Central nervous system Facts for Kids

Quick facts for kids Central Nervous System

Schematic diagram showing the central nervous system in yellow, peripheral in orange
Latin	Systema nervosum centrale pars centralis systematis nervosi
Lymph	224
MeSH	197
Code	WM1

The central nervous system (CNS) is the largest part of the nervous system. It is made up of the brain and the spinal cord.

Together with the peripheral nervous system, it has an important role in the control of behaviour. The CNS is protected by bone in the dorsal cavity: the brain in the cranial subcavity, and the spinal cord in the spinal cavity.

Parts of the vertebrate CNS

Tectum, Cerebral peduncle, Pretectum, Mesencephalic duct

Diencephalon

Epithalamus, Thalamus, Hypothalamus, Subthalamus, Pituitary gland, Pineal gland, Third ventricle

Rhinencephalon, Amygdala, Hippocampus, Neocortex, Lateral ventricles

Diagram of the columns and of the course of the fibers in the spinal cord. Sensory synapses occur in the dorsal spinal cord (above in this image), and motor nerves leave through the ventral (as well as lateral) horns of the spinal cord as seen below in the image.
Different ways in which the CNS can be activated without engaging the cortex, and making us aware of the actions. The above example shows the process in which the pupil dilates during dim light, activating neurons in the spinal cord. The second example shows the constriction of the pupil as a result of the activation of the Eddinger-Westphal nucleus (a cerebral ganglion).
A map over the different structures of the nervous systems in the body, showing the CNS, PNS, autonomic nervous system, and enteric nervous system.
Schematic image showing the locations of a few tracts of the spinal cord.
Reflexes may also occur without engaging more than one neuron of the CNS as in the below example of a short reflex.
Development of the neural tube