CIRCULATORY SYSTEM
The circulatory system is made up of the heart and blood vessels. It’s function is to move blood around the body. Blood is a fluid made out of plasma, cells and platelets that transports oxygen and nutrients (amongst other things) to all the body tissues and removes waste materials. The heart is the pump that forces blood to move. Arteries are blood vessels that carry blood away from the heart, they branch out into smaller diameter blood vessels called arterioles which then give way to capillaries. Capillaries are the smallest blood vessels in diamater and are the site of exchange of many substances at the body’s tissues. Capillaries merge into larger blood vessels called venules that carry blood away from the body tissues. Venules allow blood to drain into larger blood vessels called veins which carry blood back to the heart. Unlike the other types of blood vessels, veins contain valves to prevent backflow.
LYMPHATIC SYSTEM
The lymphatic system is an organ system which is part of the circulatory system and the immune system. It’s main function is to carry lymph from the body tissues towards the heart and to assist in immune defence. Every day around 20 litres of plasma pass from the blood into the body tissues through the capillaries. Of these 20 litres, only 17 litres are reabsorbed directly into the blood vessels. The remaining 3 litres are returned to the blood through the lymphatic system. The fluid enters the lymphatic system through lympathic capillaries and is then transported via progressively larger vessels through numerous lymph nodes until it reaches the lymph ducts which empty into the venous system, i.e. the circulatory system. Lymph nodes contain large numbers of immune cells and help fight infections by filtering the lymph that passes through them and exposing antigens to said cells.
HOW BLOOD MOVES
The heart, acting as a pump, creates positive pressure which forces blood to move through the blood vessels. As the blood travels further away from the heart the pressure gradient is progressively weaker meaning the blood has less energy to advance. Once the blood has exchanged gases and nutrients with the body tissues and has entered the venous system it needs additional help to carry on moving. On the one hand, smooth muscle in the vessel’s wall contracts to propel the blood forward, whereas the contraction and relaxation of surrounding skeletal muscles such as those in your legs also assist in helping pump the blood. The one-way valves in the veins prevent blood from flowing backward and are crucial for the correct circulation of blood.
HOW LYMPH MOVES
Unlike the circulatory system, the lymphatic system hasn’t got a heart to generate a pressure gradient that pushes the lymph through the different lymphatic vessels and nodes. Instead, and similarly to veins, lymphatic vessels have muscular walls which contract and force the lymph to move forwards. Skeletal muscles also help to propel the lymph through their contraction and relaxation. One-way valves, which are more abundant in the larger vessels, stop lymph from flowing backward and keep it moving forwards and upwards.
THE EFFECT OF GRAVITY
Both venous blood and lymph have to move upwards away from the lower limbs towards the heart. This means that when a person is standing or sitting, both fluids have to move against the pull of gravity. This in turn explains why people with poor circulation tend to get swollen feet, ankles, and/or legs since blood and lymph aren’t able to make their way up effectively.
LET’S TALK ABOUT CIRCULATION
The circulatory system is made up of the heart and blood vessels. It’s function is to move blood around the body. Blood is a fluid made out of plasma, cells and platelets that transports oxygen and nutrients (amongst other things) to all the body tissues and removes waste materials. The heart is the pump that forces blood to move. Arteries are blood vessels that carry blood away from the heart, they branch out into smaller diameter blood vessels called arterioles which then give way to capillaries. Capillaries are the smallest blood vessels in diamater and are the site of exchange of many substances at the body’s tissues. Capillaries merge into larger blood vessels called venules that carry blood away from the body tissues. Venules allow blood to drain into larger blood vessels called veins which carry blood back to the heart. Unlike the other types of blood vessels, veins contain valves to prevent backflow.
The lymphatic system is an organ system which is part of the circulatory system and the immune system. It’s main function is to carry lymph from the body tissues towards the heart and to assist in immune defence. Every day around 20 litres of plasma pass from the blood into the body tissues through the capillaries. Of these 20 litres, only 17 litres are reabsorbed directly into the blood vessels. The remaining 3 litres are returned to the blood through the lymphatic system. The fluid enters the lymphatic system through lympathic capillaries and is then transported via progressively larger vessels through numerous lymph nodes until it reaches the lymph ducts which empty into the venous system, i.e. the circulatory system. Lymph nodes contain large numbers of immune cells and help fight infections by filtering the lymph that passes through them and exposing antigens to said cells.
The heart, acting as a pump, creates positive pressure which forces blood to move through the blood vessels. As the blood travels further away from the heart the pressure gradient is progressively weaker meaning the blood has less energy to advance. Once the blood has exchanged gases and nutrients with the body tissues and has entered the venous system it needs additional help to carry on moving. On the one hand, smooth muscle in the vessel’s wall contracts to propel the blood forward, whereas the contraction and relaxation of surrounding skeletal muscles such as those in your legs also assist in helping pump the blood. The one-way valves in the veins prevent blood from flowing backwards and are crucial for the correct circulation of blood.
Unlike the circulatory system, the lymphatic system hasn’t got a heart to generate a pressure gradient that pushes the lymph through the different lymphatic vessels and nodes. Instead, and similarly to veins, lymphatic vessels have muscular walls which contract and force the lymph to move forwards. Skeletal muscles also help to propel the lymph through their contraction and relaxation. One-way valves, which are more abundant in the larger vessels, stop lymph from flowing backward and keep it moving forwards and upwards.
Both venous blood and lymph have to move upwards away from the lower limbs towards the heart. This means that when a person is standing or sitting, both fluids have to move against the pull of gravity. This in turn explains why people with poor circulation tend to get swollen feet, ankles, and/or legs since blood and lymph aren’t able to make their way up effectively.
DO YOU SUFFER FROM SWOLLEN LEGS?
Chronic venous insufficiency (CVI) occurs when the valves in the veins don’t prevent backflow causing blood to pool in the lower limbs which in turn results in an increase of blood pressure within the veins. This can cause symptoms such as swelling in feet, ankles or legs, pain or itching sensation in the legs, varicose veins, hyperpigmentation (brown colouring of the skin), and in the advanced stages, the apparition of ulcers. Several factors can increase the risk of suffering from CVI, these include but are not limited to: gender (women are more likely to suffer from CVI), smoking, pregnancy, obesity, genetics, and prolonged standing. Other conditions such as deep vein thrombosis can also cause CVI.
Treatment options will depend on the severity of the particular case of CVI and if there are other associated conditions. In most cases, treatment will include raising feet and legs to reduce symptoms, avoid prolonged standing, regular walking, and use of compression stockings.
Deep vein thrombosis (DVP) refers to formation of a blood clot in a deep vein, occurring most of the times in the legs and less frequently in other body areas such as the arms. The formation of a blood clot usually occurs as a consequence of slow blood flow, increased tendency to clot, and inflammation, as well as changes to blood vessel walls. Risk factors for developing DVP include older age, genetics, immobilization of a limb, obesity, pregnancy, some medications, and several diseases amongst others. Symptoms tend to be limited to the affected leg and can include swelling (since blood flow is restricted), pain, tenderness, and redness of the skin.
Medical treatment will be aimed at dissolving or removing the blood clot to prevent it from embolising. The best treatment is to prevent DVP from ocurring in the first place. People at risk may be asked to wear compression stockings, enjoy an active and healthy lifestyle and avoid prolonges sitting or standing. In some cases, people may be treated with medications that reduce the chances of blood clots from occuring.
A malfunctioning lymphatic system can cause the build up of lymph in the body’s tissues resulting in swelling, discoloration, and in advanced stages of the disease, ulcers. Depending on the cause of the condition, lymphedema can affect one or more body parts, including legs and arms. Lymphedema can be secondary to cancer since some forms of cancer treatment involve dissection, surgery or radiation therapy aimed at lymphatic nodes where tumoral cells are present. Certain diseases can also damage the lymphatic system affecting its function. In other cases genetics are to blame.
There is no cure for lymphedema and treatment options are aimed at reducing the symptoms.
Inflammation seconday to trauma can cause a person’s legs to swell. In this case swelling is limited to the affected body part and treatment options will vary depending on the severity, symptoms, and location of the injury. In general, after traumatic injuries such as a sprained ankle, elevation of the leg is recommended to assist fluid reabsorption and to reduce pain and swelling. Correctly applied compression bandages are also adequate.
Pregnancy can, in more than one way, cause a person’s legs to swell. During pregnancy, blood volume can increase between 20% and 100% above prepregnancy levels in response to the requirements made by the maternal, placental and fetal tissues putting the circulatory system under extra stress. Increased levels of progesterone cause the muscular walls of blood vessels to relax which makes it more difficult for the venous system to effectively move blood from the lower limbs. The increasing volume and weight of the uterus can compress the pelvic veins and inferior vena cava, restricting venous blood flow and facilitating the pooling of blood in the legs.
Having swollen legs doesn’t necessarily mean a person has a medical condition; prolonged standing or sitting, a salty diet, heat, some medications… can all be factors causing a temporary swelling of the legs.
LET ME TELL YOU HOW OUR BEDS CAN HELP
To alleviate swelling of your legs one of the simplest things you can do is to raise them slightly above heart level. Jensen’s adjustable bed models allow you to do so in a more comfortable and ergonomic way than placing cushions under your legs or elevating the foot of a regular bed. Being able to easily raise or lower the headrest while your legs are elevated is also a big benefit, making reading or sitting up in bed easier than ever.
