|
Distributing Artery
A muscular artery (or distributing artery) is a medium-sized artery that draws blood from an elastic artery and branches into "resistance vessels" including small arteries and arterioles. Their walls contain larger number of smooth muscles, allowing them to contract and expand depending on peripheral blood demand. This contrasts to the mechanism of elastic arteries, which use their elastic properties to store the energy generated by the heart's contraction for a brief moment (elastic recoil). Under the microscope, muscular arteries can be identified by their clearly defined internal elastic lamina. In constricted vessels, the elastic lamina of muscular arteries appears thick and kinky. The elastic lamina is best visualized using Verhoeff's stain, but can be easily detected in specimens stained using other techniques as a well-defined negative staining region. Examples of muscular arteries include the radial artery, femoral artery and the splenic artery In human anatomy, the spl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artery
An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pulmonary and the umbilical arteries, which carry deoxygenated blood to the organs that oxygenate it (lungs and placenta, respectively). The effective arterial blood volume is that extracellular fluid which fills the arterial system. The arteries are part of the circulatory system, that is responsible for the delivery of oxygen and nutrients to all cells, as well as the removal of carbon dioxide and waste products, the maintenance of optimum blood pH, and the circulation of proteins and cells of the immune system. Arteries contrast with veins, which carry blood back towards the heart. Structure The anatomy of arteries can be separated into gross anatomy, at the macroscopic level, and microanatomy, which must be studied with a mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastic Artery
An elastic artery (conducting artery or conduit artery) is an artery with many collagen and elastin filaments in the tunica media, which gives it the ability to stretch in response to each pulse. This elasticity also gives rise to the Windkessel effect, which helps to maintain a relatively constant pressure in the arteries despite the pulsating nature of the blood flow. Elastic arteries include the largest arteries in the body, those closest to the heart. They give rise to medium-sized vessels known as distributing arteries (or ''muscular arteries''). The pulmonary arteries, the aorta, and its branches together comprise the body's system of elastic arteries. Elastic arteries receive their own blood supply by the vasa vasorum unlike smaller blood vessels, which are supplied by diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arterioles
An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries. Arterioles have muscular walls (usually only one to two layers of smooth muscle cells) and are the primary site of vascular resistance. The greatest change in blood pressure and velocity of blood flow occurs at the transition of arterioles to capillaries.This function is extremely important because it prevents the thin, one-layer capillaries from exploding upon pressure. The arterioles achieve this decrease in pressure, as they are the site with the highest resistance (a large contributor to total peripheral resistance) which translates to a large decrease in the pressure. Structure Microanatomy In a healthy vascular system the endothelium lines all blood-contacting surfaces, including arteries, arterioles, veins, venules, capillaries, and heart chambers. This healthy condition is promoted by the ample production of nitric oxide by the en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Elastic Lamina
The internal elastic lamina or internal elastic lamella is a layer of elastic tissue that forms the outermost part of the tunica intima of blood vessels. It separates tunica intima from tunica media. Histology It is readily visualized with light microscopy in sections of muscular arteries, where it is thick and prominent, and arterioles, where it is slightly less prominent and often incomplete. It is very thin in veins and venules. In elastic arteries such as the aorta, which have very regular elastic laminae between layers of smooth muscle cells in their tunica media, the internal elastic lamina is approximately the same thickness as the other elastic laminae that are normally present.http://www.ouhsc.edu/histology/text%20sections/cardiovascular.html There is small amount of subendothelial connective tissue between basement membrane of endothelial cells and internal elastic lamina. Reduplication of internal elastic lamina can be seen in elderly individuals due to intima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verhoeff's Stain
Verhoeff's stain, also known as Verhoeff's elastic stain (VEG) or Verhoeff–Van Gieson stain (VVG), is a staining protocol used in histology, developed by American ophthalmic surgeon and pathologist Frederick Herman Verhoeff (1874–1968) in 1908. The formulation is used to demonstrate normal or pathologic elastic fibers. Verhoeff's stain forms a variety of cationic, anionic and non-ionic bonds with elastin, the main constituent of elastic fiber tissue. Elastin has a strong affinity for the iron-hematoxylin complex formed by the reagents in the stain and will hence retain dye longer than other tissue elements. This allows elastin to remain stained, while remaining tissue elements are decolorized. Sodium thiosulfate is used to remove excess iodine and a counterstain (most often Van Gieson's stain) is used to contrast the principal stain. Elastic fibers and cell nuclei are stained black, collagen fibers are stained red, and other tissue elements including cytoplasm are stained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Artery
In human anatomy, the radial artery is the main artery of the lateral aspect of the forearm. Structure The radial artery arises from the bifurcation of the brachial artery in the antecubital fossa. It runs distally on the anterior part of the forearm. There, it serves as a landmark for the division between the anterior and posterior compartments of the forearm, with the posterior compartment beginning just lateral to the artery. The artery winds laterally around the wrist, passing through the anatomical snuff box and between the heads of the first dorsal interosseous muscle. It passes anteriorly between the heads of the adductor pollicis, and becomes the deep palmar arch, which joins with the deep branch of the ulnar artery. Along its course, it is accompanied by a similarly named vein, the radial vein. Branches The named branches of the radial artery may be divided into three groups, corresponding with the three regions in which the vessel is situated. In the fore ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femoral Artery
The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery or profunda femoris artery and descends along the anteromedial part of the thigh in the femoral triangle. It enters and passes through the adductor canal, and becomes the popliteal artery as it passes through the adductor hiatus in the adductor magnus near the junction of the middle and distal thirds of the thigh. Structure The femoral artery enters the thigh from behind the inguinal ligament as the continuation of the external iliac artery. Here, it lies midway between the anterior superior iliac spine and the symphysis pubis (Mid-inguinal point). Segments In clinical parlance, the femoral artery has the following segments: *The common femoral artery (CFA) is the segment of the femoral artery between the inferior margin of the inguinal ligament and the branching point of the deep femoral artery/profunda femoris artery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Splenic Artery
In human anatomy, the splenic artery or lienal artery is the blood vessel that supplies oxygenated blood to the spleen. It branches from the celiac artery, and follows a course superior to the pancreas. It is known for its tortuous path to the spleen. Structure The splenic artery gives off branches to the stomach and pancreas before reaching the spleen. Note that the branches of the splenic artery do not reach all the way to the lower part of the greater curvature of the stomach. Instead, that region is supplied by the right gastroepiploic artery, a branch of the gastroduodenal artery. The two gastroepiploic arteries anastomose with each other at that point. Relations The splenic artery passes between the layers of the lienorenal ligament. Along its course, it is accompanied by a similarly named vein, the splenic vein, which drains into the hepatic portal vein. Clinical significance Splenic artery aneurysms are rare, but still the third most common abdominal aneurysm, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
