Control & cocordination ppt
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Control and coordination are essential in living organisms. The nervous system provides control and coordination in animals through receptors, nerves, and the brain and spinal cord. In plants, coordination occurs through growth-dependent and independent movements like tropisms and nastic movements in response to stimuli. Hormones play a key role in homeostasis, growth, and development in both animals and plants through feedback mechanisms.
Control & cocordination ppt
- 3. Control & coordination • A system of control and coordination is essential in living organisms so that the different body parts can function as a single unit to maintain homeostasis as well as respond to various stimuli.
- 4. Movements • Some movements are connected with growth ex- seed germination • Some movements are not connected with growth • Ex- -A cat running • Buffaloes chewing cud • Children playing on swings
- 6. A cat running behind the rat
- 8. Children playing on swings
- 9. What is movement • It is a response to a change in the environment of the organism Or • It is an attempt by living organism to use changes in their environment to their advantage
- 12. • All the movements in response to the environment are carefully controlled Each kind of change in the environment evokes an appropriate movement in response • The movement to be made depends on the event that is triggering it • Therefore such controlled movements must be connected to the recognition of the various events in the environment, followed by correct movement in response • In multicellular organisms specialized tissues are used to provide these control & coordination
- 13. Nervous system in animals • In animals control & coordination are provided by the nervous & muscular tissues
- 14. Receptors • To detect the changes in the environment organism has receptors. • They are present in the sensory organs
- 17. RECEPTORS IN THE TONGUE
- 18. Receptors in the ear
- 19. STRUCTURE OF THE NEURON Cell bodyCell body – main part– main part DendriteDendrite – receives action– receives action potential (stimulation)potential (stimulation) from other neuronsfrom other neurons AxonAxon – branches from– branches from cell body, where thecell body, where the action potential occursaction potential occurs Axon terminalAxon terminal – end of an– end of an axonaxon Myelin sheathMyelin sheath – lipid layer– lipid layer for protection overfor protection over neuronsneurons Nodes of RanvierNodes of Ranvier – gaps– gaps in myelin sheathin myelin sheath
- 20. Types of nerves • : A nerve is formed by the union of several nerve fibres. Nerve fibres are axons and they are enveloped by a covering made of lipid. Based on the property of nerve fibres, the nerves are classified into several types. • Sensory Nerve • it is formed by the union of sensory nerve fibres. It carries sensory impulses from the receptors to brain or spinal cord. • Motor Nerve: • It is f ormed by the union of motor nerve fibres. • It carries motor impulses from brain or spinal cord to different parts of the body.
- 21. Nerve impulse • Nerve impulses travel in the following manner from one neuron to the next : Dendrites - Cell body - Axon Nerve endings at the tip of axon - Synapse -Dendrite of next neuron.
- 22. It is the junction between the two neurons
- 23. Conduction of the nerve impulse
- 24. Conduction of the nerve impulse • The information is acquired at the end of dendritic tip of the neuron that are present in the sense organs / receptors. • This sets of a chemical reaction in the at the dendrites generating an electrical impulse.The electrical impulse thentravels from the dendritic tip to cyton and then to the axon of that neuron. When it reaches the nerve endings certainchemicals are released in response to the electrical impulse. • These chemicals cross the gap or synapse and start asimilar electrical impulse in a dendrite of the next neuron. A similar synapse finally allows the delivery of such impulse from neurons to other cells such as muscles or glands.
- 25. Conduction of the nerve impulse at synapse
- 26. Reflex acion • 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. Examples 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 • Withdraw hand or leg when it touches an hot object. • Women knitting a sweater while watching TV (conditioned reflex).
- 27. Examples of reflex action Knee jerk
- 28. Reflex actions • Touching a flame is an urgent & dangerous situation • If we think about it our hand will be burnt • The solution to solve this problem is having reflex arc connections
- 29. How does our body design solve this problem • Rather than thinking about the situation of the heat , if the nerves that detect the heat are connected to the nerves that move the muscles in simpler way , the process of detecting the signal ( input) & responding to it ( out put) may be completed quickly. Such a connection is commnly called reflex arc
- 31. ADVANTAGS OF REFLX ACTION • 1) Enables the body to give quick responses to harmful stimuli, thus protecting the body. • 2) Minimises overloading of brain. • 3) Efficient way of functioning in the absence of true thought processes.
- 32. Sudden action in response to some thing in the environment is called Reflex action Thinking is not involved in this
- 33. Where should reflex arc connections made between input nerve & an output nerve • Nerves from all over the body meet in abundle in the spinal cord on their way to the brain • reflex are formed in the spinal cord
- 34. No, brain also involves in some reflex actions Spinal cord is made up of nerves which supply information to think about We are thinking animals Thinking involves more complex mechanisms & neural connections These are concentrated in the brain, which is the main coordinating center of the brain Is the reflex action is the only function of the spinal cord
- 35. Role of the brain in reflex action • 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
- 38. The ways by which nervous system sends message to the muscles • 1. Through the spinal cord- spinal reflex • 2. Through the brain • The communication between the central nervous system& the other parts of the body is facilitated by the peripheral nervous system
- 39. It has two parts 1. Brain 2. Spinal cord
- 40. Functions of the central nervous system • They receive the information from all parts of the body & integrate it
- 43. Protection of brain tissues • Brain is covered by a brain box or cranium • inside the box brain is contained in a fluid filled ballon which provides further shock absorption Cranium
- 44. The brain allows us to think & take action sbased on the thinking
- 46. Structure of the brain • Brain has three regions • 1. Fore brain • 2. Mid brain • 3. Hind brain
- 48. FORE BRAIN • It has • 1. cerebrum • 2.Hypothalamus • It is the main thinking part of the brain • It has regions which receive sensory impulses from various receptors • Separate areas of the fore brain are specialized for hearing, smell, sight, learning • There are separate areas of association where the sensory information is interpreted by putting it together with information from other receptors as with the information that is already stored in the brain. Based on all this a decision is made about how to respond & the information is passed on to the motor area which control the movement of voluntary muscles
- 50. Mid brain & hind brain • Many of the involuntary actions are controlled by mid brain & hind brain
- 51. Hind brain • 1. Cerebellum • 2. Medulla oblongata
- 54. Components o the peripheral nervous system • 1. cranial nerves- which arise from brain • 2. Spinal nerves – Which arise fronm spinal cord
- 55. Junction between motor neuron &muscle
- 56. limitations of nervous system in human body Nervous system in human body works or communicates using nerve impulses which are form of electrical impulses. Electrical impulses are an excellent means of communication in human body but they have following limitations: • They reach only those cells that are connected by nervous tissue, not each and every cell • 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. • Due to above said limitations most multicellular organisms use another means of communication between cells, namely, chemical communication i.e. hormone or endocrine system. It is slower than nerve cells but potentially reach all cells of the body.
- 57. How do animal muscles move • The movements of muscle tissues are brought about by the contraction and relaxation of the contractile proteins inresponse to nerve impulses. • When a nerve impulse reaches the muscle, at the cellular level, the electrical impulsecauses the release of some chemicals at the neuro- muscular junction. In response to this chemical signal the musclecells move by changing their shape so that they shorten. • Muscle cells have special contractile proteins that change boththeir shape and arrangement • in the cell in response to nervous electrical impulses. When this happens, a newarrangement of the proteins gives the muscle a shorter form causing movement of muscles.
- 58. Plant movements • Coordination in Plants: • Plants lack nervous and muscular system. • Plants respond to stimuli by showing two types of movements 1. Growth independent and 2.Growth dependent.
- 59. Nastic movements • Growth independent movements are usually quicker than growth dependent ones, and involve the use of electrochemical signals by the plant. To achieve this movement, the plant cells change shape by altering their watercontent. • Eg. drooping of leaves of a touch-me-not plant when it is touched.
- 61. Tropic movements • Growth dependent movements or tropic movements are slow, occurring either towards or away from the stimulus. The movement of plants in the direction of stimulus is known as 'tropism' • Tropic movements are shown in response to environmental factors such as light, gravity, water and chemicals. • Plant roots are positively geotropic and negativelyphototropic whereas plant shoots are usually negatively geotropic and positively phototropic. • Pollen tubes show chemotropism by growing towards the ovule
- 62. Tropic movements • Phototropism • Directional movement of a plant/plant part in response to light, for example: shoots show positive • Geotropism • Directional movement of a plant/plant part in response to gravity, for example: roots show positive • • Chemotropism • Directional movement of a plant/plant part in response to chemicals, for example- growth of the pollen tube towards the ovule • Hydrotropism • Movement of a part of a plant in response to water, for example: roots • Thigmotropism • Growth of tendrils When a tendril comes in contact with a support, then the part of the tendril away from the support grows more rapidly than the part of the tendril that is in contact with the object, thus the tendril circlesaround the object and appears to cling to it.
- 64. Phototropism • Directional movement of a plant/plant part in response to light, for example: shoots show positive
- 65. Geotropism Directional movement of a plant/plant part in response to gravity, for example: roots show positive
- 66. Thigmotropism Growth of tendrils When a tendril comes in contact with a support, then the part of the tendril away from the support grows more rapidly than the part of the tendril that is in contact with the object, thus the tendril circles around the object and appears to cling to it.
- 68. Growth hormone • Source- Pitutory gland • Function- Stimulates the growth of the bones & muscles
- 69. DiSORDERS OF GROWTH HORMONE IMBALANCE • 1. Dwarfism • Cause- Less secretion of growth hormone during Child hood stage • Symptoms • Persons are abnormally short ( Dwarf)
- 70. 2. Gigantism • Cause – Excessive secretion of growth hormone during Child hood stage • Symptoms – Persons are abnormally tall
- 72. How does our body respond to emergency situations like fight? • In case of flight or fight reaction to an emergency situation, Adrenal glands release adrenaline into blood • 1. The heart begins to beat faster resulting in supply of more oxygen to the muscles. • ii. The blood to the digestive system and skin is reduced due to the contraction of muscles around small arteries in these organs.This diverts the blood to our skeletal muscles. • iii. The breathing rate increases because of the contraction of the diaphragm and the rib muscles.iv. All these responses together enable the body to be ready to deal with the situation.
- 74. Source- Pancreas Function- Controls sugar level in the blood
- 75. Disorders of insulin imbalance Diabetes • Cause- less secretion of insulin • Symptoms – High glucose level in the blood
- 76. Cause- Deficiency of Iodine which leads to the less secretion of Thyroxine Symptoms- Enlargement of thyroid gland
- 78. Feed back mechanism • A good example of negative feedback is the hormone insulin. Insulin is a hormone that is made by the pancreas. Insulin is released by the pancreas when you eat glucose (a kind of sugar). • The glucose goes from your stomach to the blood. The amount of glucose in the blood goes up. The pancreas sees this high glucose level. It makes insulin and releases it into the blood. Then the insulin goes through the whole body and tells cells to take glucose out of the blood. When cells take up glucose from the blood this makes the glucose level go down. • The pancreas sees this and stops making insulin. When the pancreas stops sending this message (insulin), the cells in the body stop taking extra glucose out of the blood. So the negative feedback works to keep the blood glucose level normal.If glucose is high, the pancreas makes insulin. The insulin causes the glucose to fall. Then this lower level of glucose tells the pancreas to stop making insulin.
- 79. Plant hormones • Plant hormones affect growth of various parts in the plant. • Auxin: When growing plants detect light, a hormone called auxin, synthesised at the shoot tip, helps the cells to grow longer. When 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. • Gibberellins: Gibberellins help in the growth of the stem. • Cytokinins: Cytokinins promote cell division, and it is natural then that they are present in greater concentration in areas of rapid cell division, such as in fruits and seeds. These are examples of plant hormones that help in promoting growth. • Abscisic Acid: But plants also need signals to stop growing. Abscisic acid is one example of a hormone which inhibits growth. Its effects include wilting of leaves. It also inhibits growth of buds. This is necessary when environmental conditions are not favourable to plants. For example during summer wilting of leaves helps prevent excess water loss due to transpiration. During winters fruit buds may be killed because of freezing temperature, so their growth is inhibited.