Ncert class 10 - science - chapter 7 - control and coordination

This presentation has important points from Chapter 7 - Control and Coordination from NCERT Class 10 - Science.

1. Control and Coordination Class X- Science-Chapter 7 Biology by Eswari Kumaravel M.Sc., M.Phil., B.Ed.

2. Co-ordination Coordination: Various organs working together in a systematic, controlled and efficient way to produce proper response to various stimuli is known as coordination. Why is it necessary? Each organ in an organism is specialized to perform a particular function . It is necessary that various organs work together to produce proper response to stimulus.

3. Control and Coordination in Humans Systems responsible for Coordination: Nervous System : through electrical impulse. Endocrine Glands : through hormones Hormones Hormones are chemical messengers made of proteins. Secreted by endocrine glands into blood stream. Act on specific tissues or organs known as target organs . Production of Hormones and functioning of hormones is controlled by Nervous system .

4. Hormonal Coordination Nervous System   Stimuli ‘Secrete” Pushes Hormone into Blood Acts on the target Organ

5. Nervous System vs. Endocrine System Endocrine System Nervous System No direct connection with organs or tissues. Direct connection and control over tissues and organs Information of coordination transmitted slowly Information is transmitted very fast Effect is long lasting Effect is short-lived Nervous coordination Hormonal coordination Network of nerves connect different body parts to Central Nervous System Hormones from Endocrine Gland, reach different parts through blood. Messages through Nerves Messages through hormones Nerves and Central Nervous System control and coordinate different functions . Every function is controlled and coordinated by special Hormone As it is an impulse, there is no such thing as quantity affecting organs. Increase and decrease of Hormone quantity affect target organs

6. Nervous System Animals have specialized structures called sense organs (receptors) to receive external stimuli. Stimulus One which brings response in an organism. Impulse Nerves pass information through electro-chemical signals known as impulse.

7. Types of Receptors Photo Receptor For light. e.g. eye Audio Receptor For Sound e.g. Ear. Olfactory Receptor For Smell e.g. Nose Gustatory Receptor: For Taste e.g. Tongue

8. Vertebrate Nervous System It is composed of two main components: Central Nervous System (CNS) Includes brain and spinal cord. Peripheral Nervous System Includes cranial, spinal and visceral nerves . For communication between CNS and other parts of the body.

9. Protective Feature of CNS Brain is protected by the bony cranium . It is covered by three membranes called Meninges Space between Meninges is filled with Cerebro Spinal Fluid . It protects brain from Mechanical Shocks . Meninges and Cerebro spinal fluid covers Spina l Cord too. Spinal Cord is protected by Vertebral Column .

10. Peripheral Nervous System Peripheral Nervous System is composed of Cranial Nerves and Spinal Nerves. 12 Pair of Cranial nerves come out of brain and cover the organs in head. 31 pair of spinal nerves come out of spinal cord and cover all the organs below head region.

11. Structure of Neuron Structural and functional unit of Nervous system is neuron . Neuron is a cell. Dendrites: Receives information from axon of another cell and conducts the messages towards cell body. Cell Body : Contains nucleus, Mitochondria and other organelle. Axon: Conducts messages away from cell body Synapse: Small gap between two adjacent neurons. Here nerve impulse passes from one neuron to other.

12. Transmission of Impulse Electrical impulse is acquired by Dendrite in the neuron. Electrical impulse travels through

13. Types of Neurons

14. Autonomous Nervous System Autonomous Nervous System Chain of nerve ganglion that runs along the spinal cord. It controls all involuntary actions . Two types 1. Sympathetic and 2. Parasympathetic nervous system. Sympathetic Nervous System Parasympathetic Nervous System Height ens the activity of an organ as per need Slows down the activity of an organ. Has a calming effect For e.g. It increases breathing rate and heart rate during running. This is to meet increase in oxygen demand For e.g. breathing rate and heart rate slows down during sleep

15. Autonomous Nervous System

16. Voluntary & Involuntary Actions Factors Voluntary Action Involuntary Action Type of Response Not automatic (With awareness) Automatic (without awareness) Part of the Brain that controls actions Cerebrum Medulla Oblangata Speed Slow Fast Nervous pathway Receptor → Spinal Cord → Cerebrum → Spinal Cord → Effector Receptor → Spinal Cord → Medulla Oblangata → Spinal Cord → Effector Examples Speaking, Walking, Writing etc Heart beat, Respiration, Peristalsis etc.

17. Reflex Action Reflex Action is an automatic and rapid response to a stimulus. Response Receptor (Sense Organ) Effectors (Muscles / glands) Sensory Neurons Motor Neurons Spinal Cord Stimulus

18. Reflex Actions - Example

19. Reflex Arc Reflex Arc is the pathway along which nerve impulse travels during the reflex action. Stimulus Receptors Sensory Neurons (sense organs) Spinal Cord Response Effectors Relay Neurons (Muscles / glands)

20. Reflex Arc

21. Differences Voluntary Action Involuntary Action Reflex Action Not automatic (with awareness) Actions which do not need thinking and performed unknowingly Rapid automatic response to a stimulus Controlled by Brain (Cerebrum) Controlled by Brain (Medulla Oblangata ) Controlled by Spinal Cord Slow Fast Sudden and Fast Example: Walking Example: Heart Beat Example : Touching a hot pan

22. How Nervous Tissues cause Muscular movements? This movement is caused by Special proteins

23. How Nervous Tissues cause Muscular movements?

24. Structure of Brain Brain is the highest coordinating Centre It is protected by cranium . It is covered by three membranes . Space between membranes is called Meninges . Meninges is filled with Cerebro spinal fluid

25. Structure of Brain

26. Structure of Brain Olfactory Lobe

27. Functions of Brain Part Function Cerebrum Main thinking part of brain Responsible for reasoning, speech, intelligence, sigh, hearing and usage of information. Thalamus Send sensory information to Cerebrum Hypothalamus Controls body temperature Maintain Water Balance Controls urge of eating, drinking Controls pituitary Gland Cerebellum Controls and coordinates different muscular actions Maintains posture and equilibrium of the body during various activities such as walking, drinking riding etc. Pons Controls breathing rate Controls facial expression, mastication of food etc. Medulla Oblangata Controls involuntary actions such as Breathing, Blood Pressure, Movement of alimentary canal etc. Regulates reflex responses like salivation and vomiting .

28. Endocrine Glands Endocrine glands are ductless glands that secrete hormones directly into blood.

29. Functions of Endocrine Glands Gland Secretion Hormone Function Pituitary Gland Growth Hormone Regulates the growth Hypothalamus Releasing Hormone Regulates the secretion of hormones from Pituitary Gland Thyroid Thyroxine Controls metabolic rate of carbohydrates, fats and proteins Parathyroid Calcitonin Parathormone Lowers blood calcium level Increases Calcium and decreases Phosphate level Adrenal Adrenaline Increases Heart rate, respiration, blood pressure during emergency situations.

30. Functions of Endocrine Glands Gland Secretion Hormone Function Pancreas Insulin Glucagon Decreases blood glucose Increases blood glucose Testis Testosterone Regulates male secondary sexual characteristics Helps in the formation of sperms Ovary Progesterone and Estrogen Progesterone: Helps to prepare the wall of uterus for attachment of fertilized egg. Maintains Pregnancy Estrogen : Controls development of female sex organs, ovulation etc. controls Menstrual cycle Thymus Thymosin Produces immunity Pineal Melatonin Stimulates muscle contraction

31. Feedback mechanism The timing and amount of hormone released is regulated by feedback mechanism. If glucose level increases in blood, pancreas secretes required amount of insulin. Insulin reduces the glucose level.

32. Why is Iodine Salt advisable? Iodine is required by Thyroid to make Thyroxin hormone. Thyroxin regulates metabolism of carbohydrate, protein and fats. Iodine deficiency in our diet causes Goitre , where Thyroid gland enlarges causing swelling in neck. Iodised common salt contains proper content of Iodine. To avoid deficiency of Iodine, iodised salt is recommended.

33. Coordination in Plants

34. Coordination in Plants Only Chemical coordination . No brain like structure in plants to adapt themselves according to change in surroundings. Growth is controlled by growth hormones .

35. Tropic and Nastic Movements - Differences Feature Nastic Movement Tropic Movement Growth Growth independent movement Growth dependent movements Time of action Immediate Slow Response to stimulus Non-directional Directional Reason for Action Change in turgor Cell division Examples Folding of leaves of touch me not (mimosa), opening and closing of stomata. Phototropism, Geotropism, Hydrotropism, Chemotropism

36. Tropic Movements Response of an organism in the direction of stimuli or away from it is called tropic movement or tropism. It may be negative (away from stimulus) or positive (towards stimulus). Phototropism Geotropism Stem tip grows in the direction of light. Positively Phototropic. Response of organism to gravity. Root grows towards pull of gravity. Positively Geotropic

37. Tropic Movements Chemotropism Hydrotropism Response to chemicals. Pollen tubes grow towards a chemical produced by ovule. Response of organism to Water Root grows towards presence of water.

38. Tropic Movements Thigmotropism Response to touch or solid surface. Tendrils and other climbers are positively Thigmotropic

39. Plant Hormones Phyto hormones help in control and coordination in plants. Present in very small quantities in plant tissues. Produced in any part of the plant and transmitted to other parts by diffusion.

40. Plant Hormones

41. Activities

42. Activity – 7.1 Put some sugar in your mouth and observe how it tastes. Block the nose and eat sugar again. Observe the difference in taste. While eating lunch, block your nose in the same way and note your observation. Observation: We don’t get the same taste of food and sugar as we had earlier.

43. Activity – 7.2

44. Activity – 7.2 Observation: Shoot bends and moves towards the light.

45. Activity – 7.2 Continued.. Rearrange the flask so that the shoots are away from light and the roots towards light. Leave it undisturbed for few days. Observation: Old Parts of the root and shoot will change their direction. There will be differences in the growth of shoot. Conclusion: Light influences the direction of growth of shoot.

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