In the heart, a<unk> is a heart chamber which collects blood from an atrium (another heart chamber that is smaller than a<unk>  and pumps it out of the heart.
In a four-chambered heart, such as that in humans, there are two<unk> :
The right<unk> pumps blood into the pulmonary circulation for the lungs.
The left<unk> pumps blood into the systemic circulation for the rest of the body.  (See Double circulatory system for details.)<unk>  have thicker walls than the atria, and thus can withstand higher blood pressure.
Comparing the left and right<unk>  the left<unk> has thicker walls because it needs to pump blood to the whole body.
The right<unk> pumps blood into the pulmonary circulation for the lungs.
The left<unk> pumps blood into the systemic circulation for the rest of the body.  (See Double circulatory system for details.)
Ventricle 
Endocardium
Cardiac muscle
Papillary muscle
Epicardium
Coronary arteries
Left ventricle
Atrioventricular node