CIRCULATORY SYSTEM AKA CARDIOVASCULAR SYSTEM

This system is a transport system Supplies oxygen from the lungs to the tissues Supplies substances absorbed from the digestive system to the tissues Removes carbon dioxide from the tissues to the lungs Removes waste products from the tissues to the kidneys Regulates body temperature – increase the size of vessel (dilate) to lose heat and reduce the size of vessel (constrict) to prevent heat loss Distributes hormones and chemicals to different parts of the body

What is the system made of Heart which functions as a pump Arteries which are vessels that carry oxygen rich blood from the heart to the body tissues Capillaries which are fine branches of vessels that allow the exchange between body cells and blood Veins which are vessels that carry oxygen depleted blood back to the heart

The heart A muscular pear shaped organ that is the size of a clenched fist Protected by the bony rib cage Located in the chest a little to the left of the center line

The heart as a pump The heart receives deoxygenated blood on the right side and pumps it to the lungs to be oxygenated Oxygenated blood returns from the lungs to the left side of the heart which pumps it to the rest of the body

blood There are three kinds of cells in the blood: red blood cells carry oxygen from the lungs throughout the body white blood cells help fight infection platelets help in clotting plasma

Red blood cells AKA erythrocytes the most numerous, making up 40-45 percent of one's blood they give blood its characteristic color shaped like tiny doughnuts, with an indentation in the center instead of a hole they contain a special molecule called hemoglobin, which carries the oxygen. In the lungs

White blood cells AKA leukocytes the body's mobile warriors in the battle against infection and invasion.

platelets AKA thrombocytes help blood to clot, in several different ways When bleeding occurs, platelets clump together to help form a clot. Also, when they are exposed to air (as they would be by a wound), platelets start breaking down and release a substance into the bloodstream. This substance starts a chain of chemical events that eventually causes a protein in the blood, fibrinogen, to turn into a different substance, fibrin, which forms long threads. These threads tangle up red blood cells to help form a clot, or scab, over the wound.

plasma about 90 percent water Much of the other ten percent comprises various kinds of protein molecules, including enzymes, clotting agents, immunoglobulins (part of the immune system), and proteins that carry hormones, vitamins, cholesterol, and other things the body needs. Plasma also contains sugar (glucose) and electrolytes like sodium, potassium, and calcium, as well as other things like the aforementioned hormones, vitamins, and cholesterol.

Blood types

Fun facts The heart beats around 3 billion times in the average person's life. About 8 million blood cells die in the human body every second, and the same number are born each second. Within a tiny droplet of blood, there are some 5 million red blood cells. It takes about 20 seconds for a red blood cell to circle the whole body. Red blood cells make approximately 250,000 round trips of the body before returning to the bone marrow, where they were born, to die. Red blood cells may live for about 4 months circulating throughout the body, feeding the 60 trillion other body cells. Blood that is rich in oxygen appears red. Blood that is poor in oxygen appears blue. The heart is surrounded by a rigid sack called the pericardium which can fill with fluid and become painful after certain viral infections