We explain what the circulatory system is and its main functions. Also, the parts that make it up and their possible diseases.
What is the circulatory system?
The circulatory system, also called the circulatory system or cardiovascular system, is a complex internal transport mechanism that the body of living beings has to varying degrees and that allows the transfer of different nutrients, regulatory substances, chemical defenses and other fundamental substances throughout the body, as well as the collection of toxins, metabolic byproducts and other waste materials for elimination.
This type of system exists in both vertebrate and invertebrate animals, although not in the same way. In the case of the former, it transports blood, a red fluid rich in iron that allows, among other things, the transfer of the oxygen necessary to obtain energy. In the case of the latter, hemolymph or other similar substances are transported; in that of plants, sap.
The circulatory system of the human body includes a vast network of blood tubes known as capillaries which connect to a larger network made up of veins and arteries. At the center of it all, a muscular pump known as the heart. When we cut or wound ourselves, blood flows because some section (usually smaller) of said network is violated. Luckily, the blood also carries cells responsible for repairing tissue and stopping minor bleeding.
See also: Respiratory system
Function of the circulatory system
As has been said, the function of the circulatory system is key: keeping the blood moving to oxygenate the body and preserve the life of the tissues. If any tissue were isolated from this vast blood network, any limb or organ, its cells would suffer from a lack of oxygen and die. This is known as ischemia.
In the same way, this device has the mission of communicating the entire body, allowing the movement of chemical substances of diverse nature such as hormones (to regulate the body's activity), white blood cells (and other defensive cells), or the nutrients necessary to produce new cells and tissues (carbohydrates, proteins and lipids). Even the medicines we take or the injections we receive use this transportation system to get to where they are needed.
Finally, the blood in circulation also passes through certain filters, such as the liver, where it is stripped of toxins, contaminants and substances that are products of metabolism. The circulatory system is, at the same time, a channel for nutrition and waste collection.
Parts of the circulatory system
The circulatory system is essentially made up of:
- Capillary vessels Small branches of the blood network that reach the most hidden corners of the body. No tissue in the body is left out of the blood flow. Some capillaries can be thinner than a human hair.
- Arteries. One of the two types of major blood vessels, it is characterized by carrying newly oxygenated blood from the lungs to the heart and from there to the rest of the body. They contain the reddest blood (due to a pigment called hemoglobin). An injury to an artery can be serious, since the volume of blood transported through them is very large, and there is not always time to repair the wound to prevent bleeding.
- Veins. Unlike arteries, these larger ducts contain unoxygenated blood, that is, blood that makes the return journey to the heart and then to the lungs, to resume the cycle. Like arteries, they are voluminous ducts and a cut or blockage in the veins is usually lethal.
- Heart. The pump that keeps the blood in constant movement is a hollow, muscular organ that weighs about 300 grams and contains four cavities: two atria and two ventricles. This construction prevents venous and arterial blood from mixing, as each is propelled to a different destination. The human heart pumps about five liters of blood per minute, which means that in about 70 years of life it pumps about 2.6 billion times, with a minuscule rest between beats of just 0.4 seconds.
Diseases of the circulatory system
The circulatory system can suffer from diseases such as:
- Arteriosclerosis An ailment that consists of the accumulation of fatty plaques and other substances on the walls of the arteries, solidifying and reducing blood flow, which slows down circulation and requires greater cardiac effort.
- Hypertension. Due to many possible causes, it consists of an excess of force in the heartbeat, which sends blood very intensely through the arteries, eventually breaking a capillary and causing a stroke, or exhausting the heart and leading to a heart attack.
- Ischemias They usually affect the heart or brain, but also other organs or members of the body. They occur when something blocks the flow of blood, causing some part of the body to not receive enough blood and begin to die.
