The Nervous system

The Nervous system

Cell is the smallest living part of our body.

Cell - Tissues - Organs - Organ system - Human body

Nervous system

The nervous system controls everything you do, including breathing, walking, thinking, and feeling. This system is made up of your brain, spinal cord, and all the nerves of your body. The nerves carry the messages to and from the body, so the brain can interpret them and take action

Multiple Choice

Group of organs working together make a?

• Tissues

• Organ system

• Human body

The nervous system is made up of three parts

• Brain

• Spinal cord

• Nerves

The Brain

• Control centre of our body.

• Brain performs all the functions by receiving and sending messages to different parts of the body.

• Divided into 3 parts- CEREBRUM, CEREBELLUM, MEDULLA

Open Ended

What are the three parts of nervous system?

The Cerebrum

• Largest part of brain- looks like walnut.

• Has many grooves and folds on its surface.

• Controls our ability to think, learn, decide, remember, dream and feel.

• It also receives and intreprets information from our sense organs .

• It also controls our voice.

The Cerebellum

• Lies below the cerebrum.

• It is smaller that cerebrum.

• It controls and coordinates all voluntary movements such as walking, running, dancing, painting etc.

• It coordinates the actions of muscles and keeps balancing the body.

• 
  

Medulla (Brain stem)

• Located below the cerebrum.

• It connects the brain to the spinal cord.

• Controls all the involuntary actions such as sneezing, coughing, vomiting, swallowing and muscle movements in the digestive system.

• Controls the heartbeat.

• Medulla is active even when we are asleep.

Multiple Choice

Which part of our brain controls the voice?

• Cerebrum

• Cerebellum

• Medulla

Spinal cord

• Thick cylinder of nervous tissue.

• Protected by vertebral column.

• It is connected to the brain.

• Messages travel from brain to spinal cord and then to all parts of our body.

• 
  

^Nerves

• All parts of nervous system are formed of special cells called nerve cells or Neurons.

• Nerve cell has following three parts:

• A cell body

• Small fibres called dendrites - which comes out of the cell body.

• A long fibre called axon which extends from one end of the cell body.

Types of Nerves

• SENSORY NERVES- Nerves carry messages from the sense organs to spinal cord and brain. These message are of pressure, temperature, smell, taste, colour etc.

• MOTOR NERVES-Nerves carry messages from the brain and spinal cord to the muscle and glands. These messages tell muscles and glands what to do.

• MIXED NERVES- Nerves carry messages to the brain and spinal cord and also bring messages from the brain and spinal cord.

• 
  

• 
  

REFLEX ACTION

Reflex action is the quick immediate and automatic response to a stimulus without the involvement of the brain.

Examples- Blinking of eyes, sneezing, coughing, vomiting and withdrawal of the foot when you step on a sharp object accidently are other examples of reflex action.

Our sense organs

Eyes

Ears

Nose

Tongue

Skin

Eyes