1. Heart
... is divided into four cavities, two of them are called atria and the other two are called ventricles. The left side of the heart houses one atrium and one ventricle. The right is the same. The smooth inside lining of the heart is the endocardium. The middle of the heart is called myocardium. And the fluid filled sac that surrounds the myocardium is the pericardium. Location: If you were to take your fist and put ... into the left atrium. Then from there the left atrium contracts sending the blood through the mitral valve and into the left ventricle. This is the strongest muscle in yo...
- Word Count: 441
- Approx Pages: 2
- Grade Level: High School