GSEB Solutions for Class 8 Science and Technology – Nervous System and Endocrine System

GSEB Solutions for Class 8 Science and Technology – Nervous System and Endocrine System (English Medium)

GSEB SolutionsMathsScience
Exercise 36:

Solution 1(a):

During winter, the temperature is very low and our body cannot resist the outside temperature; so, to avoid cold, we wear woolen clothes as they are very thick and are a bad conductor of heat.

Solution 1(b):

When we feel thirsty, we need water to quench our thirst. Water is required by our body to regulate the activities such as digestion, excretion, circulation etc.

Solution 1(c):

Our body performs various activities the whole day starting from morning to evening. The muscles of our body experience pain and we need to rest our muscles. So, we take rest when we feel tired.

Exercise 46:

Solution 1(a):

Sr. No.	Name of the Endocrine gland	Location of the gland	Hormones secreted by the gland	Functions
1	Pituitary Gland	Base of the brain	Growth Hormone	Essential for normal growth and promotes secretion of milk
2	Thyroid Gland	Neck	Thyroxine	Regulates metabolic activities and growth of the body
3	Pancreas	Abdomen (Pancreas)	Insulin and Glucagon	Regulates blood glucose level
4	Adrenal Gland	Kidney	Adrenaline/ Epinephrine	Increases the rate of the heart beat and helps in fighting mechanism
5	Testes	Male reproductive system (Beside penis)	Testosterone	Controls development of sex organs and secondary sexual characteristics
6	Ovary	Female reproductive system (Beside vagina)	Progesterone, Estrogen	Development of female secondary sexual character

Exercise 47:

Solution 1:

Functions:

1. Brain – The brain performs almost all the functions of our body like concentration, sleep, talk, rest, work and also controls the understanding of speech and language.
2. Spinal cord – The spinal cord is basically the “information highway of the body”, in which messages are sent back and forth between the brain and the rest of the body.
3. Peripheral Nervous System – The peripheral nervous system connects the central nervous system to the organs, limbs, and skin to allow for complex movements and behavior.
4. Nerve- Nerves conduct impulses from the brain or spinal cord to receptor organs as well as conducting impulses from the receptor organs back to the brain or spinal cord.

Exercise 48:

Solution 2:

1. There are three types of nervous system in our body and they are central nervous system, peripheral nervous system and sense organs.
2. The central nervous system comprises of two organs – brain and spinal cord.
3. The glands producing hormonal secretions that pass directly into the bloodstream are called endocrine glands.
4. The endocrine glands are adrenal gland, thyroid gland, pancreas, pituitary gland, testes and ovary.

Solution 3:

Sr. No.	Name of an organ	Connecting nerve	Function
1	Skin	Central nervous system	Provides insulation and helps to feel hot and cold.
2	Nose	Olfactory nerve	The olfactory cells help to sense smell.
3	Ear	Auditory nerve	Sound vibration is collected by the external ear and sent to the middle ear.
4	Tongue	Ninth cranial nerve	Taste buds help in identifying particular tastes such as sweet, salty, bitter and sour.
5	Eye	Optic nerve	The optic nerve carries the impulse to the brain, where it is interpreted and we are able to see.

Solution 4:

1. Skin
2. Nose
3. Tongue
4. Ear
5. Eye