Nervous SystemNervous systemis a network of neurons and nerve fibers. These nerves connect the brain andbody to play many functions. These neurons carry messages from brain and sendthem to the body to perform a specific function.
In return other neurons carrymessages from body to brain as output information.Structure ofnervous system Nervous systemis divided into two major divisions:· Centralnervous system· Peripheralnervous systemCentral nervoussystemCentral nervoussystem is composed of brain and spinal cord. SkullBrain isenclosed into skull. Skull is a bony outer shell that protects the brain fromphysical damage. Inside the skull, there is a protective tissues also called Meningeswhich is further divide into three layers:· Duramatter· Arachnoid· PiamatterDura matterIt is the outerthickest layer of meninges. It contain cerebrospinal fluid.
ArachnoidIt is themiddle layer of meninges and loosely attached to the pia matter by web likefibers. It allows the movement of cerebrospinal fluid to provide protection andnutrition to the brain cells. Pia matterIt is the innermost and delicate layer of meninges which is composed of connective tissuesthat cover the brain and spinal cord. This layer holds the blood vessels andprovide nutrition and oxygen to the brain.
CerebrospinalfluidCerebrospinalfluid is present in and around the brain that protects the brain from shock orany physical brain injury. It provides the nutrition and oxygen to the braincells and also remove waste to and from the brain. Brain Brain has threemain parts:· Forebrain· Midbrain· Hindbrain The table givenbelow shows the Subdivisions and principal structures of brain Main parts Sub divisions Principle structure Forebrain Telencephalon diencephalon Cerebral cortex Basal ganglia Limbic system Thalamus Hypothalamus Midbrain Mesencephalon Tectum Tegmentum Hindbrain Metencephalon Myelencephalon Cerebellum Pons Medulla oblongata ForebrainFore brain isthe main part of brain which is located on the top and front of the brain. Itis divided into two main subdivisions:· Telencephalon· DiencephalonTelencephalon