Heart, Compartments of
Diagram showing the compartments of the heart. The smaller compartments are the auricles (also known as atria) and the larger compartments are the ventricles. The middle part of the figure represents the heart with its two sides; a being the right auricle, b the right ventricle, d the left auricle, and e the left ventricle. The blood is received in the right auricle, a, from the general system, f. It then passes into the right ventricle, b, and is forced by the contraction of it through arteries to the lungs, c. From the lungs it comes back to the heart, to the left side, and enters the left auricle, d. From this it passes into the left ventricle, e, from which it is sent all over the body, represented by f.
Hooker, Worthington First Book in Physiology For the Use of Schools and Families (New York: Sheldon and Company, 1867) 47