to rupture-initiating clotting reactions.
Prothrombin-Thrombin-
Fibrinogen--Fibrin, which forms a fibrous mesh at the site of the injury.
The mesh traps blood cells, forming a clot

11. Coagulation Pathway

12. Transport Vessels
Blood circulates through the human body within closed blood vessels

13. Arteries Carry oxygen-rich blood away from the heart to the body
Thick, muscular walls to withstand blood pressure
Rhythmic expansion and contraction of the arteries produced by the heart is called the pulse.

14. Capillaries Smallest branches of arteries One cell layer thick
They are the site of exchange of materials between the blood and tissues

15. Veins Blood flows from the capillaries into veins
Veins are thin walled and carry oxygen poor blood back to the heart
Contain valves that prevent backflow of blood due to the low pressure in the veins
*Blood flow in the veins is assisted by the contraction of your muscles.

16. Intercellular Fluid and Lymph
Some of the plasma leaves the capillaries and bathes the cells. This is called Intercellular Fluid (ICF).
Excess ICF is drained into tiny vessels called lymphatic vessels. It is then called lymphatic fluid.
Lymph fluid empties into the large veins that return blood to the heart.