The Circulatory System John, Ross, Matt

Structure (Main components) Divided into 3 main parts: The Heart - Also known as the cardiac muscle. The heart is an involuntary muscle that pumps blood throughout the body through arteries. Blood - Transports oxygen to tissues, CO2 to lungs Blood vessels - Move/transport blood to and from the heart to the body

The Heart Components: Right/Left Atrium, Right/Left AV Valve, Right/Left Ventricle, Semilunar Valve, Pulmonary Artery, and Aorta Valve How it works:

The Heart Cont.

Blood Components Red blood cells are disc-shaped cells containing the protein hemoglobin, which enables the cells to pick up and deliver oxygen to all parts of the body, then pick up carbon dioxide and remove it from tissues. White blood cells are constantly on the lookout for signs of disease. When a germ does appear, the white blood cells have a number of ways by which they can attack. Some will produce protective antibodies that will defeat the germ. Others will surround and destroy the bacteria. Plasma is a clear liquid that is 90 percent water and carries the blood cells.Without plasma, the life-giving blood cells would be left floundering without transportation. Platelets are colorless bodies in blood that allow it to clot, otherwise humans would bleed out upon getting a cut.

Blood Vessels- Arteries The heart pumps blood out through one main artery called the dorsal aorta. The main artery then divides and branches out into many smaller arteries so that each region of your body has its own system of arteries that supply it with fresh, oxygen-rich blood. Arteries are made with three different layers: -An outer layer of Tissue -A Muscular middle -A smooth inner layer lined with epithelial cells The exchange of oxygen and CO2 takes place after the arteries pump the oxygen rich blood to the capillaries. Once the blood is delivered here, the arteries have completed their job.

Arteries- Structure vs. Function The middle layer of arteries is a strong and flexible muscle layer that expands to let blood flow in, and then contracts to push it along the artery. The rate of contraction is how we measure our pulse. The inner layer of the blood is very smooth. This makes for optimal performance in the arteries because it allows for limited friction as the blood travels down the arteries. Epithelial tissue is very thin, and it is also tightly woven, which prevents from fluid loss.

Veins are similar to arteries in structure, however they pump blood back to the heart, instead of away from it. After the exchange of CO2 and oxygen in the capillaries, waste-full blood is taken by the veins, and transported back to the heart. Veins- Structure vs. Function

Capillaries are only one epithelial cell thick, but can be very long. Their job is too connect arteries to veins. One at a time, red blood cells release their oxygen through the capillary wall to be absorbed by the surrounding tissue. The tissue then releases it's waste which is mostly CO2, which goes back into the red blood cell. The red blood cell then flows the opposite way through the capillary into the vein, where it is transported back to the heart. Capillaries

Red blood cells contain the protein hemoglobin, which is able to connect to oxygen as well as carbon dioxide. Hemoglobin attaches to oxygen molecules as it passes through the lungs. This oxygenated blood is transported throughout the body and is put in tissues through capillaries, very small and thin blood vessels. The capillaries are small enough that oxygen can detach from the hemoglobin and pass through the capillaries while carbon dioxide can also move through them and attach themselves to hemoglobin once the oxygen has been dropped off. The carbon dioxide rich blood is brought back to the lungs where this exchange can occur and carbon dioxide can be exhaled. Veins and arteries are too thick for this process to occur within them. Gas exchange within the capillaries VideoGas exchange within the capillaries Video Capillary gas exchange animation down concentration gradient Gas Exchange

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