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Unformatted text preview: Human Physiology Human Physiology
Welcome to your first day of class!! You Can Contact Me You Can Contact Me firstname.lastname@example.org 7602454271, ext. 2658 Physiology is… Physiology is
h the study of the function of all plants and animals in their normal state. h an integrative science Organ Systems Organ operate as integrated units How many? Can you list them? : Examples n of tion Regulatio concentra alcium Plasma c etc. pressure Blood Function and Process: Function and Process: Teleological vs. Mechanistic Approach to Science
What is the purpose or function? Why does something exist? Why does it need to be done? What are the processes involved? How does something work? Distinguish between Process & Function
Why do we breathe? Why does blood flow? Why do RBC transport O2? How do we breathe? How does blood flow? How do RBCs Integrate both for complete picture! Focus on . . . . (Concept) Mapping
1. 2. Structure – function maps Process maps or Flow charts Follow process in sequence Key Themes in Physiology:
1. Body systems work together (Integration of function) Internal vs. external failure of homeostasis
1. Homeostasis Vital to integration & homeostasis Cells communicate with other cells, tissues & organs Communication and movement across cell membranes Homeostasis Homeostasis The Wisdom of the body The ability of the body to survive in a challenging and changing environment by keeping the internal environment relatively stable
Negative Feedback Positive Feedback Negative Feedback Negative Feedback Negative Feedback Loops are Homeostatic Negative feedback loops can restore the normal state but can’t prevent the initial disturbance. Refers to the corrective effect produced by the feedback signal. The effect must be to REDUCE the DIFFERENCE BETWEEN the SET POINT and the CONTROLLED VARIABLE Negative Feedback Negative Feedback Negative Feedback The body maintains a set point until there is a perturbation. The change in the environment signals a response by the body The response is to bring the body back to homeostasis If possible! Positive Feedback Positive Feedback Positive Feedback is NOT homeostatic Positive Feedback reinforces the initial stimulus rather than decreasing or removing it. The response sends the variable being regulated even farther from its normal value This triggers a vicious cycle of everincreasing response sending the system out of control temporarily Must have a “shut off” switch or it becomes pathological. The Science of Physiology is
based on the Scientific Method
1. 2. 3. Basic steps of scientific method Parameters to consider Experimental design Basic Steps of Scientific Method: Observation (and/or study of prior knowledge)/Question Hypothesis Experimentation Collection and analysis of data (can you replicate results?) Conclusion: reject or accept hypothesis
theory Example: Company has found new artificial sweetener (S) Prior knowledge: Some food additives are not safe. Hypothesis: ? Experiments: ? Collect and analyze data Conclusion Animal vs. Human Experimentation In Physiology most knowledge is derived from _______ experimentation. Sometime human experimentation is necessary. Difficulties of Human Experimentation:
Very dissimilar test subjects Psychological aspects (placebo and nocebo effects) Ethical questions (is it o.k. to withhold potential drug from seriously ill?) ...
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