Question 1

Question 1(i)Distinguish between the following pairs on the basis of the words indicated in the brackets [].Sensory neuron and Motor neuron. [Function]

Accepted Answer

Differences between Sensory neuron and Motor neuron on the basis of function:Sensory neuronMotor neuronSensory neurons carry impulses from the sensory cells or sense organs to the spinal cord or brain.Motor neurons carry messages from the brain or spinal cord to the effector — the gland or muscles.

Question 2

Question 1(iv)Distinguish between the following pairs on the basis of the words indicated in the brackets [].Sympathetic and Parasympathetic nervous system. [Function]

Accepted Answer

Differences between Sympathetic and Parasympathetic nervous system on the basis of function:Sympathetic nervous systemParasympathetic nervous systemSympathetic nervous system produces immediate fight or flight responses against abnormal conditions.The parasympathetic nervous system re-establishes the normal conditions of the body after a fight or flight response.For example, sympathetic nervous system may increase the heart rate to meet the oxygen demand of the body during abnormal conditions.For example, parasympathetic nervous system relaxes the heart rate after the abnormal situation has passed.

Question 3

Question 2Draw a neat and labelled diagram of a nerve cell.

Accepted Answer

Below diagram shows the structure of a nerve cell or neuron:

Question 4

Question 3Given alongside is the figure of a median section of an organ. Study the same and answer the following questions :Name the organ and write its location in our body.Label the guidelines 1 to 4.Write one important function of hypothalamus.Which of the structures from 1 to 4 is considered as the master gland of the body ?Mention the basic structural unit of the organ shown in the figure and the organ system to which it belongs.

Accepted Answer

The organ shown in the given figure is the human brain. It is contained in, and protected by, a bony structure called the skull or the cranium. The brain is further enclosed in three protective membranes, collectively called as meninges, which are separated by cerebrospinal fluid.The guidelines 1 to 4 show:1 → Cereberal hemisphere2 → Cerebellum3 → Medulla Oblongata4 → PituitaryOne important function of the hypothalamus is regulating body temperature. It acts as the body's thermostat, monitoring internal temperature and initiating responses like sweating or shivering to maintain a stable internal environment.The pituitary gland is often called the "master gland" of the human body because it produces hormones that regulate many other glands and bodily functions.The basic structural and functional unit of the brain is the neuron (also known as a nerve cell). Neurons belong to the nervous system.

Question 5

Question 4A part of our nervous system is shown alongside. Study the same and answer the following questions :Identify the figure and name it.Define the structure shown.Label the part shown as X.Write the name of the protective, tubular covering of the structure shown.Mention the names of the three kinds of the structure that is shown in the figure.

Accepted Answer

The given figure shows a section of the Nerve.A nerve refers to a bundle of axons (nerve fibres) enclosed in a tubular medullary sheath, that act as a pathway for transmitting information between the brain and other parts of the body, enabling sensation and movement.The part "X" depicts Nerve fibres.The protective, tubular covering is the Myelin Sheath.Three kinds of nerves are:Sensory nervesMotor nervesMixed nerves

Question 6

Question 5Briefly describe the structure of the cerebrum in human brain and mention its functions.

Accepted Answer

Cerebrum is the largest portion of the brain. It is divided into two halves called the right and left cerebral hemispheres. Each hemisphere is internally hollow. The outer surface of the hemispheres is folded with ridges and grooves which increase the surface of the brain so as to accommodate a large number of neurons.The cerebrum has following functions:IntelligenceConsciousnessWill powerMemory

Question 7

Question 2Match the terms given in column A with those of column B .Column AColumn B(i) Sensory neuron(a) Brain and spinal cord(ii) Motor neuron(b) Somatic and autonomic(iii) Central nervous system(c) Sympathetic and parasympathetic(iv) Peripheral nervous system(d) Sense organs(v) Autonomic nervous system(e) Effectors

Accepted Answer

Column AColumn B(i) Sensory neuron(d) Sense organs(ii) Motor neuron(e) Effectors(iii) Central nervous system(a) Brain and spinal cord(iv) Peripheral nervous system(b) Somatic and autonomic(v) Autonomic nervous system(c) Sympathetic and parasympathetic

Question 8

Question 3Correct the following statements by changing the first and the last word only :Cerebrum maintains the balance of the body.The long process which extends from the cell body of a neuron is termed as a dendron.Enzymes regulate chemical coordination of the body.Motor neurons carry impulses from the sense organs to the central nervous system.Spinal cord regulates the heart beat and breathing movements.

Accepted Answer

Cerebellum maintains the balance of the body.The long process which extends from the cell body of a neuron is termed as an axon.Hormones regulate chemical coordination of the body.Sensory neurons carry impulses from the sense organs to the central nervous system.Medulla oblongata regulates the heart beat and breathing movements.

Question 9

Question 4Write one word in the space provided to complete the second pair of the related words pertaining to nervous system:Memory : cerebrum :: breathing : ...............Balance : cerebellum :: reasoning : ...............

Accepted Answer

Memory : cerebrum :: breathing : medulla oblongataBalance : cerebellum :: reasoning : cerebrum

Question 10

Question 2Define the following terms :CoordinationNeuronSynapseBrainSpinal cord

Accepted Answer

Coordination — The interlinking of various activities and organs of a living being as per the needs of the body internally or externally is called coordination.Neuron — The nervous system is made up of special cells called nerve cells or neurons. Neurons are the structural and functional units of the nervous system. They help in transmitting information throughout the body as electrical and chemical signals.Synapse — The terminal branches of the axon of one neuron lie very close to the dendrites of another neuron. This point of contact is called a synapse.Brain — The brain along with the spinal cord forms our central nervous system. It is responsible for regulating all bodily functions, processing information from the senses, controlling movement, and enabling thought, emotions, and memory.Spinal cord — The spinal cord extends from the medulla of the brain and runs down almost through the whole length of the backbone. It is a long, thin, tubular structure of nervous tissue that extends from the base of the brain down the back. It acts as a pathway for messages between the brain and the rest of the body.

Question 11

Question 3Write one important role of the following :CerebellumMedulla oblongataParasympathetic nervous system

Accepted Answer

Cerebellum — The main function of Cerebellum is to balance the body and coordinate muscular activities.Medulla oblongata — Medulla oblongata controls the activities of the internal organs.Parasympathetic nervous system — The parasympathetic nervous system re-establishes the normal conditions of the body after a fight or flight response. For example, if sympathetic nervous system increases the heart rate, parasympathetic nervous system relaxes it.

Question 12

Question 5What are voluntary and involuntary actions? Which part of the nervous system controls them?

Accepted Answer

Voluntary actions — The actions or movements that are under the control of one's own will are called voluntary actions. For example, walking, jumping, lifting books, etc. Voluntary actions are controlled by Somatic nervous system.Involuntary actions — The actions or movements that happen without consciousness or willingness of an individual are called the involuntary action. For example, beating of heart, breathing, digestion, etc. Involuntary actions are controlled by Autonomic nervous system.

Nervous System

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