BSC 197 Lecture Notes - Lecture 28: Basal Lamina, Skeletal Muscle, Coagulation
29 Dec 2016
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Cells need to obtain nutrients and oxygen and get rid of waste products and co2: there needs to be exchange of good and bad material. Some animals handle material exchange by having extremely high surface area to volume ratio. Some are only 1 or 2 cells thick. Most animals have a circulatory system that does deliveries/pickups: diffusion still important. Types of circulatory systems: open- uid called hemolymph is not always contained in the circulatory system. Leaks out and acts as uid surrounding cells-interstitial uid. Exchange of molecules between hemolymph and cells. Eventually hemolymph drains to collection points called sinuses. Hemolymph in sinuses is syphoned back into circulatory system: like a straw, closed systems-blood stays in blood vessels and exchange of molecules occurs by movement across the walls of the blood vessels. Blood doesn"t just leak out and surround tissue (normally)
