While the four system approach to negligence is helpful in identifying whether or not an injury warrants legal action, it does fail to distinguish between two distinctly important concepts in the cause/effect relationship of negligence: factual causation vs. proximate cause. Factual and Proximate Cause
Types of Neurons (Nerve Cells). The human body is made up of trillions of cells. Cells of the nervous system, called nerve cells or neurons, are specialized to carry messages through an electrochemical process. The human brain has approximately 100 billion neurons.To learn how neurons carry messages, read about the action potential.owever, neurons differ from other cells in the body because: 1  Neurons have specialize cell parts called dendrites and axons. 2  Neurons communicate with each other through an electrochemical process. 3  Neurons contain some specialized structures (for example, synapses) and chemicals (for example, neurotransmitters).
Cell differentiation refers to the normal process by which a less specialized cell goes through development and maturation in order to become more distinct in terms of form and function. It is the process in which a cell changes into another cell type. During cell differentiation, the changes may include cell shape, cell size, membrane potential, metabolic activities, and responsiveness. These changes are brought about by modifications in gene expressions. An example of cell differentiation is the development of a single-celled zygote into a multicellular embryo that further develops into a more complex multisystem of distinct cell types of a fetus. The cell size, shape, polarity, metabolism and responsiveness to signals change dramatically such that a less specialized cell becomes more specialized and acquires a more specific role.