BIOL10002 Lecture Notes - Lecture 12: Extracellular Fluid, Internal Set, Negative Feedback
21 Jul 2018
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Document Summary
Multicellular animals are composed of four tissue types and most organs contain one or more types of tissues. An internal environment makes multicellular animals possible but they require a stable internal environment. Physiological regulation achieves homeostasis of the internal environment. Regulation of the body temperature will be used to illustrate homeostasis: Animals control body temperature by altering rates of heat gain and heat loss. A control centre in the brain regulates mammalian body temperature. An internal environment makes complex multicellular animals possible: The cells of multicellular animals exist within an internal environment of extracellular fluid (ecf). About 20% of the ecf is the plasma that circulates in our blood vessels. The remaining 80% is the interstitial fluid that bathes every cell of the body. Individual cells get their nutrients from the interstitial fluid and dump their waste products into it.
