Understanding the Lymphatic and Cardiovascular Systems
The Lymphatic Circulatory System
The lymphatic system is responsible for collecting the excess liquid remaining between the cells and returning it to the blood. It also transports fats absorbed in the intestine.
The lymphatic circulatory system is simpler than the blood circulatory system. It comprises the following components:
- Lymphatic capillaries: Small, blind-ended vessels finely distributed in all tissues. They are responsible for collecting the interstitial fluid.
- Lymphatic vessels: Vessels with a similar structure to veins, resulting from the confluence of lymphatic capillaries. These vessels drain into the blood circulatory system, spilling their contents. The interior presents a series of valves that only allow movement in one direction.
- Lymph nodes: Small swellings that occur along lymphatic vessels. They remove foreign substances and microorganisms from the lymph, preventing them from entering the blood. They are also centers for the formation and maturation of some types of white blood cells.
Lymph nodes are especially abundant in the armpits, groin, neck, and around the ears. Therefore, when the number of microorganisms is very large, these are the first lymph nodes to be noticed, as they swell and grow.
The lymphatic system collects interstitial fluid, not absorbed by cells, through the thin walls of the lymphatic capillaries and leads it to the lymphatics. This interstitial fluid within the lymphatic vessels is called lymph. The lymph vessels lead to different parts of the circulatory system, causing the lymph to be incorporated into the blood.
Lymph only moves in one direction, driven primarily by contractions of the lymphatic vessels, thoracic respiratory movements, and, in some cases, by the force of gravity.
Circulatory System Diseases
Diseases affecting the heart and blood vessels are called cardiovascular diseases. Among them, one of the most important is arteriosclerosis, because it may cause other related diseases.
Arteriosclerosis
The term arteriosclerosis means hardening of the arteries. It is mainly caused by the deposition of fat and cholesterol on the inner wall of these vessels, which reduces their internal diameter and impedes blood flow. This can cause blood clots and blockages, called thrombi, which sometimes break off and travel to vital organs like the heart, brain, or lungs, blocking blood flow and causing a stroke.
Myocardial Infarction
Atherosclerosis can affect any artery in the body but is especially important when it damages the coronary arteries, which are responsible for providing the blood carrying nutrients and oxygen to the heart muscle (myocardium).
If a clot forms in one of these coronary arteries, blood flow is interrupted, and, as a result, the muscle cells that it nourishes die, resulting in a myocardial infarction, which can cause death. Infarction manifests as pain and pressure, often prolonged, in the chest, which may spread to the arms and shoulders (especially the left), back, and even teeth and jaw.
If blockage of a coronary artery partially occurs, the heart is forced to work harder, and the body is unable to increase blood flow to that organ, which triggers angina pectoris.
Cardiovascular Health
Cardiovascular diseases are the leading cause of death in the Western world. To avoid this, it is important to develop healthy habits.
Exercise
Playing a sport keeps the body in shape, facilitates blood vessel transport, and makes the heart work properly. The sport practiced must be appropriate to age and individual characteristics.
Healthy Diet
A poor diet can cause the accumulation of fat and cholesterol. Some of these substances accumulate in the arteries and cause atherosclerosis. Furthermore, excess weight increases the risk of stroke.
No Smoking
Nicotine has a hardening effect on the arterial walls, hindering the transport of blood and forcing the heart to work harder. This decreases the blood supply to all organs and increases the risk of myocardial infarction.