Circulatory System

Composition and Function of Blood Composed of plasma (55%) and formed elements (45%) Used for transport of materials through the body Used to regulate body heat (homeostasis)

Formed Elements of the Blood Formed elements are all the chemicals (usually proteins) and cells found in the blood. The formed elements are: Erythrocytes (Red Blood Cells) Leukocytes (White Blood Cells) Platelets (Cell fragments)

Erythrocytes Also called Red Blood cells Have no nucleus Thin plasma membrane Transport oxygen and carbon dioxide Ability to transport oxygen and carbon dioxide is based on the amount of hemoglobin

(Leukocytes) Neutrophils Neutrophils: 65%–75% of total WBCs Highly mobile and very active phagocytic cells Cytoplasmic granules contain lysosomes. Increase in numbers during acute infections

Eosinophils Eosinophils: 2%–5% of circulating WBCs Capable of ingesting inflammatory chemicals and proteins Increase in numbers during allergic reactions and parasitic worm infections

Basophils Motile Cytoplasmic granules contain histamine and heparin. Increase in numbers during allergic reactions and periods of inflammation

Types of Agranulocytes - Lymphocyte Lymphocytes: 20%–25% of total WBCs Two types of Lymphocytes are important in the immune response

Thrombocytes (Platelets) Function Two major functions are: stoppage of blood flow. Platelet plug formed by platelets sticking together (sticky platelets) Coagulation = formation of fibrin clot

Structure of Blood Vessel Three layers for both arteries and veins Tunica adventitia Tunica media Tunica intima

Some Major Arteries Carotids (Common, Internal and External) Subclavian Brachiocephalic Brachial Radial Ulnar Coronary Celiac Splenic Renal Mesenteric (Inferior and Superior) Abdominal Aorta Iliac (Common, Internal and External) Femoral Popliteal Tibial (Anterior and Posterior)

Some Major Veins Facial Jugular (External and Internal) Brachiocephalic Subclavian Cephalic Auxiliary Vena cava (Superior and Inferior) Pulmonary Cardiac (Great and Small) Basilic Hepatic and Hepatic portal Spleenic Mesenteric (Inferior and Superior) Iliac (Common, External and Internal) Femoral Saphenous (Great and Small) Popliteal Tibial (Anterior and Posterior)

Artery Model

Vein Model

Common Arteries

Common Veins http://www.dnwalcker.com/Laboratory4.html