Human Nervous System: Structure, Cortex, and Motor Functions

Nervous System: Definition and Functions

The nervous system is defined by its general duties, including the nervous system of the life of relation, its definition, and functions. This includes the cortex, functions of the cortex, voluntary motility, and sensitivity. It also encompasses sensory systems (olfaction, taste, sight, hearing, and touch), consciousness, dreams, and comas. Additionally, it covers the vegetative or autonomic nervous system, its definition, general duties, anatomy, afferents, efferent pathways, and physiology.

The nervous system (NS) governs relations with the outside world and adjusts and coordinates the activities of organs. This separates two functions that are interrelated but very different from each other. Thus, relations with the outside world are the responsibility of the nervous system of relation. On the other hand, setting and coordinating the activities of the organs is the charge of the vegetative or autonomic nervous system. In general, both operate under the same pattern: They receive information, process it, and produce a response.

As for structural support, just as neurons do, these connections remain linked to one another through a dedicated communication area called a synapse, making this communication through chemicals called neurotransmitters that may act by stimulating, inhibiting, or simply modulating.

This reinforces the discovery of Cajal in the sense that there would not be continuity, but contiguity only (synapses), and that the union is transmitted through functional chemical structures called neurotransmitters.

The Cerebral Cortex

The cerebral cortex is the outer surface of the brain. Consisting mainly of the bodies of the neurons (gray matter versus white matter), it is the outermost part of the brain, and to increase its surface area, it has fissures, grooves, lobes, and convolutions.

Functions of the Cortex

• Voluntary motor control
• Sensitivity
• Language
• Memory
• Higher intellectual functions (learning, abstract thinking, etc.)
• Mood and emotions

Voluntary Motor Function

Voluntary motor function is the ability to move in space, part or all of the body, by voluntary contraction of muscles which in turn act on levers that are the bones. Voluntary impulses originate in the cerebral cortex. From there, they go down to the peripheral nerve-muscle, which carries the order of contraction.

For much of its route, the fibers that carry these orders are grouped together, and their shape recalls a pyramid, which is also known as the pyramidal tract.

There are several features of note: