heart & circulatory system.हृदय और परिसंचरण तंत्र
Channel: study news
Date: 2020-06-08

The branch of science under which the heart and its structure are studied is called cardiology.
 The main function of the heart is to pump blood. Heart neither purifies blood nor impure blood. In the context of the heart, purification of blood takes place in the lungs.
In the context of heart, pure blood means oxygenated blood. Whereas impure blood means oxygen-less blood  carbon dioxide.
Pure blood flows in the arteries that go from the heart to the organs while in the pulmonary artery, impure blood flows from the heart to the lungs.
Impure blood flows 
in the veins. Which comes from the heart to the organs. Pure blood flows in the pulmonary veins that lead from the lungs to the heart.
The mesh of capillaries remains in the body.

The capillary is the place where oxygen and carbon dioxide exchange.
A man's heart is made up of cardiac tissue.
Heart is 12 cm long and 9 cm wide.
Its weighs from 300 to 350 grams.
The heart is located in the middle of both lungs in the thoracic cavity. The heart is in the form of a hollow and conical structure.
A muscle called septum found in the heart divides the heart into two parts. The left part of which is related to the circulation of pure blood and the circulation of impure blood in the right part.
Human's heart has 4 chambers. There are two atrial and two ventricles.
Two-chambered heart is found in fish, in which an atrium and a ventricle are found. 
In amphibian animals (frog), a three-chambered heart is found. Which has two atrial and one ventricle.
Three-chambered heart is found in Reptiles (snake, lizard). Which has two atrial and one ventricle.

A four-chambered heart is found in a crocodile. Which is also a reptile.
Two atrial and two ventricles are found in it.
Birds have four chamberd hearts, in which two atrial and two ventricles are found.
Mammals (humans, whales, dolphins, bats) have a four-chambered heart.
The atrium and ventricle separate from each other through the valve. The portion above the valve is the atrium and the lower part is called the ventricle. 
The left side portion has two number of valves. Hence it is called bicuspid valve or mitral valve.
Whereas the right side portion has a number of valves in three, hence this is called tricuspid valve.
The aorta is found at the top of the heart. Which is the largest artery of the body. Three valves are found in the aorta. Which are called semilunar valves due to being crescent. Whenever these valves shrink, it is called a hole in the heart.
There is a sino auricular node in the heart. Which generates electrochemical waves. Whenever this node goes bad. So an artificial machine is called in place instead of it called a pacemaker.
An A.V. node (Atrioventricular Node) is found in the heart, due to which the electrochemical waves produced have an effect on the alveolar fibers. As a result, the ventricle is narrowed and relaxed.
The contraction and relaxation phase of the heart refers to the contraction and relaxation phase of the ventricle which pressures 120 mm and 80 mm respectively on the column of mercury.
The first patient named Heill’s measured the blood pressure of a horse in 1733.
A healthy person's heart beats 72 times in 1 minute. Which is called heartbeat or pulse rate. Hearing it with a stethoscope.
The heart of the fetus beats 120 to 150 times in 1 minute. A newborn's heart beats 100-120 times in 1 minute.
The heart pumps 70ml blood in 1 minute.
The center that controls the heartbeat is the medulla oblongata.
The hormones that regulate the heartbeat are thyroxine and epinephrine or adrenaline.
Potassium is the element that controls the heartbeat, and sodium also plays a role.
The blood circulation system was discovered by William Harvey in 1628.
When there is a deposition of lipids or cholesterol in the vessels, the vessels become narrow, causing high blood pressure.
This disease occurs in children up to 8 years old. Children's ears turn red when they have a bacterial infection called Streptococcus varidiens in their ears. This bacterium enters the body through the ear. 
Whereas India's first transplant was done by Dr. Venugopal on 3 August 1994 in a hospital in New Delhi.
Zorvic-7 was produced by Robert Zorvic. Which was the world's first artificial heart, its transplant was done in 1982.

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