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Heart Structure, Function, Diagram, Anatomy, & Facts | Gurugrah

Introduction to the Heart | Gurugrah

Introduction to the Heart

The heart is a muscular, spongy, and hollow organ. Its wall is made of cardiac muscles. It weighs about 300 grams and is about the size of a first fist (12 x 9 cm). The heart has a conical shape, with a broad upper surface and a narrow lower surface.

It can be found in the cardiac notch between the lungs in the thoracic cavity. The color is radish brown.

Structure of the Heart's Protective Coverings:

The heart is surrounded by two pericardial coverings. Visceral pericardium is the inner pericardium, and partial pericardium is the outer pericardium. The pericardial cavity is the space between the two pericardia. Pericardial fluid is the fluid that fills this cavity. The pericardium itself secretes fluid to fill this space. The heart was moistened by this fluid, allowing it to move freely and without friction.

Heart's External Structure:

A septum divides the heart into two halves. Auricles and ventricles are the two chambers that communicate between each half. This gives the heart four chambers.


These are the uppermost parts of the heart. A groove known as the coronary sulcus separates the auricles from the ventricles on the outside of the heart.


The interventricles septum separates the ventricles, which make up the lower part of the heart.

Heart's internal structure: -


Because they must pump blood to the ventricles that are closest to them, auricles have thin valves. Auricles' inner surface is smooth or has a low elevation. It opens into the ventricles, and the inter-ventricular septum separates two auricles on the inside.


The left ventricles have thicker walls than the right ventricles because the right ventricles are responsible for pumping blood to the lungs, whereas the left ventricles are responsible for pumping blood to the body's farthest points under pressure. As a result, their walls are thick. Papillary muscles and low muscular ridges known as "Papillary" columnar carnie can be found on the inner surface of ventricles. The Interventricular septum separates the two ventricles.

Valves, an aperture, and enormous blood vessels:

Great blood vessels are the blood vessels that enter or leave the heart. The superior and inferior main veins supply the right auricles. The vena cava comes from the head and the lower body, respectively. The valve of the Vena-Cava, which protects the right auricle's opening, is located there. The heart's valve sends blood to a vein called the coronary vein. The right ventricle enters the right auricles. There is a Right A-V aperture in its opening. A valve known as the Tricuspid valve guards this aperture. There are three membrane flaps on it. It has a membrane that is attached to the auricles, and free ventricles and is attached to the papillary muscles with chordate tendinae.

The blood travels to the lungs via pulmonary arteries that emerge from the right ventricles. The three semilunarsemi-lunar-shaped valves, or pocket-shaped valves, are present at the artery's base. These check for blood in the back. Four pulmonary veins supply the left auricles with pure blood from the lungs. An opening known as the auricular-ventricular aperture separates the left ventricles from the left auricles. A value known as the Bicuspid valve guards this aperture. It is free in the ventricles and is attached to the papillary muscles by chordae tendinae to the left auricles. The main arteries known as the Aortic Arch originate in the upper left corner of the left ventricles and supply pure blood to all body parts. Three semi lunar-shaped pocket valves, which control blood return, are located at the base of the aortic arch.

Heart of Work:

The heart is a double pump that contracts and relaxes frequently. Systole is the contraction of the heart, and diastole is the relaxation of the heart. Three things happen in the heart. Auricular systole, or the three events, The cardiac cycle is the combination of ventricular systole and joint diastole.

Diastasis de joint:

Both the ventricles and the auricles are at this relaxed stage. The heart has more volume but less blood. From the major veins, blood flows into the respective auricles. As long as the A-V aperture remains open, some blood can also enter the Ventricles.

Systole Auricular:

Auricular systole is the contraction of the auricles that occurs now. Blood moves from the auricles to the ventricles because of this pressure, but it does not return to the great blood vessels because their openings close. Additionally, the heart contracts from its upper to lower end, pushing blood into the ventricles.

Systole of the Ventricle:

The area of the ventricles shrinks as a result of the ventricles contracting now. As a result of the A-V aperture-closing, blood pressure rises above that of the auricles in the ventricles.

The sound is known as lubb-lubb results from the closing of the A-V aperture as a result of the contraction of the ventricles.

The semi-lunar valves are still closed, which makes the pressure even higher. The semi-lunar valves are opened as a result of this movement backward. The ventricles' blood pressure is reduced as the blood moves into their respective blood vessels.

The volume of the ventricles rises as a result of relaxation, or diastole. This causes the semi-lunar valves to relax and close. Dupp-Dupp is the sound made when semilunar valves close as the ventricles relax. By placing a syhecoscope on the left side of the heart, these sounds can be heard.

Heart Health Care:

An artery known as the coronary artery supplies the heart with pure blood for delivery to the heart's wall. The heart requires more energy and material oxygen as it performs more work throughout life. The right auricles of the heart remove waste products from the heart wall through a vein known as the coronary vein.

Heartfulness of Heart:

The heart does not become exhausted throughout one's life. First, the heart contracts, then it relaxes. It rests for a while after relaxing before contracting. It works twice as long while resting. As a result, the heart doesn't get tired.

Heart Rate:

A heartbeat is the spontaneous contraction and relaxation of the heart to pump blood into and out of the body.

There are two types of heartbeat: neurogenic and regular.

It is controlled by the nervous system. It is controlled by a nerve impulse from a nerve ganglion close to the heart. In arthropods, it is.


It is controlled by a patch of muscle fibers in the heart's wall itself. If a frog's heart was taken out and kept in a saline solution. Due to the fact that it is controlled by the heart's muscles, it continues to beat for some time.

Heartbeat's Mechanism:

A wave of depolarization known as cardiac impulses, which originate in the tract known as nodal tissue, causes the heartbeat. The Sinu-auricular Node (S-A) node is what makes it up. Between the auricular node and the bundle of his (AV) bundle are Purkinje fibers and branches.

A Node S-A:

The right upper side of the right auricles contains it. It gives off waves of contractions. Because the muscles of the ventricles and the muscles of the auricles are not continuous, it moves along the wall of the auricles rather than on the wall of the ventricles.

Node Inter Auricular:

The left lower side of the Inter auricular septum contains it. Waves from the S-A node stimulate the Inter auricular node, which in turn produces waves of contraction that travel along the interventricular septum through Purkinje fibers and bundle of his bundle branches and contract the ventricles' walls.


72 times per minute, the heart beats. A smaller organism's heart beats faster than a larger organism's. Smaller organisms need to move energy and oxygen and perform more metabolic functions. An elephant's heart beats 25 times per minute, while a cat does 200.

Heart Output:

The heart beats 72 times per minute and pumps 70 milliliters in one minute. of blood, so the total amount of blood pumped by the heart in a minute is 5040 milliliters, or 72 times 70.

Heart sound:

A sound known as lubb-lubb is made when the ventricles contract, closing the A-V aperture. A dupp-dupp sound is made when the relaxation of the ventricles causes semilunar valves to close. Hubb-hubb has a slower sound, a longer duration, and a low pitch. Dupp-Dupp has a louder, shorter, and higher pitch. If the heart doesn't work right, it will make a murmuring sound. This sound is caused by an infection preventing the heart from working properly.



By Chanchal Sailani | January 18, 2023, | Editor at Gurugrah_Blogs.



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