What is the Cardiovascular System?

The cardiovascular system is also called the "circulatory system". Consists of the heart, arteries, capillaries, and veins. It is a closed circulation pipeline, in which blood flows, supplies oxygen, various nutrients, hormones, etc. to organs and tissues, and transports tissue-metabolized waste to excretory organs to maintain the steady state and metabolism of the internal environment Conduct and maintain normal life activities. [1] A system consisting of the heart, arteries, capillaries, veins, and blood flowing through them. The heart can automatically and rhythmically contract and relax under the control of the nervous system, ensuring that blood circulates in a certain direction. Arteries are connected between the heart and capillaries and carry blood from the heart to the tissues. Capillaries are connected between arteries and veins, and are connected to each other to form a network, which is the site where blood and tissue exchange materials. The veins are connected between the capillaries and the heart, collecting blood flowing back to the heart.

The cardiovascular system is also called the "circulatory system". Consists of the heart, arteries, capillaries, and veins. It is a closed circulation pipeline, in which blood flows, supplies oxygen, various nutrients, hormones, etc. to organs and tissues, and transports tissue-metabolized waste to excretory organs to maintain the steady state and metabolism of the internal environment of the body. Conduct and maintain normal life activities. [1] A system consisting of the heart, arteries, capillaries, veins, and blood flowing through them. The heart can automatically and rhythmically contract and relax under the control of the nervous system, ensuring that blood circulates in a certain direction. Arteries are connected between the heart and capillaries and carry blood from the heart to the tissues. Capillaries are connected between arteries and veins, and are connected to each other to form a network, which is the site where blood and tissue exchange materials. The veins are connected between the capillaries and the heart, collecting blood flowing back to the heart.

Chinese name

Cardiovascular System

Foreign name

The cardiovascular system

Make up

Composed of heart and blood vessels

Vasculature

Cardiovascular and Lymphatic

Related diseases

Arrhythmia, cardiac function depression, cardiomyopathy, etc.

Core

heart

Anatomy of the cardiovascular system :

1. Cardiovascular system:

The heart and blood vessels form a network of blood transportthe cardiovascular system. Through this system, blood is pumped into the body's large vascular system, which transports nutrients and oxygen to the cells and removes waste products produced by cell metabolism. There are three types of blood vessels in the body: arteries, veins and capillaries. Under pressure, blood leaves the heart and is transported throughout the body through the branching system of the arteries. The last level of arteries, the arterioles, transports oxygen-rich blood to the capillaries. Oxygen, nutrients, waste products produced by metabolism, and other substances in extracellular fluid are exchanged in a capillary bed composed of capillaries. Blood then travels through the capillary bed into thin-walled venules similar to capillaries. The blood from the venous veins flows into the small veins, which then flow into the larger veins. Finally, the large veins, the vena cava, transport blood with lower oxygen content back to the heart.

2. Heart:

The heart is the power organ of the vascular system, located in the chest cavity, between the two lungs, like a slightly flat front and back cone. The heart is divided into four chambers, the left and right atrium and the left and right ventricle. The atrial septum and the septum divide the heart into left and right halves, and each half is divided into the upper atrium and the lower ventricle by the atrioventricular opening and surrounding valves. The left atrium receives blood from the left and right lungs, which is arterial blood. The left ventricle receives blood from the left atrium and presses it into the aorta when it contracts, pushing the large circulation. The right atrium receives venous blood that flows back to the heart throughout the body, constricting the blood into the right ventricle. When the right ventricle contracts, blood is pushed into the pulmonary veins. This shows that the heart is a blood pumping organ. Cardiac output (the amount of blood ejected by the heart per minute) is an important indicator of pumping function. The average heartbeat of healthy adults is 75 beats per minute, and the calculated cardiac output is about 51. During strenuous exercise, the cardiac output can increase 5 to 6 times of that during quietness. It can be seen that the pumping function of the heart has a certain reserve. The heart has a structure that conducts excitement and regulates the rhythmic beat, called the heart conduction beam. The cardiac conduction bundle is composed of specialized myocardial fibers, including the sinoatrial node, the atrioventricular node, the atrioventricular bundle, and the left and right bundle branches. The sinoatrial node is the pacemaker of the heartbeat. One contraction and relaxation of the heart is called the cardiac cycle. During the cardiac cycle, blood flows in a certain direction due to changes in pressure and volume in the various chambers of the heart, and the opening and closing of valves. Coupled with the role of the cardiac conduction system, the heart contracts and relaxes rhythmically throughout life, which promotes and maintains continuous blood circulation and ensures blood supply in the body. [2]

3. Blood vessels:

Blood vessels are the conduits for blood circulation. Divided into arteries, veins and capillaries. The blood vessels that carry blood from the heart to the various organs in the body are called arteries, which branch gradually from large to small, and become smaller and smaller, and finally divided into many capillaries. The capillaries converge to form a vein and return to the heart. Arteries and veins are pipes that carry blood, and their structures have the same thing in common, that is, the wall of the tube can be divided into three layers: the adventitia, media, and intima. However, after all, there are differences between the two, such as the small lumen of the arteries, the thick wall of the arteries, and the large elasticity, so the arteries can withstand the high-pressure blood pumped from the heart, and use the retraction of smooth muscles to push the blood forward. There are more veins than arteries, the diameter is larger, and the lumen is more irregular. The vein has a venous valve to prevent blood from flowing backwards. The capillary diameter is the thinnest, and the wall is the thinnest and most widely distributed. Its tube wall has a simple structure, which is mainly composed of an endothelium and a thin layer of basement membrane, and is surrounded by a layer of connective tissue. The total cross-sectional area of the capillaries is very large, the blood flow is slow, and there is greater permeability, which ensures the material exchange between blood and interstitial fluid.

Cardiovascular system Mechanisms of the cardiovascular system:

The cardiovascular system consists of different organs that transport blood throughout the body. Blood is a liquid containing oxygen and essential substances for cells. At the same time, blood takes away the cell's metabolites. These metabolites cannot be used by the body and are even toxic to the body.

The cardiovascular system is centered on the heart in the thorax. The heart acts as a "power pump" that sends oxygenated blood through a dense network of arteries to all parts of the body.

The arterial network starts from the heart. Arteries, arterioles, and capillaries form a system that supplies oxygen and nutrients to various parts of the body. Due to the strong contraction of the systolic heart, blood is pumped by the arterial system.

Hypoxic blood is collected by capillaries and large and small veins in the venous network. Due to the relaxation and relaxation of the myocardium, the venous network transports these venous blood containing cell metabolites back to the heart.

In addition to the arterial and venous networks, the human body also has a third network system called the lymphatic system. The lymphatic system is similar to the venous system, transporting a clear, yellow, blood-derived fluid called lymph.

The process by which arteries and veins supply blood to the body is called the systemic circulation; the body also has another circulation pathway, the pulmonary circulation. Like the systemic circulation, the pulmonary circulation starts and ends in the heart. Pulmonary circulation transports venous blood rich in carbon dioxide from the heart to the lungs. Through the breathing process of the lungs in the respiratory system, carbon dioxide is expelled and venous blood becomes arterial blood filled with oxygen again. The oxygenated arterial blood flows back to the heart and begins the next systemic cycle.