Introduction of the Nervous System

Introduction of the Nervous System

Introduction

Introduction of the Nervous System

The nervous system is consisted of nerves, spinal cord and brain. The brain and spinal cord are found in the central part of the body and performing the principal function; hence constitute the central nervous system. The nerves are part of peripheral nervous system; each nerve is starting from the brain and through the spinal cord reaches the extremities of the body. The essential element of function for both the systems is neuron. (The nervous system)

Discussion

Nervous system has two chief systems; central as well as peripheral nervous system. Spinal cords and brain are most important organs of the central nervous system. The spinal cord and cranial nerves send the nerve impulses to the brain. The important functions of the brain are distributed among its parts like hind brain, forebrain and mid brain.

According to the role, there are three types of neurons; motor, sensory and interneuron. Interneurons are as well recognized as association neurons. Sensory neuron observes the surrounding condition of the body and conveys the perceived incentives to the brain and spinal cord. Central nervous system receives the message from sensory neurons and responds according the condition through interneuron. Motor neuron sends the order of the brain to the muscles, glands and other effectors. Each neuron has following body parts; cell body, dendrites, axons and terminal. Depending upon the anatomy, there are three neurons; multipolar neuron, bipolar neuron and unipolar neuron (Introduction to the nervous system).

The central nervous system is organized by grey and white matter. Grey matter contains the cell body of the neuron and white matter contains part of neuron other than the cell body i.e. the extensions.

The nervous system works through certain chemicals known as neurotransmitters. The examples of neurotransmitter are acetylcholine, biogenic amines, nitric oxide, amino acids (glutamate, aspartate, gamma-amino butyric acid) and neuropeptides (substance P, endorphins). Brain Pathway

The spinal cord obtain signal of any external stimuli through the afferent axons, which then come into the dorsal horn. On the other hand, muscles and glands get information through ventral horn. The dorsal column and the lateral spinothelamic tract of spinal cord sense the signal, convey it to the thalamus and then to upper nervous centers. The first order of dorsal column reaches the spinal cord and goes up to the medulla, on the same side (ipsilaterally), in the brain stem. After that, ...