Circulatory System

Heart

Blood

Blood Vessels

Four main functions:

Organ that pumps the blood through the system

Connective tissue that has a fluid component called plasma

Passageway to transport blood to the body's cells

Arteries

Carry blood away from the heart

Arterioles

Smaller vessels

Capillaries

Nutrients are exchanged

Venules

Enlarge and become veins

Veins

Carry blood toward the heart, they have valves and thinner walls. They are more numerous and have larger capacity

Jugular Veins:

Largest veins that take blood from your head to the heart

Carotid artery:

Largest arteries on the side of the neck that take blood from the heart to the head

Carry blood to various parts of the body

Pump materials throughout the body

The movement of materials facilitates the delivery of vital materials like O2 and nutrients to the cells of the body and remove cellular waste

Return Excess Fluid (often in the form of lymph) to general circulation

About the size of your fist

Located slightly left of the center of chest

Right side of heart collects blood from body and sends it to lungs; left side of heart collects blood from lungs and sends it to rest of body

Outer layer of the heart:

Pericardium (Epicardium)

Middle layer of the heart:

Myocardium

Inner Layer of the heart:

Endocardium

Disorders:

CHF (heart failure)

Heart cannot move blood efficiently

Myocardial Infarction

Inadequate or absent blood flow to area of heart muscle

Disorders:

Arteriosclerosis

Thickening of inner layer (hardening) of the arteries

Athersclerosis

Fatty deposits called plaques build up on inner lining of blood vessels

Hematology: The branch of medicine that is concerned with the study of blood and blood disorders

Three functions of blood:

Transportation

Regulation

Protection

Blood Composition:

Plasma

Formed Elements

Yellowish, straw colored liquid that comprises about 55% of bloods volume

90% water, other 10% contains nutrients, salts, oxygen, hormones, and other regulatory substances

Red Blood Cells (RBC's) or erythrocytes

White Blood Cells (WBC's) or leukocytes

Basophils

Eosinophils

Lymphocytes

Monocytes

Neutrophils

Thrombocytes or platelets

Aid in clotting

Polymorphonuclear Granulocytes:

Mononuclear Cells:

Composed of Three layers:

Innermost layer: Tunica interna

Middle layer: Tunica media

Outermost layer: Tunica externa