BISC 1112 Lecture Notes - Lecture 8: Systolic Geometry, Heart Murmur, Exhalation
Document Summary
Circulation- all organisms need to bring nutrients they have consumed and absorbed to their cells so that they can produce atp through cellular respiration. Gas exchange- all organisms need a way of disposing of the carbon dioxide that results from the biochemical process of cellular respiration (circulation) Movement of gases and nutrients in protists- accomplished by diffusion across the cell membrane: limitations to diffusion- movement of substances by diffusion is bery slow for distances more than millimeter or 2. Time is proportional to the square of the distance (. 1nm 1 second; 1. 0 nm 100 seconds) Multicellular organisms- 2 basic adaptations that permit effective exchange for all of an animal"s cells: 1) body that places all (for most) cells in direct contact with the environment. Body plan- gastrovascular cavity in cnidarians- the sac-like digestive cavity functions in the distribution of substances throughout the body. The body wall is only two cell layers thick. In flatworms- the gut branches throughout the body.
