A mature osteocyte contains a single nucleus that is located toward the vascular side and has one or two nucleoli and a membrane. The cell also exhibits a reduced size endoplasmic reticulum, Golgi apparatus and mitochondria, and cell processes that radiate towards the mineralizing matrix.
The Paleolithic was the first era in human history. During it people lived as hunter-gatherers. It is when people learnt to make tools, to use fire, and to clothe themselves. The era produced some amazing artwork, the fabulous cave painting that have been found in Spain and in the Dordogne in southern France.
There were not many humans at this time, and they were spread out, rather than living close together. Experts think there were no more than one million humans living during any time of the Paleolithic Era. That might sound like a lot of people, but today there are about seven billion people, 7,000 times more people than in the Paleolithic Era. Archaeological evidence points to humans beginning in the continent of Africa, and later migrating to other continents.