BISC 205 Principles of Physiology Spring 2025 PDF

BISC 205 Simon Fraser University respectfully Principles of Physiology acknowledges the unceded traditional territories of the Coast Salish peoples, including the s...

BISC 205 Simon Fraser University respectfully Principles of Physiology acknowledges the unceded traditional territories of the Coast Salish peoples, including the səlilwətaɬ (Tsleil-Waututh), kʷikʷəƛ̓əm (Kwikwetlem), Sḵwx̱wú7mesh Spring 2025 Úxwumixw (Squamish) and xʷməθkʷəy̓əm (Musqueam) Nations, on which SFU Burnaby is located. Page 1 of 82  BIOLOGICAL SCIENCES 205 Principles of Physiology Spring 2025 INSTRUCTORS: TEACHING ASSISTANT: Jim Mattsson Hannah Jones [email protected] [email protected] Gordon Rintoul [email protected] Office hours TBA - Canvas Use email addresses above NOT Canvas email Page 2 of 82  LECTURES Mondays, Wednesdays & Fridays 9:30AM - 10:20AM Available for each lecture (see Canvas for both): Lecture Notes (PDFs) Video recordings The lecture notes (PDF of slides) are not intended to be complete lecture notes. Page 3 of 82  Copyright notice Lecture notes, animations and videos are provided for students registered in BISC 205 only. BISC 205 students may make copies of these for their personal use for the duration of the course. Distribution of these materials to third parties is a violation of copyright and is prohibited. All figures are copyright Pearson Canada, unless otherwise indicated. Page 4 of 82  Textbook Freeman, S., et.al (2018) Biological Science. 3rd Canadian Edition, Pearson, Canada **eBook is available as an alternative from www.vitalsource.com Question: Do I need to buy the textbook? Page 5 of 82  IMPORTANT If you have a question, who do you ask? About the tutorials – Your TA About the lecture material – The instructor who presented the material General course questions – either instructor Page 6 of 82  For questions about the course material presented in lectures: 1) Consult the textbook. 2) Attend office hours session of the instructor who presented the material (Time & day – TBA see Canvas page) *Email for very short questions only please.* Page 7 of 82  8 Date Lecture Topics Tentative schedule – check Canvas for updates Mon Jan 6 A1. Animal form and function Wed Jan 8 A2. Cells to organ systems Date Lecture Topics Fri Jan 10 A3. Cellular interactions in animals Mon Jan 13 A4. Membrane transport and potential Mon Mar 10 A12. Sensory systems 1 Wed Jan 15 A5. Nervous systems 1 Wed Mar 12 A13. Sensory systems 2 Fri Jan 17 A6. Nervous systems 2 Fri Mar 14 A14. Gas exchange and circulation 1 Mon Jan 20 A7. Nervous systems 3 Wed Jan 22 A8. Muscles & movement 1 Mon Mar 17 A15. Gas exchange and circulation 2 Fri Jan 24 A9. Muscles & movement 2 Wed Mar 19 A16. Water and electrolyte balance 1 Mon Jan 27 A10. Animal nutrition Fri Mar 21 A17. Water and electrolyte balance 2 Wed Jan 29 A11. Energy - Review lecture? Mon Mar 24 P11. - Sugar transport in plants Fri Jan 31 Animal physiology midterm Wed Mar 26 P12. - Competence for and induction of flowering Mon Feb 3 P1. Plant embryogenesis Wed Feb 5 P2. Vegetative development Fri Mar 28 P13. - The ABCs of flower development Fri Feb 7 P3. Plant sensors and hormone signaling Mon Mar 31 P14. Defense against abiotic stress Mon Feb 10 P4. Modification of growth in response to the environment P15. Detection and signaling in response to Wed Apr 2 pathogens and herbivores Wed Feb 12 P5. Modification of growth in response to the environment II P16. Defense by chemical warfare and how humans Fri Feb 14 P6. Refresher; photosynthesis - the light reactions Fri Apr 4 use those chemicals Feb 17-21 Reading Week - No lectures or tutorials Mon Apr 7 P17. The green revolution Mon Feb 24 P7. Refresher; photosynthesis - the carbon reactions P18. Adapting to climate change and a growing Wed Feb 26 P8. Mechanisms to reduce photorespiration Wed Apr 9 population Fri Feb 28 P9. Plant water transport Mon Mar 3 P10. The dilemma of water loss and gas exchange Wed Mar 5 Review and questions Fri Mar 7 Plant physiology midterm Page 8 of 82  MARK DISTRIBUTION: 25% - Midterm 1 - Animal Physiology Fri Jan 31, in class 25% Midterm 2 - Plant Physiology Fri Mar 7, in class 30% Final Exam - Plant & Animal Physiology Date & time TBA 20% Tutorials NOTE CHANGES FROM ONLINE INFO Page 9 of 82  What is an academic concession? Academic concessions are granted when unexpected situations or circumstances prevent students from participating in course-related activities, which could include missing a class, or completing graded work or exams. Situations or circumstances that may call for an academic concession include illness, accident, family situation, and similar unanticipated changes in personal responsibilities that create a conflict, or warrant particular compassion. Concessions are normally granted at the discretion of individual instructors and/or in accordance with established departmental or Faculty policies and procedures. Students should always speak to their instructor as a first step. The link to the academic concession self-declaration form is on Canvas. Page 10 of 82 https://www.sfu.ca/students/academic-success/academic-concessions.html  University is stressful! If you are experiencing difficulties with stress and/or anxiety or other issues, there are SFU resources, including councillors available 24/7: https://www.sfu.ca/students/health/resources/mental-health-sfu/support-options.html "For that 24/7 support. My SSP is a free support service available to all SFU graduate and undergraduate students. Students have immediate access to confidential support and counselling in multiple languages. Accessible from anywhere in the world by phone or through the downloadable app. Call 1.844.451.9700. Outside of North America? call 001.416.380.6578 Helpful support resources are also available through the app." IMPORTANT: If you are struggling to cope with stress/anxiety and/or other mental health/health issues, such that it will impair your ability to successfully complete the course, please contact us by email and we will try to help you get through the course. All communications are confidential. Page 11 of 82  12 BISC 205 Principles of Physiology Animal Physiology Section 1 Gordon Rintoul [email protected] Office hours Mondays 12:30-1:20PM B8244 and Zoom - see Canvas Page 12 of 82  Date Lecture Topics Textbook Reference Weekly Tutorial 13 Ch 39.1, 39.2, No tutorials this Mon Jan 6 A1. Animal form and function 39.3, 39.4, 39.5 week Wed Jan 8 A2. Cells to organ system 7.2, 7.3, 7.6 Ch 11.1, 11.3, 11.3, Fri Jan 10 A3. Cellular interactions in animals 46.1, 46.2, 46.3 Ch 6.1, 6.2, 6.3, Mon Jan 13 A4. Membrane transport and potential 6.4 Ch 43.1, 43.2, Wed Jan 15 A5. Nervous systems 1 43.3, 43.4 Ch 43.1, 43.2, Fri Jan 17 A6. Nervous systems 2 43.3, 43.4 Ch 43.1, 43.2, Mon Jan 20 A7. Nervous systems 3 43.3, 43.4 Wed Jan 22 A8. Muscles & movement 1 Ch 45.1, 45.2, 45.3 Fri Jan 24 A9. Muscles & movement 2 Ch 45.1, 45.2, 45.3 Mon Jan 27 A10. Animal nutrition Ch 41.1, 41.2, 41.3 Wed Jan 29 A11. Energy - Review lecture? Fri Jan 31 Animal physiology midterm Page 13 of 82 Animal lecture 1: 14 Animal form and function Introduction to physiology  What is physiology?  Unifying themes of physiology Surface area/volume relationships Thermoregulation  Physical constrains & adaptations  Heat exchange Page 14 of 82 Animal Form and Function Next lecture Copyright © 2019 Pearson Canada Inc. 39 - 15 Page 15 of 82  What is physiology? The branch of science that deals with the normal functioning of living organisms and their systems and organs. Also: the functional processes of an organism, organ, or system. Page 16 of 82  What is physiology? Organisms are generally studied through anatomy and physiology – Anatomy refers to an organism’s physical structure or form – Physiology is the study of how the physical structures in an organism function Page 17 of 82  What is physiology? Anatomy – An elephant’s large ears are loaded with blood vessels Physiology – Elephants shunt blood to the surface of their ears where body heat can be transferred to the environment African elephants have ears two to three times as large as those of Asian elephants – why? Page 18 of 82 Biological Levels of Organization Moyes & Shulte, Animal Physiology, 2009 Page 19 of 82 Page 20 of 82 Created with BioRender.com Page 21 of 82  26 Unifying Themes in Physiology 1. Physiological processes obey physical and chemical laws 2. Physiological processes are shaped by evolution 3. Physiological processes are usually regulated 4. Physiology is integrative Page 22 of 82  27 Unifying Themes in Physiology 1. Physiological processes obey physical and chemical laws 2. Physiological processes are shaped by evolution 3. Physiological processes are usually regulated 4. Physiology is integrative Page 23 of 82  1. Physiological processes obey the laws of physics and chemistry – Physical properties of cells and tissue are linked to structure and function – Molecular interactions are governed by chemical laws Thermodynamics and kinetics – Electrical laws describe membrane function; especially excitable cells E.g. Nerves and muscles Page 24 of 82  29 Recall: Unifying Themes in Physiology 1. Physiological processes obey physical and chemical laws 2. Physiological processes are shaped by evolution 3. Physiological processes are usually regulated 4. Physiology is integrative Page 25 of 82  2. Physiological processes are shaped by evolution Biologists who study anatomy and physiology are studying adaptations – Heritable traits that make individuals more likely to survive and reproduce in a certain environment better than individuals that lack those traits Adaptation results from evolution by natural selection Page 26 of 82  Humans and octopuses can both…. 1) Detect a small portion of the electromagnetic spectrum. 2) Interpret visual information and modify their behaviour appropriately, act upon visual information, using a brain https://imagine.gsfc.nasa.gov Page 27 of 82 Modified from: How intelligent is a cephalopod? Lessons from comparative cognition Biological Reviews, Volume: 96, Issue: 1, Pages: 162-178, First published: 06 September 2020, DOI: (10.1111/brv.12651) Page 28 of 82  Structural similarities between human and octopus eyes. Atsushi Ogura et al. Genome Res. 2004;14:1555-1561 Page 29 of 82 Cold Spring Harbor Laboratory Press  Octopus and human brains Octopuses, Squid & Cuttlefish Ole G. Mouritsen, Klavs Styrbæk Purves et al, Neuroscience, 2018 Page 30 of 82 2022  37 Recall: Unifying Themes in Physiology 1. Physiological processes obey physical and chemical laws 2. Physiological processes are shaped by evolution 3. Physiological processes are usually regulated 4. Physiology is integrative Page 31 of 82  Homeostasis: General Principles (1 of 2) Homeostasis is defined as stability in chemical and physical conditions within an organism’s cells, tissues, and organs – The internal conditions remain relatively stable even though an organism’s environment may change Two different approaches to maintaining homeostasis—regulate or conform – Most animals fall somewhere between these two extremes Page 32 of 82  Homeostasis: General Principles (2 of 2) Many organisms are able to regulate their internal conditions – They can actively maintain relatively constant internal conditions even when the environment fluctuates – Example: A polar bear maintains a constant body temperature despite fluctuations in ambient temperature But some organisms conform to their external environment  Example: The body temperature of Antarctic rock cod closely matches that of the surrounding seawater Page 33 of 82  Physiological processes are usually regulated Moyes & Shulte, Animal Physiology, 2009 Page 34 of 82  Why Is Homeostasis Important? Example: Enzyme function Enzymes are the proteins that catalyze chemical reactions within the cells Temperature, pH, and other physical and chemical conditions have a dramatic effect on the structure and function of enzymes Molecules, cells, tissues, organs, and organ systems function at an optimal level when homeostasis occurs Page 35 of 82  What Factors Affect Enzyme Function? An enzyme’s structure is critical to its function Protein structure is dependent on folding Enzyme function is dependent on certain conditions – Temperature – pH – Interactions with other molecules – Modifications of its primary structure Page 36 of 82  Enzymes Are Optimized for Particular Environments Temperature affects – Folding – Movement of the enzyme – Kinetic energy of substrates pH affects – Enzyme’s structure and function by affecting: – The charge on carboxyl and amino groups in residue side chains – The active site’s ability to participate in reactions that involve the transfer of protons or electrons Page 37 of 82  Enzymes Have an Optimal Temperature and pH [Extra Page 38 ofslide] 82 The Role of Regulation and Feedback (1 of 4) Most animals have regulatory systems that constantly monitor internal conditions such as temperature, blood pressure, blood pH, and blood glucose Each variable has a set point―a normal or target value for that variable A homeostatic system is based on three general components: 1. A sensor 2. An integrator 3. An effector Page 39 of 82 The Role of Regulation and Feedback (2 of 4) A sensor is a structure that senses some aspect of the external or internal environment – Example: Temperature receptors in the skin An integrator evaluates the incoming sensory information by comparing it to the set point and determining whether a response is necessary – Example: The hypothalamus compares the set point to the current body temperature Page 40 of 82 The Role of Regulation and Feedback (3 of 4) An effector is any structure that helps restore the internal condition being monitored – Example: Shivering to generate warmth or fluffing of fur to insulate and retain heat Page 41 of 82 The Role of Regulation and Feedback (4 of 4) Homeostatic systems are based on negative feedback, in which effectors reduce or oppose the direction of change in internal conditions – Examples: Control of blood pH, pressure, and temperature (thermoregulation) Three common features of negative feedback systems: 1. Redundancy 2. Antagonistic pairs 3. Continuous feedback Page 42 of 82 Mammals Regulate Body Temperature through Negative Feedback Integrator Page 43 of 82 Modified from: https://openstax.org/books/anatomy-and-physiology/pages/1-introduction  Physiology is integrative Atoms make up molecules such as proteins Molecules support the activity of cells Cells with similar functions are organized into tissues Tissues are organized into specialized structures called organs Organs are part of larger units called organ systems, which consist of groups of tissues and organs that work together to perform one or more functions – Example: The small intestine is composed of muscle, nervous, connective, and epithelial tissue Page 44 of 82 Our study of physiology Molecule 55 Organelle Cell Tissue Organ Organ System Page 45 of 82 Our study of physiology – an example 56 Organ Organ System Molecule Organelle Cell Tissue ATP Mitochondrion Synthase Cardiomyocytes Cardiac Muscle Heart Lai et al., Molecular Cell 83, 2137–2147 2023 Cardiovascular System Created with BioRender.com Page 46 of 82 Animal lecture 1: 57 Animal form and function Introduction to physiology  What is physiology?  Unifying themes of physiology Surface area/volume relationships Thermoregulation  Physical constrains & adaptations  Heat exchange Page 47 of 82  58 Recall: Unifying Themes in Physiology 1. Physiological processes obey physical and chemical laws 2. Physiological processes are shaped by evolution 3. Physiological processes are usually regulated 4. Physiology is integrative Page 48 of 82 How Does Body Size Affect Animal Physiology? The laws of physics affect the anatomy and physiology of living organisms – Example: The force of gravity limits how large an animal can be and still move efficiently Body size has pervasive effects on how animals function – Large animals need more food than smaller animals do, produce more waste, take longer to mature, reproduce more slowly, and tend to live longer – Smaller animals lose heat and water more rapidly Page 49 of 82 Surface Area/Volume Relationships: Theory The cell surface area determines the rate at which nutrients diffuse across the membrane into a cell and the rate at which waste products diffuse out The cell volume determines the rate at which nutrients are used and waste is generated – As a cell gets larger, its volume increases much faster than its surface area does The ratio of surface area to volume affects the animal’s overall physiology Page 50 of 82 Surface Area and Volume Change as a Function of Overall Size Page 51 of 82 Surface Area and Volume Change as a Function of Overall Size Larger animals have smaller surface area/volume ratio compared to smaller animals ie Larger animals have less relative surface area compared to smaller animals Page 52 of 82 Surface Area and Volume Change as a Function of Overall Size Larger animals have smaller surface area/volume ratio compared to smaller animals ie Larger animals have less relative surface area compared to smaller animals Page 53 of 82 Adaptations that Increase Surface Area Effective ways for structures to have a high surface area/volume ratio: 1. Flattening  Example: Fish gills have flattened, sheet-like structures called lamellae to increase oxygen uptake 2. Folding  Example: The mammal small intestine has folds called villi for increased nutrient exchange 3. Branching  Example: Small blood vessels called capillaries are highly branched to increase oxygen delivery to tissues Page 54 of 82  Adaptations that Increase Surface Area Created with BioRender.com Page 55 of 82  Certain Structures Increase the Surface Area of Tissues Page 56 of 82 Certain Structures Increase the Surface Area of Tissues Lake Titicaca Frog https://www.cnn.com/2020/07/28/americas/bolivia-scrotum-frog-intl-hnk-scli-scn/index.html Page 57 of 82 Animal lecture 1: 75 Animal form and function Introduction to physiology  What is physiology?  Unifying themes of physiology Surface area/volume relationships Thermoregulation  Physical constrains & adaptations  Heat exchange Page 58 of 82  76 Recall: Unifying Themes in Physiology 1. Physiological processes obey physical and chemical laws 2. Physiological processes are shaped by evolution 3. Physiological processes are usually regulated 4. Physiology is integrative Page 59 of 82  Thermoregulatory Strategies (1 of 3) How do animals obtain heat? – An endotherm produces adequate heat to warm its own tissue – An ectotherm relies on heat gained from the environment Is an animal’s body temperature held constant? – Homeotherms keep their body temperature constant – Poikilotherms allow their body temperature to change depending on environmental conditions Page 60 of 82  Thermoregulatory Strategies (2 of 3) Humans are endothermic homeotherms Many animals lie somewhere between these extremes – Example: African elephants allow their body temperature to rise during the hotter part of the day— they are somewhat poikilothermic – Example: Japanese honeybees exhibit poikilothermy when defending their hives from predatory hornets  They contract their flight muscles repeatedly to produce heat endothermically, and the rise in temperature kills the hornet Page 61 of 82  Thermoregulatory Strategies (3 of 3) Small mammals that inhabit cold climates lose heat rapidly because their surface area is large relative to their volume To survive when temperatures are cold, species such as dormice reduce their metabolic rate and allow their body temperature to drop—a form of poikilothermy. – Torpor—a temporary drop in body temperature – Hibernation—a longer drop in body temperature Page 62 of 82  Comparing Endothermy and Ectothermy (1 of 3) Endotherms can warm themselves because their basal metabolic rates are extremely high – Heat given off by high rate of chemical reactions is enough to warm the body – Mammals and birds retain this heat because they have elaborate insulating structures such as feathers or fur Ectotherms gain heat directly from the environment and only generate a small amount of heat as a by-product of metabolism – Most heat gain is by radiation or conduction Page 63 of 82  Comparing Endothermy and Ectothermy (2 of 3) Endothermy and ectothermy are best understood as contrasting adaptive strategies Endotherms have higher metabolic rates and thus can be more active at all times – But this costs a lot of energy and focuses that energy on producing heat vs. other energy-demanding processes Page 64 of 82  Comparing Endothermy and Ectothermy (3 of 3) Ectotherms are able to thrive with much lower intakes of food and can use a greater proportion of their total energy intake to support reproduction – But muscle activity and digestion slow as body temperature drops, making them vulnerable in the cold Page 65 of 82  Heat Exchange Heat exchange is critical in animal physiology – Overheating can cause proteins to denature and cease functioning – High temperatures can lead to excessive water loss and dehydration – Low body temperatures can slow down enzyme function and energy production Page 66 of 82  - Gord’s phone Page 67 of 82 https://globalnews.ca/news/8008202/billion-sea-creatures-die-bc-heat-wave/ Mechanisms of Heat Exchange Conduction is the direct transfer of heat between two physical bodies that are in contact with each other Convection is a special case of conduction in which heat is exchanged between a solid and a liquid or gas rather than between two solids Radiation is the transfer of heat between two bodies that are not in direct physical contact Evaporation is the phase exchange that occurs when liquid water becomes a gas Page 68 of 82 Four Methods of Heat Exchange Page 69 of 82 Thermal conductivity Conduction is the direct transfer of heat between two physical bodies that are in contact with each other Conduction depends upon the material Moyes & Shulte, Animal Physiology, 2009 https://www.smithsonianmag.com Page 70 of 82 Convection – Transfer of thermal energy between an object and an external medium that is moving – Rate of heat exchange depends on:  The thermal gradient  The rate of flow of the fluid  The conductivity of the fluid -Patrick Doyle / Canadian Press via AP Page 71 of 82  Insulation – Layer of air/water/tissue which decreases heat loss  Tissue – Blubber  External – Hair – Feathers https://www.boredpanda.com/norwegian-forest-cats-sampy-hiskias/ – Air – Water Heat loss depends on thickness and conduction Page 72 of 82 https://www.si.edu/stories/keeping-warm-winter-birds Recall: Surface Area and Volume Change as a Function of Overall Size Larger animals have smaller surface area/volume ratio compared to smaller animals ie Larger animals have less relative surface area compared to smaller animals Page 73 of 82 Body size and heat Allen’s rule - Species found in cold climates display shorter limbs and appendages than species located in warm environment. Bermann’s rule - Species with larger body sizes are found in colder climates, whereas smaller body-sized species are located in warm areas. ie surface-area-to-volume ratio tends to correlate with average environmental temperature - low in cold climates and high in hot climates. Oikos, Volume: 2022, Issue: 6, First published: 11 February 2022, DOI: (10.1111/oik.09152) Page 74 of 82  Countercurrent Heat Exchangers Some animal structures conserve heat with countercurrent heat exchangers in which arteries are wrapped with several small veins – Heat flows freely from warm arteries to cool veins, thus retaining heat – Countercurrent exchangers are efficient because they maintain a gradient between the two fluids along their entire length Page 75 of 82 Countercurrent Exchangers Conserve Heat Examples: The tongue of the gray whale, flippers of whales and dolphins, and the legs of animals that live in cold environments Page 76 of 82 Countercurrent Heat Exchanger Moyes & Shulte, Animal Physiology, 2009 Page 77 of 82 Page 78 of 82 Mammals Regulate Body Temperature through Negative Feedback Page 79 of 82 Learning Objectives (1 of 2) : You should be able to Explain in general terms the field of study of physiology. Describe where physiology fits into the different levels of biological organization. Describe the unifying themes of physiology. Provide examples for each theme. Explain what is meant by “homeostasis” in Physiology. Provide examples of homeostatic processes. Explain why homeostasis is important in living organisms. Describe the roles of regulation and feedback in homeostasis. Describe the integrative nature of physiologic systems. Page 80 of 82  Learning Objectives (2 of 2) : You should be able to Describe how the relationship between surface area and volume changes as body size increases or decreases. Describe mechanisms of heat exchange. Describe how feedback loops are used to maintain homeostasis. Compare and contrast the different methods by which animals thermoregulate. Explain how the adaptations of a particular animal (e.g. polar bear) conserves/dissipates heat Describe how countercurrent heat exchangers operate. Describe how mammals regulate body temperature through negative feedback Page 81 of 82 Animal lecture 1: 109 Animal form and function Introduction to physiology  What is physiology?  Unifying themes of physiology Surface area/volume relationships Thermoregulation  Physical constrains & adaptations  Heat exchange END Page 82 of 82