Grade 4 | Science | Nervous System, Human Body and Health, Olympiad, CBSE, ICSE, Maths Olympiad, Science Olympiad, English Olympiad
The nervous system controls our body. Our sensory organs work with the help of nervous system. The nervous system is responsible for communication between different body parts. The nervous system consists of the brain, spinal cord, sensory organs, and nerves. Nerves connect sensory organs with different parts of the body. Neurons are nerve cells.
The brain is the most important part of our nervous system.
The brain and spinal cord comprise the central nervous system (CNS).
The brain is located in the cranial cavity and is surrounded by skull bones. Skull bone or cranium protects our brain.
The spinal cord is covered and protected by the vertebral column.
Sensory organs, sensory nerves and motor nerves form the peripheral nervous system. Nerves are like wires which transmit communication signals between the brain and body parts. Nerve comprises of nerve cells. A nerve cell is called neuron.
Sensory nerves: Our sensory organs sense things and send signals to the brain. Sensory nerves are used for this purpose. Thus brain becomes aware of senses like touch, hear, see, smell and feel. The flow of signal is from sense organ to sensory nerves and then to the brain.
Motor nerves: Brain controls our muscles with the help of motor nerves. Brain signals muscles to expand or collapse so that a movement is performed. The flow of signal is from the brain to motor nerves.