Detailed explanations in West Bengal Board Class 10 Life Science Book Solutions Chapter 1D Response and Physical Coordination in Animal Nervous System offer valuable context and analysis.
WBBSE Class 10 Life Science Chapter 1D Question Answer – Response and Physical Coordination in Animal Nervous System
Short Answer Type Questions : 2 Marks
Question 1.
What do you mean by reflex action? Give examples of reflex actions?
Answer:
It is defined as fast, unconscious, immediate, automatic and involuntary response of the body (through effectors) to a stimulus. It is monitored through spinal cord.
Example of reflex actions :
- Closing eyes when bright light falls on the eyes
- Knee-jerk
- Withdraw hands when pricked by a pin
- Choking stimulates cough reflex
Question 2.
What are the different type of reflexes?
Answer:
There are two type of reflexes
1. Unconditioned reflexes
2. Conditioned reflexes
Unconditioned or Unconditional reflexes are those which are inherited. Our brain does not learn these reflexes. Eg. when we touch a hot plate, we immediately moves away our hand.
Conditioned reflexes are those which our brain has learned by repeating the action number of times. Eg. a typist is typing a letter without looking at the typewriter keys.
Question 3.
What is reflex are?
Answer:
The structural and functional unit that carries our reflex action is called a reflex arc. It consists of :
- A receptor
- Sensory nerve (afferent)
- Spinal cord and interneuron
- Motor nerve (efferent)
- Effector.
Question 4.
Which signals will get disrupted in case of a spinal cord injury?
Answer:
In case of a spinal cord injury, the signals coming from the nerves as well as the signals coming to the receptors will be disrupted. As both these signals meet in a bundle in spinal cord, so if there is any spinal cord injury then both these signals are disrupted.
Question 5.
What is myelinated nerve? What is Node of Ranvier?
Answer:
Node of Ranvier : At regular interval, the nerve fibre possesses constriction of neurilemma known as node of Ranvier.
Question 6.
What is a choroid? What is its function?
Answer:
Choroid is the middle layer of the eyeball, present just below the outer sclera and covers the 5/6th part of eyeball.
Function i. Prevents reflection as melanin is present.
ii. Supplies nutrients and oxygen as it contains blood vessels.
Question 7.
What is the difference between a reflex action and walking?
Answer:
| Reflex Action | Walking |
| i. A reflex action is an automatic and rapid (spontaneous) response to a stimulus. | i. Walking is a voluntary action. |
| ii. It is spontaneous reaction. Spinal cord is involved in it. | ii. It is a conscious and deliberate action i.e. it is done after a thought is processed by the brain. |
| iii. It does not involve any kind of thinking or feeling to control the reaction. | iii. It is the voluntary action that we have acquired through learning. |
| iv. Spinal cord is directly involved in it. | iv. It is directly controlled by hindbrain (cerebellum.) |
| v. When a bright light is focused on your eyes, we immediately close it. A knee-jerk are examples of reflex action. | v. Examples : Walking in a straight line, riding a bicycle, picking up a pencil (Voluntary actions and precision control). |
Question 8.
What happens at the synapse between two neurons?
Answer:
Synapse is a very small gap between the last portion of axon of one neuron and the dendron of the other neuron. It acts as a one way valve to transmit impulses. This is one directional flow of impulses because the chemicals are produced only on one side of the neuron i.e. the axon’s side. Via axon, the impulses travel across the synapse to the dendron of the other neuron.
Question 9.
How do we detect the smell of an agarbatti (incense stick)?
Answer:
The forebrain is the main thinking part of the brain. It has regions which receive sensory impulses from various receptors. Separate areas of the forebrain are specialised for hearing, smell, sight and so on. Olfactory receptors (present in nose) send the information about the smell of incense stick to forebrain. The forebrain interprets it along with information received from other receptors as well as with information that is already stored in the brain.
Question 10.
List the functions performed by Cerebrum.
Answer:
The cerebrum performs the following functions :
- It governs our mental abilities like thinking reasoning, learning, memorising etc.
- It controls our feelings, emotions and speech.
- It controls all involuntary functions.
Question 11.
What are the functions of cerebellum?
Answer:
- Maintains equilibrium or balance of the body.
- Coordinates muscular movement.
- Controls posture of the body.
Question 12.
How brain is protected inside a human body?
Answer:
Brain is protected by a bony box called cranium, within which are present 3 layers of fluid-filled (called cerebrospinal fluid) membranes (called menings) for absorbing shock and buoyancy.
Question 13.
What is the role of the brain in reflex action?
Answer:
Brain has no role to play in creation of reflex action response. Instead spinal cord is the control centre of a reflex action. In fact brain becomes aware after the reflex arc has been formed.
Question 14.
State the function of cerebellum?
Answer:
The function of cerebellum are :
i. It regulates tone, posture and equilibrium of the body.
ii. It controls muscular construction.
Question 15.
State the functions of hindbrain?
Answer:
The functions of hindbrain are :
- Pons-It controls micturition
- Cerebellum- It controls muscular construction.
- Medulla Oblongata- It controls respiration, heart rate and secretion of saliva.
Question 16.
What is binocular vision?
Answer:
In case of human with the help of binocular vision single object is observed by both the eyes together.
Question 17
What are the different Parts of forebrain?
Answer:
The different parts of forebrain are
cerebrum, thalamus, hypothalamus and epithalamus.
Question 18.
What is synapse? What is its function?
Answer:
A synapse is junctional region in nervous system where one neuron ends and another neuron begins.
Function : It is to conduct nerve impulse from one neuron to another neuron.
Question 19.
Write any one function of each of cerebrum, cerebellum and medulla oblongata?
Answer:
Functions :
- Cerebrum : It uses information from our senses to tell us what’s going on around us and tells our body how to respond.
- Cerebellum : It controls muscular construction.
- Medulla oblongate : It controls respiration, heart rate and secretion of saliva.
Question 20.
What is reflex arc?
Answer:
The complete neural path way involved in the phenomenon of reflex action is called reflex arc.
Question 21
What is blind spot?
Answer:
It is the spot where the optic nerve is joined on to the retina.
Question 22.
Write two difference between blind spot and yellow spot.
Answer:
| Yellow spot | Blind spot |
| i. Yellow spot is a particular area on the retina located almost at the centre of the horizontal axis of eye ball. | i. Blind spot is a particular disc like area within eyeball located just below the yellow spot. |
| ii. In contains cone cells and is the area of eye with best vision. | ii. It does not contain any photoreceptors and so image falling on it cannot be received. |
Question 23.
What is blind spot? Mention its function.
Answer:
Blind spot : A particular disc like area within the eyeball which is located just below the yellow spot and contains as photorecptors is called optic disc or blind spot.
Function : As there are no photoreceptors, image falling in this place cannot be received i.e. no vision takes place, hence the name blind spot.
Long Answer Type Questions : 5 Marks
Question 1.
Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Answer:
| Nervous System Mechanism | Hormonal Mechanism |
| i. It consists of nerve impulses between PNS, CNS and Brain | i. It consists of endocrine system which secretes hormones directly into blood. |
| ii. The axons and dendrites transmit the information through a coordinated effort. | ii. The information is transmitted or transported through blood. |
| iii. The flow of information is rapid and the response is quick. | iii. The information travels slowly and the response is slow. |
| iv. Nerve impulses are not specific in their action. | iv. Each hormone has specific actions. |
| v. Effects are short lived | v. It has prolonged effects. |
Question 2.
What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?
Answer:
| Movement in sensitive plants | Movement in our legs |
| i. The movement in a sensitive plant is a response to stimulus (touch) which is a involuntary action. | i. Movement in our legs is a voluntary action. |
| ii. No special tissue is there for the transfer of information. | ii. A complete system CNS and PNS is there for the information exchange. |
| iii. Plant cells do not have specialised protein for movements. | iii. Animal cells have specialised protein which help muscles to contract. |
Question 3.
What is the need for a system of control and coordination in an organism?
Answer:
There are various organs in an organism. These organs must be carefully controlled and coordinated for the survival of an organism. In the body of an organism various fluids are secreted from the glands of the endocrine system. These hormones are responsible for the overall growth and development of an organism. All other daily decisions that include voluntary and involuntary action are controlled by central nervous system(CNS).
Question 4.
How are involuntary actions and reflex actions different from each other?
Answer:
Involuntary action is the set of muscle movement which do not require thinking. But it is controlled by brain, for example-beating of heartbeat, while on the other hand, the reflex action is rapid and spontaneous action in response to any stimulus. For example closing of eyes immediately when bright light is focused.
Question 5.
Name the three parts of hindbrain. Write function of each.
Answer:
| Parts of hindbrain | One function of each |
| i. Cerebellum | It maintains muscle tone, equilibrium and body posture |
| ii. Pons | It maintains respiration, heart rate and blood pressure. |
| iii. Medulla Oblongata | It controls visceral reflexes. |
Question 6.
Which part of the brain is known as relay station?
Answer:
Thalamus is known as relay station because :
i. Thalamus acts as chief relay centre for all sensory impulses inferring the cerebrum.
ii. It is also the relay centre for motor impulses coming out of the cerebrum in the central nervous system.
Question 7.
Illustrate the classification of human nervous system through a table
Answer:
Question 8.
Mention two structural and one functional difference between axon and dendron.
Answer:
Question 9.
What is meninges? Mention two refractory media present in the eyeball. What is unconditioned reflex action. Give example.
Answer:
The three layered fibrous covering of the Central Nervous System (Brain and spinal cord) to called meninges.
Two refractory media of eyeball-cornea, lens.
Unconditional reflex action: The reflexes which are not acquired but present at the time of birth is called unconditioned reflex action.
Example : Removal of fingertip from hot object.
Question 10.
Mention the functions of pupil, retina and ear ossicles.
Answer:
| Functions | |
| Pupil | It allows light to enter the interior of the eye |
| Retina | Rod cells present in retina are responsible for dim light vision and cone cells are responsible for detail perception. |
| Ear ossicles | Conduct sound vibration from ear drum into the membrane of the oval window of the internal ear. |
Question 11.
Write four differences between cerebrum and cerebellum.
Answer:
| Cerebrum | Cerebellum |
| i. Largest part of forebrain. | i. Largest part of hindbrain |
| ii. Present at the top of brain stem | ii. Present at the posterior side of brain stem. |
| iii. Corpus collosum joins the two hemispheres. | iii. Vermis joins the two hemispheres |
| iv. Seat of intelligence, judgement, memory etc. | iv. Regulation posture and balance of the body. |
Question 12.
Difference between afferent and efferent nerves.
Answer:
| Afferent nerves | Efferent nerves |
| i. It conducts nerve impulse from recteptors to Central Nervous System. | i. It conducts nerve impulse from Central Nervous System to effector organs. |
| ii. It is generally made up of pseudo- unipolar nerves | ii. It is generally made up of multipolar nerves. |
| iii. Its dendrites are longer than axon. | iii. Its dendrites are smaller than axon. |
| iv. Axon exters CNS. e.g. Olfactory nerves |
iv. Axon emerges out of CNS. e.g. Hypoglossal nerves. |
Question 13.
What is the relationship between ‘neurotransmitter’ and ‘synapse’?
Answer:
Neurotransmitters are secreted from the synaptic vesicles of the presynaptic knob of a synapse. The impulse through the neurotransmitter passes within synaptic fluid and is received by the receptors present or the postsynaptic knob of that synapse. Three fore-neurotransmitters are transmitting the impulse through the synapse from one neuron to another.
Question 14.
What is reflex arc? Mention its different parts. What is ganglion?
Answer:
| Definition | Different Parts | |
| Reflex arc | Reflex arc is spontaneous involuntary (automatic) motor response due to sensory stimulus | Receptor Afferent or sensory neuron Centre Efferent or motor neuron. |
Ganglion : The group or collection of nerve cell bodies ensheathed by a connective tissue layer outside the Central Nervous System is called ganglion.
Question 15.
What is the difference between nerve fibre and ganglion? Write two functions of lacrimal gland.
Answer:
The difference between nerve fibre and ganglion is :
| Nerve fibre | Ganglion |
| i. The single long unbranched process which arises from the cell body is called nerve fibre. | i. The group or collection of nerve cell bodies ensheathed by a connective tissue layer present outside the central nervous system is called ganglion. |
Two functions of lacrymal gland:
i. It keeps the eye moist.
ii. It secretes lysozyme enzyme that destroys bacteria.
Question 16.
Mention two functions each of medulla oblongata and spinal cord. State the rule of yellow spot and iris in vision.
Answer:
Role of yellow spot and iris for vision :
Yellow spot : It helps movement of eyes from word to word as we read a line through a printed page. It occurs to focus particular word at the yellow spot for acute vision.
Iris : It acts as shutter and adjust the amount of light entering the eye.
Question 17.
What is reflex arc? State two differences between conditioned and unconditioned reflexes?
Answer:
An arc like neural path through which reflex action takes place is called reflex arc.
| Conditioned reflex | Unconditioned reflex |
| i. It is acquired after birth | i. It is present from the birth. |
| ii. Its path can be changed through practices. | ii. Its path cannot be changed. |
Question 18.
Mention types of reflex action of the following with reasons :
(a) Removal of fingertip from hot object, (b) closure of eyelid due to falling of dust particles, (c) Playing a musical instrument.
Answer:
(a) Removal of fingertip from hot object is unconditioned reflex because this reflex is inborn.
(b) Closure of eyelid due to falling of dust particles is unconditioned reflex because this reflex is inborn.
(c) Playing a musical instrument is a conditioned reflex because it is acquired after continuous training.
Question 19.
Compare corpus callosum and vermis.
Answer:
Comparison of corpus callosum and vermis according to similarities :
i. Corpus callosum and vermis both are broadband of fibres.
Comparison of corpus callosum and vermis according to dissimilarities :
Corpus Callosum :
ii. Joins two cerebral hemispheres
Vermis:
ii. Joins two hemispheres of cerebellum
Question 20.
Discuss the components a typical reflex are with diagram
Answer:
Receptor : It is a specialised sensory ending which is stimulated by the environmental changes.
Afferent or sensory neurons : It forms afferent limbs of the reflex path. It conducts impulse from receptor to the centre.
Centre : The grey matter of the Central Nervous System acts as centre. Hence, the afferent neuron makes the synaptic connection with efferent neurone directly or through internuncial neurons, thus forming synapse or synapses respectively. In the synapse the sensory impulse is converted into the motor impulse.
Efferent or motor neuron : It forms the efferent limbs of reflex path. It carries nerve impulse from centre to effector organs.
Effector organ or effector: The muscle or gland where the motor neurone ends is called effector (muscle or gland).
Long Answer Type Diagram : 5 Marks
Question 1.
Draw a diagram of buman eye.
Answer:
Question 2.
Explain in brief the structure of human eye.
Answer:
The orbit is the bony cavity that contains the eyeball, muscles, nerves, and blood vessels, as well as the structures that produce and drain tears. Each orbit is a pear-shaped structure that is formed by several bones.
The outer covering of the eyeball consists of a relatively tough, white layer called the sclera (or white of the eye). Near the front of the eye, in the area protected by the eyelids, the sclera is covered by a thin, transparent membrane (conjunctiva), which runs to the edge of the cornea. The conjunctiva also covers the moist back surface of the eyelids and eyeballs.
Light enters the eye through the cornea, the clear, curved layer in front of the iris and pupil. The cornea serves as a protective covering for the front of the eye and also helps focus light on the retina at the back of the eye. After passing through the cornea, light travels through the pupil (the black dot in the middle of the eye). The iris – the circular, colored area of the eye that surrounds the pupil – controls the amount of light that enters the eye.
The pupil dilates (enlarges) and constricts (shrinks) like the aperture of a camera lens as the amount of light in the immediate surroundings changes. The iris allows more light into the eye when the environment is dark and allows less light into the eye when the environment is bright. The size of the pupil is controlled by the action of the pupillary sphincter muscle and dilator muscle. Behind the iris sits the lens. By changing its shape, the lens focuses light into the retina. Through the action of small muscles (called the ciliary muscles), the lens becomes thicker to focus on nearby objects and thinner to focus on distant objects.
The retina contains the cells that sense light (photoreceptors) and the blood vessels that nourish them. The most sensitive part of the retina is a small area called the macula, which has millions of tightly packed photoreceptors (the type called cones). The high density of cones in the macula makes the visual image detailed, just as a high-resolution digital camera has more megapixels. Each photoreceptor is linked to a nerve fibre. The nerve fibres from the photoreceptors are bundled together to form the optic nerve. The optic disk, the first pair of the optic nerve, is at the back of the eye. The photoreceptors in the retina convert the image into electrical signals, which are carried to the brain by the optic nerve.
There are two main types of photoreceptors: cones and rods. Cones are responsible for sharp, detailed central vision and color vision and are clustered mainly in the macula. The rods are responsible for night and peripheral (side) vision. Rods are more numerous than cones and much more sensitive to light, but they do not register color or contribute to detailed central vision as the cones do. Rods are grouped mainly in the peripheral areas of the retina.
Question 3.
Draw the synaptic region.
Answer:
Question 4.
Write in a tabular form the different parts of human brain with function.
Answer:
Question 5.
Write about the functional differences between sympathetic and parasympathetic nervous system.
Answer:
Question 6.
Differentiate the structural differences between sympathetic and parasympathetic nervous system.
Answer:
Multiple Choice Questions : 1 Mark
Question 1.
The brain is responsible for .
(a) thinking
(b) regulating the heartbeat
(c) balancing the body
(d) all of the these
Answer:
(d) all of the these
Question 2.
The gap between two neurons is called a
(a) dendrite
(b) synapse
(c) axon
(d) impulse.
Answer:
(b) synapse
Question 3.
The seat of intelligence and voluntary action in the brain is
(a) Diencephalon
(b) Cerebrum
(c) Cerebellum
(d) Medulla Oblongata
Answer:
(b) Cerebrum
Question 4.
The activities of the internal organs are controlled by the
(a) Central Nervous System
(b) Peripheral Nervous System
(c) Autonomic Nervous System
(d) None of these
Answer:
(c) Autonomic Nervous System
Question 5.
Part of brain that controls respiration, heartbeat and peristalsis is
(a) Cerebrum
(b) Cerebellum
(c) Pons
(d) Medulla
Answer:
(d) Medulla
Question 6.
Which body organ is surrounded by meninges?
(a) Heart and Lungs
(b) Brain and Heart
(c) Brain and Spinal Cord
(d) Spinal Cord and Lungs
Answer:
(c) Brain and Spinal Cord
Question 7.
Part of brain that controls muscular coordination is –
(a) Cerebrum
(b) Cerebellum
(c) Pons
(d) Medulla
Answer:
(b) Cerebellum
Question 8.
Which part of the brain controls the posture and balance of the body?
(a) Cerebrum
(b) Cerebellum
(c) Pons
(d) Medulla
Answer:
(b) Cerebellum
Question 9.
Which of the following is not found in the central nervous system?
(a) Brain Stem
(b) Spinal Cord
(c) Sensory Neurons
(d) Cerebrum
Answer:
(c) Sensory Neurons
Question 10.
Look at the diagram below. What is the arrow pointing to?
Answer:
(c) Brain Stem
Question 11.
Two lobes of cerebral hemispheres are connected by
(a) vermis
(b) corpora quadrigemina
(c) corpus striatum
(d) corpus callosum
Answer:
(d) corpus callosum
Question 12.
Which of the following would be controlled by the cerebrum?
(a) Balance
(b) Breathing
(c) Remembering answers for a test
Answer:
(c) Remembering answers for a test
Question 13.
Why are brain stem injuries so serious?
(a) The brain stem stores your memories
(b) The brain stem controls your breathing.
(c) The brain stem gives you personality.
Answer:
(b) The brain stem controls your breathing.
Question 14.
How do the Peripheral Nervous System and the Central Nervous System differ?
(a) Only the PNS is made up of neurons
(b) The PNS stores our memories, the CNS does not
(c) The PNS receives sensory information from the outside world; the CNS interprets that information.
Answer:
(c) The PNS receives sensory information from the outside world; the CNS interprets that information.
Question 15.
Which system are the nerves in your fingers a part of?
(a) CNS
(b) PNS
(c) None
Answer:
(b) PNS
Question 16.
The peripheral nervous system allows you to
(a) Touch
(b) Smell
(c) Both of these
Answer:
(c) Both of these
Question 17.
Which of the following is one of the senses?
(a) Taste
(b) Sight
(c) Both of the these
Answer:
(c) Both of the these
Question 18.
What is it called when you pull your hand quickly away from a hot stove when you have accidentally touched it?
(a) Smart
(b) Reflex
(c) Cerebro impulse
Answer:
(b) Reflex
Question 19.
How does a reflex reaction differ from other types of reactions?
(a) Reflexes are not responded to by our brain, only our spinal cord
(b) Reflex reactions are carefully thought out in our cerebrum.
(c) The spinal cord is not involved.
Answer:
(a) Reflexes are not responded to by our brain, only our spinal cord
Question 20.
What does the iris of the eye do?
(a) It expands and contracts to allow different amounts of light in
(b) It sends the picture to the brain.
(c) It contains cones and rods to help create pictures of what we see.
Answer:
(a) It expands and contracts to allow different amounts of light in
Question 21.
Where does light enter first when it goes into the eye?
(a) optic nerve
(b) cornea
(c) retina
Answer:
(b) cornea
Question 22.
Which of the following best describes the autonomic nervous system?
(a) In general, these are the motor nerves that we control.
(b) These nerves are not under our control.
(c) They are the same as somatic nerves.
Answer:
(b) These nerves are not under our control.
Question 23.
Which of the following could be said about a neuron?
(a) A bundle of them together make up a nerve.
(b) Neurons transmit messages along their axons to the next neuron.
(c) Both of the above.
Answer:
(c) Both of the above.
Question 24.
Which of the following is the function a neuron?
(a) It is a sticky substance that protects the brain
(b) It surrounds the axons of many neurons to help transmit messages.
(c) It carries O2
(d) It supplies nutrient to brain.
Answer:
(b) It surrounds the axons of many neurons to help transmit messages.
Question 25.
Which of the following diseases attacks the myelin sheath of cells?
(a) Huntington’s disease
(b) Multiple sclerosis
(c) Arthritis
Answer:
(b) Multiple sclerosis
Question 26.
What are some possible symptoms of MS?
(a) Numbness
(b) Inability to walk for certain periods of time
(c) Both of the above
Answer:
(c) Both of the above
Question 27.
Which of the following is not found in the central nervous system?
(a) Cerebrum
(b) Brain Stem
(c) Spinal Cord
(d) Sensory Neurons
Answer:
(d) Sensory Neurons
Question 28.
Look at the diagram below. What is the arrow pointing to?
Answer:
(b) Cerebellum
Question 29.
Which of the following would be controlled primarily by the cerebrum?
(a) Balance
(b) Breathing
(c) Remembering answers for a test
(d) Reflexes
Answer:
(c) Remembering answers for a test
Question 30.
Why are brain stem injuries so serious?
(a) The brain stem stores your memories
(b) The brain stem controls your breathing.
(c) The brain stem gives you personality
(d) Brain stem injuries are extremely painful.
Answer:
(b) The brain stem controls your breathing.
Question 31.
We read a story about Phineas Gage. He was the man who had the large metal rod jammed through his face and the front part of his skull. Why do doctors think his personality changed so dramatically?
(a) His cerebrum was injured
(b) His cerebellum was damaged.
(c) His brain stem was severed.
(d) He lost his sense of sight.
Answer:
(a) His cerebrum was injured
Question 32.
How do the Peripheral nervous system and the Central Nervous System differ?
(a) Only the PNS is made up of neurons
(b) The CNS receives sensory information from the outside world; the PNS does not
(c) The PNS stores our memories, the CNS does not
(d) The PNS receives sensory information from the outside world; the CNS interprets that information.
Answer:
(d) The PNS receives sensory information from the outside world; the CNS interprets that information.
Question 33.
Name the system whose nerves are part of our fingers
(a) CNS
(b) PNS
(c) Immune system
(d) None
Answer:
(b) PNS
Question 34.
The peripheral nervous system allows you to
(a) Taste
(b) Touch
(c) Smell
(d) All of these
Answer:
(d) All of these
Question 35.
Which of the following has nerves that are part of the PNS?
(a) Brain
(b) Spinal Cord
(c) Skin
(d) Cerebellum
Answer:
(c) Skin
Question 36.
What is it called when you pull your hand quickly away from a hot stove when you have accidentally touched it?
(a) Smart
(b) Reflex
(c) Cerebro impulse
(d) None of these
Answer:
(b) Reflex
Question 37.
How does a reflex reaction differ from other types of reactions?
(a) Reflexes are not responded to by our brain, only our spinal cord.
(b) Reflex reactions are carefully thought out in our cerebrum.
(c) The spinal cord is not involved.
(d) B and C only.
Answer:
(a) Reflexes are not responded to by our brain, only our spinal cord.
Question 38.
What does the iris of the eye do?
(a) It expands and contracts to allow different amounts of light in
(b) It sends the picture to the brain
(c) It protects the eye from injury.
(d) It contains cones and rods to help create pictures of what we see.
Answer:
(a) It expands and contracts to allow different amounts of light in
Question 39.
Label the following arrows in the diagram of cross section of human eye?
Answer:
(b) Ligament
Question 40.
Which of the following is the correct path of light travelling into the eye?
(a) lens, cornea, retina, pupil, optic nerve
(b) cornea, optic nerve, pupil, retina, lens
(c) cornea, pupil, lens, retina, optic nerve
(d) retina, pupil, cornea, optic nerve, lens
Answer:
(c) cornea, pupil, lens, retina, optic nerve
Question 41.
Which of the following best describes the autonomic nervous system?
(a) It is the same as a reflex:
(b) In general, these are the motor nerves that we control
(c) These nerves are not under our control
(d) They are the same as somatic nerves.
Answer:
(c) These nerves are not under our control
Question 42.
Which of the following could be said about a neuron?
(a) It is the smallest functioning unit of the nervous system
(b) A bundle of them together make up a nerve
(c) Neurons transmit messages along their axons to the next neuron
(d) All of these
Answer:
(a) It is the smallest functioning unit of the nervous system
Question 43.
Which structure is labelled with the letter “X” in the following diagram?
(a) Dendrite
(b) Axon
(c) Synapse
(d) Neurotransmitter
Answer:
(d) Neurotransmitter
Question 44.
Myelin sheath is important because
(a) It is a sticky substance that protects the brain
(b) It surrounds the axons of many neurons to help transmit messages.
(c) It is the name of the man who had the first MRI.
(d) It is the same as a reflex reaction.
Answer:
(b) It surrounds the axons of many neurons to help transmit messages.
Question 45.
Which of the following diseases attacks the myelin sheath of cells?
(a) Huntington’s disease
(b) Multiple sclerosis
(c) Arthritis
(d) Sarin Gas
Answer:
(b) Multiple sclerosis
Question 46.
What are some possible symptoms of MS?
(a) Vertigo
(b) Numbness
(c) Inability to walk for certain periods of time.
(d) All of these
Answer:
(d) All of these
Very Short Answer Type Questions : 1 Mark
Question 1.
Which is the largest and most prominent part of the brain?
Answer:
Cerebrum.
Question 2.
Which part of the brain maintains posture and equilibrium of the body?
Answer:
Cerebellum
Question 3.
What is schwann cell?
Answer:
Membrane of a cell that surrounds the axolemma or myelin sheath of nerve fibre is called schwann sheath. The sheath contain cells at regular interval known as schwann cell.
Question 4.
What is the other name of long sightedness?
Answer:
Hyperopia
Question 5.
What is the other name of forebrain?
Answer:
Hypothalamus.
Question 6.
Name the part that joins brain and spinal cord?
Answer:
Medulla Oblongata
Question 7.
The following is a motor nerve.
Answer:
Oculomotor
Question 8.
The Part of brain that is joining it with spinal cord is –
Answer:
Medulla
Question 9.
Short Sightedness is also called
Answer:
Myopia
Question 10.
Where is node at ranvier located?
Answer:
Myelinated axon
Question 11.
Where is pupil situated?
Answer:
Iris
Question 12.
The balance organ of brain is
Answer:
Cerebellum
Question 13.
Cerebrum is the part of
Answer:
Forebrain
Question 14.
Where is image formed in eye?
Answer:
Retina
Question 15.
Which of the following is associated with schwann cell?
Answer:
Cell and body
Question 16.
Name the structure on which image is formed in the eye.
Answer:
Retina
Question 17.
Name the main part of CNS?
Answer:
Brain and spinal cord
Question 18.
Shape of lens of human eye –
Answer:
Convex
Question 19.
What is Corpus Callosum?
Answer:
Corpus callosum is a broad band of fibres which connects to cerebral hemispheres.
Question 20.
What is neurofibril?
Answer:
Neurofibrils are very fine filaments which are through the cell body from the dendrites to the axon (also present in axon and dendrites.)
Question 21.
The first pair of cranial nerve is –
Answer:
Olfactory nerve.
Question 22.
State one function of Iris.
Answer:
The Iris acts as shutter and adjusts the amount of light entering the eye.
Question 23.
In human, the number of spinal nerves is –
Answer:
31 pairs.
Question 24.
Where is vitreous humor located? What is its function?
Answer:
It is present in the compartment behind the lens.
Its function is refraction of light rays, maintenance of eyeball pressure.
Question 25.
The part of the body concerned with balance in human is –
Answer:
Cerebellum
Question 26.
Name the enzyme present in tear and state its function.
Answer:
Enzyme present in tear is Lysozyme.
It destroys bacteria.
Question 27.
The black pigmented tunic of human eye is –
Answer:
Choroid
Question 28.
What type of reflex will it be conditioned or unconditioned, where saliva is secreted due to chewing the food?
Answer:
Unconditioned reflex.
Question 29.
The region of human brain that regulates ‘body balance’ is
Answer:
cerebellum
Question 30.
Name the tenth cranial nerve.
Answer:
Tenth cranial nerve is Vagus.
Question 31.
Name the tissue that connects the lobes of the cerebellum.
Answer:
The tissue that connects the lobes of the cerebellum is vermis.
Question 32.
Name the fully like fluid present in the compartment of the eye.
Answer:
Vitreous humor.
Question 33.
Which chemical matter transmits nerve impulse from one neuron to another?
Answer:
Neurotronsmitter (eg. acetylcholine)
Question 34.
What is lacrimal gland?
Answer:
Lacrimal gland : At the upper and outer border of each eye, there is an almond shaped gland, known as lacrimal gland.
True and False :
1. The central nervous system is made up of the cerebrum, cerebellum, brain stem and spinal cord. [ ]
2. The cerebrum is part of the spinal cord. [ ]
3. The cerebellum is also called the “higher brain.” [ ]
4. The brain stem stores all of our memories. [ ]
5. A concussion is a bruise on the brain. [ ]
6. Injury to the brain may cause personality change. [ ]
7. Our senses are not a part of the Peripheral Nervous System. [ ]
8. Neurons look exactly like other body cells. [ ]
9. Nerve agents affect people in many different ways. [ ]
10. Damage to the nervous system is always the result of injury. [ ]
11. Multiple Sclerosis is a disease that affects the nervous system. [ ]
12. PNS stands for “Peripheral Nervous System” [ ]
13. The cerebellum helps to control our muscles and our balance. [ ]
14. Reflex actions happen slower than other types of reactions. [ ]
15. Nothing can be done to prevent concussion. [ ]
Answer:
1. True
2. False
3. False
4. False
5. True
6. True
7. False
8. False
9. True
10. False
11. True
12. True
13. True
14. False
15. False
Fill in the blanks :
1. ______ and ______ are two of the five senses.
2. The brain and spinal cord make up the ______ nervous system.
3. The space between two neurons is called the ________
4. Name three things that can cause damage in the nervous system _______, _______
5. _______ is the substance passed between two neurons.
6. Myelin sheath helps neurons to conduct messages ______
Answer:
1. sight, hearing
2 . central
3. synapse
4 . injury, chemicals, diseases
5. Neurotransmitter
6 . quickly