BIOL 1108 Edition 1nd Exam 4 Study Guide Lectures 15 19 Lecture 15 October 22 Salt and Water Balance Learning Objectives 1 Relate osmoconformers and osmoregulators to their environments 2 Relate animals nitrogenous wastes to an animal s environment and energy use 3 Compare contrast evolutionary structural variations for osmoregulation and excretion In The News Why does Nathan Siegal find Apeel Sciences appealing A biological film allows fruit from rotting as fast Prevent chemical signals of the food from getting to insects eating them Keeping the moisture inside slowing down rotting and bacterial growth Increases shelf life decrease need of pesticides Common pesticide application are airborne that can reach into other areas other than just crops contamination pollution affects bodily functions of certain organisms Pesticide Pros increase yields enhance industrialization Pesticide Cons create resisting organisms hit non target organisms harming environment Effects on Natural Systems biomagnification pesticides effects increase the higher the food chain BET in birds soft shells dead offspring Organic farms even have detection of pesticides because of the spread o Alternatives organic farming rotating crops eat local less cost biofilms like in Apeel Sciences Effects on humans reproduction nervous and even immune systems o Organophosphorus pesticides Inhibits acetlycholrinesesterase Degrades acetylcholine in synapse Toxicity results Autonomic dysfunction Involuntary movements Affects muscle fibers Respiratory depression OSMOREGULATION A process by which animals control their solute concentrations and balance their water gain and loss Linked structurally and functionally with the excretory system Water travels to more concentrated areas Hyperosmotic water moves into cell as the inside of the cell as more solutes This causes the cell to burst or lyse Isoosmotic the concentrations outside and inside the cell are the same making the exchange of water equal Hypoosmotic water moves out of cell as the outside of the cell has more solutes This causes the cell to shrink and shrivel Osmoconformers conform to their environments o Consist in mostly marine invertebrates o There are similar concentrations of solute between the cell and water Osmoregulators are independent to the environment o Mostly terrestrial vertebrates The problem land animals struggle with is to retain water Adaptations include type of waste being produce type of skin ect o Must maintain cellular concentration from changing environment TOPHAT QUESTION Freshwater fish are hyperosmotic to their environment and gain water TOPHAT QUESTION Most marine fish are hypposmotic to their environment and lose water Marine fish are adapted to have gills that excrete solutes whereas freshwater fish absorb more solutes through their gills TOPHAT QUESTION Compare to a freshwater fish you would expect a marine fish to Have more concentrated urine EXCRETION Riding the body of nitrogenous metabolites Linked structurally and functionally with osmoregulation Nitrogenous wastes o Ammonia Most toxic Most aquatic animals because water can easily break down solutes Requires more water to excrete o Urea Mammals most amphibians sharks and some bony fish o Uric Acid Many reptiles including birds insects and land snails Least toxic Most lay eggs so the solutes aren t as harmful to offspring Needs the most energy to produce endotherms require more energy ex Predators EVOLUTIONARY STRUCTURAL VARIATIONS Protonephridia o Ex Flatworms long thin body plan o Use cilia to pull bodily fluids into the flame bulb and filters it o Useful products return back into the body Metanephridia o Ex Annelids o Diffusion occurs between capillaries and tubules o Excreting unhelpful products through body opening Malpighian Tubules o Ex Terrestrial arthropods o Surface area to volume ratio increases absorption o Least toxic waste need to conserve water o Pulls in salts and wastes into the gut o Has no filtering process but can re absorb helpful products o Helps conserve energy and water Kidneys o Ex Vertebrates and other chordates o Blood flows into kidneys o Nephrons of the kidneys conserve water Lecture 16 October 24 Kidney Structure Function and Regulation Learning Objectives 1 Describe the structures and process of blood filtration to urine formation in kidney nephrons 2 Describe a kidney regulation process EXCRETORY SYSTEM FUNCTION OVERVIEW Filtration o Hydrostatic pressure blood pressure pushes bodily fluids blood hemolymph coelomic in contact with a selectively permeable membrane transport epithelium o Diffusion depends on the concentration of solutes Re absorption o Recovering useful molecules and water from the filtrate water and solutes and then returning it to the bodily fluids Secretion o The discharge of wastes from the bodily fluids to the filtrate Excretion o Filtrate with nitrogenous wastes and is released from the body as urine FUNCTIONS 1 Excretion of waste unwanted products of metabolism a Filtration starts at the Bowman s Capsule where there is a lot of pressure 2 Salt and water balance osmoregulation BLOOD FILTRATE TO URINE Filtration of blood flows to the Bowman s Capsule as active transport lots of energy In the proximal tubule the filtrate goes through reabsorption before heading down the Loop of Henle o The longer the loop the more the organism can conserve water The descending part of the Loop of Henle contains many aquaporins in order for water to reabsorb back into the kidneys more hyperosmotic As the loop ascends salt solutes are being pulled out of the filtrate through passive transport o This part of the Loop of Henle is impermeable to water and contains no aquaporins o The higher the filtrate travels the more diluted it gets At the distal tubule the diluted filtrate controls body pH through reabsorption active transport Lastly while the filtrate travels down the collecting duct there is more water reabsorption and active removal of salt Osmolarity gradient in each kidney increases in intestinal fluid 300 mOsm L blood 1200 mOsm L urine 1000 mOsm L ocean water REGULATION Pituitary gland produces endocrine hormones to signal out kidneys o Releases Antidiuretic hormone to reduce urination if water in blood is low Hypothalamus regulates water content in blood Lesson 17 October 27 Chemical Signals Learning Objectives 1 2 3 4 5 6 7 Describe an endocrine system and how it works Compare and contrast posterior and anterior pituitary endocrine signaling