BIOB32H3 Lecture Notes - Lecture 4: Nephron, Brainstem, Collecting Duct System
Document Summary
Freshwater: rivers, lakes, wet, ion poor environment: marine: ocean, wet, salty. Homeostasis of the extracellular fluids: (cid:862)regulatio(cid:374) of its i(cid:374)ter(cid:374)al (cid:373)ediu(cid:373) frees a(cid:374) a(cid:374)i(cid:373)al fro(cid:373) its exter(cid:374)al e(cid:374)(cid:448)iro(cid:374)(cid:373)e(cid:374)t; thus, a(cid:374)i(cid:373)als ca(cid:374) adapt to fresh(cid:449)ater a(cid:374)d deserts alike(cid:863) Animals are able to thrive in different environments by homeostasis of the extracellular fluids. If animals regulate interstitial fluid, properties of external environment are not relevant. Animals regulate interstitial fluid by regulating blood because the nature of this fluid is dependent on the nature of the blood: osmolarity is the total solute concentration of a fluid. If you put cells in a hypotonic solution (low osmotic pressure = low solute, diluted solution), you will see the cells swell. If you put the cell in a concentrated hypertonic solution, the osmotic gradient will pull water out of the cell. It is important to regulate osmolarity of interstitial fluid because that has an effect on the volume of cells and things like cell-cell interaction.
