Usually, accessing vascular structures is done through a needle to puncture the vessel percutaneously, followed by a wire introduced through the needle to secure the vascular access. The needle is then removed and a sheath is advanced over the wire. Vascular sheaths are hollow structures with a built in diaphragm to prevent bleeding. Catheters are then placed into and out of the sheath with a minimal loss of blood.11
I found the differences between arteries and veins are their functions they provide to the heart as well as their structure. Arteries transfers blood away from the heart into the periphery resulting in the pressure of the blood in the arteries being high. Where as, the veins transfer blood towards the heart. Arteries carry oxygenated blood distributing it in the periphery as the pulmonary artery moves deoxygenated blood into the lungs for purification. The wall of an artery consists of three layers machining it thicker than veins. The elasticity within the layers of the muscle allows arteries to handle great pressures of blood within it. The thickest layer is known as tunica media as the other two are recognized as tunica externa, and tunica interna. The vein obtains blood from the periphery and carries it towards the heart. Veins are known to carry deoxygenated blood and transfers it the heart for purification. The pulmonary vein is known to carry oxygenated blood. However, there are semilunar valves found within the vein that does not allow retrograde flow of blood in preventing blood to flow in the opposite direction. Veins are thinner when compared to arteries consisting of thin elastic muscle layers with one thick layer being the tunica adventitia. Arteries consist of: carrying oxygenated blood expect for the pulmonary artery; deeply found in the body; thick walled and
ANSWER: The lymph vessels and the veins both have valves that are one way, and allow the blood to return to the heart. The valves looks like gateways for the blood flow (1 p. 372 and 399).
* How would you describe the structure and function of this animal’s circulatory system? Include any unique characteristics. A shark’s heart is a two-chambered S-shaped tube, small in proportion to body size located in the head region.
According to Patton and Thibodeau (2012), the kidneys are a pair of bean-shaped organs found along the posterior muscular wall of the abdominal cavity. The convex side of each kidney is located laterally and the concave side medial. The renal hilum on the concave side is the point where the renal artery enters, the vein and ureter leave the kidney. Deep to the perirenal fat, the kidney is surrounded by fibrous connective tissue called the renal capsule. Deep to the renal capsule is the renal cortex, which surrounds the renal medulla with their apexes facing inward toward the centre of the kidney. Nephrons, the basic structural and functional unit that filters blood to produce urine, are located within the cortex and medulla. The minor calyces that collects urine are connected to the papilla of each pyramid, and merge to form major calyces, which further merge into the renal pelvis. Urine drains into the ureter at the renal hilum where renal pelvis exits the kidney (Brenner, 2007).
Both the arterial system and venule system play a key role within the circulatory system, but this is possible because of their differences. An artery will pump blood away from the heart at high pressure, due to its think walls and small/round lumen. Arteries also possess numerous amount of that allows it to stretch. A vein will pump blood away from the heart at low pressure, while acting against gravity, due to its thin walls, multiple valves, and large size and irregular shaped lumen. Arteries contains vasa vasorum and nervi vasorum on its tunica externa, while the veins possess them on both the tunica externa and tunica media.
The cardiovascular systems function is to pass blood through ones body keeping their muscles oxygenated, to keep nutrients that are needed in the body and to help get rid of metabolic waste. The cardiovascular system is made up of three components, these are; the heart, the blood and the blood vessels.
There are three main types of blood vessels: arteries, veins, and capillaries. Arteries are vessels that usually carry highly oxygenated blood away from the heart and to the rest of the body. (The pulmonary trunk and related arteries are exceptions, as they actually carry blood from the lungs toward the heart.) Because arteries must transport high volumes of blood being forcefully pumped out by the heart and must therefore withstand greater pressure, most have thick, muscular walls and are more flexible as well. Arterioles, smaller types of arteries with thinner walls, branch off of the arteries to carry blood to another type of vessel, called the capillary. Capillaries are the most abundant blood vessels in the body. Thinner and smaller than the other blood vessels, the role of capillaries is to exchange substances like water, gases, chemicals, nutrients, wastes, etc. with the tissues of the body. The third type of blood vessel is the vein. Although they are generally larger than the other blood vessels, veins tend to have thinner, less flexible walls, as they are not forced to deal with such high blood pressures. Venules (veins’ versions of arteries’ arterioles) connect the capillaries to the veins, which then transport blood back
The arteries are thicker and more elastic because of the fast pumping of blood that leaves the heart to other organs to the body, as where the veins are small due to the low blood flow because of the slow movement from the capillaries to the veins not like the forceful pumping from the heart to the arteries to the rest of the body. The Oxygenated blood goes through the arteries except the pulmonary arteries. Then Deoxygenated blood goes through the veins except the pulmonary veins. The lumen of the artery is narrow, were as the lumen of the veins is wider. There are not valves in the arteries, were as the valves are present in veins. In the arteries, endothelial cells of tunica intima are more long then wider, and have more elastic membrane that is more developed. Then the Tunica media is more muscular, and the tunica extrema is not as developed. In veins, the endothelial cells of tunica intima are not as long and have more elastic membrane then being developed. The Tunica media is less muscular were the tunica extrema is more developed. Arteries are deep within and the veins are more superficial. Capillaries are microscopic vessels; they carry blood from the arterioles then go to the small veins or venules. The wall of the capillary made up of a