The difference between pinocytosis and receptor-mediated endocytosis is that

Receptor-mediated endocytosis is a very specific and ligand binds to a certain receptor on the cell membrane...

Pinocytosis is when a liquid material is absorbed and engulfed. Receptor-mediated endocytosis is a process by which cells engulfed molecules into a cell by the inward budding of plasma membrane vesicles containing proteins with receptor sites specific to the molecules being engulfed.

Receptor-mediated endocytosis uses transport proteins in the cell membrane to do this, whereas pinocytosis is more like a pinching of the cell membrane to bring stuff in.

Pinocytosis is a process that is happening all of the time...

RMW is more efficient over pinocytos

Explanation:

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.