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Form 5 note_chapter_3

  1. 1. FORM 5 CHAPTER 3COORDINATION AND RESPONSE K ( hinkTnkC irsten T a entre)
  2. 2. COORDINATION AND RESPONSE1. An organism experiences changes in its internal and external environments all the time2. The changes which cause responses in the body are called stimuli3. There are two types of stimuli: a)internal b)external4. Mammals detect stimuli through highly specialised sensory cell called receptor.5. Effectors in the body carry out the responses to stimuli K ( hinkTnkC irsten T a entre)
  3. 3. COORDINATION AND RESPONSE1. When the stimuli are detected and eventually resort in an appropriate response, it is called coordination2. The roles of coordination and response are carried out by two different coordinating systems, namely the nervous system and the endocrine system K ( hinkTnkC irsten T a entre)
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  5. 5. The main component and pathway involved in detecting and responding to changes in the external environment puteri57 58 5
  6. 6. T e min co p n n an p wy in lve in d te g h a mo e t d ath a vo d e ctina d re o d g to ch ge in th in rn l e v n e t n sp n in an s e te a n iro mn puteri57 58 6
  7. 7. THE ROLE OF HUMAN NERVOUS SYSTEM• Organisation of the nervous system2. The human nervous system consist of a giant network of nerve cells or neurones, and nerve tissues which convey information between the sensory receptors, the organs and effectors.3. It is divided into main subsystem: a) central nervous system (CNS), consist of brain and spinal cord b) peripheral nervous system (PNS), consist of cranial nerves and spinal nerves. puteri57 58 7
  8. 8. Human nervous system puteri57 58 8
  9. 9. puteri57 58 9
  10. 10. Cerebrum• Divided into two halves called the cerebral hemispheres (left and right)• It is responsible for many mental abilitiesCerebellum• Coordinating centre for body movements• Evaluates the information and relays the need for coordinated movements back to the cerebrum• Then sends appropriate commands to the muscle puteri57 58 10
  11. 11. Medulla oblongata• Regulates the internal body processes that do not requires conscious effort, that is, automatic functions such as the heart beat and breathing.• Reflex centre for vomiting, coughing, sneezing, hiccupping and swallowing.• Important role in homeostatic regulation.• Control centre of the endocrine system puteri57 58 11
  12. 12. Pituitary gland• Secretes hormones that influence other glands and body function• Controls the release of several hormones from the pituitary gland and thereby serve as important link between the nervous and endocrine system.Hypothalamus• Responsible for sorting the incoming and outgoing information in the cerebral cortex• Integrates the information from the sensory receptor to the cerebrum by enhancing certain signals blocking others. puteri57 58 12
  13. 13. The spinal cord and its function2. Contain within the vertebral column3. It is consist of white matter and grey matter a) in cross section, grey matter looks like a butterfly or the letter H b) consist mainly of cell bodies of neurones c) surrounded by white matter d) the white matter comprises myelin-coated axons of neurones that extend the whole length of the spinal cord puteri57 58 13
  14. 14. A cross section of the spinal cord showing the white matter and puteri5578 grey matter the 14
  15. 15. The neurones• The nervous system is made up of millions of nerve cells called neurones• Neurones transmit nerve impulses to other nerve cells, glands or muscles puteri57 58 15
  16. 16. Types of neurones  Nu n s affe n e ro e re t (se so ) n ry • C se so in rm n arry n ry fo atio fro re p r ce to m ce to ll th b an sp al e rain d in cord. puteri57 58 16
  17. 17. Types of neurones  Nu n s e re t e ro e ffe n • carry in rm n fo atio fro th b o m e rain r sp al co to th in rd e e cto th is th ffe rs, at e mscle o glan ce u r d lls K ( hinkTnkC irsten T a entre) 17
  18. 18. Types of neurones  Interneurones • convey nerve impulses between the various parts of the brain and spinal cord, transmit nerve impulses between afferent and efferent K ( hinkTnkC irsten T a entre) 18
  19. 19. The transmission of information across synapses• Synapse is the site where two neurons, or a neuron and a effector cell communicate.• The transmission of information across a synapse involve the conversion of electrical signals in the form of neurotransmitter• The function of synapses include controlling and integrating the nerve impulses transmitted by the stimulated receptors K ( hinkTnkC irsten T a entre) 19
  20. 20. Voluntary action and involuntary action• The PNS has two main function2. It transmits signal to the CNS for processing3. It transmits responses from the CNS to the rest of the body• Voluntary actions such as walking and talking are under conscious control• Involuntary actions that involve skeletal muscle allows immediate action that does not require conscious effort K ( hinkTnkC irsten T a entre) 2 0
  21. 21. • For example, if a finger touch a hot stove, the reaction is to pull the finger immediately without having to think about it• In such circumstance when the responses to stimuli are involuntary, they are called reflexes.• The nerve pathway involved in a reflex action is called a reflex arc• The effectors involved in involuntary action are smooth muscle and cardiac muscle K ( hinkTnkC irsten T a entre) 2 1
  22. 22. Diseases of the nervous systemParkinson’s disease• Is a progressive disorder of a CNS that typically affect victims around the age of 60 years onwards.• Parkinson’s disease affect muscular movements, causing tremors or trembling of the arms, jaws legs and face• Patients also have difficulty in maintaining normal postures and experience impaired balance and coordination K ( hinkTnkC irsten T a entre) 2 2
  23. 23. Alzheimers disease• Alzheimers disease is a neurological disorder which affect victims around the age of 60yearsonwards, causes the loss of reasoning and the ability to care for oneself.• Individual of Alzheimers disease often become confuse, forgetful, and lose their way although they are in place which are familiar to them.• As their mind continue to deteriorate, patients may lose the ability to read, write, eat, walk and talk.• the cause of this disease still unknown, but the factors such as genetic, environmental or the aging process itself can lead to Alzheimers disease K ( hinkTnkC irsten T a entre) 2 3
  24. 24. The role of hormone in human• Endocrine system consists of a number of glands that secrete hormones.• Hormones are the chemical messenger produce by the endocrine glands.• Although the hormones travel in the blood of the body, they affect and influence only the specific target cell.• Once the hormone binds to its target cell, the hormone cause the cell to respond in the specific manner. K ( hinkTnkC irsten T a entre) 2 4
  25. 25. T e tran o o h rmn s to targe ce h sp rt f o o e puteri57 58t lls 2 5
  26. 26. The need for the endocrine system1. The endocrine system and nervous system play important roles in maintaining homeostasis.2. Both this system often works together. K ( hinkTnkC irsten T a entre) 2 6
  27. 27. The nervous system The endocrine system• Control voluntary and • controls involuntary actions involuntary actions • Conveys chemical signal• Conveys electrical signals (hormones)• Messages are conducted • Messages are conveyed via via neurones. the bloodstream• Messages are conveyed • Message are conveyed rapidly slowly• Messages are carried • Messages are carried from the source to the various between specific destination locations • The response or effects are• The responses or effect long-lasting are temporary K ( hinkTnkC irsten T a entre) 2 7
  28. 28. Regulation of hormones secretion• The pituitary gland is regarded as the master endocrine gland because it secrete several hormones that control other endocrine gland• Pituitary gland itself controlled by the hypothalamus.• Pituitary gland consist of two parts: a) posterior pituitary b) anterior pituitary• The posterior pituitary contains the axons and synaptic terminals of the neurosecretory cells that originate in the hypothalamus K ( hinkTnkC irsten T a entre) 2 8
  29. 29. T e ro o th h p th u in re latin th se tio h le f e y o alams gu g e cre n o h rmn s fro th p itary glan f o o e m e itu d HypotHalamus Anterior pituitary Anterior pituitary ADH oxytocinKidney tubules Smooth muscle in the uterus GrowthACTH TSH FSH & LH hormones prolactinAdrenal Thyroid Ovaries, testes Bones, tissues Mammarycortex puteri57 58 glands 29
  30. 30. • ADH and axytocin are synthesised in the neurosecretory cells of the hypothalamus but secrete by the posterior pituitary• The hypothalamus controls the hormone secretion of the anterior pituitary gland and therefore, affect the secretion of many other endocrine glands indirectly.• The anterior pituitary controls the secretions of hormones from the thyroid gland, the adrenal gland and gonad. All of which are also endocrine glands. K ( hinkTnkC irsten T a entre)
  31. 31. Negative feedback mechanism in hormone regulation HypotHalamus Thyroid-releasing Hormone, TRH Stimulates the anterior Negative pituitary to secrete TSH feedback inhibits the aNtERIoR pItuItaRy release of Thyroid-stimulating TRH Hormone, TSH Negative feedback Stimulates the target gland to inhibits the secrete Thyroxine release of TSH taRGEt GlaND Thyroxine When the thyroxine concentration exceeds a certain level in the blood, its inhibits TRH production in the hypothalamus and TSH production from the 57 puteri5anterior pituitary 8 3 1
  32. 32. HOMEOSTASIS IN HUMAN• Homeostasis is the maintenance of a relatively constant internal environment.• Physical factor such as body temperature and blood pressure while chemical factor are sugar level and osmotic pressure such as partial of carbon dioxide and oxygenThe excretory system• Plays an important role in homeostasis• The primary organs of the excretory system are the kidneys. K ( hinkTnkC irsten T a entre) 3 2
  33. 33. Function of the kidneys2. Helps to regulates the water and salt balance in the body by excreting more or less salt, and increasing the in take or loss of water.3. Regulate the osmotic pressure and ionic levels in the blood4. Excrete waste products.5. Regulate the blood pH• Waste products excreted by the kidneys are substances that are not useful to the body such as waste products from the metabolic reaction (urea, creatinine and uric acid) and foreign substances in the diet (drugs or toxins) K ( hinkTnkC irsten T a entre) 3 3
  34. 34. The human kidney• The kidneys filter the blood and form the urine which is exits the body through the ureters, urinary bladder and urethra.• Urine consists of water, urea and other dissolved waste, and some excess nutrients.• Human kidney has two distinct region:e) Renal cortexf) Renal medulla K ( hinkTnkC irsten T a entre) 3 4
  35. 35. puteri57 58 3 5
  36. 36. The nephron• The functional unit of the kidney is the nephron.• The human kidney consists of about 1 million nephrons.• A nephron consists of three major parts:e) Glomerulusf) Bowman’s capsuleg) Renal tubule• Renal tubule is made up of the:i) Proximal convoluted tubulej) Loop of Henlek) Distal convoluted tubuleankCentre) K ( hinkT irsten T 3 6
  37. 37. puteri57 58 Nephron 3 7
  38. 38. • Nephron perform three basic process:2. Ultrafiltration3. Reabsorption4. SecretionUltrafiltration• When the blood enters the glomerulus, ultrafiltration take place when the high pressure forces fluid through the filtration membrane into the capsular space• The fluid that enters into the capsular space is called the glomerular filtrate• glomerular filtrate contain water, glucose, amino acid, urea, mineral salt and other small molecule. Some composition as blood plasma but not contain red blood cells and plasma protein 3 8
  39. 39. Ultrafiltration in bowman’s capsule puteri57 58 3 9
  40. 40. Reabsorption• Reabsorption take place when the substance moves across the renal tubule into the capillary network.• In the proximal convoluted tubule, there are abundance of mitochondria to generate ATP for the process of active transport that used to reabsorb glucose and amino acid.• Solute concentration in the capillary network is increase, so that water moves into the blood capillary by osmosis• In the loop of Henle, water, sodium and chloride ions are reabsorbed.K ( hinkTnkC irsten T a entre) 4 0
  41. 41. • At the distal convoluted tubule, more water, sodium and chloride ions are reabsorbed.• B the time, the filtrate reaches the collecting duct, very little salt left and 99% of water has been reabsorbed into the bloodstream.• Only 1% of water in the filtrate actually leaves the body as urine.• Some urea diffuses out into the surrounding fluid and blood because of its small molecular size.• Finally, about 45% of the original urea remain in the collecting duct to be excrete in the urine. K ( hinkTnkC irsten T a entre) 4 1
  42. 42. Secretion• Not everything is filtered, only 20% of the plasma leaves the blood vessels and enters the renal tubule. Hence there are waste product in the blood which were not filtered originally.• Secretion is a process in which waste and excess substances that were not initially filtered are secreted into the renal tubule.• Secretion take place in the renal tubules and collecting ducts but is especially active at the distal convoluted tubule.• Secretion occurs by passive diffusion and active transport. K ( hinkTnkC irsten T a entre) 4 2
  43. 43. Detected by An increased Increased permeability ofosmoreseptors in in ADH distal convoluted tubulehypothalamus released from and collecting duct to posterior water pituitaryDecrease in solute Greater proportion ofpotential water reabsorption in renal tubulesD sed ecrea A small volume ofwter inta a ke concentration urine Plasma solute potential increases producedNormal plasmaosmotic level Plasma solute potential decreases A large volume of dilute urine producedIncrea sedwter inta a keIncreased in solute smaller proportion ofpotential water reabsorption in renal tubules A decreased inDetected by ADH released Decreased permeability ofosmoreseptors in from posterior distal convoluted tubulehypothalamus pituitary and collecting duct to water R G LA IO O A HP O UT N E U T N F D R DC IO
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  45. 45. Notes about Kidney Dialysis:The main stages that blood passes through during thedialysis process include:•Blood enters machine from body (under pressure fromradial artery).•Pump (some diagrams show a roller pump) controlspressure and flow rate.•Anticoagulant added to prevent clotting.•Blood passes through dialysis membrane (equivalent tokidney nephrons).•Bubble Trap removes any gas bubbles from blood.•Blood is filtered then returned to the patients radial vein. puteri57 58 4 5
  46. 46. puteri57 58 4 6
  47. 47. After meal During fasting or after exercise Rise in blood glucose level Drop in blood glucose level Secretion of more insulin or less Secretion of less insulin or more glucagon by pancreas glucagon by pancreasLiver cells absorb Increase in glucose Liver cell break Decrease in glucoseglucose from blood + uptake by body cells down glycogen into + uptake by body cells to form glycogen for respiration glucose for respiration Blood glucose level returns to normal B O G C S LE E INT E B D LO D LUOE VL H O Y
  48. 48. Practising a healthy lifestyle• Drugs can alter brain functions and the rates at which neurones release neurotransmitters• There are some types of drug and their effects on the body: K ( hinkTnkC irsten T a entre) 4 8
  49. 49. Stimulants• Increase the activity of the central nervous system• Cocaine, nicotine, amphetamines & caffeine increase the heart rate and alertness• Hallucinations, LSD perceive things that do not exist K ( hinkTnkC irsten T a entre) 4 9
  50. 50. Depressants• Slow down the activity of the central nervous system• Alcohol, barbiturates & heroin slow down the breathing rate &lower blood pressure K ( hinkTnkC irsten T a entre) 5 0
  51. 51. Plants hormones• Plants hormones is a chemical substances which is produced by the plants and influences the growth and development of the plants. Examples auxins and ethyleneAuxins• Auxins controlled the plants respond to stimuli by growing in a certain direction called tropism.• Growth of shoots towards sunlight is called +ve phototropism and growth of shoots away from sunlight is called -ve phototropism.• Auxins promotes the elongation of cells in the shoot K ( hinkTnkC irsten T a entre) 5 1
  52. 52. • The growth movement of a plant is response to gravity is called geotropism.• Auxins is used to:• Increase the stem length by increasing the rate of cell division• Stimulate the growth of adventitious roots from the stem• Parthenocarpy, produce seedless fruit• Promotes growth of plants cells. Delay fruit ripening and prevent fruit from falling off the plant before it is ripe K ( hinkTnkC irsten T a entre) 5 2
  53. 53. Ethylene• Ethylene is a plant hormones which is synthesised during the ripening of fruits.• The synthesis of ethylene occurs in fruits, leaves and stems• Speedup the ripening of fruits by stimulating the production of cellulase that used to hydrolyses the cellulose in plants cells walls, making the fruits soft.• Promotes the breakdown of complex carbohydrates into simple sugar. That is why a ripe fruit tastes sweeter than an unripe fruit K ( hinkTnkC irsten T a entre) 5 3
  54. 54. tHEEND puteri57 58 5 4