they are the ventricles
the left side of heart is thick walled.
Arteries carry blood containing oygen and nutrients away from the heart. They are thick walled and elastic to cope with the pressure exerted by the contraction of the heart.
Thicker
an artery
Muscular arteries
arteries
arteries
veins
there are four chambers in the heart. two are atriums and two are ventricles
frogs heart has five chambers namely. 1-Sinus Venosus =Thin walled 2-Right auricle =Thin walled 3-Left auricle =Thin walled 4-Ventricle =Thin walled and muscular 5-Truncus arteriosus =Tabular thick walled
artery
there are only 2 vessels that take blood from the heart. The Pulmonary trunk that bifurcates into the (right and left) pulmonary arteries. and the aorta. the aorta is the largest vessel in the body and certainly would be considered thick walled.