CBSE Class 5 Science Nervous System And Sense Organs Worksheet

Sense Organs
1. We become aware of our surroundings by seeing, hearing, feeling and tasting.
2. We use our sense organs to obtain information about our environment.
3. Sense organs are the organs that give messages about our surroundings to our nervous system.
4. The sense organs include the eyes, the ears, the nose, the tongue and the skin.

Eyes
1. We get most of the information about the environment through our eyes.
2. The eyelids and Eyelashes protect our eyes from dirt, strong light and injuries.
3. The eye is covered over by a transparent covering called cornea.
4. Iris is the coloured layer that gives people distinct eye colour.
5. Light enters the eye through an opening called pupil.
6. The lens is present behind the iris.
7. The inner part of our eye has a very thin layer of tissues called the retina which captures the light that enters the eye and send it to the brain through the optic nerve.
8. The eyes are connected to the brain by the optic nerves that carry messages to the brain and the brain tells us what we are looking at.

Nose
1. As a sense organ the function of nose is to smell.
2. In addition to smelling nose also helps us to breathe.
3. The nose has two holes called nostrils.
4. The shape of the nose is due to the bones and cartilages.
5. The nasal septum separates the nostrils and divides the nasal cavity into two.
6. The nasal cavity is separated from the mouth by a bony structure called the palate.
7. Olfactory nerves are there in nose that helps it to smell.
8. When the inhaled air comes in contact with the Olfactory nerves, they send signals to the brain and then smell is identified. 

Ears
1. The ears help us to hear sounds.
2. The outer part of the ear that we can see is called the pinna.
3. Pinna gathers sound and sends it to the eardrum.
4. The eardrum vibrates when hit by sound and transmit the vibration to the internal ear through the middle ear.
5. From here, they are carried to the brain through a special nerve as messages for interpretation.

Tongue
1. The tongue is a fleshy sense organ.
2. It helps us to speak, chew and taste.
3. The tongue has thousands of taste buds which have nerve endings that carry messages to the brain.
4. The primary tastes that the tongue sense are sweet, salty, sour and bitter.

Skin
1. The skin is the largest organ and the outer covering of the body.
2. It protects the internal organs of the body.
3. It has millions of nerve endings that can detect sensations like heat, cold, pain and pressure. The skin carries out many functions needed for our survival which include wound healing, protection, maintaining the body temperature and preventing infections.

I. FILL IN THE BLANKS

1. _______________ gives shape and support to our body.

2. The ______________ protects the brain.

3. The part of the eye on which an image is formed is the _____________________.

4. The nerve at the back of the retina is ________________.

5. The __________________ is the thinking part of the brain.

6. The nerves are made up of __________________.

7. ____________________ nerves carry impulses to the brain.

8. The little brain is the __________________.

9. The heart and lungs are protected by the ____________________.

10. Reflex actions are due to the messages sent by the _________________.

11. Nerves which carry messages from the brain are ___________.

12. Eyeballs are protected by __________________.

NAME THE FOLLOWING

1. The system that controls all other systems of our body.
___________________________

2. The other name of the brain stem.
___________________________

3.The largest part of the brain.
___________________________

4. The actions controlled by the spinal cord
___________________________

5. The control centre of the body.
___________________________

6. The three kinds of nerves.
a____________________b______________c ________________

7. The part of the brain that helps to control the movements during reflex action. ___________________________

8. The nerve cells which bind together to form a nerve.
______________________

9. The organ that controls our heartbeat and breathing.
_______________________

10. The part of the brain that helps to control the movements during reflex action.

WRITE TRUE or FALSE

1. The skin forms a covering to protect the internal organs in our body. _______________

2. Medulla makes up 90 percent of the brain tissues. ____________

3. The total length of all the nerves present in the body of an adult human being is about 72 km. __________________

4. We must always breathe through the mouth. ____________

5. It is dangerous to clean our ears with a hairpin or toothpicks. __________

6. Nerve cells have special thread like parts called fibres. ___________

7. The medulla helps to maintain our body balance. ____________

8. Coughing, sneezing, blinking and jumping are human reflexes _________