3020 Lecture 1
Amber Stokes・44 minutes read
Physiology involves studying functions in living systems influenced by the environment, with various approaches like mechanistic, evolutionary, and environmental. Organisms exchange substances with the environment to maintain homeostasis, utilizing strategies like avoidance, tolerance, and active regulation to deal with disturbances and fluctuations.
Insights
- Physiology encompasses the study of how living systems function and are influenced by their environment, including chemical, physical, and biological factors at different levels of organization.
- Homeostasis plays a crucial role in maintaining internal stability despite external fluctuations, with organisms employing strategies like avoidance, tolerance, and active regulation to respond to disturbances, while feedback mechanisms and proximate and ultimate causes further contribute to understanding physiological processes and adaptations.
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Recent questions
What is physiology?
The study of function in living systems.
How does the environment influence physiology?
Organisms' physiology is influenced by factors like temperature, radiation, and food.
What are the central themes in physiology?
Physical and chemical laws, regulation, and physiology and evolution.
How do organisms maintain homeostasis?
Through dynamic constancy of the internal environment.
What are the different approaches to studying physiology?
Mechanistic, evolutionary, comparative, environmental, integrative.
Related videos
Summary
00:00
"Exploring Human Physiology in Various Environments"
- Lecture one of the summer term, watch the welcome video for insights into the semester's workings.
- Human physiology coverage will be broad, not as in-depth as previous knowledge.
- Notes are used to pace information delivery, students encouraged to take notes.
- Google doc for each class period allows anonymous questions, answered weekly.
- Physiology defined as the study of function in living systems.
- Organisms' physiology influenced by their environment.
- Environment encompasses various factors like temperature, radiation, food, etc.
- Environment includes chemical, physical, and biological components.
- Three levels of environment: habitat, biome, micro-environment.
- Physiology can be studied at atomic, molecular, organism, and ecosystem levels.
- Approaches to studying physiology: mechanistic, evolutionary, comparative, environmental, integrative.
- Mechanistic approach focuses on understanding life-sustaining functions like heart contractions.
- Evolutionary approach studies how traits aid organisms in their environment.
- Comparative approach compares physiological functions across different organisms.
- Environmental approach explores the interaction between physiology and ecology.
- Integrative approach considers all levels of organization in understanding physiological mechanisms.
24:10
Levels of organization and functions in physiology.
- Physiology involves understanding different levels of organization working together for specific functions.
- Central themes in physiology include physical and chemical laws, regulation, and physiology and evolution.
- Organisms like bacteria and elephants take in nutrients, water, minerals, salts, oxygen, and heat from the environment.
- They release organic waste, water, minerals, salts, carbon dioxide, work, and heat back into the environment.
- All organisms, regardless of size, need to exchange and transport substances for survival.
- Exchange involves short-distance processes like diffusion, while transport involves long-distance movements.
- Surface area to volume ratios impact the efficiency of diffusion in organisms.
- Large organisms rely on organ systems for efficient transport due to small surface area to volume ratios.
- Organisms have strategies like avoiding, conforming, or regulating to deal with environmental stressors.
- Homeostasis is the dynamic constancy of the internal environment, maintaining stability despite small fluctuations.
48:36
Maintaining Body Temperature: Homeostasis and Regulation
- Body temperature fluctuates slightly but generally remains constant around 98.6 degrees Fahrenheit.
- Exposure to cold or hot environments can cause temporary changes in body temperature.
- Homeostasis is the process of maintaining internal parameters within narrow limits.
- Traditional view of homeostasis suggests constant active regulation of all body systems.
- Imperfect homeostasis applies only to some parameters, not all body systems.
- Organisms have options of avoidance, tolerance, and active regulation in response to disturbances.
- Avoidance involves avoiding disturbances, while tolerance copes with internal changes.
- Active regulation, or homeostasis, is the last resort due to high energy requirements.
- Negative feedback in homeostasis reduces disturbances by compensating for deviations.
- Positive feedback increases disturbances, like in childbirth, to continue a process until completion.
- Feedforward mechanisms anticipate future disturbances, preparing the body to reduce the impact, as seen in premigratory fattening in birds or pre-hibernation fattening in mammals.
01:10:19
Physiology and Evolution: How and Why
- Proximate causes in physiology and evolution focus on the "how" questions, delving into the mechanisms of physiological processes, such as how a giraffe breathes or pumps blood to its brain, highlighting the mechanistic aspects of these processes.
- Ultimate causes, on the other hand, address the "why" questions, exploring the adaptive significance of traits like the giraffe's long neck, aiming to understand why certain mechanisms or adaptations have evolved and how they benefit the organism in its environment.
