Question

Complete the passage comparing the atria (singular: atrium) and ventricles.

Paired atria form the superior portion of the heart and ________ Two ventricles, which make up ________ receive blood from the atria and are located inferiorly. Due to the positioning of the heart in the chest, the _____________ forms the majority of the anterior heart surface. The ventricles _____________and, as such, contain significantly ____________ walls than the atria. The thickest‑walled chamber is the ____________ Distinct ridges of myocardium called _______ line the inner surfaces of both ventricles. Similar but less pronounced muscle bundles called ____________ are found in the right atrium and in the wrinkled, pouchlike structures called _________ that increase the filling capacity of the atria.

Answer 1

The atria are the superior receiving chambers of the heart, while the ventricles are the lower, primary pumping chambers. The right ventricle forms most of the anterior heart surface, and the ventricles have thicker walls than the atria, with the left ventricle being the thickest. Ridges called trabeculae carneae and pectinate muscles are found in the ventricles and right atrium respectively.

Step-by-step explanation:

Complete the passage comparing the atria and ventricles. Paired atria form the superior portion of the heart and act as receiving chambers for blood. Two ventricles, which make up the primary pumping chambers of the heart, receive blood from the atria and are located inferiorly. Due to the positioning of the heart in the chest, the right ventricle forms the majority of the anterior heart surface. The ventricles pump blood to the lungs or to the rest of the body and, as such, contain significantly thicker muscular walls than the atria. The thickest-walled chamber is the left ventricle. Distinct ridges of myocardium called trabeculae carneae line the inner surfaces of both ventricles. Similar but less pronounced muscle bundles called pectinate muscles are found in the right atrium and in the wrinkled, pouchlike structures called auricles (atrial appendages) that increase the filling capacity of the atria.