This is a tear between the inner and outer layers of the aorta wall. The tear can cause the wall to separate and burst. This can cause serious bleeding. Limb ischemia say "iss-KEE-mee-yuh".
This means that your limb, usually a leg, is not getting enough oxygen. It happens when a blood clot moves from the aorta to an artery in a leg. The blood clot cuts off blood supply to the leg. It can permanently damage the tissue. Cholesterol medicines, such as statins and other medicines to lower cholesterol.
Medicine that prevents blood clots, such as aspirin. These medicines prevent blood clots that can cause a heart attack. Lifestyle changes Do not smoke. If you need help quitting, talk to your doctor about stop-smoking programs and medicines.
These can increase your chances of quitting for good. Eat heart-healthy foods such as fruits, vegetables, whole grains, fish, lean meats, and low-fat or non-fat dairy foods. Limit sodium, sugars, and alcohol. If your doctor recommends it, get more exercise.
Walking is a good choice. Bit by bit, increase the amount you walk every day. It is fine to be active in blocks of 10 minutes or more throughout your day and week.
Stay at a healthy weight. Lose weight if you need to. Be safe with medicines. Take your medicines exactly as prescribed. Call your doctor or nurse call line if you think you are having a problem with your medicine. If you take a blood thinner, be sure to get instructions about how to take your medicine safely. Blood thinners can cause serious bleeding problems. Do not take any vitamins, over-the-counter drugs, or herbal products without talking to your doctor first.
For example, call if: You passed out lost consciousness. You have severe pain in your belly, back, or chest. You have severe trouble breathing. You have severe leg pain; numbness; or pale, blue-black skin. You cough up blood. You have symptoms of a heart attack. These may include: Chest pain or pressure, or a strange feeling in the chest. Shortness of breath. Nausea or vomiting. Pain, pressure, or a strange feeling in the back, neck, jaw, or upper belly or in one or both shoulders or arms.
Light-headedness or sudden weakness. A fast or irregular heartbeat. You have symptoms of a stroke. These may include: Sudden numbness, tingling, weakness, or loss of movement in your face, arm, or leg, especially on only one side of your body.
Sudden vision changes. Sudden trouble speaking. Sudden confusion or trouble understanding simple statements. Sudden problems with walking or balance. Anatomy of the Arterial Wall : Arterial wall layers including the tunica intima and the tunica media. In elastic arteries, the tunica media is rich with elastic and connective tissue. The aorta : The aorta makes up most of the elastic arteries in the body.
Arterial elasticity gives rise to the Windkessel effect, which through passive contraction after expansion helps to maintain a relatively constant pressure in the arteries despite the pulsating nature of the blood flow from the heart. Due to position as the first part of the systemic circulatory system closest to the heart and the resultant high pressures it will experience, the aorta is perhaps the most elastic artery, featuring an incredibly thick tunica media rich in elastic filaments.
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.
The term angiogenesis denotes the formation of new capillaries from pre-existing blood vessels. Capillaries do not function independently. The capillary bed is an interwoven network of capillaries that supplies an organ. The more metabolically active the cells, the more capillaries required to supply nutrients and carry away waste products. A capillary bed can consist of two types of vessels: true capillaries, which branch mainly from arterioles and provide exchange between cells and the circulation, and vascular shunts, short vessels that directly connect arterioles and venules at opposite ends of the bed, allowing for bypass.
Capillary beds may control blood flow via autoregulation. This allows an organ to maintain constant flow despite a change in central blood pressure.
This is achieved by myogenic response and by tubuloglomerular feedback in the kidney. When blood pressure increases, the arterioles that lead to the capillary bed are stretched and subsequently constrict to counteract the increased tendency for high pressure to increase blood flow. In the lungs, special mechanisms have been adapted to meet the needs of increased necessity of blood flow during exercise. When heart rate increases and more blood must flow through the lungs, capillaries are recruited and are distended to make room for increased blood flow while resistance decreases.
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