Unit 1

MAINTAINING DYNAMICEQUILIBRIUM II

Suggested Time: 23 Hours 20% of public

Introduction Cells, tissues, organs, organ systems and ultimately organisms mustmaintain a biological balance despite changing external conditions.Homeostasis is the state of internal balance so critical to existence. Itrepresents a dynamic equilibrium displaying constant interactions andchecks and balances both within organisms and between organisms andtheir environment. There are a variety of systems within living thingsresponsible for the maintenance of this delicate balance and this unitwill identify and introduce the role of some of the nervous(electrochemical) and endocrine (chemical) systems in humans.

Focus and Context This unit focuses primarily on decision-making (STSE) as social andenvironmental issues are considered. This STSE component contributes tothe development of scientific literacy and a sense of global citizenship. Inaddition, numerous opportunities for problem-solving and scientific inquiry

are incorporated into the discussion of electrochemical and chemical controlsystems.

ScienceCurriculum Links

Biology students have studied the components of body systems at anumber of different levels prior to Biology 3201. Students in theprimary grades are introduced to the importance of maintaining a healthylifestyle. When they reach the elementary level, students begin to discuss therole of growth and reproduction in human system. They are introduced tothe major components of the structure and function of the digestive,excretory,respiratory, circulatory and nervous systems. The skeletal,muscular and nervous systems and theircontributions to movement are alsointegrated into this study. In addition, the curriculum provides an

opportunity for students to discuss body defences against infection andnutritional requirements to promote health. When students reach Biology2201, they begin to consider the factors that affect the functioning and

efficiency of the human respiratory, circulatory, digestive, and excretorysystem and are encouraged to discover and describe examples of theinterdependence of various systems of the human body. This provides a

good background for the study of the role of biological systems in themaintenance of homeostasis within an organism. A cross-curricular linkexists between the life sciences and physical sciences in the discussion of

dynamic equilibrium incorporated into the provincial chemistry and physicscurriculum.

CHAPTER 12

Ch. 12 – The Nervous System (pp. 390-419)

→ structures of the nervous system→ disorders of the nervous system

→ the brain→ drugs and the nervous system

→ the spinal cord→ the eye

→ neuron structure and function→ the ear

Nervous System: Structures

Analyze the nervous system and explain its structure and dynamics (116-7)

Web sites:

  1. Explain the basic structure and function of the central nervous system and be able to label a diagram. (Page 392-393)Include:
  2. Brainb. spinal cord
  1. Explain how the nervous system is protected and be able to label a diagram. (Page 393) Include:
  2. Skullb. Meningesc. cerebrospinal fluid
  1. Explain the basic structure and function of the brain and be able to label a diagram. (Pages 399-401) Include:

  • Cerebrum
/
  • Cerebellum
/
  • Medulla

  • Thalamus
/
  • Hypothalamus
/
  • Midbrain

  • Pons
/
  • corpus callosum

  1. Describe the basicfunctions of a peripheralnervous system. Students can prepare a chart to visually contrast the sympathetic and parasympathetic components of the autonomic nervous system on various parts of the body (e.g., heart, digestive tract, blood vessels, bladder, bronchi, eye). (pages 392-394) Include:
  2. Sympathetic
  3. Parasympathetic

Nervous System: Neurons

Explain how the nervous system helps to maintain homeostasis (317-1) (Page 392)

Web Sites:

  1. Describe the structure of the typical neuron and explain the function of each part. (Page 395 and 404)Include:
  2. Dendrite
  3. cell body
  4. axon
  5. axon terminal
  6. Schwann cells (myelin sheath and nodes of Ranvier)
  1. Describe the function of sensory neurons, motor neurons and interneurons. (Pages 395-396)
  1. Explain the ion distribution on the membrane of a neuron (at rest, depolarization and polarization) and theinfluence of myelin. Ensure “action potential” and the “Na/K pump” are included in the explanation. (Pages 402-404)
  1. Explain the meaning of theterm threshold anddescribe the all-or-noneprinciple. (Pages 402-403)
  1. Describe the transmissionof an impulse along thelength of a neuron, across asynapse or neuromuscularjunction, and the effects oftransmitters involved. (Pages 405-406)

  1. Acetylcholine
/
  1. Noradrenaline

  1. Glutamate
/
  1. GABA

  1. Dopamine
/
  1. serotonin

  1. Students should investigate the neurological and physiological basis behind the effectiveness of acupuncture and the production of a “runners high”. Students can investigate how nerve poisons interfere with synaptic transmission (curare, botulism, tetanus, organophosphate pesticides, nerve gas).
  1. Identify the role of certaincompounds to neuronfunction (oxygen, glucose,ATP, sodium ions) (314-2) (pages 397, 402)
  1. Analyze homeostaticphenomena to identify thefeedback mechanismsinvolved and describe a reflex arc (317-2) (pages 395-396)
  1. Perform an experiment “The Nervous System and Reflex Responsespages 396-397CORE LAB #1”toinvestigate and collect data onthe nervous system (reflexes)and identify specific variablesinvolved (212-6). Pay particular attention to:
  2. compiling and organizing data,using appropriate formats anddata treatments to facilitateinterpretation of the data(213-5)
  3. identify and explain sources oferror and uncertainty inmeasurement and expressresultsfrom this nervoussystem activity in a form thatacknowledges the degree ofuncertainty (214-10)

Nervous System: Disrupting Homeostasis (Disorders)

  1. Describe disorders linked to the nervous system and their effect on homeostasis of the system and the organism as a whole. (317-4) “Pages 406-408” Include:

  1. Multiple Sclerosis
/
  1. Alzheimer’s Disease

  1. Parkinson’s Disease
/
  1. Meningitis

  1. Huntington’s Disease

  1. Analyze why and how technologies related to the treatment of nervous system disorders were developed and improved over time (115-5) “Pages 398-399” Describe the technologies:
  2. MRIb. EEGc. CAT Scan
  1. Describe the methods used to treat stroke and spinal cord injury. “Pages 404-405”

Nervous System: Disrupting Homeostasis (Drugs)

  1. Describe how the use of prescription and nonprescription drugs can have a role in maintaining or disrupting homeostasis (317-7) (Page 408) Include:

  1. Anaesthetics
/
  1. illegal drugs

  1. prescription drugs
/
  1. legalized drugs (alcohol, nicotine, caffeine)

  1. Conduct Core STSE #1: “Drugs andHomeostasis”, Appendix C and pay particular attention to:
  2. Distinguish between questions that can be answered by science and those that cannot, and between problems that can be solved by technology and those that cannot (118-8) for example:
  3. Debate the merits of using drugs for treatments of nervous disorders against the long-term side effects
  1. Propose courses of action on social issues related to science and technology, taking into account an array of perspectives, including that of sustainability. (118-10) For example:
  2. Debate the legalization of certain drugs such as marijuana for medicinal purposes.

Nervous System: Sense Organs (EYE) (Pages 409-413)

Explain how the eye as a sense organ helps maintain homeostasis (317-1)

  1. Describe the general structure and function of the eye.Include: (i) lens (ii) iris (iii) retina (iv) cornea (v) choroid layer (vi) fovea (vii) rods (viii) cones (ix) pupil (x) blind spot
  1. Trace the path of light through the eye and explain how the amount of light entering the eye is regulated
  1. Analyze and describe examples of disorders of the eye and where technologies for the correction of visual defects were developed based on scientific understanding (116-4) Include eye disorders; glaucoma, astigmatism, myopia, hyperopia.
  1. Describe treatments for eye disorders. Include: corneal transplant, laser surgery.

Nervous System: Sense Organs (EAR) (Pages 414-416)

  1. Describe the general structure and function of the ear. Include: (i) tympanic membrane (ii) ossicles (i.e., malleus, incus, stapes) (iii) eustachian tube (iv) semi-circular canals (v) cochlea
  1. Analyze and describe examples of disorders of the ear and where technologies for the correction of auditory defects were developed based on scientific understanding (116-4) Include ear disorders – conduction deafness, nerve deafnes.
  1. Describe treatments for ear disorders - eustachian tube implants, hearing aids
  1. Evaluate, considering ethical issues, the consequences of medical treatments for visual and auditory disorders (317-5) Include sense of exclusion and mandatory organ donation.

CHAPTER 13

Ch. 13 – The Endocrine System (pp. 420-455)

→ main glands→ feedback mechanisms (stress response)

→ main hormones→ disorders of the endocrine system

Nervous System: Sense Organs (Endocrine Glands)

Explain how the endocrine system helps maintain homeostasis (317-1)

  1. Understand the general concept of a hormone and target cell or organ. page 422
  2. Explain how protein and steroid hormones cause changes in target cells pages 424-425
  3. Identify the location and function of principal endocrine glands in the human organism. page 422 Include:

  1. Pinealpage 438
/
  1. Hypothalamuspage 427

  1. Pituitary pages 427-431
/
  1. pancreas (Islets of Langerhans) page 435

  1. Adrenalpage 441
/
  1. thymus page 440

  1. Thyroidpages 431-432
/
  1. ovariespages 490-493

  1. Parathyroidpages 433-434
/
  1. testespages 486-487

Endocrine System: Maintaining Homeostasis (hormones)

  1. Identify and describe the structure and function of important biochemical compounds, including protein and steroid hormones (314-3) pages 424-425
  1. Identify the following hormones, their source gland, and explain their general effect on the human organism. Include:

(i) melatonin page 440 / (iii) adrenaline pages 444-446
(ii) thyroxine page 432 / (iv) somatotropin (HGH–human growthhormone) pages 428-429

Endocrine System: Maintaining Homeostasis (feedback systems)

Analyze homeostatic phenomena to identify the feedback mechanisms involved (317-2)

  1. Explain how the hypothalamus-pituitary complex functions as a feedback control pages 427, 432
  2. Describe the regulation of blood sugar by controlled release of insulin and glucagon and explain the consequences of any malfunction pages 435-438

Endocrine System: Disorders

  1. Describe disorders and treatments linked to the secretions of the endocrine system and their effect on the homeostasis of the system and the organism as a whole. (317-4) Include:

(i) dwarfism page 429 / (ii) giantism page 439 / (iii) hyperthyroidism page 432
(iv) hypothyroidism page 437 / (v) diabetes mellituspage 439
  1. Analyze examples of Canadian contributions to science and technology (117-11) Example investigate the role played by Frederick Banting and Charles Best in the discovery of insulin

Endocrine System: Feedback Mechanisms

  1. Perform an experiment (Identifying Diabetes Mellitus CORE LAB #2 pages 436-437) to investigate and collect data on the endocrine system and identify specific variables involved (212-6)
  2. Explain how neural and endocrine systems help maintain homeostasis (317-1) pages 441, 445-446 Include:
  3. reaction to stress
  4. Distinguish between questions that can be answered by science and those that cannot, and between problems that can be solved by technology and those that cannot (118-8) Page 445For example:
  5. debate the merits of developing and using life support technology, identifying questions that are scientific, technological and social in nature
  6. Propose courses of action onthe social issues related to lifesupport technologies, takinginto account an array ofperspectives (118-10)

Page 1 of 5