Chapter 1 – (d) Response And Physical Coordination In Animals-Nervous System | Life Science Solution Class 10

1. Nephron,
2. Neurone,
3. Neuroglia,
4. Nerve.

1. Peripheral nervous system, 
2. Autonomic nervous system,
3. Central nervous system, 
4. None of the above.

Question

1. ____ is the structural unit of the nervous system.
2. The outermost thin covering of the axon is called ____.
3. The central nervous system consists of ____ and ____.
4. The three layered membranous covering of the human brain is collectively called ____.
5. Ear has two functions one is hearing another is and ____.
6. Cone cells are responsible for ____ light vision and vision.
7. Rod cells are responsible for ____ light vision.
8. Organ of Corti is present in the ____ ear.

Answer

1. Neuron
2. Myelin Sheath
3. Brain and Spinal cord
4. Meninges
5. Balance (equilibrium)
6. Color vision
7. Low light vision
8. Inner ear

Very Short Answer (VSA) type questions

Question 1

What is ganglion ?

Answer

A ganglion is a group of nerve cell bodies located outside the central nervous system.

Question 2

Answer

The nervous system is a complex network of specialized cells and tissues that coordinates and regulates the activities of the body, allowing for communication between different parts of the body and the external environment.

Question 3

Mention the characteristic of each of afferent nerve and efferent nerve.

Answer

Afferent nerves carry sensory information from the sensory organs and tissues to the central nervous system (CNS), while efferent nerves carry motor information from the CNS to the muscles and glands.

Question 4

(i) Where synapse is found? (ii) What is its function?

Answer

(i) Synapse is found at the junction between two neurons or between a neuron and a target cell such as a muscle or gland.

(ii) The function of the synapse is to transmit information from one cell to another through the release and reception of neurotransmitters, allowing for communication between neurons and the regulation of various physiological and behavioral processes.

Question 5

What is reflex action? Give an example of reflex action.

Answer

Question 6

Explain simple reflex action.

Answer

A simple reflex action is an automatic and involuntary response to a stimulus that occurs without conscious thought, involving a neural pathway called a reflex arc.

Question 7

What is Ganglion?

Answer

A ganglion is a group of nerve cell bodies located outside the central nervous system, typically in clusters along the course of peripheral nerves. They can function as sensory or autonomic ganglia, and play a role in the integration and processing of neural signals from different parts of the body.

Question 8

What is reflex action?

Answer

Reflex action is an automatic and involuntary response to a stimulus that occurs without conscious thought, involving a neural pathway called a reflex arc.

Question 9

What are sense organs ?

Answer

Sense organs are specialized structures or tissues within the body that are responsible for detecting and processing sensory information from the external environment or internal body conditions. These include the eyes, ears, nose, tongue, and skin.

Question 10

What are the functions of ear?

Answer

The ear is a sensory organ that plays a crucial role in the detection and processing of sound, as well as maintaining balance and equilibrium.

Question 11

Which organs of the body maintain the equilibrium of the body?

Answer

The ear is the organ of the body that maintains the equilibrium of the body.

Short Answer (SA) type questions

Question 1

Mention the important functions of the nervous system in the animal (human) body.

Answer

The important functions of the nervous system in the human body are

• Receives and processes sensory input from the environment.
• Coordinates and integrates the received sensory information with internal body conditions.
• Responds to changes in the environment by controlling and coordinating muscular and glandular responses.
• Regulates the physiological functions of the body, such as breathing, digestion, and heart rate.
• Facilitates learning and memory by acquiring, processing, and storing information for future use.

Question 2

What is nerve?

Answer

A nerve is a bundle of specialized cells called neurons that transmit electrical impulses and signals throughout the body to coordinate and regulate bodily functions, sensation, and movement. Nerves can be found in both the central nervous system (CNS) and the peripheral nervous system (PNS), and play a vital role in communication between different parts of the body.

Question 3

What are the structural differences between dendrons and axons?

Answer

Here are the structural differences between dendrites and axons

• Dendrites receive signals, while axons transmit signals.
• Dendrites are shorter and branched, while axons are longer and unbranched.
• Dendrites lack axon terminals, while axons have specialized structures at their ends called synaptic boutons.

Question 4

Mention the functions of any three parts of a neurone.

Answer

The functions of the three parts of a neuron are

• Dendrites: Receive incoming signals and transmit them to the cell body.
• Cell Body (Soma): Integrates incoming signals and generates nerve impulses.
• Axon: Transmits nerve impulses away from the cell body towards other neurons or target cells.

Question 5

What is the relation between neurone and nerve?

Answer

A neuron is a specialized cell that transmits electrical signals and information throughout the body, while a nerve is a bundle of neurons (nerve fibres) that transmit electrical impulses and signals to coordinate and regulate bodily functions, sensation, and movement.

Question 6

What is ganglia?

Answer

Ganglia (singular: ganglion) are collections of nerve cell bodies located outside the central nervous system, typically along the course of peripheral nerves. Ganglia can be sensory or autonomic, and play a role in the integration and processing of neural signals from different parts of the body.

Question 7

Describe in brief the structure of the axon of the nerve cell.

Answer

The axon is a long, cylindrical fibre that extends from the cell body of a nerve cell (neuron) and transmits electrical impulses and signals away from the cell body towards other neurons or target cells. The structure of the axon includes:

• Axon hillock: A cone-shaped region at the base of the axon that connects to the cell body and initiates nerve impulses.
• Myelin sheath: A layer of fatty insulation that covers the axon and helps to increase the speed of nerve impulses. The myelin sheath is made up of specialized cells called Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system.
• Nodes of Ranvier: Gaps in the myelin sheath along the length of the axon that allow for the rapid conduction of nerve impulses.
• Axon terminals: Specialized structures at the end of the axon that transmit signals across the synapse to other neurons or target cells. The axon terminals contain vesicles filled with neurotransmitters that are released in response to a nerve impulse, allowing for communication between neurons.

Question 8

What are the organs of the special senses? In which type of organism is it found? Mention the major functions of eye and ear.

Answer

The organs of special senses are specialized organs or structures in the body that are responsible for detecting and processing sensory information from the environment. These include the eyes, ears, nose, tongue, and skin, and are found in higher organisms such as mammals, birds, and reptiles.

The major functions of the eye are:

• Detecting and processing visual information
• Focusing light on the retina for clear vision

The major functions of the ear are:

• Detecting and processing auditory information (hearing)
• Maintaining balance and equilibrium

Question 9

What is sclera? Where is the sclera located? What is its function?

Answer

Definition: The sclera is a tough, fibrous outer layer that covers the eyeball. It is also known as the white of the eye due to its opaque, whitish appearance.

Location: The sclera is located at the posterior (back) part of the eye.

Function: It helps to maintain the shape of the eye and prevent it from collapsing.

Question 10

What is blind spot ? Or, What is optic disc? Why optic disc is called blind spot?

Answer

The optic disc, also known as the optic nerve head, is the area at the back of the eye where the optic nerve exits and sends visual information to the brain. It is called the blind spot because it lacks photoreceptor cells, which are responsible for detecting light and creating visual signals.

Question 11

Write any one function of each of the cerebrum, cerebellum and medulla oblongata.

Answer

• Cerebrum: Controls higher cognitive functions and voluntary movements.
• Cerebellum: Regulates voluntary movements, balance, and coordination.
• Medulla Oblongata: Controls vital functions such as breathing, heart rate, and blood pressure.

Long Answer (LA) type questions

Question 1

What is nervous system?

Answer

The nervous system is a complex network of specialized cells, tissues, and organs that work together to regulate and coordinate the functions of the body. It is responsible for receiving and processing sensory information from the environment, integrating this information with previous experiences and memories, and generating appropriate responses to stimuli. The nervous system consists of two main parts: the central nervous system (CNS), which includes the brain and spinal cord, and the peripheral nervous system (PNS), which includes all the nerves and ganglia outside the CNS.

Question 2

Write the name of the structural and functional unit of the nervous system. Mention the functions of any three parts of that unit.

Answer

The structural and functional unit of the nervous system is the neuron.

The three main parts of a neuron and their functions are:

1. Dendrites: Receive incoming signals from other neurons or sensory receptors and transmit them to the cell body.
2. Cell Body: Contains the nucleus and other cellular organelles, and integrates incoming signals from the dendrites to generate a new electrical signal (action potential).
3. Axon: Conducts the action potential away from the cell body towards the axon terminals, where it triggers the release of chemical messengers (neurotransmitters) that carry the signal across the synapse to other neurons or target cells.

Question 3

(a) What is nerve ? (b) What is its function?

Answer

a) A nerve is a bundle of axons (long, slender projections of neurons) that are wrapped in connective tissue and serve as the communication pathway of the nervous system.

b) Functions of nerve:

• Transmits electrical signals (nerve impulses) between the brain, spinal cord, and other parts of the body, such as muscles, glands, and organs.
• Sensory nerves transmit signals from sensory receptors (such as those in the skin, eyes, and ears) to the central nervous system.
• Motor nerves transmit signals from the central nervous system to muscles and glands, causing them to contract or secrete.
• Mixed nerves contain both sensory and motor fibers and can transmit signals in both directions.

Question 4

Mention the characteristic features of two main types of nerve. Give examples.

Answer

Here are the characteristic features of two main types of nerves along with examples:

1. Sensory Nerves:

• Transmit signals from sensory receptors to the central nervous system.
• Have cell bodies located outside the central nervous system.
• Unipolar in shape, with a single axon branching into two parts (peripheral and central).
• Examples include the optic nerve, auditory nerve, and dorsal root ganglia.

2. Motor Nerves:

• Transmit signals from the central nervous system to muscles and glands.
• Have cell bodies located in the central nervous system.
• Multipolar in shape, with a single axon and multiple dendrites.
• Examples include the facial nerve, sciatic nerve, and phrenic nerve.

Question 5

What is reflex action? Give examples of reflex action.

Answer

Reflex action is an involuntary and automatic response to a stimulus that occurs without conscious thought or effort. It is a protective mechanism that helps to prevent injury or damage to the body by quickly and automatically responding to potential threats in the environment.

Examples 

• Closing of eyes when a bright light hits our eyes.
• Sudden withdrawing hands or legs when they touch something hot or pricking.
• Coughing or sneezing due to irritants in the nasal passage.

Question 6

What is reflex action? Explain reflex action with an example.

Answer

Reflex action is an involuntary and rapid response to a stimulus that occurs automatically without conscious thought or effort. It is a protective mechanism that helps to prevent injury or damage to the body by quickly and automatically responding to potential threats in the environment.

Here is an example of a simple reflex action, the knee-jerk reflex:

• When a doctor taps the patellar tendon just below the kneecap with a rubber hammer, it stretches the quadriceps muscle in the front of the thigh.
• This stretch is detected by sensory receptors called muscle spindles, which send a signal through sensory neurons to the spinal cord.
• In the spinal cord, the sensory neuron synapses with a motor neuron that controls the quadriceps muscle.
• The motor neuron receives the signal and immediately sends an action potential back to the quadriceps muscle, causing it to contract and extend the lower leg.
• This contraction of the quadriceps muscle is what causes the characteristic “knee-jerk” movement.

Question 7

What are the component parts of simple reflex arc?

Answer

The component parts of a simple reflex arc are:

1. Sensory Receptor: A specialized cell or group of cells that detects a stimulus and converts it into an electrical signal (nerve impulse).
2. Sensory Neuron: A nerve cell that transmits the electrical signal from the sensory receptor to the central nervous system (spinal cord or brainstem).
3. Interneuron: A nerve cell located in the spinal cord or brainstem that receives the incoming signal from the sensory neuron and sends a response signal to the motor neuron.
4. Motor Neuron: A nerve cell that transmits the response signal from the central nervous system to the effector (muscle or gland).
5. Effector: A muscle or gland that responds to the signal from the motor neuron by contracting (in the case of a muscle) or secreting a substance (in the case of a gland).

Question 8

What is neurone? Discuss the relation between the neurone and nerve. What is ganglion?

Answer

Neuron: A neuron, also known as a nerve cell, is the basic structural and functional unit of the nervous system. It is responsible for transmitting and processing information in the form of electrical signals (nerve impulses) throughout the body.

Relation between neuron and nerve:

• A nerve is a bundle of axons (long, slender projections of neurons) that are wrapped in connective tissue and serve as the communication pathway of the nervous system.
• In other words, a nerve is a collection of neurons bundled together to transmit signals to and from different parts of the body.

Ganglion: A ganglion is a group of nerve cell bodies located outside the central nervous system (CNS).

Question 9

Distinguishes between afferent sensory neurone and efferent motor neurone.

Answer

Question 10

What is a synapse? Where is it present? Mention the functions of synapse.

Answer

Synapse: A synapse is a junction between two neurons (or between a neuron and an effector cell, such as a muscle or gland).

Location of synapse: Synapses are present throughout the nervous system, including in the brain, spinal cord, and peripheral nerves.

Functions of synapse:

• Synapses play a crucial role in transmitting information between neurons and from neurons to effector cells.
• They enable communication and coordination of different parts of the nervous system.

Question 11

Write the names of the five parts of the human brain with their functions.

Answer

Cerebrum:

• Responsible for conscious thought, memory, emotion, sensation, and voluntary movement.

Cerebellum:

• Coordinates and regulates muscle activity and balance.

Brainstem:

• Controls basic vital functions such as breathing, heart rate, and blood pressure.

Thalamus:

• Acts as a relay station for sensory information, directing it to the appropriate part of the cerebral cortex for further processing.

Hypothalamus:

• Regulates homeostasis by controlling body temperature, hunger, thirst, and hormone release.

Question 12

Distinguish between cerebrum and cerebellum.

Answer

Drawing based questions

Question 1

Draw a typical neuron and label it any six parts.

Answer

Question 2

Draw a typical simple disynaptic reflex arc and label its different parts. Show with the help of an arrow the direction of conduction of nerve impulses in the figure.

Answer

Question 3

Draw a simple reflex arc and label its Afferent neurone, Efferent neurone, Effector organ and Posterior root ganglion. Indicates the direction of conduction of stimulus with arrows.

Answer

Question 4

Draw a longitudinal/vertical section of human eye and label its different (six) parts.

Answer

Question 5

Draw a diagram of the structure of the human ear and label its different parts.

Answer

Question 6

Draw a neat diagram of a nephron and label the following parts: Bowman’s capsule; Glomerulus; Proximal convoluted tubule; Distal convoluted tubule; Henle’s loop and collecting tubule.

Answer

Question 7

Draw a neat diagram of a vertical section of human eye and label the following parts: cornea, lens, sclera, retina, pupil and yellow spot.

Answer