Unit 5 Flashcards
Clearly distinguish between the function of an artery and a vein
An artery is meant to carry oxygenated blood around the body.
Veins are ment to carry deoxygenated blood around the body.
Explain how the strucutre of an artery wall is related to an artery’s function
It not only provides support for the vessel but also changes vessel diameter to regulate blood flow and blood pressure. The outermost layer, which attaches the vessel to the surrounding tissue, is the tunica externa or tunica adventitia.
Describe the uniqe function of a capillary (not shared with other types of blood vessels)
They’re unique because they carry oxygenated blood. All other veins carry only deoxygenated blood. Systemic veins. The systemic circuit carries deoxygenated blood from the rest of the body back to your heart, where it then enters the pulmonary circuit for oxygen.
Capillaries have a unique morphology, consisting of only a single layer of endothelium, enabling them to carry out their function in delivering needed nutrients to organs and tissues
Explain how the unique structure of a capillary relates to its function
Their single-layer endothelium composition, which varies among the different types of capillaries, and surrounding basement membrane makes capillaries a bit “leakier” than other types of blood vessels. This allows oxygen and other molecules to reach your body’s cells with greater ease.
Describe the function of a metartiole, making special note of the function its precapillary sphincter in particular
The precapillary sphincters, circular smooth muscle cells that surround the capillary at its origin with the metarteriole, tightly regulate the flow of blood from a metarteriole to the capillaries it supplies
Structural differences between a vein and an artery
Arteries have thick walls with muscle tissue. Veins have thinner walls and use valves to keep your blood flowing
Structual differences beween an elastic artery, a muscular artery and an arteriole
Elastic arteries: These are elastic and stretch in response to the pulse.
Muscular arteries: These arteries branch further into resistance vessels, including small arteries and arterioles.
Arterioles: These are small arteries carrying blood to tissue level.
Structural differences between an arteriole, a metarteriole and a capillary
Arterioles range from 10 to 150 μm in diameter and regulate the distribution of blood flow to capillaries (0.5–1 μm). Small arterioles (metarterioles) can bypass the capillary beds, shunting flow directly into the small venules (10–40 μm).
A metarteriole is a type of vessel that has structural characteristics of both an arteriole and a capillary. Slightly larger than the typical capillary, the smooth muscle of the tunica media of the metarteriole is not continuous but forms rings of smooth muscle (sphincters) prior to the entrance to the capillaries.
Structural differences between a vein, a venule and a capillary
Venules are small veins that collect blood from the capillaries and return it to the larger veins, whereas capillaries form a network between arterioles and venules, and provide a path for nutrients, oxygen, carbon dioxide, and wastes exchange between the bloodstream and tissues.
Veins have thicker walls than capillaries. Veins use valves to transport blood towards the heart, but capillaries don’t have valves. Capillaries diffuse blood and nutrients between veins and arteries through their thin walls.
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