Which chamber of the heart has the thickest walls

The order of thickness of the heart wall from thin to thick is auricles, right ventricle and left ventricle.

Both auricles are with comparatively thin walls. Because both auricles receive blood from vena cava and pulmonary veins.
From right auricle blood enters right ventricle. Right ventricle is with thick wall. This is because the blood is to be circulated in lungs and is to bring back from lungs.
Left auricle receives blood from lungs. The left ventricle is with thickest walls. This is because from left ventricle blood is squeezed through literally thousands of kilometers of blood vessels. (In adult person of 60 kg. is with approximately 25,000 kilometers of blood vessels)

The chamber of human heart, which has thickest wall isA. Right atriumB. Left atriumC. Right ventricleD. Left ventricle

Answer

Verified

Hint:-Human heart is an organ which is a part of the cardiovascular system, and it is the only
muscle which works continuously throughout the lifetime, it is generally in the size of one’s fist, and it
weights generally 8 to 12 ounces, and it almost pumps a lot of gallons of the blood in its lifetime.

Complete step-by-step solution:-
1. The human heart is located in between the lungs and it is nearer to the left breast bone.
2. Where the heart has 4 chambers, the upper two chambers are called atria, while the lower two
chambers are called ventricles.
3. Atria are of again divided as left and right atria and the ventricles are also divided into left and
right ventricles, so the right and left atria and ventricles are separated by atrioventricular septa.
4. In the body various metabolic activities takes place, where the oxygen are utilized and blood is
depleted with oxygen which becomes deoxygenated blood.
5. This deoxygenated blood is carried to the right atrium through the venous system.
6. Blood from right atria comes to right ventricle through tricuspid valves, and the blood from right
Ventricles travel through pulmonary arteries and enter the lungs. And in lungs oxygenation of
blood takes place.
7. Blood enters the left atria through pulmonary veins, and this pumps into left ventricles through
mitral valve.
8. Then blood from ventricles enters the systemic aorta, so that blood reaches to all body parts.
9. The contraction of left ventricle should be more pressure and it have to send blood to systemic
parts, and this is the reason where the left ventricle has thickest wall.
So the correct option is D.

Note:- During the process of filling and emptying of chambers of heart with blood results in blood pressure and pressure created by the arteries during the contraction of left ventricle, create the systolic pressure and refilling of ventricles after contraction creates diastolic pressure.

Our own in-build mechanical pump that works 24/7 without taking a break! Check this page out to discover how this amazing organ works.

Chambers of the heart

The heart is made up of four chambers.  The chambers on the right side of the heart are the right atrium and right ventricle. 

The right atrium receives deoxygenated blood from the body via the superior and inferior vena cava (major veins). 

The blood then flows to the right ventricle where it is then pumped, via the pulmonary circuit, through the pulmonary artery to the lungs for gaseous exchange (CO2 out, O2 in).

The chambers on the left side of the heart are the left atrium and left ventricle.  The left atrium receives oxygenated blood from the lungs via the pulmonary veins. 

The blood then flows to the left ventricle where it is then pumped, via the systemic circuit, through the aorta and then pumped out to the to the organs and tissues of the body to supply them with oxygen and nutrients, and pick up waste products for expulsion.

Follow the arrows on the diagram above as this shows the direction of blood flow through the heart.

Being a muscle which requires nutrients for fuel, the heart also has its own blood supply. 

It receives the oxygenated, nutrient rich blood that it needs from the coronary arteries which branch off the aorta.  The deoxygenated blood is then returned to the right atrium through the cardiac veins. 

It is damage to the coronary arteries that often leads to heart problems such as heart attacks.

The left ventricle also has a thicker muscular wall than the right ventricle, as seen in the adjacent image.  This is due to the higher forces needed to pump blood through the systemic circuit (around the body) compared to the pulmonary circuit.

Valves of the heart

There are four valves within the heart which serve to prevent backflow of blood as it passes through the various chambers of the heart and out through the associated arteries.

The tricuspid valve and the mitral valve are known as ‘atrioventricular’ valves as they are situated between the atria and ventricles on both sides of the heart. 

The tricuspid valve is positioned between the right atrium and ventricle, and the mitral valve sits between the left atrium and ventricle, as seen in the adjacent image.

As blood is pumped out of the ventricles through the aorta and the pulmonary arteries, these valves close to ensure the blood does not get pumped back into the respective atria it came from.

The other two valves are the pulmonary and aortic valves, which are collectively known as the ‘semilunar’ valves. 

The pulmonary valve sits between the right ventricle and the pulmonary artery.  Its role is to prevent the backflow of blood into the right ventricle after it contracts.  The aortic valve sits between the left ventricle and the aorta and prevents backflow of blood into the left ventricle after it contracts.

How the heart beats

One heart beat consists of one contraction phase and one relaxation phase. 

The contraction phase, known as ‘systole’, occurs when blood is pumped out of the heart.  The relaxation phase, known as ‘diastole’, occurs when the heart is relaxing and filling with blood.  These phases can be seen in the following image.

There are two unique sounds associated with the heart beat (which you can hear through a stethoscope placed on a friend’s chest). 

There is a low pressure ‘lub’ sound which is the closing of the atrioventricular valves, followed quickly by a higher pressure ‘dub’ sound as the semilunar valves close.

The heart beat is controlled by the sympathetic and parasympathetic branches of the autonomic nervous system. 

The sympathetic system stimulates the heart to beat faster while the parasympathetic system returns the heart rate to its normal resting level.

Electrical impulses (action potentials) from both systems are sent to the sino-atrial (SA) node. The SA node, known as the hearts ‘pacemaker’, then sends out an impulse that stimulates both atria to contract and this stimulus is also sent to the atrioventricular (AV) node.  This is shown on the below image.

The AV node then further distributes the impulse from the SA node to both ventricles which contract a fraction of a second after the contraction of the atria. 

The rate at which the SA node sends out impulses determines the rate at which the heart beats.  As well as receiving impulses from the autonomic nervous system, the rate at which the SA node sends impulses can also be influenced by hormones such as adrenaline. 

When released into the system adrenaline stimulates the SA node to send impulses at a faster rate, thus increasing the rate at which the heart beats.