Chambers of the Heart: Atria and Ventricles (Nursing)

00:01 So recall that there are four chambers in the heart.

00:07 The features of these chambers include two superior atria which are our receiving chambers of the heart, two inferior ventricles which are our pumping chambers of the heart.

00:20 There are also several thickened walls known as septa in the heart.

00:25 We had the interatrial septa which are going to separate the atria in the heart and in between these, we also have an indentation known as the fossa ovalis.

00:39 This is a remnant of the foramen ovale of the fetal heart which is a shunt that allows for blood to go from the right atrium to the left atrium, skipping the lungs in the fetus since fetuses are not using their lung.

00:55 This foramen is going to close at birth and become the fossa ovalis.

01:02 We also have the interventricular septum which is going to separate the left and the right ventricle.

01:12 So starting with our receiving chambers, we noticed that the atria are small, thin-walled chambers that are going to contribute actually very little to the propulsion of blood Within these chambers, we have the auricles which are appendages that increase the volume of the atria.

01:35 The left atrium of the heart is going to receive oxygenated blood that is returning to the heart from the lungs.

01:44 There are four pulmonary veins that are going to feed into this left atrium from the lungs.

01:54 The right atrium of the heart is going to receive deoxygenated blood that is returning to the heart from the body's tissues.

02:04 There are three main veins that empty into this right atrium.

02:08 We have the superior vena cava which is going to be returning blood from regions above the diaphragm, the inferior vena cava which is going to be returning blood to the heart from regions below the diaphragm and then we have the coronary sinus which is going to be returning blood from the coronary veins in our coronary circulation.

02:37 So the next chambers are our discharging chambers are pumping chambers.

02:42 These are referred to as ventricles.

02:45 These are going to have much thicker walls than that of the atria.

02:49 and the reason why is because these are going to be involved in the actual pumping of the heart.

02:56 The ventricles also make up most of the volume of our heart.

03:02 The right ventricle is going to be on the anterior surface of the heart.

03:08 It's going to be pumping blood into the pulmonary circuit by way of the pulmonary trunk.

03:16 The left ventricle is located on the posteroinferior surface of the heart and it's going to pump blood into the aorta.

03:27 The aorta is the largest artery in the body and is going to be responsible for pumping blood to the rest of the body's tissues by way of the systemic circuit.

03:39 Within these ventricles, we have structures known as the trabeculae carneae.

03:44 These are irregular ridges of muscles on the ventricular walls.

03:50 Also, we have the papillary muscles which project into the ventricular cavity and anchor these little chords known as chordae tendineae.

04:01 These are going to be attached to the heart's valves.