Dorothy FarrarBlood vessels
The blood vessels are responsible for transporting the blood . They are tubular and together with the heart form the circulatory system . Depending on the direction of flow, blood vessels are subdivided into arteries (artery), capillaries (hair vessels) and veins (blood vessels).
Definition
Blood vessels are so-called hollow organs that form the anatomical basis for blood circulation. They transport the blood and are therefore responsible for the supply of nutrients and oxygen to the body. Blood vessels are divided into arteries , arterioles , capillaries , venules and veins .
arteries
Arteries (artery, wrist artery) are all blood vessels that transport blood away from the heart. The large artery (aorta) is the largest artery that distributes the oxygen-rich blood in the body with its branches.
Aorta
The shape of the aorta resembles a curved walking stick. It emerges from the left ventricle and subsequently forms the ascending part of the aorta, the aortic arch and the descending part of the aorta.
The descending part of the aorta becomes the thoracic aorta in the mediastinal space. It then becomes the abdominal aorta as it passes through the diaphragm, which divides into two iliac arteries at the level of the fourth lumbar vertebra.
They come
Veins (blood vessels) are blood vessels that carry oxygen-poor blood from the body back to the heart. In contrast to the bright red, oxygen-rich blood in the arteries, the oxygen-poor blood in the veins is dark red.
Anatomy
The wall of a blood vessel consists of three layers: the intima (tunica intima), the media (tunica media) and the adventitia (tunica externa). The intima consists of endothelial cells, the subendothelial connective tissue and a basement membrane and is responsible for the liquid, substance and gas exchange between tissue and blood.
The closed association of the endothelial layer is important for coagulation and to prevent thrombus formation. The media is a muscular layer of elastic connective tissue, or smooth muscle, that distinguishes between muscular and elastic arteries. On the outside, a blood vessel is surrounded by the adventitia, which forms a network of collagen fibers and thus anchors the surrounding vessels.
Function
Blood vessels can change diameter and modify blood flow by contracting the muscle layer. The fibers of the autonomic nervous system are responsible for this, causing the vessels to either widen or narrow. This mechanism allows the blood volume to be optimally distributed. In addition, nutrients and oxygen reach the cells and individual organs.
In exchange, degradation products or carbon dioxide are transported away with the help of the blood vessels. In addition, blood vessels also control blood circulation in the skin and thus regulate body temperature. The arteries carry blood away from the heart, which then flows into the arterioles. The capillaries act as a link between veins and arteries. They only consist of a very thin cell layer, which means that an optimal exchange of oxygen, nutrients and metabolic products can take place.
The blood finally returns to the heart through the veins. To prevent blood from flowing back, veins have so-called venous valves, which ensure that blood flows to the heart. Thin, small veins are called venules. In order to do justice to their task, blood vessels for the nutrients must be continuous and sufficiently available.
If a deficiency is signaled, the blood vessels pump the blood through the circulatory system at high pressure and one speaks of elevated blood pressure. Furthermore, the body can also increase the dissolved particles in the blood, which is then measured as increased cholesterol levels .
Diseases
The majority of vascular diseases are caused by calcification of the arteries (arteriosclerosis), which occurs when calcium or connective tissue deposits form on the walls of the vessels.
Arteriosclerosis leads to blockages (stenoses), which can trigger a stroke or heart attack . The causes of the disease are high blood pressure , high cholesterol, obesity , diabetes and smoking.
If the coronary arteries are narrowed, coronary heart disease can occur. The heart muscle is then not supplied with blood properly, the lack of oxygen damages the cells in the heart and chest pain and sweating occur . A sudden thrombosis can lead to a stroke. The patients then suffer from neurological deficits, paralysis , blurred vision , dizziness or confusion.
If the extremities are not supplied with sufficient blood, this is referred to as arterial occlusive disease. At the beginning, the disease does not show any symptoms, but later pain occurs after a long walk and those affected complain of a feeling of coldness in their legs or feet.
Varicose veins or venous thrombosis are very common vein diseases. The superficial leg veins then dilate as the venous valves no longer function properly, causing blood to back up. Varicose veins are favored by sitting or standing for a long time, but sometimes there is also a congenital weakness of the connective tissue . The skin then has bluish nodules and the legs swell in the ankle area.
If the blood circulation in the leg arteries is disturbed, this is referred to as the so-called “window disease” or peripheral arterial occlusive disease, which was also known as “smoker’s leg” for a long time. If the blood flow slows down, venous occlusion can occur, which is particularly favored by being bedridden, lack of exercise, obesity or infectious diseases. There is pressure pain on the inside of the foot, calf pain and the superficial veins are clearly visible on the skin.
An embolism caused by a thrombosis can be life-threatening.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.