Central nervous system

The most important part of the nervous system, the central nervous system. Here stimuli are evaluated and then sent back effectors for the authority, who can then respond. The central nervous system consists of the brain and spinal cord.

Brain and spinal cord


  • managing and integrating body (all functions of the human body are controlled)
  • It contains from 50 to 100 billion nerve cells and synapses to quadrillion
  • brain is divided into the brainstem, diencephalon and cerebrum

More information on the brain in a separate article here.

Spinal cord

  • neural tube inside the spine adjoining to the spinal cord in the brain
  • Length is 40-50 cm, ending at the lumbar spine, where it disintegrates into individual nerve fibers
  • spinal cord has 31 sections, from which on each side withdraws nerve fiber which controls an authority and region
  • 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal
  • in the middle of the spinal cord is a channel around it is gray matter (high number of neurons), gray matter surrounding the white matter, in which there is almost no neuron only axons that transmit impulses between them.

Functional status CNS

Functional status (especially the brain) changes throughout the day. They are characterized by two basic states – waking and sleeping. In every phase is focused on CNS and other stimuli during wakefulness is more wary. Each of these phases is clearly noticeable on the EEG(electroencephalogram).

Sleep has two parts – nonREM called. Slow sleep, gradually decreasing heart rate and blood pressure, slows breathing, reduces muscle tone, eyes eyelids move very slowly. REM is typical flick bulbs, loss of muscle voltage, bruxism, heart rate and pressure varies depending on the dreams. This type of sleep lasts about 20 minutes. Throughout the rest of this turns up 5-7 times a night. In the adult form the REM phase 20% of total sleep time. Most dreams appears at this stage.

Protective Packaging CNS

  • Dura mater (dura mater) – strong connective diaper is tightly connected with the cranial bones. To the dura are zavzaté venous sinuses through which blood is withdrawn from the brain.
  • Arachnoid mater (arachnoidea) – a thin membrane that contains no blood vessels. Between the dura and arachnoid mater is only a small subdural space. The structure reminds the net, hence its name.
  • Soft diaper (pia mater) – fine fibrous membrane. Just follow the contours of the brain and spinal cord. The space between the arachnoid mater and soft diaper is filled with cerebrospinal fluid circulating and is called the subarachnoid.

Cerebrospinal fluid

It is a clear, slightly yellowish liquid that constantly forms filtration of blood plasma into the brain ventricles. Mok is present between the chambers and fills cavities in the brain and spinal cord. It is absorbed into the veins on the surface of the brain and spinal cord.Hydrocephalus is the accumulation of MM and compress the tissue. MM is important to protect the brain from impact, relieve the it, and creates a favorable environment for the functioning of nerve cells.

CNS blood supply

To enable nerve cells to work and transport information, need oxygen and nutrients, they are fed into the brain and artery. Basilar. The circuit that carries blood into the individual lobes called Willis. Just 10 seconds without oxygenation and the person becomes unconscious.If no supply restored within 5 minutes, begin the nerve cells of the brain stem die. Brainstem lasts 20 to 30 minutes without oxygen. It is the same with the supply of glucose, which is very important for the activity of nerve cells. The decline in blood glucose leads to significant changes.The lack of these substances leads to death.