Organs of the Nervous System

Have you ever thought how can you feel the various sensations, react to pain or a tickle, how you can instantly solve a simple mathematical problem or cry when you are sad and laugh when you are happy? Well, all these sensations and emotional responses are due to the organs of the nervous system. They help sending instant messages to the brain and impulses from the brain in a jiffy. They consists of specialized cells that form a network called neurons. In this article we will discuss the various nervous system organs and functions.

What Organs Make Up the Nervous System?
The nervous system of vertebrates, that includes humans consists of two parts, central and peripheral. The central nervous system (CNS) consists of brain, spinal cord and the retina. If either of the major organs are damaged, it could result in many disorders like paralysis, memory loss, blindness, loss of motor skills, speaking ability, hearing loss, coma, etc. The peripheral nervous system consists of sensory neurons, ganglia (clusters of neurons), and nerves that connect the each other as well as the CNS.

A subsystem of the peripheral nervous system is the enteric nervous system. This system has the capacity to function independently after being severed from the rest of the nervous system through the vagus nerve connection. It tends to control the gastrointestinal system in the body. There are innumerable problems associated with the nervous system organs and functions that can affect the human body system and causes a lot of damage to the different organs.

Central Nervous System Organs and Functions
The main organs of the nervous system, that is brain and spinal cord are placed in the central nervous system. Let us go into the details of both the organs.

Brain
The brain is one of the most important organs in the human body system. The brain is the center of all commands and monitors all the conscious and unconscious processes of the body. The brain coordinates various organs of the body and controls all the voluntary movements in the body. The brain is the organ that helps you remember things, learn, understand, think, create, talk, hear, taste, etc. The brain is divided into three segments, that is, fore brain, mid brain and the hind brain.

The fore brain consists of the cerebral hemispheres and olfactory lobes. The mid brain is the region that mostly contains optic lobes and the hind brain is the region that includes the cerebellum and the medulla oblongata. The pituitary gland is present in the lower side of the fore brain. It is called the 'master gland' as it tends to regulate the function and secretion of many other glands in the body.

Spinal Cord
The spinal cord is a bundle of nerves that run down the back from the brain in the spinal column. The spinal cord is about 40 cm in length and as wide as the thumb. The function of the spinal cord is to relay all the impulses, information and sensations from all around the body, internally and externally, to the brain. If the spinal cord is broken, it will severe some or most of the connections between the brain and other parts of the body. Thus, leading to paralysis in different parts of the body like the upper and lower limbs.

Peripheral Nervous System Organs and Functions
There are 31 pairs of spinal nerves that help connect the spinal cord to the body. The peripheral nervous system organs and functions involve carrying nerve impulses like sensations and information from the body to the spinal cord and from the spinal cord to the body. The peripheral nervous system organs are divided into two groups. These groups have different functions and are known as sensory neurons and motor neurons.

The sensory neurons functions involves providing the body all the information regarding the environment. When you feel cold or hot, it is the sensory neurons that are doing their work. The motor neurons are reactors, that help the body react to different environment. For example, the immediate pulling away of your hand when you touch a hot stove is a motor neuron reaction. There are somatic motor neurons that send sensations to the muscles. The autonomic neuron helps control the heart and other organs.

The Vegas nerve is divided into sympathetic and parasympathetic nerves. The sympathetic nerves functions involve dilation of eye pupils, stimulation of sweating, production of goose bumps, decrease in digestion, etc. The parasympathetic nerves involve functions such as constriction of eye pupils, increase in secretion of saliva, increased digestion, decrease in heartbeat, etc.

Different Spinal Nerve Organs and Functions
The 31 pairs of spinal nerve branch off and reach out to different parts of the body and perform different functions. The nerves of the cervical region supply information to the back of the head, neck, shoulders, arms, hands and the diaphragm. The nerves of the thoracic region supply information to the chest and some parts of the abdomen. The lumbar region nerves are supplied to the lower back, parts of the thighs and the legs. The nerves of the sacral region are supplied to the buttocks, most of the leg, feet, anal and genital area.

Special Sensory Organs
There are five special sensory organs of the nervous system that help the brain in knowing more about the external factors. These special senses are:

Eyes
The eyes help you see. The lens in the eyes magnify an image and the vitreous disc bends and rotates the image against the retina. The retina translates the image formed and lighted by a set of cells. The rods and cones and other tissues convert the image into a nerve impulse transmitted along the optic nerve. It reaches the brain that converts it into memory.

Ear
The ear helps you hear. The sound waves are translated into vibrations through the complex inner ear structure and transmitted to a nerve that sends it to the brain to interpret and store in memory. You can read in detail about the working and functions of the ear in the exclusive article on the ear and its function.

Tongue
The tongue is the organ that senses taste. The tongue is divided into four sections that help detecting bitter, salty, sour and sweet taste. The taste buds convert the taste into a nerve impulse and send it to the brain. The brain differentiates between different tastes and helps you like or dislike foods.

Nose
This olfactory organ helps you know different smells. There are tiny hair cells in the nose that capture the smell and send it to the olfactory bulb that has a set of sensory nerves. These nerve impulses travel through a complicated route and reach the smell sensory cortex of your brain. This part is located between the eye and the ear. The brain interprets the smell and stores it in memory.

This was a bit of insight on the different organs of the nervous system. The nervous system is not as simple as it sounds. It is a complex and complicated network of nerves and neurons running throughout the body that send each and every minute detail of the surrounding and environment to the brain and bring back instant message to the concerned part. Every action is processed and all reactions are carried out before you can say 'go'. The human body is a wonderful unit that has the functions and solutions to every problem.