Bio 117 WVU Exam 3 Study Guide 2024

Osmoregulation - The control of water balance and solute composition Nitrogenous waste - Formed by the breakdown of proteins and nuclei acids, toxic ammonia is produced Directly excreted - Toxic, needs lots of water, most invertebrates and fresh water fish Waste converted to urea - Low toxicity, requires ATP, turtles mammals marine fish amphibians Waste converted to Uric acid - Relatively nontoxic, largely insoluble in water, birds Four nephron parts - Renal corpuscle, proximal tube, loop of henle, distal tube (All parts located in renal cortex except for the loop of henle) How do kidneys filter - Fluids moved into bowmans capsule, going down the defending limb we gain water and keep salt, going up the ascending limb we keep water and lose salt through osmosis, active transport happens in the thick part of the ascending limb Antidiuretic hormone - Causes a more concentrated urine to form Diabetes insipidus hormone - Causes very dilute urine to form Diffusion of oxygen - Gas exchange over respiratory surfaces happens entirely by diffusion. The diffusion requires surface area, thin gas permeable surface, and water Flicks law - Rate of diffusion = k * A * (p2-p1)/D K= diffusion constant A= area Ps= difference of pressure on either side of barrier D= distance or thickness of barrier Does the atmosphere or water have more oxygen? - Atmosphere Gills - Use countercurrent to maximize oxygen diffusion Tracheae - Found in insects, air tubes that branch through the body connected to pores in the exoskeleton known as spiracles, muscle contractions pump the air in and out Lungs - Work off of negative pressure(except for frogs) to keep them inflated, air comes down the trachea through the bronchi to the bronchioles and into the alveoli then air diffuses into capillaries