Remsegek cirkusza online dating
Remsegek cirkusza online dating - Adult dating sites accept debit cards
In vertebrate species it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body.
The vertebrate nervous system can also be divided into areas called grey matter ("gray matter" in American spelling) and white matter.
The sensory information from these organs is processed by the brain.
In insects, many neurons have cell bodies that are positioned at the edge of the brain and are electrically passive—the cell bodies serve only to provide metabolic support and do not participate in signalling.
The nervous system is the part of an animal's body that coordinates its actions and transmits signals to and from different parts of its body.
Nervous tissue first arose in wormlike organisms about 550 to 600 million years ago.
In the insect nervous system, the brain is anatomically divided into the protocerebrum, deutocerebrum, and tritocerebrum.
Immediately behind the brain is the subesophageal ganglion, which is composed of three pairs of fused ganglia.The nervous system derives its name from nerves, which are cylindrical bundles of fibers (the axons of neurons), that emanate from the brain and spinal cord, and branch repeatedly to innervate every part of the body.Nerves are large enough to have been recognized by the ancient Egyptians, Greeks, and Romans, but their internal structure was not understood until it became possible to examine them using a microscope.Both autonomic and enteric nervous systems function involuntarily.Nerves that exit from the cranium are called cranial nerves while those exiting from the spinal cord are called spinal nerves."It is difficult to believe that until approximately year 1900 it was not known that neurons are the basic units of the brain (Santiago Ram? Equally surprising is the fact that the concept of chemical transmission in the brain was not known until around 1930 (Henry Hallett Dale) and (Otto Loewi).