The Atria and ventricles of the heart Are the chambers that make up this organ, which is the main of the cardiovascular system.
The heart is responsible for pumping blood from the blood vessels into the arteries and then into the rest of the body.
This organ receives oxygen-poor blood and sends it to the pulmonary arteries to be purified. Once cleaned, it returns to the heart and from there it is sent to the rest of the body through the circulatory system.
The heart is a hollow muscle tissue that is divided into cavities thanks to a series of membranes. It has four cameras responsible for pumping blood through the circulatory system and the pulmonary.
The upper chambers are called atria and are responsible for receiving blood from the blood vessels. The lower ones are called ventricles and are responsible for pumping blood.
The atria
The atria are the upper cavities of the heart, responsible for receiving the blood. They are relatively small chambers and the membranes that cover them are really thin because the force that must be used to send the blood to the ventricles is minimal.
Right atrium
The right atrium is one of the four heart cavities. This is located in the upper right part of the organ, just above the right ventricle. This chamber receives deoxygenated blood from the blood vessels.
Deoxygenated blood enters the right atrium through three major veins: Superior vena cava , the Inferior vena cava And coronary veins.
The superior vena cava carries blood from tissues above the heart, ie the tissues of the head, neck, and upper chest.
The inferior vena cava, for its part, carries blood from tissues below the heart (lower chest, abdomen and legs). Finally, blood drained by the myocardium (heart membrane) is collected by the coronary vein.
The right atrium communicates with the respective ventricle through an atrioventricular opening that has a valve that allows the passage of blood in only one direction (which prevents blood from returning to the cavity from which it emerged).
The right valve is called a tricuspid. Similarly, a thin membrane separates the right atrium from the left atrium. This membrane is known as the atrial septal wall.
Left atrium
This heart chamber receives the purified blood from the lungs and pumps it into the left ventricle.
The left atrium is a small, hollow structure located in the upper part of the heart. It is separated from the right atrium by the atrial septal defect and left ventricle by the mitral valve.
While the vena cava, upper and lower, and the coronary veins carry the blood to the right atrium, the blood flow received by the right atrium comes from four pulmonary veins.
The ventricles
The ventricles are the pumping chambers. These cavities are larger than the atria and the membranes that cover them are much thicker than those of the atria.
This is because the ventricles must use much more force than the atria to pump the blood to different parts of the body.
Right ventricle
The right ventricle pumps the deoxygenated blood from the right atrium to the trunk or pulmonary artery to purify it. It is separated from the left ventricle by the interventricular septum.
Two valves control blood flow through the right ventricle. The tricuspid valve connects this ventricle with the corresponding atrium, which means it controls the entry of blood into the cavity. The pulmonary valve connects this cavity with the pulmonary arteries, that is, it controls the outflow of blood.
Left ventricle
The left ventricle has membranes thicker than the right ventricle because it must pump the oxygen-rich blood from the left atrium to the aorta, the largest artery in the body. Thus blood enters the circulatory system again.
Summary of the functioning of the atria and ventricles
- The atria are the upper chambers of the heart, while the ventricles are the lower chambers
- The atria act as receptors for deoxygenated and oxygenated blood, while the ventricles pump blood from the atria to the pulmonary trunk (in the case of deoxygenated blood) and to the aorta (in the case of oxygenated blood).
- The membranes that cover the atria are thinner than those covering the ventricles, because the latter are contracted with greater force to be able to pump the blood to different parts of the body.
- Blood enters the right atrium through the vena cava.
- Deoxygenated blood passes into the right ventricle through the tricuspid valve.
- The right ventricle pumps blood to the pulmonary trunk, where blood is purified.
- The oxygenated blood is received by the left atrium and passes into the left ventricle through the mitral valve.
- The right ventricle pumps blood to the aorta.
References
1) Medical Definition of Heart. (S.f.). Retrieved on February 21, 2017, from medicinenet.com.
2) From Fortuna, S. (2015). What Are the Organs of the Cardiovascular System? Retrieved on February 21, 2017, from livestrong.com.
3) The Cardiovascular System: The Heart. (S.f.). Retrieved on February 21, 2017, from pearsonhighered.com.
4) Tony Curran and Gill Sheppard. (October 2011). Module 1: Anatomy and Physiology of the Heart. Retrieved on February 21, 2017, from cdhb.health.nz.
5) Taylor, T. (1999-2017). Right auricle. Retrieved on February 21, 2017, from innerbody.com.
6) Taylor, T. (1999-2017). Left auricle. Retrieved on February 21, 2017, from innerbody.com.
7) Taylor, T. (1999-2017). Right ventricle. Retrieved on February 21, 2017, from innerbody.com.
8) Taylor, T. (1999-2017). Left ventricle. Retrieved on February 21, 2017, from innerbody.com.
9) Healthline Editorial Team. (S.f.). Left ventricle. Retrieved on February 21, 2017, from healthline.com.
10) What is the difference between atria and ventricles? (S.f.). Retrieved on February 21, 2017, from reference.com.
11) Difference Between Atria and Ventricles. (S.f.). Retrieved on February 21, 2017, from differencebetween.net.