The heart is at the center and blood flows through the body. That much is clear to most people. But what mechanism ensures that the blood reaches the desired destination? How does the circulatory system work?
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Article overview
Blood vessels - the body's blood supply system
The blood vessels are a widely branched system of blood vessels of essential importance for circulation and metabolism. In most cases, medical problems in the blood vessel system have foreseeable, serious consequences for the interaction in the human body. It is therefore worth taking a look at how the blood vessels work and the most important diseases.
By User:Sansculotte - self-drawn, CC BY-SA 2.5, Link
The different types of blood vessels
Blood vessels basically come in five different varieties. The best known are the vein and the artery. Veins carry deoxygenated blood back to the heart, while arteries provide oxygen-rich blood flow to organs and peripheral areas.
Veins and arteries are connected by a system of branches called blood capillaries. The capillaries connect the venous and arterial vessels. In addition, there are connecting vessels that form a transition from the large blood vessels to the capillaries. Doctors refer to these as venules (originating from the vein) and arterioles (originating from the artery).
The largest and most important blood vessel is the aorta. Doctors refer to the aorta as the main artery of the body. It runs from the carotid arteries via the heart to the renal arteries and is 30 to 40 centimeters long with a diameter of 2.5 to 3.5 centimeters.
This video shows the aorta (explanations in English)
Structure and function of the blood vessels
The blood vessels are based on a tubular structure. They are elastic and can therefore be stretched and contracted. Blood vessels run through the entire body and act as transport vehicles for the vital blood circulation. The pumping action of the heart causes blood to travel through the vessels to the various regions of the body. The arteries transport oxygen and nutrients, while the veins return the now depleted blood to the heart.
The expansion of the blood vessels is determined by the blood pressure. This results from the cardiac output and the resistance in the blood vessels. Dilation of the vessels (vasodilation) can be caused by an increase in blood pressure on the one hand and by relaxation of the vascular muscles on the other. A narrowing of the vessels (vasoconstriction) is based on a decrease in pressure or a tightening of the vascular muscles.
The network of blood vessels works in conjunction with the heart to maintain the cardiovascular system. Doctors refer to the cooperation between the heart and blood vessels as the cardiovascular system.
Diseases of the blood vessels
One of the most important vascular diseases is thrombosis, which affects all types of blood vessels, but mostly the veins.
However, doctors generally divide diseases of the blood vessels into two classes, arterial and venous diseases (arteriopathies and venopathies). The most important vascular diseases are listed below.
Arteriopathies:
- Raynaud's syndrome
- Atherosclerosis
- Takayasu's arteritis
- Microscopic polyangiitis
- Polyarteritis nodosa
- Endangiitis obliterans
- Giant cell arteritis
Venopathies:
- Chronic venous insufficiency (CVI)
- phlebectasias
- varices
Doctors usually obtain an initial indication of the presence of a vascular disease by measuring blood pressure and taking the pulse in various parts of the body. If there is a suspicion of a previously unknown clinical picture, an ultrasound examination helps to determine this more precisely. Body scans are also used (e.g. X-rays with contrast medium or magnetic resonance tomography of vascular regions).
Symptoms, risk factors and preventive measures
Symptoms of vascular diseases
The symptoms of vascular diseases are wide-ranging and specific to many clinical pictures. Overarching symptoms are, for example
- Pain and discomfort
- Rapid fatigue
- Circulatory disorders
- Fever, sweating and anaemia (in the case of inflammation)
- Discoloration of the skin and swelling (especially with thrombosis)
Risk factors for vascular diseases
Some possible causes of vascular disease, including age, genes and gender, cannot be actively influenced. Other risk factors, however, depend on lifestyle and can be avoided. These controllable risk factors include
- Smoking
- High blood pressure
- stress
- lack of exercise
- being overweight
- High cholesterol
Prevention of vascular disease
The first measure to prevent vascular disease is sufficient exercise. Exercise prevents blood from building up in the vessels and obstructing blood flow. Chronic stress can also cause blood clots in the vessels over time. Avoiding stress prevents the development of cardiovascular diseases.
A balanced, healthy diet is also of central importance. Cholesterol impairs the elasticity of the blood vessels and inhibits blood flow in the long term. Make sure you eat more natural foods (e.g. fruit, vegetables, nuts) and avoid foods with additives and animal products (especially red meat). Adjusting your diet will also prevent you from becoming overweight, another risk factor.
