ALL IT’S PARTS AND FUNCTIONS Circulatory System ALL IT’S PARTS AND FUNCTIONS

Fucntions: Transporting nutrients and oxygen to cells all over the body Transporting wastes (urea, carbon dioxide, salt) to excretory organs Fighting disease and infections

Vocabulary Pulmonary – means anything dealing with the lungs Cardiac – means anything dealing with the heart

Organs: Heart – pumps the blood through the body Arteries – carry blood away from the heart Veins – Carry blood back to the heart Capillaries – Tiny blood vessels, where exchange of materials occurs

Heart The human heart has 4 chambers 2 atria (on top) 2 ventricles (on bottom) There are valves between the chambers, arteries and veins to keep blood in the proper compartments Remember when looking at the heart your left is its right

Heart Unoxygenated blood flows into the right atrium from the vena cava. When the tricuspid valve opens up, the blood enters the right ventricle. The ventricle is more muscular and is used to pump the blood through out the body. Then the right ventricle squeezes shut it pushed the blood through the pulmonic valve. The blood enters the pulmonary arteries which take it to the lungs. The red blood cells have iron, which binds to oxygen and the blood releases carbon dioxide

Heart After the blood exchanges gases in the lungs it returns to the left atrium through the pulmonary veins. When the mitrial valve opens up the oxygenated blood flows from the left atrium into the left ventricle. The left ventricle is the most muscular chamber because it must pump the blood through the entire body. The left ventricle squeezes the blood through the aortic valve into the aorta. The aorta takes the blood to other arteries that will carry the blood to all the major organs of the body.

Heart The organs take the oxygen and from the blood Blood picks up nutrients from the villi in the small intestine. The now unoxygenated blood then returns to the right atrium through the vena cava to star the cycle all over again! This cycle happens about once second! Your heart pumps 100,000 times a days and moves 2,000 gallons of blood a day!

Blood Your blood is made up of: Red blood cells (erythrocytes) – contain hemoglobin (which makes them red), hemoglobin allows the blood to bind to oxygen and carry it to cells that need it. White blood cells (leukocytes) – fight infection, blood carries them to the sites of infection to kill germs in the body. Platelets – This allows the blood to clot, when the blood is exposed to air platelets group together and mix with fibrogen to form a scab Plasma – fluid that composes that makes up the blood, mostly water (90%), but also contains salts and minerals.

Blood Types Each blood cells has certain antigens attached to it, which allows the body to recognize it There are four different blood types: A – has A-antigens, and B-antibodies (so if type B blood is introduced into the body it will be destroyed) B – has B-antigens, and A-antibodies AB – has A and B antigens, and no antibodies (universal recipient) O – has no antigens, and A and B antibodies (universal donor)

Blood Types Your blood will also have a Rh factor, making it negative or positive. If you are Rh positive, you have D-antigens on the surface of your red blood cells. If you are Rh negative you do not have these antigens. This may become a problem during pregnancy because the baby shares blood with the mother, but the mother can be Rh negative and baby Rh positive. Both the ABO system and Rh factors need to be taken into account when finding a donor.

Sino-Atrial Node In your heart you have a group of cells in your right atrium, which controls your heart beat. You have many pacemaker cells, but only one will be active at one time. These cells send an electric charge through the cells of the heart causing it to beat. These are independent from the brain. http://www.youtube.com/watch?v=SMXBR_YFocs&feature=related