A S L 3 Lecture Notes - Lecture 13: Walter Bradford Cannon, Homeostasis, Observational Learning
Document Summary
Each organism has an internal (glucose, ph, oxygen levels) and external environment (temperature, living resources) There are huge fluctuations in the external environment but the internal stays constant. Mechanisms monitor the internal environment and work to maintain stability or internal equilibrium. Deviations from homeostasis create a biological tension (drive) Reduction of that drive explains behaviour/nerve activity. Immediate mechanism; autonomic nervous system (ans) through hypothalamus. Underpinned by basic biological motivation centres (hypothalamus) Examples: endotherms (mammals/birds); use mechanisms to maintain stable body temperature, exotherms (fish); able to withstand large variations in internal measures. Made up of several different nuclei (clusters of neurons) Thermoregulation experiment: probe inserted into specific area of hypothalamus of cats, when probe was heated, cats began to pant and showed vasodilation. Homeostasis mechanisms play a crucial role in regulation of eating. If animals are deprived of food, they later eat enough to make up for it. If they are force fed more than they want, they reduce consumption afterwards.
