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Blood Circulatory System

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What is Blood Circulatory System?

The blood circulatory system, also known as the cardiovascular system, delivers oxygen and nutrients to every cell in the human body. Blood vessels( arteries and veins) and heart are the components of the system. The heart pumps blood away through arteries, and veins bring it back to the heart. The cardiovascular system appears like a tree; the trunk the main artery (aorta) divides itself into large arteries, leading to smaller vessels, the smallest forms a network of blood vessels called capillary network. Blood must always flow to uphold life.


Two Kinds of the Circulatory System

There are two different types of blood circulatory system operating in the human body. The systemic circulation is responsible for carrying oxygen and other essential nutrients with blood to organs, tissues, and cells. The pulmonary system is a part of the cardiovascular system, which takes away deoxygenated blood and returns oxygenated blood in the system.


How the System works

Blood circulation starts between the two heartbeats when the heart rests. In expansion, the blood flows from the upper two chambers (atria) to the lower two chambers (ventricles). From ventricles, the blood is supplied in larger arteries, in a stage named the ejection period. 


In the systemic circulation, the heart supplies oxygenated blood from the left vertical to the aorta. From there, the blood travels through the large arteries finish up in the capillary network. In the process, the blood carries necessary oxygen and other nutrients and returns the deoxygenated blood into the right atrium and ventricle of the heart. In the process, the blood carries oxygen, vital nutrients, and collects the resident substance and carbon dioxide. The blood moves to those lungs to replace carbon dioxide for oxygen and return to the left atrium. The oxygenated blood flows from the left atrium to the left ventricle and starts systemic circulation again.


The right ventricle pumps the blood low in oxygen content into the pulmonary artery to begin the pulmonary circulation. The artery, which divides itself into smaller arteries and capillaries, the capillaries in the lungs for a fine network around the pulmonary vesicles, which are air sacs, looks like grapes. Carbon dioxide is released from the bloodstream into the air inside the pulmonary vesicles. When we breathe out, carbon dioxide is released from the body. As we breathe in, new oxygen enters into the bloodstream via alveoli, and oxygen content rises in the blood. The oxygenated blood travels from the lungs through pulmonary veins and into the left ventricle. The next heartbeat initiates a new systemic circulation.

 

The Cardiovascular System

The blood circulatory system, which is also known as the cardiovascular system, delivers oxygen and nutrients to every cell in the human body. The Blood vessels, which are the arteries and veins, along with the heart are the components of this system. The heart pumps blood away via the arteries, and the veins bring it back to the heart. The cardiovascular system when looked at anatomically appears like a tree, where the trunk which is the main artery (aorta) divides itself into large arteries, leading to smaller vessels, the smallest forms a network of blood vessels known as the capillary network. The Blood must always be flowing through our body to uphold life. 


Types of Circulatory System

There are basically two different types of blood circulatory systems operating inside the human body. The systemic circulation system is responsible for carrying oxygen and other essential nutrients with blood to organs, tissues, and cells. The pulmonary system, which is a part of the cardiovascular system, takes away deoxygenated blood and returns oxygenated blood in the system. The Heart is the most important organ of the human body to survive and hence we must take proper care to keep it in a good condition.


The Blood circulation starts between the two heartbeats when the heart rests. During expansion, the blood flows from the upper two chambers (atria) to the lower two chambers (ventricles). From the ventricles, the blood is supplied in larger arteries, in a stage that is named the ejection period. The heart is also the center of the circulatory system and pumps blood to the rest of the body, to all the organs and cells. This hollow muscular body of the heart is made up of four chambers, the left and right atriums make the upper two chambers while the left, and right ventricles form the lower two chambers. One way valves are incorporated between chambers to ensure that the blood flow is in the right direction.


Heart of the Circulation System

The heart is the center of the circulatory system and pumps blood to the rest of the body, to all organs and cells. This hollow muscular body is made up of four chambers; left and right atriums make the upper two chambers and left, and right ventricles form the lower two chambers. One way valves are incorporated between chambers to ensure the right direction of blood flow. Two independent networks of blood vessels work together to complete the circulation system, they are pulmonary and systemic. A cluster of cells known as sinus nodes located at the top of the right atrium controls the heartbeat; relaxation and contraction. Electrical signals are emitted from the sinus node, through an electrical conduction system of the heart to direct the muscles to relax or contract.


There are two segments in a heartbeat; the systole and diastole phase. In systole, the ventricles contract and thrust the blood into the aorta or pulmonary artery. The one-way valve situated between the atria and ventricle closes, stopping the blood from flowing backward. In the diastole phase, the valve linking to the atria opens, allowing the ventricle to be filled with blood. The sinus node controls the pace of these two phases. 


In an average adult human, around five to six liters of blood are pumped through their bodies. A heart beats around 100,000 times per day, pumping 7,570 liters of blood through 96,560 kilometers of blood vessels. In a mere 20 seconds, the blood covers the entire circulatory system. 


The Lymphatic System

The lymphatic system is also a network of vessels that run throughout the body. These vessels do not create a complete circulatory system and are not governed by the heart. This system is an open one, where fluid moves from one direction to limits towards two drainage points into veins, just above the heart. Due to the absence of pressure, lymphatic fluid moves at a slower space than blood. Small lymph capillaries interact with blood capillaries in the interstitial spaces in the tissues. Tissue fluids enter the lymph capillaries and are carried away. The lymph fluids contain a large number of white blood cells


The lymphatic system has two kinds of lymphoid tissues; the primary lymphoid tissues consist of bone marrow and thymus. There are hematopoietic stem cells (HSC) in the bone marrow which gradually matures into a different type of blood cells and lymphocytes. The secondary lymphatic tissues consist of the spleen, lymph nodes, and diffuse lymphoid tissues; the spleen is an encapsulated formation which filters blood and screens pathogens and antigens. Lymph nodes are found throughout the body, which are bean-shaped. There are clusters of them in the armpits, neck, and in the pelvic region. Swollen lymph nodes indicate your body is fighting an infection. It returns to a standard size when the job is over. 


Structure of the Circulatory System

The heart creates pressure, which pushes the blood into arteries; in pressure, the arteries expand, and blood is forced into the smallest capillaries. There are many smooth muscles around veins, which helps the blood to travel through low-pressure veins back to the heart. A minute is taken to complete the blood circulation system from and to heart. Arteries lead to smaller and smaller forming capillaries that provide oxygenated blood to tissues. Veins carry deoxygenated blood, along with other residual substances back to the heart. The waste products are excreted in the lungs and later filtered by the liver and kidney.


Circulatory System Function

The circulatory system functions to provide oxygen and necessary nutrients to cells and remove carbon dioxide from the bloodstream, produced by metabolism. Oxygen is bound to molecules called hemoglobin that are situated at the facade of red blood cells. The cardiovascular system is like an internal highway network, linking all parts of the body through blood vessels, arteries and veins, arterioles and venules, and capillaries. Nutrients like glucose generated from digested carbohydrates are delivered to muscles and organs. Hormones secreted by endocrine are transported by blood vessels to targeted organs; waste products are carried to the lungs and urinary system for expulsion from the body. The cardiovascular system works with the respiratory system to deliver oxygen to cells and remove carbon dioxide.


Conclusion

Exercise for thirty minutes a day, eat healthy balanced food, and maintain a healthy weight to keep your blood pressure robust and optimal. Avoid fast and processed food as they are rich in saturated fat, which often stiffens the walls of the blood vessels. A finely tuned circulatory system carries nutrients, oxygen, electrolytes and hormones throughout the body.

Last updated date: 22nd Sep 2023
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FAQs on Blood Circulatory System

1. What is the artery?

The artery is one kind of muscular tube inside the human heart, which is followed by smooth tissues that deliver oxygen-enriched blood from the heart to tissues and cells. Each of the arteries consists of three layers; the first one is the intima, the second one is the media, and the third one is the adventitia. The largest artery is known as the aorta that is situated at the left ventricle of the heart.

2. How many muscles are there in the human body?

If objectively calculated, there are over 650 named skeletal muscles in the human body and if one counts other muscle tissues like smooth muscles at the cellular level, then there are billions of smooth muscles in the body. These Muscles perform various activities like facilitating movement, moving food in the digestive tract, and allowing the heart to pump blood.

3. What are WBC and RBC?

The Red blood cells (RBC), also known as erythrocytes, are flattened disk-like objects containing an important enzyme called hemoglobin, a protein that carries oxygen. Whereas, the White blood cells (WBC), also known as leukocytes, are the immune system cells that protect the body from infectious disease and foreign invaders. There are different types of WBC, with different life spans and all these WBC carry their important functionalities. Both the RBC and WBC are extremely important for the health of a human.

4. What are platelets and plasma?

Platelets, also known as thrombocytes, are oval-shaped cells that are responsible for blood clotting. In a situation, when a blood vessel ruptures, platelets gather around the region to seal it. The Platelets are generated by the bone marrow and survive for around nine days. Whereas, Plasma is a light yellow fluid that carries water, salt, and enzymes to different parts of the body. Plasma transports the nutrients, hormones, and proteins to various parts of the body. The Cells also excrete waste products into plasma.

5. What should be done to keep the heart healthy and functioning?

The Human heart is a very delicate organ, although it never stops functioning for the entirety of the lifespan of a human being, the proper conditioning of the heart is extremely important to maintain the blood and nutrient flow in the body. Exercise of 30 mins daily should be practiced by everyone that will give the body a chance to get into a fir shape. Morning Walks are found to be very helpful. Meditation and Yoga have been found to be particularly helpful to patients who have been struggling with heart disease or conditions of stress.


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