The composition of the human nervous system

            The nervous system has the functions and roles are very important for living things. Nervous system collect and process information, react to various stimuli and also arranged a variety of cells. Relation to the disciplines of psychology of the nervous system is also a driver of behavior. For example stimulus received a bad news and then he became upset and sad feelings are manifested in crying, it is a small example of how the nervous system plays a very important role in human behavior. The nervous system was essentially divided into two namely: 1) The central nervous system and 2) Peripheral nervous system. A. Central nervous system
           Central nervous system has the function of receiving, processing and interpreting or interpreting and storing sensory information coming from sensory nerves like the taste, sound, smell, color and pressure on the skin, internal organs and glands others. Central nervous system also functions to send messages to muscles, glands and internal organs. Central nervous system has two components, namely the brain and spinal marrow (spinal cord)

 

1) Brain The brain regulates all human activities. The brain is located in the skull cavity and covered by three layers of meninges membrane that is strong. Outermost membrane called the dura mater, the innermost and the middle is piamater called arachnoid. Among the three membranes that are fluid called cerebrospinal function is to reduce the impact or shock. The human brain is divided into three parts, namely a large brain (cerebrum), cerebellum (cerebellum) and advanced marrow.
a) big brain (cerebrum) Cerebrum has a surface that folds and is divided into two parts. The left hemisphere to serve the body right and the right hemisphere to serve the body left. The cerebrum consists of two layers. Gray outer layer called the cortex, containing the bodies of nerve cells. The inner layer contains white nerve fibers (neurit / axons). Big brain serves as a center of conscious activities such as thinking, remembering, talking, seeing, hearing, and moving.
b) Little Brain (Cerebellum) The cerebellum is located under the rear of the cerebrum. Small brain structures such as large brain. Consisting of the right and left hemispheres. Right and left hemispheres of the cerebellum are connected by bridges Varol. Divided into two layers as outer layers of the cerebrum that is gray and white inner layer. The cerebellum serves to regulate the body's balance and coordinate the muscles work when we move. c) advanced Marrow Advanced marrow (medulla oblongata) is divided into two layers, namely layers in the gray because it contains a lot of weight nerve cells and the outer layer is white because it contains neurit (axons). Advanced marrow serves as the central control of breathing, blood vessels constrict, regulate heartbeat, regulate body temperature and other activities that are not realized.
2). Spinal cord (spinal cord)
Is an extension of the brain. Bemula spinal cord from the base of the brain, then ran along the middle of the back and protected by the backbone. Spinal nerves have a role as a bridge that connects the brain to other parts of the body that lies below the neck. Spinal cord is capable of producing reflex movements automatically without any help from the brain and without involving conscious effort. For example, when a person touches the iron unwitting intentionally he will pull his hand from the iron. Before the brain processes the events that have occurred. Nerve impulses carrying messages to the spinal cord and spinal send commands in the form of impulses to the muscles pull the hand away from the iron hand. 

B. Peripheral nervous system             Peripheral nervous system or peripheral nervous system plays with messages and information coming out of the central nervous system. Peripheral nervous system is divided into two namely: 1) somatic nervous system and 2) the autonomic nervous system. Somatic nervous system (skeletal nervous system) consists of the nerves associated with sensory receptors that make a person able to feel the world. Skeletal muscles also allows one to perform deliberate actions such as turning on the lights, feel the insect was walking on his body, somatic system is active. Autonomic nervous system function as a regulator of blood vessels, glands and internal organs such as bladder, stomach and heart. When someone is angry then his ears flushed or emotion until the heartbeat is increased, then that's where the autonomic nervous system is on. Autonomic nervous system is divided into two parts, namely the sympathetic nervous system and the parasympathetic nervous system, where each of the nervous system is working in the opposite order to the body can adapt to the environment. For example, the sympathetic nervous system makes a person's face became red, issued a drought and the energy issue, improve heart  rate and blood pressure, sympathetic nervous system works when a person is in a situation that demands for a fight, escape and overcome the condition. The workings of the parasympathetic nervous system does not actually stop the process in the body but tend decrease and keep everything running smoothly. For example, the parasympathetic nervous system causes the body to conserve and save energy, and when someone is fleeing from the pursuit of making the nervous system increases heart rate is slow again aan heart rate and keep the heart rhythm in order to stay regular.