The Nervous System: The Brain And The Nervous System

The nervous system is a complex network of nerves and cells that carry messages to and from the brain and spinal cord to various parts of the body.

The nervous system includes both the Central nervous system and Peripheral nervous system. The Central nervous system is made up of the brain and spinal cord and The Peripheral nervous system is made up of the Somatic and the Autonomic nervous systems. The nervous system is responsible for coordinating all of the body 's activities. It controls not only the maintenance of normal functions but also the body 's ability to cope with emergency situations. lies within the skull and is shaped like a mushroom. The brain consists of four principal parts:

• the brain stem

• the cerebrum

• the

The spinal cord is composed of a series of 31 segments. A pair of spinal nerves comes out of each segment. The region of the spinal cord from which a pair of spinal nerves originates is called the spinal segment. Both motor and sensory nerves are located in the spinal cord.

The spinal cord is about 43 cm long in adult women and 45 cm long in adult men and weighs about 35-40 grams. It lies within the vertebral column, the collection of bones (backbone).

Other parts of the central nervous system

The meninges are three layers or membranes that cover the brain and the spinal cord. The outermost layer is the dura mater. The middle layer is the arachnoid, and the innermost layer is the pia mater. The meninges offer protection to the brain and the spinal cord by acting as a barrier against bacteria and other microorganisms.

The Cerebrospinal Fluid (CSF) circulates around the brain and spinal cord. It protects and nourishes the brain and spinal cord.

• The nervous system is made up of two parts the central (CNS) and the peripheralPNS). The CNS includes the brain, found in the head, and the spinal chord, found running through the spine. The PNS includes all of the peripheral nervesthat run to all parts of the body, and so are found almost

Peripheral system nerves branch from either the brain stem or the spinal cord. Each nerve is connected to a particular area of the torso or limbs and is responsible for communication to and from those regions.

The PNS can also be subdivided into smaller components: the somatic and autonomic systems. The somatic involves parts of the body a person can command at will, and the autonomic helps run involuntary functions such as pumping blood.

Information conveyed through the nervous system moves along networks of cells called neurons. These neurons can only send information one way. Those transmitting to the brain are sensory neurons; those that transmit from the brain are known as motor neurons.

The nervous system can suffer from a number of afflictions, including cancer (e.g., brain tumors). Other problems include multiple sclerosis, in which damaged nerves prevent signals from traveling along them, and meningitis, which causes an inflammation of the membranes surrounding the brain and spinal cord. The nervous system is formed of two parts that are integrally linked with each other. The brain and the nervous system has multiple functions that are vital for normal functioning of the body.

Transmission of nerve