What kind of arteries are there

The aorta is so thick that it requires its own capillary network to supply it with sufficient oxygen and nutrients to function, the vasa vasorum. When the left ventricle contracts to force blood into the aorta, the aorta expands.

This stretching generates the potential energy that will help maintain blood pressure during diastole, when the aorta contracts passively. Additionally, the elastic recoil helps conserve the energy from the pumping heart and smooth the flow of blood around the body through the Windkessel effect. Distributing arteries are medium-sized arteries that draw blood from an elastic artery and branch into resistance vessels.

Splenic Artery : Transverse section of the human spleen showing the distribution of the splenic artery and its branches. Muscular or distributing arteries are medium-sized arteries that draw blood from an elastic artery and branch into resistance vessels, including small arteries and arterioles.

Muscular arteries can be identified by the well-defined elastic lamina that lies between the tunicae intima and media. The splenic artery lienal artery , the blood vessel that supplies oxygenated blood to the spleen, is an example of a muscular artery. It branches from the celiac artery and follows a course superior to the pancreas. The splenic artery branches off to the stomach and pancreas before reaching the spleen and gives rise to arterioles that directly supply capillaries of these organs.

An anastomosis refers to any join between two vessels. Circulatory anastomoses are named based on the vessels they join: two arteries arterio-arterial anastomosis , two veins veno-venous anastomosis , or between an artery and a vein arterio-venous anastomosis. Anastomoses : The blood vessels of the rectum and anus, showing the distribution and anastomosis on the posterior surface near the termination of the gut.

Anastomoses between arteries and anastomoses between veins result in a multitude of arteries and veins serving the same volume of tissue. Such anastomoses occur normally in the body in the circulatory system, serving as backup routes for blood to flow if one link is blocked or otherwise compromised, but may also occur pathologically. Arterio-arterial anastomoses include actual joins e. Important examples include:. The Circle of Willis : Schematic representation of the circle of Willis—arteries of the brain and brain stem.

Blood flows up to the brain through the vertebral arteries and through the internal carotid arteries. Pathological anastomoses result from trauma or disease and are usually referred to as fistulae.

They can be very severe if they result in the bypassing of key tissues by the circulatory system. An arteriole is a small diameter blood vessel in the microcirculation system that branches out from an artery and leads to capillaries. An arteriole is a small-diameter blood vessel which forms part of the microcirculation that extends from an artery and leads to capillaries.

Capillary : Arterioles are part of the microcirculation system, along with capillaries, arteries, veins, venules, and tissue cells. The microcirculation involves the flow of blood in the smallest blood vessels, including arterioles, capillaries, and venules. Arterioles have muscular walls that usually consist of one or two layers of smooth muscle. They are the primary site of vascular resistance. This reduces the pressure and velocity of blood flow to enable gas and nutrient exchange to occur within the capillaries.

Arterioles are innervated and also respond to various circulating hormones and other factors such as pH in order to regulate their caliber, thus modulating the amount of blood flow into the capillary network and tissues.

They are surrounded by a thin basal lamina of connective tissue. Structure of a capillary : Capillaries are of small diameter with the vessel wall being a single cell thick. Capillaries are surrounded by a thin basal lamina of connective tissue. Capillaries form a network through body tissues that connects arterioles and venules and facilitates the exchange of water, oxygen, carbon dioxide, and many other nutrients and waste substances between blood and surrounding tissues.

The thin wall of the capillary and close association with its resident tissue allow for gas and lipophilic molecules to pass through without the need for special transport mechanisms.

This allows bidirectional diffusion depending on osmotic gradients. During embryological development, new capillaries are formed by vasculogenesis, the process of blood vessel formation occurring by de novo production of endothelial cells and their formation into vascular tubes.

Arteries are a type of blood vessel. They work to carry blood away from the heart. In contrast, veins carry blood back to the heart. Because arteries are moving blood being pumped out by the heart, the walls of arteries are thicker and more elastic than those of veins. This is because the blood in the arteries is passing through with a higher pressure than in veins. The thick, elastic walls of arteries accommodate that pressure. Arteries can also be divided into elastic and muscular arteries based off of the material of their tunica media or middle layer.

Arteries come in a variety of sizes. The largest artery of the body is the aorta, which begins at the heart. As they move further from the heart, arteries branch off and become increasingly smaller. The smallest arteries are called arterioles. Arterioles connect to capillaries, which are the smallest blood vessels and are where the exchange of oxygen, nutrients, and waste occurs between the blood and the cells of the body.

After this exchange occurs, the blood enters the venous system , where it travels back toward the heart. Below are some of the major arteries that are found in the body and the organs and tissues that they service. The largest and most important artery in the circulatory system is the aorta. The aorta is connected to your heart via the aortic valve. The arteries are blood vessels in the circulatory system that move blood away from the heart. This occurs through two different circuits. The systemic circuit supplies the organs and tissues of the body with oxygen and other nutrients.

The pulmonary circuit allows blood to acquire fresh oxygen while getting rid of carbon dioxide. Damaged or narrowed arteries can lead to the body not getting an adequate blood supply, which can put you at risk for things such as heart attack or stroke.

There is a well defined circular layer of smooth muscle in the tunica media. The tunica intima has an endothelium of flattened endothelial cells. The tunica media is primarily a layer of smooth muscle, with some elastin an collagen. The Tunica Adventitia is very broad, and mostly contains collagen and elastin. Can you identify the tunica intima and tunica media layers of this elastic artery?

Can you identify the tunica intima , IEL and tunica media of this muscular artery. This is a photo of some stained smaller arterioles. The TA layer is difficult to see, but concentric rings of muscle can be seen in the T. This shows a diagram of an arteriole. The internal elastic lamina layer is still present. The T. Arterioles are small arteries that deliver blood to capillaries. Arterioles control blood flow through capillary beds by contracting or dilating the the size of the lumen, and therefore the tunica media layer contains concentric rings of smooth muscle to do this.