Align-ju STUDENT
ABSTRACT The cardiovascular system is a complex and vital system that keeps an animal alive . It is made up of different organs working in synchrony to enable the body to function correctly .
This article outlines the cardiovascular system – including the blood , capillaries , veins , arteries and heart – and the conditions affecting the system .
Keywords cardiovascular system , heart , blood
Introduction
The cardiovascular system could be described as one of the most important biological structures within the body , and it is vital to a healthy and functioning animal . The cardiovascular system transports blood around an animal ' s body , helping to supply the organs with oxygen , as well as carrying nutrients and hormones to their required locations .
The cardiovascular system is made up of different structures : the heart , capillaries , veins and arteries . These are then associated with other organs , tissues and bones within the body , where nutrients , oxygen and waste products are exchanged and transported around the body through the circulatory system .
The circulatory system
In mammals , there are two types of circulation . They both consist of blood vessels that transport blood around the body . Blood within an animal ' s body passes through the heart twice in the course of being distributed to the rest of the body .
Pulmonary circulation
The pulmonary circulation is responsible for carrying deoxygenated blood from the heart to the lungs and oxygenated blood from the lungs back to the heart [ 1 ] .
Systemic circulation
The systemic circulation carries oxygenated blood from the heart to the organs and tissues within the body . It then returns deoxygenated blood back to the heart [ 1 ] .
Components and function of blood
Blood can be described as the largest connective tissue within an animal ' s body . It carries oxygen , nutrients and hormones , and collects waste products that have been produced by the organs and tissues [ 1 ] .
Blood makes up approximately 7 % of an animal ' s body weight . Within the blood , the components of blood are suspended in a liquid , known as plasma ( or serum ; see the section on blood composition below ). The pH of blood is usually around 7.4 [ 1 ] .
Blood has many different functions , which connect all of the body systems together , allowing them to communicate . Blood can contain a variety of different elements , which can vary in their abundance depending on processes that are occurring within an animal ' s body .
Hormones and enzymes
Hormones , produced by endocrine glands , travel throughout the body via the bloodstream to reach their destination in other tissues or organs [ 1 ] . For example , the adrenal glands , located at the top of each kidney , may release the hormone aldosterone into the blood ; this hormone would then pass through the circulatory system to reach its target organ , the kidney . Aldosterone acts on the kidney to regulate the salt and water balance in the blood , which then regulates blood pressure .
Waste materials
The body creates waste materials such as urea and creatinine as a product of metabolism . These waste products are then transported by the blood to the kidneys and liver , where they are processed ready for excretion [ 1 ] .
Nutrients
After digestion , nutrients are made available to the body in order for it to function correctly . These nutrients are transported by the blood to the liver and different tissues throughout the body [ 1 ] . The liver will then convert these nutrients into products that the body can use .
Gases
Blood contains gases as a result of respiration . Blood that has travelled from the lungs carries oxygen and this is transported to different organs and tissues . Carbon dioxide is then collected from the tissues and carried back to the lungs [ 1 ] . Once deoxygenated blood reaches the heart , it is then sent to the lungs for oxygenation , before being redispersed back into circulation .
Blood composition
Blood has two components : a liquid element known as plasma or serum , and a solid element that contains blood cells . Plasma forms part of the body ' s extracellular fluid and contains water , salts , clotting factors and proteins . Serum contains the same components as plasma , minus the clotting factors . Each component has a different role within the blood [ 1 ] .
Volume 38 ( 4 ) • August 2023
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