â¢ The cell cycle is a series of events that takes. place from one cell division to the next. â¢ The time is takes to complete a cell cycle is. not the same in all cells.
A neuron is a nerve cell. The brain is made up of approximately 100 billion neurons. Neurons are similar to other cells in the body in some ways such as: Neurons are surrounded by a membrane. Neurons have a nucleus that contains genes. Neurons contain cytoplasm, mitochondria and other organelles.
Later, during life, a relatively small number of new cells will be added in several parts of the adult brain related to memory and learning. Amazingly, each of the remaining neurons can connect with up to a hundred thousand other cells. This number of connections is a truly enormous number: 10 thousand trillion. Even further complicating this picture is that these connections occur in many different ways, including different placements on neurons, as well as connections with the larger number of other brain cells that arenât neurons.