WHAT IS THE FUNCTION OF THE CIRCULATORY SYSTEM?
Your body needs nutrients, oxygen, and other things to keep it alive and running. The circulatory system
acts as a transportation system for the body, like a train, plane, or bus in a town.
The blood that circulates from your heart has oxygen from your lungs, nutrients from your digestive
system and collects other things as it goes around in your body. The blood cells go through arteries and veins. The
blood cells bring the vital things your other cells need from other specialized cells.
HOW DOES THE CIRCULATORY SYSTEM WORK WITH THE OTHER BODY SYSTEMS?
Respiratory System: The blood pumps into the lungs (this is called pulmonary circulation). The
blood drops off carbon dioxide (so we can breathe out) and collects oxygen (to share with other cells).
All Systems: The blood drops off nutrients and absorbs waste and carbon dioxide to bring to the
lungs (systemic circulation).
Urinary System: As the blood circulates, it gives all the solid waste to the kidneys (systematic
circulation).
WHAT ARE SOME DISORDERS OR DISEASES OF THE CIRCULATORY SYSTEM?
SICKLE CELL ANEMIA- caused by an abnormal type of hemoglobin (protein). The hemoglobin stacks and
creates a sickle type shape. This is normally fixed when re-oxygenated. If it doesn’t, the sickle cell might get stuck
in small blood vessels and cut off circulation there.
BLOOD CLOT- caused by overeating. Cholesterol rises and so does waste. The blood becomes too big and
may cut off circulation in that area.
LEUKEMIA- White blood cells defend the body from dangerous viruses. When they become cancerous,
they cannot perform this task. Leukemia comes from the tissues where white blood cells are made. Leukemia is a
cancerous white blood cell. When huge amounts gather in a part of the body, they interfere with the production
red blood cells, which bring nutrients to your body cells and tissues.
WHAT ARE SOME PARTS (ORGANS) OF THE CIRCULATORY SYSTEM?
HEART
ARTERIES, VEINS, AND CAPILLARIES
BLOOD (WHITE BLOOD CELLS, RED BLOOD CELLS, AND PLATETES)
WHAT ARE THE FUNCTIONS OF EACH PART (ORGANS)?
Your heart pumps blood through the veins and arteries (also capillaries). Your heart has two parts the top
part called the atria and the second, bottom parts are the ventricles. The atrium (atrium is the non-plural form of
atria) fills with returning blood. There is a left and right atrium. The ventricles squirt blood out of the heart into
your body and lungs. In the middle of your heart is a thick muscle called the septum. It divides left from right. The
four parts (atria and ventricles) work together to collect blood, and then pump it out.
The blood comes out of the heart through arteries. The arteries extend out through the body gathering
waste and giving away oxygen. Then veins protrude from the arteries (they have the same job), then the capillaries
multiply out into the rest of your body.
White blood cells defend against diseases and bacteria. Red blood cells carry oxygen, waste, and carbon
dioxide. Platelets create scabs by preventing blood flow to go out of the body.
VOCAB
HEART: A hollow pump-like organ that circulates blood through your arteries, veins, and capillaries through your
body.
ARTERY: The largest of all the vessels that circulate blood through your body.
VEIN: The second largest of the vessels that circulate blood through your body.
CAPILLARY: The smallest of the vessels that circulate blood through your body.
CIRCULATE: To move through a circle or circuit out and then back.
SYSTEMATIC: Having or involving a system or method; A continuing system or method.