Neural Control And Coordination Notes PDF Download- FREE
Section–A (1 Mark Questions)
1. How many pairs of cranial nerves are present in man?
Ans. 12 pairs of cranial nerves are present in man.
2. Name the band of nerve fibres that joins the two cerebral hemispheres in mammals.
Ans. Corpus callosum is the band of nerve fibres that join the two cerebral hemispheres in mammals.
3. Rearrange the following in the correct order of involvement in electrical impulse movement- Synaptic knob, dendrites, cell body, Axon terminal, Axon.
Ans. Synaptic knob → Dendrites → Cell body → Axon → Axon terminal.
4. What is the function ascribed to Eustachian tube?
Ans. Eustachian tube carries extra sound in tympanic cavity to the pharynx. It is done to maintain optimum pressure around ear drum.
5. Name the fluid that surrounds and protects the brain.
Ans. Cerebrospinal fluid surrounds and protects the brain.
Section–B (2 Mark Questions)
6. Define neurotransmitter.
Ans. Neurotransmitter is a chemical substance that acts as a signalling molecule which is released at the end of nerve fibre. It diffuses across the synapse and transmits the impulse to the next neuron, muscle or other structure.
7. The flowchart given here shows functional organization of the human neural system.
Identify A to E.
Ans.
8. Complete the following paragraph by selecting the option that gives the correct sequence of words.
When a stimulus is applied at a site on the polarised membrane, the membrane at that site becomes freely permeable to __(i)__ ions. It causes rapid influx of __(ii)__ ions leading __(iii)__ of the membrane.
Ans. (i) Sodium ions.
(ii) Sodium ions
(iii) Depolarization
9. Answer the following:
(a) Which part of the human brain is the most developed?
(b) Which part of our central neural system acts as a master clock?
Ans. (a) Forebrain is the largest and the most developed part of the human brain.
(b) Hypothalamus acts as a master clock in the human body.
10. What happens when the membrane of a nerve cell carries out a sodium pump?
Ans. When the membrane of a nerve cell carries out a sodium pump, it transports 3 Na+ ions outwards and 2 K+ ions into the cell. As a result, the outer surface of the axonal membrane becomes a positively charge while its inner surface is negatively charged. It restores its resting membrane potential.
11. Name the meninges that surround the brain from outside to inside.
Ans. Dura mater
Arachnoid Layer
Pia mater
PDF Summary - Class 11 Biology Neural Control and Coordination Notes (Chapter 18)
Neural Control and Coordination
The interaction of two or more organs among each other and to complement each other’s function is known as coordination.
Neural System
The structural and functional units of the neural system are known as neurons. They can detect, receive, and transmit stimuli.
Human Nervous System
The classification of the nervous system is done into two types-
(i) central nervous system (CNS)
(ii) peripheral nervous system (PNS).
The brain and Spinal cord are the 2 parts of the Central nervous system whereas the peripheral nervous system is composed of all the nerves present in the brain and the spinal cord. The two types of nerve fibers present in PNS are-
(a) afferent nerve fibers or sensory nerve fiber
(b) efferent nerve fibers or motor nerve fiber
Impulses are carried from organs/tissues to the CNS in Afferent nerve fibers whereas, in efferent nerve fibers, impulses are transmitted from CNS to the target tissue/organ.
PNS Is Classified Into Two Types-
(i) somatic nervous system
(ii) autonomic nervous system.
Impulses are transmitted from the CNS to skeletal muscles in the somatic nervous system while the autonomic nervous system innervates cardiac and smooth muscles of the glands which transmit the impulses from the CNS to the involuntary part of the body. The classification of the autonomic nervous system is done into two types-
(i) sympathetic nervous system
(ii) parasympathetic nervous system
Structure and the Function of the Neuron
A neuron is the structural and functional unit of the nervous system. It comprises 3 parts-
(i) cell body
(ii) dendrites
(iii) axon.
The cell body is made up of cytoplasm that contains granular bodies called Nissl’s granules. Short, several, finger-like projections that arise from the cell body are called dendrites. Dendrites carry nerve impulses towards or into the cell body. Axon is a long, single structure whose distal end is branched. Each of the axons ends into a bulb-like structure known as the synaptic knob, which contains neurotransmitters. The cells of the axon which produce and cover the myelin sheath are known as Schwann cells. The interruption between the two-adjacent myelin sheath is known as Nodes of Ranvier.
Types of Neurons
Multipolar Neurons- Several processes arise in them, having one axon and many dendrites. For example, in the cerebral cortex.
Bipolar Neurons- They are the ones with one axon and one dendrite. For example, retina.
Unipolar Neurons- Unipolar neurons have only two fibers arising close together, i.e., one axon, no dendrite. For example, embryonic stage.
Generation and Conduction of Nerve Impulses
The cells which can be stimulated and electrically excited are called neurons. The membrane of the neurons is in a polarized state. The membrane contains selectively permeable ion channels with varying permeability to different ions. The membrane becomes more permeable to potassium ions and impermeable to sodium ions when no nerve impulse is being transmitted. This is the resting membrane potential. Therefore, there is a high concentration of potassium ions present in the membrane as compared to sodium ions. But, the case becomes opposite outside, high concentration of potassium in comparison to sodium. A concentration gradient gets developed due to the difference in the concentration of these ions. Sodium potassium pump helps in maintaining this gradient by actively transporting 3 sodium ions outside and 2 potassium ions inside the neuronal membrane. Thus, the outer surface of the axonal membrane possesses a positive charge and its inner surface becomes negatively charged. This is the reason behind the depolarization of the membrane. The membrane becomes freely permeable to sodium ions when a stimulus reaches a neuronal membrane. Thus, it will cause an influx of sodium ions inside the neuronal membrane. The inner side of the membrane becomes positively charged whereas outside the membrane is negatively charged due to this polarity. An electrical potential difference gets created called action potential.
The permeability of sodium ions decreases, and the permeability of potassium ions increases with time. In the axonal membrane, there is an efflux of sodium ions polarization which occurs from inside to outside. Again, the polarity is reversed. This sequence of events is repeated along the complete axon which helps in the conduction of the nerve impulse.
Transmission of Impulses
The transmission of the nerve impulse from one neuron to another neuron via junctions called synapses. Synapse is a junction connecting the membrane of pre-synaptic neuron and postsynaptic neuron separated by a gap known as the synaptic cleft.
Two Types of Synapses are There-
(i) Electrical synapse
(ii) Chemical synapse.
In an electrical synapse, there is proximity between pre-and post-synaptic neurons. There can be the direct flow of electric current from one neuron to another neuron. This mode of nerve impulse transmission is quicker than the chemical synapse.
In chemical synapses, pre-and post-synaptic neurons are separated by a fluid-filled space referred to as synaptic cleft. There are neurotransmitters involved in these synapses. There are axon terminals present which contain vesicles that are filled with neurotransmitters. By the time, the impulse reaches the axon terminal, synaptic vesicles start moving towards the membrane and fuse with it. This leads to the discharge of the neurotransmitters from the synaptic cleft. Now, the neurotransmitters bind with the receptors which are present on the post-synaptic neuron. Thus, ion channels get opened and it results in the transmission of fuse nerve impulses.
Central Nervous System
The brain controls and coordinates all the functions of the body thus, performing as a command and control system. The protection of the human brain is inside the skull. The covering of the brain is done in 3 layers known as meninges. They are-
(i) outermost dura mater,
(ii) middle arachnoid,
(iii) innermost pia mater.
The division of the brain is into:
(a) forebrain,
(b) midbrain,
(c) hindbrain.
The forebrain consists of 3 parts- cerebrum, thalamus, and hypothalamus. The cerebrum is considered to be the largest part of the brain. The division of the cerebrum into two halves is known as the left and right cerebral hemispheres. These hemispheres are joined by a great white central canal white commissure called the corpus callosum. The covering of cerebral hemispheres by a layer of cells is known as the cerebral cortex. The thalamus is the area present at the center of the forebrain. It is involved in sensory and motor signaling. Hypothalamus lies at the base of the thalamus. The urge for eating, drink, and body temperature is all controlled and regulated by it.
The location of the midbrain is in between the forebrain and hindbrain. There are 4 lobes present known as Corpora quadrigemina.
The parts of the hindbrain are- pons, cerebellum, and medulla oblongata. The cerebellum is considered to be the second-largest part of the brain. The medulla oblongata is placed between the spinal cord below and the pons above. The medulla controls gastric secretion, control respiration, and cardiovascular functions.
5 Important Topics of Biology Class 11 Chapter 18 You Shouldn’t Miss!
Importance of Class 11 Neural Control and Coordination Notes
Class 11 Biology Chapter 18 Notes break down difficult concepts like nerve impulse transmission, neuron structure, and brain functions into easy-to-understand explanations.
Visuals such as diagrams of neurons, synapses, and the brain help students visualise and retain information more effectively.
The notes are designed to cover key topics aligned with the CBSE syllabus, ensuring that students focus on the most important areas for their exams.
Neural Control And Coordination Class 11 Notes are organised systematically, allowing students to quickly review and revise the core concepts of the chapter.
Understanding neural control and coordination is fundamental for studying more advanced biology topics in higher education, and Neural Control And Coordination Notes lay a strong foundation for future learning.
Tips for Learning the Class 11 Biology Chapter 18 Neural Control and Coordination
Understand the Basics: Start by understanding the basic structure of neurons and how nerve impulses are transmitted. This forms the foundation for the entire chapter.
Use Diagrams for Better Retention: Study the diagrams of neurons, synapses, and the human brain to visually grasp the concepts. Labelling important parts will help in better retention.
Focus on Key Terms: Pay attention to important terms like synapse, neurotransmitters, reflex actions, and nerve impulse transmission. These are frequently asked in exams.
Break Down Complex Processes: Divide complex processes, like synaptic transmission or brain functioning, into smaller steps to make them easier to learn and remember.
Revise Regularly: Regular revision is essential. Go through summaries and key points to memorise what you've learned.
Conclusion
Neural Control And Coordination Class 11 Notes provide a clear and simplified understanding of how the human nervous system works. By covering important topics such as neuron structure, nerve impulse transmission, and the functions of the brain and spinal cord, these notes help students grasp the complexities of neural control. With detailed explanations and diagrams, students can easily revise key concepts and prepare well for exams. Neural Control And Coordination Notes not only strengthen the basics but also help students build a solid foundation for future studies in biology.
Related Study Materials for Class 11 Biology Chapter 18 Neural Control And Coordination
Students can also download additional study materials provided by Vedantu for Biology Class 11, Chapter 18–
Chapter-wise Class 11 Biology Notes PDF Download
Related Study Materials Links for Class 11 Biology
FAQs on Neural Control And Coordination Class 11 Notes: CBSE Biology Chapter 18
1. What is a neuron, and what are its main parts in Class 11 Biology Chapter 18 Notes?
A neuron is the structural and functional unit of the nervous system. It consists of three main parts: the cell body, dendrites, and axon.
2. What is the Difference Between Afferent and Efferent Neurons?
The afferent nerve fibres transmit impulses from tissues or organs to the CNS whereas the efferent fibres transmit from the CNS to the concerned to the peripheral tissues or organs.
3. What are neurotransmitters, and why are they important?
Neurotransmitters are chemical messengers that transmit signals across synapses between neurons. They are crucial for proper communication in the nervous system, with examples like acetylcholine and dopamine.
4. Name the Structure Involved in the Protection of the Brain.
The Skull well protects the brain. The cranial meninges cover the brain that consists of an outer layer called dura mater. Dura mater is a very thin middle layer called arachnoid and an inner layer called pia mater.
5. What are the three main parts of the brain?
The brain is one of the most important and complex organs of our body. Our skull protects this important organ. Three main parts of the brain are: Cerebrum, Hypothalamus and Thalamus. Out of these three cerebrum is the most important part of the brain. Hypothalamus controls various functions of our body such as the release of hormones. Thalamus is the part of the brain that transmits information received by our senses to the cortex.
6. What is the difference between the central neural system and the peripheral neural system?
The central neural system (CNS) comprises the brain and the spinal cord. On the other hand, the peripheral neural system (PNS) consists of the spinal and cranial nerves. There are no subdivisions in the CNS but the peripheral neural system is further subdivided into the autonomic nervous system and the somatic nervous system. PNS transmits impulses to the CNS which then processes the information and sends the responses to various parts of the body.
7. How to write good answers to score well in Chapter 18 of Class 11 Biology?
To score well in Chapter 18 of your Class 11 Biology exam, the most important thing is that the basics of this chapter must be strong and clear. Understand the pattern of the exam. Understand what the demand of the question is. Write your answer in simple language and use short sentences and appropriate terms. You should include appropriate diagrams, flow charts and tables in your answer. Make your answer look presentable and convey to the teacher that you know the concept.
8. How important is it to practice questions given in Class 11 Chapter 18?
Practising questions from Chapter 18 of Class 11 Biology provides you with an effective way to check your understanding. When you study a topic, you may forget it after some time, but if you practise the questions related to the topic, the information stays with you for a long time. Practising sufficient questions helps you find the right way to present your answers in the exam. It makes it easier for you to recall information in the exam and is an efficient way to revise what you have studied. To revise the chapter students can download the NCERT Notes for Class 11 Biology Chapter 18 FREE of cost from the Vedantu website (vedantu.com).
9. What is given in Class 11 Biology Chapter 18?
The chapter explains to you the neural system of animals and their coordination. The nervous system enables communication within our mind and body. The neural system helps us detect and respond to various stimuli. The chapter differentiates between the Central Neural System and the Peripheral Neural System. It explains the basic structure of the nervous system and the functions of the organs involved. It also teaches you how your sensory organs function. To revise the chapter and know more about it students can download the vedantu Website.
10. Why are Class 11 Neural Control and Coordination Notes important in Class 11 Biology?
Neural Control And Coordination Notes PDF Download lays the foundation for understanding the nervous system's role in coordinating various physiological processes, which is crucial for advanced studies in biology and medicine.
