How does the Nervous System Work

The human nervous system is a highly specialized network that contains billions of neurons and is responsible for controlling and coordinating all the functions of the body. The nervous system consists of two components, the central nervous system and the peripheral nervous system.

The central nervous system consists of the brain and the spinal cord, while the peripheral nervous system consists of all the neurons of the body, excepting those found in the brain and spinal cord. The peripheral nervous system can be divided into somatic nervous system, autonomic nervous system and enteric nervous system, depending on their specific functions. The somatic nervous system receives external stimuli and coordinates body movements, while the autonomic nervous system is responsible for those functions that are not under conscious control. The autonomic nervous system can be again classified into sympathetic, parasympathetic and enteric division. The sympathetic nervous system responds to stress or anxiety, while the parasympathetic nervous system works when a person is sleeping or relaxing. The enteric nervous system, on the other hand, manages every aspect of digestion.

How does the Nervous System Work

The nervous system is a network that controls and coordinates all the activities by transmitting messages or signals from the brain to the different regions of the body and vice versa. The nervous system works with the help of nerves or neurons, which conduct the signals or impulses between the two components of the nervous system, i.e. central and peripheral nervous system. The neurons can be of different types, such as sensory and motor neurons. In addition to neurons, glial cells, which surround and support the neurons, also participate in the transmission of signals. The sensory neurons generate and transmit the stimuli received from the sensory organs like the eye, nose or skin, to the central nervous system, i.e. to the brain and the spinal cord. The brain in turn processes these stimuli and sends them back to the other parts of the body telling them to react to a particular type of stimulus. The motor neurons are responsible for receiving signals from the brain and spinal cord and transmitting them to the other organs of the body. The neurons use electrochemical signals or neurotransmitters in the transmission of signals or impulses from one neuron to another.

The human brain can be divided into three parts, forebrain, midbrain and hindbrain, that regulate some specific functions of the body. The forebrain consists of the cerebrum, which is the largest part of the brain and is the center of intelligence, memory, emotion, personality, speech and the ability to feel. The outer layer of cerebrum is cortex, which receives the information collected by the sensory nerves and sends them to other regions of the brain for further processing. The inner part consists of the thalamus, hypothalamus and pituitary gland. The thalamus transmits the messages from the sensory organ to the cortex, while the hypothalamus is responsible for regulating pulse, appetite and automatic processes. Pituitary glands secrete hormones that regulate growth, metabolism, sexual maturity and response to stress.

The midbrain is located underneath the middle of the forebrain and is the coordinator of the messages or impulses coming in and out of the brain. On the other hand, the hindbrain, which is located below the back end of the cerebrum, consists of the cerebellum, pons and medulla. The cerebellum controls movement and balance, while the pons and the medulla coordinate messages and automatic functions like breathing, heart rate, digestion and blood pressure.

In this way, different parts of the brain control different functions of the body through a specialized network of neurons. A proper functioning of the nervous system depends on the coordination between the central and the peripheral nervous system.