GENERAL NEUROLOGY
The nervous system is a complex of anatomical and physiological interrelated structures that regulate and coordinate the activity, behaviour and experience of humans during adaptation. It is also the seat of higher functions, such as intelligence, memory, learning, and emotion. This system encodes information about pain, tactile sensations, sounds, etc and conducts it, sometimes over considerable distances, and then transmits it to target organs (neural or non-neural structures such as muscles or glandular cells). Different centres analyze, integrate, process, and modify the functions of tissues and organs by feedback.
The nervous system is divided into the central nervous system (systema nervosum centrale) and the peripheral nervous system (systema nervosum periph-ericum). The central nervous system (CNS) consists of the brain (encephalon) and the spinal cord (medulla spinalis). The peripheral nervous system (PNS) includes trunks, cords, ganglions, plexuses, nerves, nerve terminals, and nerve fibres.
The structural and functional unit of the nervous system is the nerve cell, or neuron (neuron). The neuron consists of a cell body, the perikaryon (perikaryon), processes, or nerve fibres (neurofibrac), nerve endings (terminationes neurales) (Fig. 1). Information is coded in patterns of transient depolarizations and repolarizations of the membrane potential, known as action potentials or nerve impulses. The perikaryon receives the nerve impulses via short processes named the dendrites, the axon conducts the impulses from the cell body; the axon is a single elongated process. The axon can give off branches (axon collaterals) and finally divides to terminate with small endbulbs, the terminal bou-tons, on nerve or muscle cells.