Circulatory System

Parts Blood Blood Vessels Heart

Arteries Carry blood away from heart Under very high pressure Carry oxygenated blood

Capillaries Tiny tubes Run close to every cell in your body Blood cells have to travel in single file Capillary walls are so thin that oxygen, CO2 and nutrients can pass through them. What’s a bruise?

Veins Carry blood back to heart Blood is deoxygenated Lower pressure Veins have a one-way valve Contracting muscle squeezes veins, forcing blood back to heart.

Function How? Carry needed substances to cells Carry wastes and products away from cells The blood brings oxygen and nutrients to the cells. The blood takes away carbon dioxide and other wastes. Carrying disease fighting cells. White blood cells prevent you from getting sick by killing bacteria or other things in the blood.

The Hearts Structure Atrium- receives the blood that is coming into the heart. Found at the top of the heart. Ventricle- pumps the blood out of the heart. Found at the bottom of the heart. Valve- A flap of tissue that prevents the blood from moving backwards.

How the heart works The heart muscles relax, blood fills the heart. The heart muscles contract, the blood is pumped out of the heart.

Hypertension (High Blood Pressure) Blood pressure is the pressure of blood against the blood vessel walls as the heart pumps. When someone has hypertension (high blood pressure), the heart and arteries have a much heavier workload. The heart has to pump harder and the arteries are under greater strain as they carry blood. Having high blood pressure puts someone at a higher risk for stroke, heart attack, kidney failure, loss of vision, and atherosclerosis (hardening of the arteries). While high blood pressure doesn't always cause symptoms, it still affects the body and puts a person at risk for long-term health problems. In rare cases, severe hypertension can cause headaches, visual changes, dizziness, nosebleeds, heart palpitations, and nausea.

Heart Attack When a blood clot or other blockage cuts blood flow to a part of the heart. A heart attack, also called a myocardial infarction, can be fatal, but treatment has improved dramatically over the years.  Common heart attack signs and symptoms include: Pressure, tightness, or pain, in your chest or arms that may spread to your neck, jaw or back, nausea, indigestion, heartburn or abdominal pain, shortness of breath, and cold sweat.