1 BIO3303 Intro to course and physiology.pdf

Bio 3303 Animal Physiology I Teaching Team ME: Dr. Matthew Pamenter (Assoc. Prof. BIO) Primary instructor Comparative neurophysiologist Teaching Team ME: Dr. Matthew Pamenter (Assoc. Prof. BIO) Primary instructor Comparative neurophysiologist Dr. Michael Jonz (Full Prof. BIO) Neurophysiology (lectur...

Bio 3303 Animal Physiology I Teaching Team ME: Dr. Matthew Pamenter (Assoc. Prof. BIO) Primary instructor Comparative neurophysiologist Teaching Team ME: Dr. Matthew Pamenter (Assoc. Prof. BIO) Primary instructor Comparative neurophysiologist Dr. Michael Jonz (Full Prof. BIO) Neurophysiology (lectures 10-13) Course Objectives Explore physiological processes: Control systems (nervous and endocrine) Sensory systems Energetics (muscle function and locomotion) Approach: Comparative Evolutionary context Resources - Course Text Purchase at bookstore Short-term digital subscription ($10.99/month) Supplementary but assigned content is fair game for evaluations Resources - Course Site Posted lectures from previous year available in.ppt and.mp4 formats. Course question board Resources – Teaching Staff Course question board Unit review sessions with TA before each quiz Professor availability around lecture times No office hours Evaluation Quizzes – Best 2 out of 3 -> 50% Final exam -> 50% total Quizzes will not be cumulative Questions will be mostly multiple choice and short answer? Why? Drastic Cut to Science TA Budget Summer 2023: Faculty TA budget slashed by Dean of Science Louis Barriault ([email protected]) Previously we had 1 TA/40 students Now 1 TA/60 students 1 TA contract = 65 hrs Therefore, we now have 1 TA hour/student in this course (loss of 3 TAs) Evaluation There will be no make-up quizzes – if inability to write quiz is justified, remaining quizzes will be re-weighted to make up the difference Questions/concerns about grading are to be directed to me. If you wish to request a re-grading of an assignment or quiz, be aware that the assignment or quiz will be re-graded in its entirety, and this may result in your grade increasing or decreasing. Set yourself up for success Listen to lectures regularly and read the relevant sections of the text… don’t leave things to the last minute! Use class time and review session opportunities to ask questions, talk through concepts, and engage with others in the course Post questions to the class discussion board Course units Control systems I – Nervous system (Chpts. 5 and 8) Sensory physiology (Chpt. 7) Control systems II - Endocrinology (Chpt. 4) Muscles, locomotion and animal energetics (Chpts. 6, 12 and 14) Course schedule Questions? Lecture 1: Objectives By the end of this lecture, you should be able to… Define Physiology Understand the unifying themes of Physiology Scales of physiology Chemical and physical laws dominate physiology Evolution, adaptation, acclimation, acclimatization and plasticity Homeostasis, enantiostasis, conformers and regulators Introduction to Physiology What is physiology? How organisms work The study of the function of organisms as integrated systems of molecules, cells, tissues, organs and organ systems Links genes and gene regulation to function Shaped by evolution Normal and diseased states Myelinating cells of the CNS - S.F. Kornfeld Frilly shark - australiangeographic.com.au Introduction to Physiology Incorporates concepts from many fields Chemistry, physics, math, molecular biology, ecology, etc… Comparative physiology The study of functional diversity among animals Or… Understanding how and why different species work differently Comparative Physiology and the Krogh Principle “For such a large number of problems there will be some animal of choice, or a few such animals, on which it can be most conveniently studied.” Krogh AJP 1929 Evolution has probably already figured it out… Unifying Themes in Physiology 1. Physiology is integrative. 2. Physiological processes obey the laws of chemistry and physics 3. Physiological processes are shaped by evolution 4. Physiological systems are usually regulated 1 – Physiology is integrative Fig. 1.3 2 - Physiological processes obey laws of chemistry and physics Chemical laws govern interactions between biological molecules – temperature, diffusion, mechanics, electricity Ex: enzyme kinetics, membrane fluidity are sensitive to temperature Fig. 3.38 Fig. 3.14 2 - Physiological processes obey laws of chemistry and physics Ex: diffusion affects gas exchange and circulation (Fick’s second law of diffusion) Fig. 11.2 2 - Physiological processes obey laws of chemistry and physics Ex: mechanical concepts apply to circulation flow, pressure, resistance, strain, fluid dynamics, etc. Ex: electrical gradients drive action potentials in neurons and myelin insulation allows quick propagation of signals Fig. 5.19 3 – Physiological processes are shaped by evolution Phenotype = morphology (how it looks) + physiology (how it works) + behaviour (how it acts) Genotype: the specific genetic makeup of an organism. codes for Photo: ALAMY Wikipedia.org/wiki/Gene Genotype + Environment = Phenotype 3 – Physiological process are shaped by evolution Fig. 1.2 3 – Physiological process are shaped by evolution Single genotype can result in more than one phenotype Phenotypic plasticity: production of different phenotypes by a single genotype as a result of environmental changes. Physiological changes can be reversible or irreversible Reversible physiological changes: Acclimatization: process of physiological change in response to naturally changing environmental conditions Acclimation: process of physiological change in response to a controlled or manipulated environmental variable (under laboratory conditions) 3 – Physiological process are shaped by evolution Phenotypic plasticity Irreversible physiological changes Polyphenism (developmental plasticity): development under different conditions results in different adult phenotypes. E.g. Water fleas (Daphnia) Reaction norm: the range of phenotypes that can be produced by a given genotype when it is exposed to different environments Fig. 1.10 3 – Physiological process are shaped by evolution Physiological adaptations -> Evolutionary adaptations Adaptation: change in the genetic structure of a population as a result of natural selection Do not use adaptation in the context of phenotypic plasticity: beneficial change that occurs over the course of a lifetime (e.g. exercise). Requirements for adaptive evolutionary change: 1 – Must be variation among individuals in the trait 2 – Trait must be heritable 3 – Trait must increase fitness 4 – Relative fitness of different genotypes depends on environmental conditions 4 - Physiological systems are usually regulated Two strategies for dealing with environmental changes Conformers: allow internal conditions to change with variation in external conditions Regulators: maintain constant internal conditions regardless of the external conditions.→ Homeostasis (c) actual animals Fig. 25.3, Hill et al. 2004 4 - Physiological systems are usually regulated Negative and Positive feedback loops disturbance + (positive feedback) - (negative feedback) Controlled error sensor signal controller variable output ‘set-point’ 4 - Physiological systems are usually regulated Negative feedback loops: maintain parameters within optimal physiological range (homeostasis) Fig. 1.4/1.9 Positive feedback loops: maximize changes in regulated physiological parameters (explosive response) →Fever 4 - Physiological systems are usually regulated Homeostasis vs. Enantiostasis Homeostasis: maintenance of a constant internal state (e.g. body T⁰ in mammals = 37⁰C) Enantiostasis: maintenance of function when physiological variables are changing E.g. Maintaining membrane fluidity at different T⁰ (functions retained) Fig. 15.14 Key Points Physiology is how organisms work Focussed on all levels of biological organization from molecular to ecological The basis of integrative biology – physiology is the link between genes and function Incredibly diverse, but based upon a number of unifying themes Next Lecture… Introduction to nervous systems