Write a note on heart describe it's structure, location and working
Answers
Answer:
The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system.[1] The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to the lungs.[2] In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest.[3]
In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles.[4][5] Commonly the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart.[6] Fish, in contrast, have two chambers, an atrium and a ventricle, while reptiles have three chambers.[5] In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow.[3] The heart is enclosed in a protective sac, the pericardium, which also contains a small amount of fluid. The wall of the heart is made up of three layers: epicardium, myocardium, and endocardium.[7]
The heart pumps blood with a rhythm determined by a group of pacemaking cells in the sinoatrial node. These generate a current that causes contraction of the heart, traveling through the atrioventricular node and along the conduction system of the heart. The heart receives blood low in oxygen from the systemic circulation, which enters the right atrium from the superior and inferior venae cavae and passes to the right ventricle. From here it is pumped into the pulmonary circulation, through the lungs where it receives oxygen and gives off carbon dioxide. Oxygenated blood then returns to the left atrium, passes through the left ventricle and is pumped out through the aorta to the systemic circulation−where the oxygen is used and metabolized to carbon dioxide.[8] The heart beats at a resting rate close to 72 beats per minute.[9] Exercise temporarily increases the rate, but lowers resting heart rate in the long term, and is good for heart health.[10]
Explanation:
Explanation:
As a central part of the circulatory system, the heart is primarily responsible for pumping blood and distributing oxygen and nutrients throughout the body. Because of this task, the heart may be considered one of the most important organs of the body, such that even small dysfunctions or abnormalities may cause drastic changes or effects in the human organism.
The heart is a muscle whose working mechanism is made possible by the many parts that operate together. The organ is divided into several chambers that take in and distribute oxygen-poor or oxygen-rich blood. These chambers are accompanied by veins and arteries that facilitate the same function. With all of its parts working together towards the same goal, the heart successfully pumps blood with ease.
Normally, a good-functioning adult heart could go on three cardiac cycles or 72 beats per minute. This rate changes for children whose heart rates are normally and relatively faster.
Structure of the Heart
The heart can be found at the center of the chest, underneath the sternum in a thoracic compartment. It is made up of four chambers and several valves that regulate the normal flow of blood within the body.
Two chambers called atria are located in the upper portion of the heart and receive oxygen-free blood. The valves that separate these chambers are called atrioventricular valves which is composed of the tricuspid valve on the left and the mitral valve on the right.
On the other hand, ventricles are chambers found on the lower portion of the heart; they pump oxygen-enriched blood into all organs of the body, reaching even the smallest cells. Similar to the atria, the ventricular chambers are also separated by valves. Collectively-termed as semilunar valves, these are comprised of the pulmonary and aortic valve