EVS CH-6 NERVOUS SYSTEM (NOTEBOOK AND WORKBOOK EXERCISE)
NERVOUS SYSTEM (NOTEBOOK AND WORKBOOK EXERCISE)
NEW WORDS
reflex action
cerebrum
cerebellum
medulla
cerebrospinal fluid
neurons
cranium
stimuli
stimulus
cardiac muscles
multicellular
NEW TERMS
involuntary muscles – muscles that are not under our control
impulse- sudden force or desire, electrical charge ,pulse
Answer the following questions.
a. What is cerebrum? What is its function?
ANS. The cerebrum is the largest part of the brain which performs many important functions.
FUNCTION: Planning, memory, reasoning, intelligence, speech, problem solving are performed by the cerebrum. It is also known as the thinking part of the brain.
b. What is a reflex action? Give one example.
ANS. A reflex is an involuntary action that our body does in response to something. So the automatic response of the body to an event is called a reflex action.
Reflex action are due to messages sent by the spinal cord.
Example: When we accidentally touch a hot object, we immediately withdraw our hand. Such fast and automatic reactions are controlled by the spinal cord. The spinal cord processes the information that the object is hot and automatically sends a message to the hand asking it to withdraw.
c. Write the functions of all sense organs.
ANS. 1. Eyes are the organs of sight. They collect visual messages from our surroundings. Optic nerves in eyes carry messages from the eyes to the brain.
2. Ears are the organs of hearing. They also help to maintain the balance of the body. The auditory nerves in ears carry messages from the ears to the brain.
3. Nose helps us to breathe and smell. Several nerves connected to the inner lining of the nose carry messages to the brain.
4. Tongue is the organ of taste. Taste buds present on the surface of the tongue help in tasting food by carrying messages to the brain.
5. Skin is the largest sense organ and helps us feel different sensations such as heat, cold, pain and so on.
NOTE: Q.1,3,4 TO BE DONE IN TEXTBOOK
ALSO DRAW A DIAGRAM OF BRAIN (CREATIVELY) AND WRITE ITS FUNCTION.TO BE DONE IN SCRAP BOOK--COMPULSORY
WORKBOOK EXERCISE LINK
