CapillariesPrint10

CapillariesPrint10 - Capillaries Capillary hemangioma is...

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Capillary hemangioma is seen involving the entire right upper lid of the sleeping patient. Even when awake, elevation of the right upper eyelid is severely restricted. Got your attention? A hemangioma is a benign tumor caused by the cells that line the capillary-endothelial cells. Although it looks dangerous, they are usually gone by the age of 7years of age. Capillary networks are the lifeline of all cells. Read on! Capillaries
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Capillaries The capillaries are the link between the arterial and venous circulations. They are the only anatomical avenue by which oxygen and nutrients reach the cells. They are considered to be like the freeways to your cells or another way of looking at them as specialized river ways to go to all your cells. Yes, they supply, nourish and remove metabolic products from cells. To keep us alive, all 100 trillion cells in our bodies must be no less than 3-4 cell lengths from a capillary. There are three types of blood vessels: arteries, veins, and capillaries. Arteries and veins run parallel throughout the body with a web-like network of capillaries, embedded in tissue, connecting them. The arteries pass their oxygen and nutrient-rich blood to the capillaries and allow exchange of oxygen for carbon dioxide and wastes. The capillaries then pass their waste-rich blood to the veins. The arteries carry blood away from the heart at high blood pressure. Most of this pressure is lost in the capillaries, the veins then carry blood back to the heart at lower pressures and use one-way valves to prevent backflow. The pressure loss through the large capillary networks of the lungs and the combined capillary networks of the remaining organs is also why the blood circulation requires the heart to have a separate pumping component for each. Although these terms have been explained in previous emodules,
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there are presented again to reinforce some basic concepts. Arteries have three layers: an outer layer of tissue, a muscular middle, and an inner layer of epithelial cells. The muscle in the middle is elastic and very strong. The inner layer is very smooth so that the blood can flow easily with no obstacles in its path. Like arteries, veins have three layers: an outer layer of tissue, muscle in the middle, and a smooth inner layer of epithelial cells. However, the layers are thinner and not as strong, containing less tissue. Veins also have one-way valves to prevent backflow. Capillaries are where the transported substances actually enter and leave the blood. No exchange of materials takes place in the arteries and veins, whose walls are too thick and impermeable. Unlike the arteries and veins, capillaries are very thin and fragile. The capillaries are actually only one epithelial cell thick. The three types of capillaries vary in the degree of permeability to solutes.
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CapillariesPrint10 - Capillaries Capillary hemangioma is...

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