![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/KSEEB-Solutions.png\")
<\/p>\nQuestion 1.
\nExpand CSF.
\nAnswer:
\nCerebro Spinal Fluid.<\/p>\n
<\/p>\n
Question 2.
\nName tie disorder characterised by the loss of motor function in human.
\nAnswer:
\nParalysis.<\/p>\n
Question 3.
\nName-the part of human brain concerned with homeostatic functions.
\nAnswer:
\nCerebellum<\/p>\n
Question 4.
\nWhich part of CNS is concerned with reflex action?
\nAnswer:
\nAM, Medulla oblong and spinal cord.<\/p>\n
<\/p>\n
Question 5.
\nMention the arrungeetestt of grey matter and white matter in the spinal cord.
\nAnswer:
\nIn the spinal cord there will be inner grey matter and outer white matter.<\/p>\n
Question 1.
\nDraw a neat labelled diagram of T.S. of spinal cord.
\nAnswer:
\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-21-Neural-Control-and-Coordination-4.4.png\")
<\/p>\n
Question 2.
\nDescribe the structure of cerebellum.
\nAnswer:
\nIt consists of two lateral halves called cerebellar hemispheres. They are joined together by an elongated worm like median structure called vermis. The cortex, or the thin surface of the cerebellum consists of grey matter. Its surface is heavily folded and pleated and the folds are Called folia. It encloses white matter called cerebellar medulla which resemble a tree, called arbor vitae.<\/p>\n
<\/p>\n
Question 3. These ionic gradients across the membrane, are maintained by the active transport of ions by the sodium-potassium pump, which transports three Na outwards and two K+<\/sup> inwards. So the outer surface of the axonal membrane has a positive ch\u00e1rge and the inner surface of the membrane elaxoplasm is negatively charged the membrane is said to be polarised.<\/p>\n Action Potential: As a result, there is a rapid inflow of Na ions and there is a reversal in the polarity of the membrane. The potential difference across the membrane at the site of stimulation is known as action potential. Question 4. (b) Most neurons have a cell body, an axon, and dendrites. The cell body contains the nucleus and cytoplasm. The axon extends from the cell body and often gives rise to many smaller branches before ending at nerve terminals. Dendrites extend from the neuron cell body and receive messages from other neurons.<\/p>\n (c) The thalamus also plays an important role in regulating states of sleep and wakefulness. … The hypothalamus controls body temperature, hunger, thirst, fatigue, sleep, and circadian cycles. The epithalamus functions as a connection between the limbic system and other parts of the brain.<\/p>\n (d) The cerebellum makes up the remaining part of the brain. The cerebrum controls voluntary movement, intelligence and memory.<\/p>\n Question 6. Question 7. Question 8. Question 1. (b) Conduction of nerve impulse occurs due to the presence of active and electronic potentials along the conductors. Transmission of signals internally between the cells is achieved through a synapse. The ionic currents pass through the two cell membrane when the action potential reaches the stage of such synapse.<\/p>\n (c) At chemical synapses, impulses are transmitted by the release of neurotransmitters from the axon terminal of the presynaptic cell into the synaptic cleft. … Multiple cytosolic proteins including synapsin recruit synaptic vesicles to the active zone of the plasma membrane adjacent to the synaptic cleft.<\/p>\n Question 1. (ii) Axon : Axon is the elongated branch originating from a region called Axon hillock. The axon gives off branches at the end, called telodendria. Usually axon is covered by a continuous sheath called myelin sheath or medullary sheath. Schwann cells are present which are called neurilemma. This layer of Schwann Cells shows number of constrictions. These constrictions are called Nodes of Ranvier.<\/p>\n Question 2. Question 3. Cross section of spinal cord shows outer white matter and inner grey matter. White matter comprises of nerve fibres and grey matter comprises of cell bodies. Grey matter covers a central canal and appears in the form of letter H. In spinal cord there is a prominent cleft in the ventral side called ventral fissure. Similarly there is a thin separating line on the dorsal side called dorsal sulcus.<\/p>\n 31 pairs of spinal nerves arise from the spinal cord. Each nerve is formed by the junction of two roots. The dorsal root is little swollen and comprises sensory nerve fibre and the ventral root consists of motor nerve fibres. Within this spinal cord the dorsal and ventral roots are connected by adjustor neurons.<\/p>\n Question 4. Human brain comprises of about 1000 billion neurons and is divisible into, Fore Brain : Fore brain comprises of cerebrum, diencephalon, (thalamus and hypothalamus) and olfactory lobes.<\/p>\n Cerebrum : It is the largest part of the brain. It consists of two hemispheres. Cerebral cortex is chiefly composed of cell bodies (cyton) of the neurons and is called grey matter, whereas cerebral medulla is chiefly composed of nerve fibres and is the seat of intelligence. Surface of the cerebral cortex shows number of folds and deep grooves . Folds of the cerebral cortex are called \u2018gyri\u2019 and the deep grooves are called \u2018fissures\u2019. Cerebrum also shows shallow furrows termed as \u2018sulci\u2019. These fissures divide each cerebral hemisphere into five lobes, namely.<\/p>\n (i) Frontal lobe : It is the largest of the four lobes making up the anterior one third of each hemisphere. Diencephalon : Diencephalon is the part of a fore brain which connects the cerebrum with mid brain. Diencephalon comprises of thalamus and hypothalamus.<\/p>\n (i) Thalamus : It is the region of diencephalon which receives all the sensory stimuli and relays them to different areas of the cerebral cortex.<\/p>\n (ii) Hypothalamus : It is the region of the diencephalon found below the thalamus. It is associated with pituitary and pineal glands (pineal gland secretes the hormone melatonin). A stalk like infundibulum connects it with the pituitary gland, it controls various metabolic activities like regulation of the heart beat, regulation of body temperature, regulation of sleep, B.P, water electrolyte balance, etc.<\/p>\n Optic chiasma : Just below the hypothalamus there is a region at which the optic nerves cross each other. This region is called optic chiasma.<\/p>\n Olfactory lobes : These are extended part of the frontal lobes. They are olfaction in function and are poorly developed in human beings.<\/p>\n Mid Brain : It comprises of cerebral peduncles and corpora quadrigemina. Cerebral peduncles connect brain stem (midbrain, pons and medulla oblongata) with the cerebrum, where as corpora quadrigemina extend as optic lobes. These are centers for visual and auditory reflexes.<\/p>\n Hind Brain : Hind brain comprises of cerebellum, pons varoli and medulla oblongata.<\/p>\n Cerebellum : It is the first part of hind brain, and also the second largest part of the brain. It has two lobes. Cerebellum is concerned with co-ordination and smoothness of movement. It helps to maintain body balance and co-ordinated speech.<\/p>\n Medulla oblongata : It is the last part of the hind brain which posteriorly continues as spinal cord. It controls respiratory activities, dilation of blood vessels (It initiates impulses that cause constriction and dilation of the blood vessels), reflexes such as sneezing, coughing, vomitting and winking. Medulla oblongata also has control over heart beat and secretory activities of the alimentary canal.<\/p>\n Pons varoli: It is the bundle of nerve fibres situated between midbrain and medulla oblongata. It also bridges two lobes of the cerebellum. It regulates respiration.<\/p>\n Different parts of the brain contain inner spaces. These inner spaces of the brain are called ventricles. They are filled with Cerebro Spinal Fluid (CSF). The first and second ventricles are in the hemispheres of the cerebrum. Third one in the diencephalon and fourth in the medulla oblongata.<\/p>\n Question 5. (b) 1. Coordination:<\/p>\n 2. Neural System in animals:<\/p>\n 3. Human Neural System: Nervous system Consists ofNeurons (Structural and functional unit of Nervous wste cells and Nerve fibers. It helps in the reception of stimuli, transmission of impulse and storage of memory and information.<\/p>\n Structurally, r.iervous system is divided into 2 types. Namely, 2. Peripheral Nervous System (PNS): This includes 31 pairs of spinal nerves and 12 pair of cranial herves. Cranial nerves carry impulses to and the from the brain. Spinal nerves carry impulses to and from the spinal cord. PNS is further divided into two parts, depending on the direction in which they carry impulses.<\/p>\n a. Afferent (Sensory) System : Consists of the sensory nerve pathways, which carry information from the receptors distributed all over the body, towards the central nervous system.<\/p>\n b. Efferent (Motor) system : Consists of the motor nerve pathways, which carry information away from the central nervous system to the motor organ, namely muscles and glands.<\/p>\n The motor system is further divided into two:- ii. Autonomic Nervous System : They cany information to the smooth cardiac muscles and glands. This system is said to be involuntary [They work independently] and is of two types.<\/p>\n (a) Sympathetic Nervous System: This prepares an individual to overcome emergency situations involving fear, fight and fright.<\/p>\n (b) Parasympathetic Nervous System: It prepares an individual during normal conditions (non-emergency situations). It works antagonistically to sympathetic nervous system.<\/p>\n 4. Types of Neurons:<\/p>\n 5. Structure of Neurons:<\/p>\n 6. Generation And Conduction Of Nerve Impulses:<\/p>\n (i) Resting Membrane Potential: So the axoplasm (interior) of the axon has a high concentration of negatively charged proteins, Cl–<\/sup> ions and potassium ions but a low concentration of Na+<\/sup> ions.<\/p>\n Contrary to this, the extracellular fluid (exterior) has a high concentration of Na+<\/sup> ions and low concentration of K+<\/sup> ions.<\/p>\n These ionic gradients across the membrane, are maintained by the active transport of ions by the sodium-potassium pump, which transports three Na+<\/sup> outwards and two K inwards.<\/p>\n – So the outer surface of the axonal membrane has a positive charge and the inner surface of the membrane\/axoplasm is negatively charged the membrane is said to be polarised.<\/p>\n (ii) Action Potential: As a result, there is a rapid inflow of Na+<\/sup> ions and there is a reversal in the polarity of the membrane. The potential difference across the membrane at the site of stimulation is known as action potential. (iii) Repolarisation Withm a fraction of a second, K+<\/sup> diffuses outside and restores the resting potential of the membrane at the tike site of excitation.<\/p>\n At this stags, the membrane is said to be repolarised, the next polarised region and through the ECF from Use polarised region to the depolarised region.<\/p>\n As a result, the action potential is generated in the next segment and this process continues along the length of the nerve fibre.<\/p>\n 7. Transmission Of Impulses Across The Synapse: Electrical Synapses: Chemical Synapses: In the chemical synapses, the axon terminal called synaptic knob contains a number of synaptic vesicles in its axoplasm.<\/p>\n The synaptic vesicles contain the neurotransmitter.<\/p>\n When an impulse arrives at the axon terminal, it stimulates the movement of the synaptic vesicles towards the membrane, where they fuse with the membrane and release the neurotransmitter into the synaptic cleft. This binding stimulates the opening of ion channels that can generate the action potential in the postsynaptic neuron.<\/p>\n 8. The Human Brain:<\/p>\n The brain can be differentiated into three regions-fore brain, mid brain and hindbrain. 1. Fore Brain (Prosencephalon):<\/p>\n Cerebrum: It is the largest part of the human brain and is called greater brain. The cerebrum is divided into right and left cerebral hemispheres by longitudinal fissures. However, they are internally connected by a thick bundle of nerve fibres called corpus callosum. Extension of the duramater called Flax cerebri separates the two hemispheres of cerebrum.<\/p>\n The substance of the cerebrum can be divided into an outer cerebral cortex and an inner cerebral medulla. Cerebral cortex is packed with cell bodies and dendrites of neurons. It forms the grey matter of brain. Cerebral medulla consists of myelinated nerve fibres. It forms the white matter. Functions: Functions: II. Mid Brain (Mecencephalon): Functions: 1. Cerebellum :<\/p>\n Functions : Functions : Functions : Note: Mid brain, ponsveroli and medulla oblongata together form brain stem. Functions : It involves following components. Note : There are 12 pairs of cranial nerves and 31 pairs of spinal nerves in human.<\/p>\n Karnataka 1st PUC Biology Question Bank Chapter 21 Neural Control and Coordination 1st PUC Biology Locomotion and Movement One Marks Questions and Answers Question 1. Expand CSF. Answer: Cerebro Spinal Fluid. Question 2. Name tie disorder characterised by the loss of motor function in human. Answer: Paralysis. Question 3. Name-the part of human brain concerned …<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/88631"}],"collection":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/comments?post=88631"}],"version-history":[{"count":0,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/88631\/revisions"}],"wp:attachment":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/media?parent=88631"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/categories?post=88631"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/tags?post=88631"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nCompare the following:
\n(a) Central neural system (CNS) and Peripheral neural system (PNS).
\n(b) Resting potential and action potential.
\nAnswer:
\n(a) Central Nervous System (CNS): This includes brain and the spinal cord.
\n(b) (i) Resting Membrane Potential:
\nAt the resting stage i.e., when the neuron is not involved in the conduction of impulses, the membrane of neuron is more permeable to K+<\/sup> ions than to Na+<\/sup> ions. The membrane is impermeable to the negatively charged proteins of the axoplasm and also Cl–<\/sup> ions. So the axoplasm (interior) of the axon has a high concentration of negatively charged proteins, Cl–<\/sup> ions and potassium ions but a low concentration of Na ions. Contrary to this, the extracellular fluid (exterior) has a high concentration of Na ions and low concentration of K+<\/sup> ions.<\/p>\n
\nWhen a thrishold stimulus is applied at a site on the polarised membrane, the membrane permeability at that site changes and becomes freely permeable to Na+<\/sup> ions.<\/p>\n
\nThe interior\/axoplasm now becomes positively charged while the exterior becomes negatively charged and this is called depolarisation.<\/p>\n<\/p>\n
\nNow the current flows through the axoplasm from the depolarised region to the depolarised region.
\nAs a result the action potential is generated in the next segment and this process continues along the length of the nerve fibre.<\/p>\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-21-Neural-Control-and-Coordination-3.3.png\")
<\/p>\n
\nDifferentiate between:
\n(a) Myelinated and non-myelinated axons.
\n(b) Dendrites and axons.
\n(c) Thalamus and Hypothalamus.
\n(d) Cerebrum and Cerebellum.
\nAnswer:
\n(a) Thus there are a variety of differences between the myelinated and non- myelinated axons that impacts the transfer of nerve impulses.<\/p>\n<\/p>\n
\nAnswer the following:
\n(a) Which part of the human brain is the most developed?
\n(b) Which part of our central neural system acts as a master clock?
\nAnswer:
\n(a) Cerebrum
\n(b) Pineal gland.<\/p>\n
\nDistinguish between:
\n(a) Afferent neurons and efferent neurons.
\nAnswer:
\n(a) Afferent neurons carry signals to the brain and spinal cord as sensory data. … This neuron’s response is to send an impulse through the central nervous system. Efferent neurons are motor nerves. These are motor neurons carrying neural impulses away from the central nervous system and toward muscles to cause movement.<\/p>\n
\nWrite short notes on the following: [ Two marks each].
\n(a) Forebrain.
\n(b) Midbrain.
\n(c) Hindbrain.
\n(d) Synapse.
\nAnswer:
\n(a) Fore Brain (Procencephalon): Includes cerebrum and diencephalon (Thalamus and Hypothalamus)
\n(b) Mid Brain (Mecencephalon): It is a highly reduced part in human.
\n(c) Hindbrain (Rhombencephalon): It includes cerebellum, ponsveroli and medulla oblongata (Stalk of the brain).
\n(d) A synapse is the functIonal junction between two neurons, formed by the membranes of a pre-synaptic neuron and a post-synaptic neuron.<\/p>\n1st PUC Biology Locomotion and Movement Three Marks Questions and Answers<\/h3>\n
\nExplain the following processes:
\n(a) Depolarisation of the membrane of a nerve fibre.
\n(b) Conduction of a nerve impulse along a nerve fibre.
\n(c) Transmission of a nerve impulse across a chemical synapse.
\nAnswer:
\n(a) When an electrical stimulus is given to a nerve fibre, an action potential is generated. The membrane becomes permeable to sodium ions than to potassium ions. This results into positive charge inside and negative charge outside the nerve fibre. Hence, the membrane is said to be depolarized.<\/p>\n<\/p>\n1st PUC Biology Locomotion and Movement Five Marks Questions and Answers<\/h3>\n
\nExplain the structure of a multipolar myelinated neuron.
\nAnswer:
\nNeuron consists of two important regions.
\n(i) Cyton
\n(ii) Axon.
\n(i) Cyton : It is the cell body which is spherical or oval in shape. It contains a nucleus at the center and surrounded by cytoplasm. Cytoplasm is called Neuroplasm which contains minute fibers in a network and also special bodies called Nissl granules. These granules are believed to take part in protein synthesis. Periphery of the cyton produces branched processes. These short branches of cyton are called dendrites. One of these branches is much elongated and is called axon.<\/p>\n<\/p>\n
\nDraw a neatly labelled diagram of sagittal section of brain.
\nAnswer:
\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-21-Neural-Control-and-Coordination-5.5.png\")
<\/p>\n
\nWith a labelled diagram, describe the structure of human spinal cord.
\nAnswer:
\nTubular posterior extension of medulla oblongata is called the spinal cord. It comes out of the skull through an opening called \u2018Formen magnum\u2019 and is lodged within a canal of the vertebral column. As in brain, spinal cord is also covered by meninges such as piameter, archnoidmenter, durameter and CSF.<\/p>\n
\nDescribe briefly the structure of human brain.
\nAnswer:
\nHuman brain is a soft nervous structure, weighing about 1280 to 1380 gms. It is protected by cranium of the skull and meninges. Meninges are the three membranes covering central nervous system (brain and spinal cord).<\/p>\n
\n1. Fore brain (Prosencephalon).
\n2. Mid brain (Mesencephalon).
\n3. Hind brain (Rhombencephalon).
\nSagittal section of brain reveals the following details.<\/p>\n<\/p>\n
\n(ii) Parietal lobe : It lies behind the frontal lobe and is separated from it, by a fissure of Rolando or central fissure.
\n(iii) Temporal lobe : It lies below and behind the frontal lobe and is seperated from it by a lateral sulcus.
\n(iv) Occipital lobe : It lies behind the parieto-occipital sulcus.
\n(v) Insula (Island of Reil) : It is not visible because it is located deep with in the lateral sulcus. It is covered by parts of frontal, parietal and temporal lobes.
\nCorpus callosum : It is the network of nerve fibres connecting two hemispheres of cerebrum.<\/p>\n<\/p>\n<\/p>\n
\nDraw labelled diagrams of the following:
\n(a) Neuron
\n(b) Brain.
\nAnswer:
\n(a)<\/p>\n\n
\n<\/p>\n1st PUC Biology Neural Control and Coordination Text Book Questions and Answers<\/h3>\n
\n
\n
<\/p>\n
\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-21-Neural-Control-and-Coordination-1.1.png\")
<\/p>\n
\n1. Central Ne;rvous System (CNS): This includes brain and the spinal cord.<\/p>\n<\/p>\n
\ni. Somatic Nervous System (SNS) : They carry information to the skeletal muscles. This system is said to be voluntary (This is under the control of our will)<\/p>\n\n
![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-21-Neural-Control-and-Coordination-2.2.png\")
<\/p>\n\n
\n
<\/p>\n\n
\nAt the resting stage i.e., when the neuron is not involved in the conduction of impulses, the membrane of neuron is more permeable to K+<\/sup> ions than to Na+<\/sup> ions. The membrane is impermeable to the negatively charged proteins of the axoplasm and also Cl–<\/sup> ions.<\/p>\n
\nWhen a threshold stimulus is applied at a site on the polarised membrane, the membrane permeability at that site changes and becomes freely permeable to Na+<\/sup> ions.<\/p>\n<\/p>\n
\nThe interior\/axoplasm now becomes positively charged while the exterior becomes negatively charged and this is called depolarisation.<\/p>\n<\/p>\n
\nNow the current flows through the axoplasm from the depolarised region to the depolarised region.
\nAs a result the action potential is generated in the next segment and this process continues along the length of the nerve fibre.<\/p>\n
\nAt the site of stimulation, the stimulus-induced permeability to Na+<\/sup> ions is extremely short lived is quickly followed by an increase in the permeability to K+<\/sup> ions.<\/p>\n
\nA synapse is the functional junction between two neurons, formed by the membranes of a pre-synaptic neuron and a post-synaptic neuron.
\nThere are two types of synapses namely:
\n(i) Electrical synapses and
\n(ii) Chemical synapses.
\nThe differences between the two types of synapses are given below:<\/p>\n
\n(i) The membranes of the pre-synaptic and post synaptic neurons are in close proximity
\nand there is no synaptic cleft.
\n(ii) Electrical current can flow directly from one neuron to the other.
\n(iii) Impulse conduction is faster.
\n(iv) Electrical synapses are rare in the human system.<\/p>\n<\/p>\n
\n(i) The membranes of the pre-synaptic and post-synaptic membranes are separated by a fluid-filled called space the synaptic cleft.
\n(ii) Transmission involves chemicals called neurotransmitters.
\n(iii) Impulse conduction is relatively slower.
\n(iv) Chemical synapses are the most common type of synapses in human.<\/p>\n
\nThe released neurotransmitter molecules bind to their specific receptors present on the post-synaptic membrane.<\/p>\n\n
\nI. Fore Brain (Procencephalon) : Includes cerebrum and diencephalon (Thalamus and Hypothalamus)
\nII. Mid Brain (Mecencephalon) : It is a highly reduced part in humans.
\nIII. Hindbrain (Rhombencephalon) : It includes cerebellum, ponsveroli and medulla oblongata (Stalk of the brain).<\/p>\n
\nThe surface area shows numerous infoldings or convolutions. The upfolds are called Gyri (Gyrus) and deep down folds are called Fissures and shallow folds are called Sulci (Sulcus).<\/p>\n
\nEach cerebral hemisphere is divided into four lobes, namely, frontal, parietal, temporal and occipital lobes by three deep and wide fissures.<\/p>\n\n
<\/p>\n
\nThe cerebrum is the seat of intelligence, memory, consciousness, vision, speech and voluntary muscular movements.
\nThalamus : It is a large oval structure present at the centre of fore brain.
\nFunctions : It serves as a relay station that interprets sensory impulses and then channels them to the appropriate regions of the cerebral cortex.
\nHypothalamus : It is present below the thalamus and largely consists of grey matter.<\/p>\n
\na. Controls and integrates autonomic nervous system. Hence it is called head of the autonomous nervous system.
\nb. Regulation of body temperature.
\nc. Regulation of water and electrolyte balance.
\nd. Control of eating and drinking (hunger and thirst) through Satiety centre, and thirst centre.
\ne. Feeling of rage and aggression.
\nf. Regulation of sleep and wakefulness.
\ng. Regulation of heart rate and blood pressure.
\nh. It controls the release of honnones of anterior pituitary.
\ni. It secretes oxytocin and vasopressin hormones that are stored and released from posterior pituitary.<\/p>\n
\nThis comprises of optic lobes that occurs as two pairs of corpora quadrigemina.<\/p>\n
\nThe corpora quadrigemina are the reflex centers of eye and auditory responses. They also control eye ball movement in response to changes with the movement of head.
\nIII. Hindbrain:
\nIt consists of the following three parts:-<\/p>\n\n
<\/p>\n
\na. Maintenance of body posture and equilibrium.
\nb. Regulates certain voluntary movements that are initiated by cerebral cortex and also involved in subconscious reflexes.
\n2. Pons varoli :
\nIt lies just above the medulla and acts as a bridge carrying ascending and descending tracts between brain and spinal cord.<\/p>\n<\/p>\n
\nIt is a controlling centre for salivation, mastication and facial expression etc.
\n3. Medulla Oblongata :
\nIt is the posterior most part of the brain and continues into the spinal cord. The medulla contains Vital control centres for cardiac, respiratory and vasomotor centres.<\/p>\n
\n1. Contains the cardiac and respiratory centers, and controls the heart rate and respiratory rate.
\n2. Contains vasomotor centers that control reflexes like sneezing, coughing and hiccough etc.
\n3. It is a point of origin for several cranial nerves.<\/p>\n
\nFunctions of various Topographical Areas of Cerebrum :
\nCerebral cortex is broadly divided into three areas, based on the functions it controls:
\n1. Motor areas : Transmit impulses and control voluntary movements of various organs of the
\n2. Sensory areas : Receive sensory impulses and interpret them like what we see, hear, feel smell or taste.
\n3. Association areas : Associated with memory, learning, reasoning and intelligence.<\/p>\n<\/p>\n
\n1. It serves as two-way conduction system as it carries stimulus from the-body tissues to the brain and from brain to various parts of the body.
\n2. It also carries out reflex action.
\nReflex action is an automatic response to any kind of stimulus without conscious involvement of brain.
\nReflex arc is the nerve pathway involved in reflex action.<\/p>\n
\na. A receptor organ : It is a sensory cell where the stimulus is received.
\nb. A sensory neuron : It lies in the ganglion of the dorsal roof of the spinal cord, and conducts the impulses from receptor to the CNS.
\nc. An associated neuron : It lies in the spina! cord. It serves to transmit the impulse from the sensory neuron to the motor neuron.
\nd. A motor neuron : It lies in the ventral horn of the spinal cord and serves to transmit the impulse to the effector organ.
\ne. Effector organ : It is a muscle or gland, which responds to the impulse received.<\/p>\n<\/p>\n1st PUC Biology Question Bank with Answers<\/a><\/h4>\n","protected":false},"excerpt":{"rendered":"