One of the most intelligent invertebrate animal is the octopus. These animals belong to the cephalopod class of molluscs. These animals demonstrate relatively complex reasoning especially when capturing prey. They also demonstrate their intelligence by their communicating skills and some even show signs of learning.
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Pectinate muscles are parallel ridges in the walls of the atria of the heart. The name is due to their resemblance to the teeth of a comb (pecten). The heart is the organ pumps blood to all parts of the body. It is made up of four chambers, that is, right and left ventricles, left and right atria, and the blood vessels, Pulmonary artery, pulmonary vein, aorta, and venacava. An auricles are pouch like structure that increase the total filling capacity of the atrium and also increase the volume of blood that an atrium is able to contain.
