Vascular System

The Vascular System

The vascular system or network is a substrate for blood circulation in the body in order to carry and transport oxygen; carbon dioxide; Foodstuffs; hormones; Blood cells and fluids in all parts of the body. The vascular system consists of: network of arteries; network of veins and network of lymphatic vessels.

• The arterial system transfers oxygen-rich blood to all organs, tissues and cells with the help of a wide network of large, medium and small arteries and peripheral capillaries.
• The venous system, which contains a high concentration of carbon dioxide, directs and transfers it through the superficial and deep veins of the organs to the large central veins and finally to the heart and lungs.
• The lymphatic system is made up of a wide network of lymphatic vessels whose job is to transfer lymph fluid containing toxins, waste chemicals and some types of proteins directly to the heart.

Venous system

An adult person with a normal body has about 4-6 liters of blood in his circulatory system, which is pumped and circulated through the vascular network approximately 1500 times a day. This means that about 7,000 liters of blood return to the heart through the venous network every day. In this way, the venous system has a heavy duty. Especially when we pay attention to the fact that in the lower limbs, it is necessary to move the volume of blood towards the heart against the direction of the pressure caused by the weight.

Anatomy and structure of the venous system. Superficial veins and deep veins

Expanded venous capillaries in all organs and tissues are connected to larger venous branches called superficial veins.

• Superficial veins are located in the subcutaneous tissues between the outer layer of the skin and muscles, and they collect the volume of venous blood from the capillaries of the superficial tissues and transfer it to the deep veins.
• The deep veins are located between the muscles of the organs and are responsible for transferring the blood flow to the heart, and they do this with the help of the contraction activity of the muscles of the surrounding organs.
• Communicating veins are a series of veins that connect superficial and deep veins.

Leg muscle pump and venous valves

Since the blood pressure caused by the pumping action of the heart has decreased along the arterial vessels and in the end parts of the capillary branches of the arteries, there is not much pressure anymore; Therefore, the most important mechanism of blood transfer against the direction of weight in the lower body organs; It is the leg muscle pump system that is done with the help of venous valves. in deep veins at several intervals; There are crescent-shaped two-lattice valves that separate the length of the veins into separate parts in the space between the two valves. These valves, which are called pigeon nest valves, are placed in such a way that when the vein is compressed by the muscles of the side limb; They allow the compressed blood to pass towards the heart, but when the muscle pressure is reduced and the vein becomes relaxed and uncompressed again and the blood moves downward due to the weight, the valve slats are closed and the blood is allowed to pass in the opposite direction. They do not give the direction of the heart. In this way, these valves act as a mechanical barrier, and the blood flow travels the length of the veins towards the heart with each contraction of the leg muscles.

Why is mobility vital for us?

The leg muscle pump is active only when we use the muscles. For example, when walking or running, these muscles constantly contract and expand and put pressure on the deep veins. Continuous standing or sitting and inactivity of the motor muscles of the legs reduces the pumping function of the heart and as a result disrupts the venous blood transfer of the lower limbs to the heart, and if this situation continues for a long time and other conditions are present, it leads to venous insufficiency It is the disruption of the normal and proper function of the pigeon nest valves of the veins and in this condition the blood flow in the lower deep veins is reversed and a large volume of blood is stored in the veins and leads to the occlusion of these vessels. Venous insufficiency in this condition is the starting point of many other venous disorders such as spider veins; varicose veins; Swelling of the feet and even more serious conditions include inflammation and changes in skin color and skin wounds.

Lymphatic system

The lymphatic system is a vast network of vessels and lymph nodes that play a very basic and important role in the transfer of lymph fluid; safety performance; It has homeostasis, purification and filtering of blood. In fact, the lymphatic system is the body’s waste transfer and recycling unit and transports all kinds of toxins and compounds resulting from metabolic metabolism and inflammatory activities, and all kinds of proteins and fats found in interstitial fluids and abdominal cavities. The extensive network of lymphatic vessels drains the collected lymph fluid into the bloodstream through the thoracic lymphatic duct at the junction with the jugular vein. Lymph liquid is a liquid that is activated from inside the capillary network of arteries under hydrostatic pressure to the interstitial space and contains protein (smaller than albumin); fibrinogen and other coagulation factors; small molecules and ions in blood serum; leukocytes; immunoglobulins; Fats in the form of chylomicrons; remnants of cell destruction; It is a by-product of tissue metabolism and bacteria. Lymph fluid is collected by primary lymphatic sinuses. These sinuses; a series of elevated vessels; They have small holes through which liquids and small particles smaller than albumin can pass. The lymph fluid entered in this primary vascular network then enters the larger branches of blood vessels and collecting systems. These collecting vessels and networks are equipped with one-way valves similar to venous pigeonhole valves, whose role is to prevent fluid from returning to the tissue. Also, in the spaces between the lymphatic vessels, there are muscle units called lymphangion, which with the contraction of the muscles of the walls of these units; The lymph liquid moves to the lymph nodes in the direction that the valves allow to pass. There are hundreds of lymph nodes in the whole body (mainly around the neck, around the intestines, armpits and groin). The most important functions of lymph nodes are: transfer of cellular wastes, regulation of lymph protein level, immune response, recycling of lymphocytes and their re-transfer to blood circulation and reabsorption of water. In healthy and normal conditions, the lymphatic system collects and transports about ten liters of interstitial fluid daily. In conditions where there is a disturbance and obstruction in the network of lymphatic vessels and the lymphatic system suffers from failure, or when the amount of fluid secretion and production in the interstitial space is greater than the absorption capacity of the lymphatic system, excess fluids accumulate in the intercellular space of the tissues and Swelling and edema occur in the body. This disorder is called lymphedema.