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CHAPTER 07, , Control, &, Coordination, 1
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Acknowledgment, • Images & video clips have been taken, from various sources on the internet., • Some images and video clips have been, modified according to the syllabus., Images courtesy: google.com, Video clips courtesy: youtube.com, Use this presentation for Education purpose, only., 2
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Contents, , Neuron, , Coordination in, animals, , Reflex Action, , Endocrine glands, , CNS, , Exercise (MCQ), , Coordination in, plants, Activity 7.2, Trophic movement, 3
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Need for control & coordination, In animals, the control and coordination, movements are provided by nervous and, muscular systems. The nervous system, sends messages to and away from the, brain. The spinal cord plays an important, role in the relay of messages. In the, absence of this system of control and, coordination, our body will not be able to, function properly., 4
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Neuron, Neuron is the basic unit of the nervous, system., , 5
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Parts of Neuron, The parts of a neuron are cyton or cell, body, dendrites and axon., Cyton or cell body, Dendrites, , Axon, , 6
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Synapse, The very fine gap between axon of one neuron, and dendrite of another neuron is called, synapse., Synapse, , 7
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What happens at the synapse?, Synapse acts as a one way valve to, transmit impulses in one direction only., This uni-direction transfer of impulses, occurs as the chemicals are produced, in only one side of the neuron, , 8
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Functions of parts of neuron, 1. Dendrite – It carries impulse, towards cyton., 2. Axon – It carries impulse from cyton, to effector organs like muscles and, glands., , 9
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Receptors, Receptors are sensory structures, (organs/tissues or cells) present all over, the body. The receptors are either grouped, in case of eye or ear, or scattered in case of, skin., , 10
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How do we detect that we are touching a hot object?, , The receptors of skin sets off chemical, reaction that creates an electric, impulse. This impulse travels from, neurons to other cells and reaches the, brain or spinal cord., , 11
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Reflex Action, , Reflex action is a quick automatic, response to a stimulus without the, involvement of the brain., , 12
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Reflex Arc, , The path that an impulse takes in a, reflex action is called reflex arc., , 13
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Trace the sequence of events when a hot, object is touched, , Heat/pain receptors in the, Skin Sensory neuron Relay neuron, Motor neuron Muscle in the, arms., , 14
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Difference between reflex action &, Walking, , A reflex action is a rapid, automatic, response to a stimulus. It does not, involve any thinking. Walking is a, voluntary action. It is under our, conscious control., , 15
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Identify the parts of the reflex arc, , A – Sensory neuron, B – Spinal cord (CNS), C – Motor neuron, D – Effector (muscle in arm), 16
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Divisions of human nervous system, The human nervous system consists of, three components namely, a) Central Nervous System (CNS), b) Peripheral Nervous System (PNS), c) Autonomic Nervous System (ANS), , 17
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Central Nervous System, , Central nervous system consists of, brain and spinal cord., , 18
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Peripheral Nervous System, , Peripheral nervous system consists of, cranial nerves arising from the brain, and spinal nerves arising from the, spinal cord., , 19
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Parts of the brain, , Brain is divided into three parts –, Fore brain, Mid brain, Hind brain., , 20
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Functions of the brain, , 1. Brain receives information from all, parts of the body and integrates it., 2. It is involved in the voluntary, actions like writing, talking, etc., 3. It sends messages to the muscles., 4. The brain allows us to think and, take actions based on that thinking., 21
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Functions of the fore-brain, , 1. The fore-brain is the main thinking, part of the brain., 2. It has regions which receives, sensory impulses from various, receptors., 3. It has separate areas for hearing,, smell, sight, etc., 22
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Functions of the fore-brain, , 23
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Parts of hind brain, , Pons, Medulla, Cerebellum, , 24
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Functions of the hind brain, , All involuntary actions including blood, pressure, salivation, vomiting are, controlled by medulla in the hindbrain., , 25
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Functions of the cerebellum, , a) Cerebellum controls activities like, walking in a straight line, riding a, bicycle, picking up a pencil, etc., b) It is responsible for precision of, voluntary actions and maintaining, the posture and balance of the, body., 26
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Protection of brain, , a) Brain sits inside a bony box., b) Brain is contained in a fluid-filled, balloon which provides further, shock absorption., , 27
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Mention the part of the brain involved in, the following., a) Walking in a straight line - Cerebellum, b) Picking up a pencil - Cerebellum, c) Blood pressure – Hind brain, d) A question is being asked by the, teacher in a class –cerebrum (fore brain), e) Change in size of the pupil in response, to intensity of light – Mid brain, 28
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Types of movement in plants, , a) Movement dependent on growth, b) Movement independent of growth., , 29
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Movement dependent on growth, , The directional movement of a, seedling is caused by growth., , 30
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Movement independent on growth, , The leaves of the sensitive plant move, very quickly in response to touch., , 31
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Coordination in plants, , 32
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How does the plant detect the touch and, how do the leaves move in response?, In plants there is no specialized tissue in plants, for the conduction of information. The plants, use electrical-chemical means to convey this, information from cell to cell., Plant cells change shape by changing the, amount of water in them, resulting in swelling, or shrinking, and therefore in changing shapes., , 33
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Growth in pea plants, In plants like the pea plant climb up other, plants or fences by means of tendrils., These tendrils are sensitive to touch. When, they come in contact with any support, the, part of the tendril in contact with the, object does not grow as rapidly as the part, of the tendril away from the object. This, causes the tendril to circle around the, object and thus cling to it., 34
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Growth in pea plants, , 35
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State how concentration of auxins stimulates the, cells to grow on the side of the shoot which is away, from light., , When growing parts detect light, a hormone, called auxin is synthesized at the shoot tip, which helps the cells to grow longer. When the, light is coming from one side of the plant, auxin, diffuses towards the shady side of the shoot., This concentration of auxin stimulates the cells, to grow longer on the side of the shoot which is, away from light. Thus, the plant appears to, bend towards light., 36
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(Activity 7.2) Fill a conical flask with water. Cover the neck of the, flask with a wire mesh. Keep two or three freshly germinated, bean seeds on the wire mesh. Take a cardboard box which is, open from one side. Keep the flask in the box in such a manner, that the open side of the box faces light coming from a window., After two or three days, you will notice that the shoots bend, towards light and roots away from light. Now turn the flask so, that the shoots are away from light and the roots towards light., Leave it undisturbed in this condition for a few days., Have the old parts of the shoot and root changed direction?, The old parts of the roots and shoots change directions., Are there differences in the direction of the new growth?, New growth in shoot is in direction of sunlight., What can we conclude from this activity?, Shoot shows growth towards the light., 37
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Phototropic movement, The growth in a plant part in response to light is, called phototropic movement., , 38
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Phototropic movement, The flower head of sunflower is positively, phototropic and hence it moves from east to, west along with the sun., , 39
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Phototropic movement, The ovary stalk of groundnut is positively, phototropic before fertilization and becomes, negatively phototropic after fertilization, so that, the fruit is formed underground., , 40
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Trophic movement, The growth in a plant part in response to the, gravity is called geotropic movement., , 41
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Hydrotropism, The growth of roots in the soil towards the, nearest source of water is called hydrotropism., , 42
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Experiment to demonstrate Hydrotropism, Take two small beakers and label them as A and, B. Fill beaker A with water. Now make a, cylindrical-shaped roll from a filter paper and, keep it as a bridge between beaker A and, beaker B, as shown in the figure. Attach few, germinating seeds in the middle of the filter, paper bridge. Now, cover the entire set-up with, a transparent plastic container so that the, moisture is retained., 43
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Experiment to demonstrate Hydrotropism, , Observation:, The roots of the germinating seeds will grow towards beaker, A. This experiment demonstrates the phenomenon of, hydrotropism., 44
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Chemotropism, The growth or movement of a plant or plant, part in response to a chemical stimulus is called, chemotropism., , 45
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Controlled direction growth, Our arms and fingers grow in certain directions, and not haphazardly., , 46
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Limitations of electrical impulse, a) Electrical impulses will reach only those, cells that are connected by nervous tissue., Not each and every cell in the animal body., b) Cells cannot continually create and transmit, electrical impulses., , 47
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Cells cannot continually create and transmit, electrical impulses., Once an electrical impulse is generated in a cell, and transmitted, the cell will take some time to, reset its mechanisms before it can generate and, transmit a new impulse., , 48
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Chemical communication between the cells, Stimulated cells release a chemical compound,, this compound would diffuse all around the, original cell. If other cells around are able to, detect this compound using special molecules, on their surfaces, then they would be able to, recognize information and transmit it., , 49
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Advantage of chemical communication, a) Chemical communication can reach all cells, of the body, regardless of nervous, connections., b) It is steady and persistent., c) They act by diffusion to the area of action., , 50
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Plant hormones, Hormones are chemical compounds which help, to coordinate growth, development and, responses to the environment., , 51
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Functions of Plant hormones, a), b), c), d), , Auxins help in the growth of shoot., Gibberellins help in the growth of stem., Cytokinins promote cell division., Abscisic acid inhibits growth. It also help in, wilting of leaves., , 52
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Chemical, Coordination, in, animals, 53
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Chemical coordination, Chemical coordination in animals takes place, through hormones. There are several endocrine, glands which secrete various kinds of, hormones. These hormones regulate different, functions in the body. These hormones are, poured into blood through which they reach the, target tissue or organ to act. For example;, insulin is a hormone which regulates the blood, sugar level., 54
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Hormones, Hormones are chemical messengers that, regulate the biological processes in living, organisms., , 55
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Characteristics of Hormones, 1. Hormones are directly released into the, blood., 2. They are released in very little quantity., 3. They act on specific tissues or organs., 4. They are generally slow in action., 5. They act away from the site of production., , 56
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Target organs, Target organ are the specific tissues on which, hormones acts., , 57
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Adrenal gland, It is located above each kidney., It secretes a hormone called adrenaline., , 58
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Adrenaline, • Adrenaline secreted acts on the heart., • The heart beats faster, resulting in supply of more, oxygen to our muscles., • The blood to the digestive system and skin is, reduced due to contraction of muscles around, small arteries in these organs., • This diverts the blood to our skeletal muscles., • The breathing rate also increases because of the, contractions of the diaphragm and the rib muscles., • All these responses together enable the animal, body to be ready to deal with the situation., 59
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When a boy was followed by a stray dog, he got, frightened and started running., a) Name the hormone that prepared him to escape, from the stray dog., Adrenaline, b) Locate the position of the gland in our body which, secrets this hormone., Adrenal gland is located on the upper part of each, kidney., c) Mention two effects of this hormone in human, body., The heart starts beating faster. More amount of, oxygen is supplied to the muscles., 60
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Thyroid Gland, • Thyroid gland is located in the neck region., • It secretes a hormone called thyroxin., , 61
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Thyroxin, , Thyroxin regulates carbohydrate, protein, and fat metabolism in the body so as to, provide the best balance for growth., Deficiency of Thyroxin, , Deficiency of thyroxin causes a disease, called goitre., It is caused due to deficiency of iodine in, the diet., 62
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Goitre, , Symptom of goitre is swelling in the neck, caused due to enlarged thyroid gland., , 63
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Why is Iodised salt made compulsory?, , Iodine is necessary for the thyroid gland to, make thyroxin hormone. Deficiency of, iodine in our diet causes goitre. To reduce, the occurrence of goitre, it is made, mandatory to use iodised salt., , 64
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Pituitary gland, , Pituitary gland is located at the base of the, brain., It produces the growth hormone., , 65
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Growth hormone, , Growth hormone regulates growth and, development of the body., Puberty, , Puberty is period (10 – 12 years of age), during which there are physical changes in, boys and girls., , 66
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Dwarfism, , Dwarfism is a condition caused due to, deficiency of growth hormone in, childhood., , 67
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Gigantism, , Gigantism is a condition caused due to over, secretion of growth hormone in childhood., , 68
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Testosterone, , Testosterone is a hormone produced in, males. It causes changes in the appearance, during puberty., Oestrogen, , Oestrogen is a hormone produced in, females. It causes changes in the, appearance during puberty., , 69
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Pancreas, , Pancreas produces a hormone called, insulin., Insulin helps in regulating blood sugar, levels., , 70
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How is the secretion of insulin regulated?, , If the sugar levels in blood rise, they are, detected by the cells of the pancreas which, respond by producing more insulin. As the, blood sugar level falls, insulin secretion is, reduced., , 71
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Diabetes, , Diabetes is a disease caused due to low, secretion of insulin., The sugar level in the blood rises causing, many harmful effects., Some cases of diabetes can be controlled, by taking insulin injections., , 72
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Feedback mechanism, , The feedback mechanism regulates the, timing and amount of hormone to be, secreted., , 73
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Name the disorder caused by the following, situations:, , a) Under secretion of growth hormone, Dwarfism, b) Over secretion of growth hormone, Extremely tall (giants), c) Under secretion of insulin, Diabetes, d) Deficiency of iodine, Goitre, 74
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Name the hormone responsible for the, following functions., a) Regulating the blood sugar level, Insulin, b) Regulating the carbohydrates, proteins and, fat metabolism in the body, Thyroxin, c) Changes at puberty in human females, Oestrogen, d) Regulating the growth and development of, the body, Growth hormone, 75
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Name the gland and the hormone secreted by the, gland, which are associated with the following, , a) A girl has grown extremely tall, Pituitary gland, Growth hormone., b) A woman has a swollen neck, Thyroid gland, Thyroxin, c) A gland present in female but not in, males, ovary, d) A gland associated with kidneys, Adrenal gland, , 76
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Comparison between nervous system mechanism, and hormonal system mechanism, Nervous system mechanism Hormonal system, mechanism, 1. The information is, 1. The information is, conveyed in the form of, conveyed in the form of, electric impulse., chemical messengers., 2. The axons and dendrites 2. The information is, transmit the information, transmitted or transported, through a coordinated, through blood., effort., 3. The flow of information is 3. The information travels, rapid and the response is, slowly and the response is, quick., slow., 4. Its effects are short lived. 4. It has prolonged effects.77
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Comparison between movement in sensitive plants, and movement in our legs, Movement in sensitive plants, 1. The movement that takes place, in a sensitive plant such as, Mimosa pudica occurs in response, to touch (stimulus)., 2. For this movement, the, information is transmitted from, cell to cell by electrochemical, signals as plants do not have any, specialized tissue for conduction, of impulses., 3. For this movement to occur, the, plant cells change shape by, changing the amount of water in, them., , Movement in our legs, 1. Movement in our legs is an, example of voluntary actions., , 2. The signal or messages for, these actions are passed to the, brain and hence are consciously, controlled., , 3. In animal muscle cells, some, proteins are found which allow, the movement to occur., 78
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Given is an outline diagram of human body, showing the position of endocrine glands., a) Name the parts 1 – 4., 1 – Pituitary gland, 2 – Thyroid gland, 3 – Pancreas, 4 – Adrenal gland, b) Name the nutrient, which is essential for, the normal working of, part 2., Iodine, 79
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Given alongside is the outline of the human, body showing important glands., a) Name the glands marked 1 – 4, 1 – Pituitary gland, 2 – Thyroid gland, 3 – Pancreas, 4 – Adrenal gland, b) Give one important function, of part 2, Thyroxin regulates carbohydrate,, protein and fat metabolism, in the body so as to provide the, best balance for growth., c) Name the gland that secretes, the fight or flight hormone., Adrenal gland, 80
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1., , Which of the following is a plant, hormone?, , (a) Insulin, (b) Thyroxin, (c) Oestrogen, (d) Cytokinin, , 82
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2., , The gap between two neurons is, called a, , (a) dendrite., (b) synapse., (c) axon., (d) impulse., , 83
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3., , The brain is responsible for, , (a) thinking., (b) regulating the heart beat., (c) balancing the body., (d) all of the above., , 84
