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.
Out of these, 16 billion (or 19% of all brain neurons) are located in the cerebral cortex (including subcortical white matter), 69 billion (or 80% of all brain neurons) are in the cerebellum. The cerebral hemispheres (the cerebrum) form the largest part of the human brain and are situated above other brain structures.