NERVOUS SYSTEM

The nervous system coordinates all of the bodys functions.It is the responsible for intellectual function,emotions and feelings.

The human nervous system is divided into two parts:the central nervous system,formed bof the brain and the spinal cord;and the peripheral nervous system´formed of all the nerves and the nerve ganglia throughout the body.

CENTRAL NERVOUS SISTEM
In humans the central nervous system is responsible for higher cognitive functions.It is also responsible for general sensory integration and coordination.
At microscopic level,the central nervous system is formed of two parts:the grey matter,formed of neuron and somas and dentrites,and the white matter,formed of neuron axons covered in the myelin sheat.

• The central nervous system consists of the brain and the spinal cord.These are protected by:
• The skull and spinal column.
• The meninges,These are three protective membranes of connective tissue that surround the brain and spinal cord.The three layers are the pia mater(inside),and arachnoid mater(middle) and dura mater(outside).

BRAIN 

The human brain consists of the cerebrum, the brainstem and the cerebellum. The brain is the organ that controls most of the activities of the body.The brain processes, integrates, and coordinates all of the information it receives from the sense organs.

The Cerebrum: The cerebrum is the largest part of the human brain, associated with higher brain function such as thought and action.

The Cerebellum: The cerebellum is similar to the cerebrum. This structure is associated with regulation and coordination of movement, posture, and balance.

The brainstem: is the posterior part of the brain, adjoining and structurally continuous with the spinal cord.

The brainstem regulates vital cardiac and respiratory functions and acts as a vehicle for sensory information




SPINAL CORD

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. The brain and spinal cord together make up the central nervous system (CNS)
The spinal cord has three major functions: as a conduit for motor information, which travels down the spinal cord, as a conduit for sensory information in the reverse direction, and finally as a center for coordinating certain reflexes.


PERIPHERAL NERVOUS SYSTEM

The peripheral nervous system consists of the nerves and nerve ganglia.The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body.The peripheral nervous system is divided into the somatic nervous system, and the autonomic nervous system. The somatic nervous system is under voluntary control, and transmits signals from the brain to end organs such as muscles. The sensory nervous system is part of the somatic nervous system and transmits signals from senses such as taste and touch 

NERVES:a group of axons isolate by their myelin sheat and covered in a layer conective tissue.A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons to peripheral organs.

NERVE GANGLION:a cluster nerve cell bodies.Nerve ganglia are 

distributed along the nerve pathway. Ganglia house the cell bodies of afferent nerves and efferent nerves.

NEURON

Is an electrically excitable cell that processes and transmits information through electrical and chemical signals. These signals between neurons occur via specialized connections called synapses. Neurons can connect to each other to form neural networks. Neurons are major components of the brain and spinal cord of the central nervous system.

DENTRITES are short cells protections with many branches.most neurons nave multiple dentrites.

The AXON is a long cell projection.It is only branched at one end.There is usually only one axon.

The MYELIN SHEAT is a protective covering that surrounds fibres called axons.This sheath is composed of protein and lipids.

The CELL BODY integrates synaptic input and determines the message to be transmitted to other cells by the axon. The cell body also is responsible for a variety of complex biochemical processes.

The NUCLEUS of a neuron is separated from the intracellular fluid and other organelle of the cell, containing the genetic information that guides cellular function.