Cardiovascular System Describe the factors affecting blood flow

Circulatory System • Transports oxygen, nutrients & other substances throughout the body & removes waste from tissue • Arteries: pump oxygen-rich blood AWAY from the heart (RED) • Veins/Capillaries: bring oxygen-depleted blood INTO the heart (blue)

Circulation • HEART has 2 PUMPS 1) Oxygen-depleted blood to LUNGS to be exhaled( 2) Oxygen-rich blood to BODY (all arteries, except PULMONARY ARTERY, which pumps carbon dioxide to lungs to be exhaled) 1) Capillaries-smallest blood vessels, exchange oxygen & CO 2 2) Veins-brings blood back to heart

Blood • Human body contains 4 -6 Liters • Helps regulate body temperature • Fight infections • Clots to prevent blood loss • Plasma = 90% water • Main function of RED blood cells is to transport OXYGEN

White Blood Cells • “army of Circulatory system” • Guard against infection, fight parasites & attack bacteria • Out numbered 1000 to 1 by RED blood cells

White Blood Cells • MACROPHAGES: engulf pathogens • LYMPHOCYTES: Immune response • B Lymphocytes: produce antibodies that fight infection • T Lymphocytes: fight tumors & viruses

Factors that AFFECT blood flow • blood pressure: is the pressure exerted by circulating blood upon the walls of blood vessels. • Affected by the resistance of the blood vessels to blood flow. • Has to do with the WIDTH of the Blood Vessel • Resistance to blood flow increases Heart rate because has to make a greater effort disease and exercise

Blood Volume & Blood Flow • Regulated by the KIDNEYS • Low blood volume, called hypovolemia , may be caused by bleeding, dehydration, vomiting, severe burns, or some medications used to treat hypertension. • Excessive fluid volume, hypervolemia, may be caused by retention of water and sodium, as seen in patients with heart failure, liver cirrhosis, some forms of kidney disease, hyperaldosteronism, and some glucocorticoid steroid treatments

Diseases of the Cardiovascular System • Coronary artery disease: Damage or disease in the heart's major blood vessels. • High blood pressure: A condition in which the force of the blood against the artery walls is too high. • Cardiac arrest: Sudden, unexpected loss of heart function, breathing, and consciousness. • Congestive heart failure: A chronic condition in which the heart doesn't pump blood as well as it should. • Arrhythmia: Improper beating of the heart, whether irregular, too fast, or too slow. • Peripheral artery disease: A circulatory condition in which narrowed blood vessels reduce blood flow to the limbs. • Stroke: Damage to the brain from interruption of its blood supply. • Congenital heart disease: An abnormality in the heart that develops before birth.

Lack of Exercise & blood flow • This is because exercise: lowers blood pressure, which is a major risk factor for heart disease. . may reduce levels of bad LDL cholesterol that can form fatty deposits in the arteries and contribute to heart disease. improves circulation by preventing blood clots that can lead to heart attack and stroke.

Key Topics 1) 2) 3) 4) 5) Describe the structure & function of the Cardiovascular System Compare & contrast arteries, veins & capillaries List & explain the role of blood in the Human body How does high blood pressure affect a person’s blood flow? Compare & contrast the issues associated with high & low blood volume 6) List & describe 6 diseases that effect blood flow 7) How does exercise or lack of exercise affect blood flow?