BIOL 1108 Edition 1nd Lecture 16 Outline of Last Lecture I Learning Objectives II In The News III Osmoregulation IV Excretion V Evolutionary Structural Variations Outline of Current Lecture I Learning Objectives II Excretory System Function Overview III Functions IV Blood Filtrate to Urine V Regulation Current Lecture I II Learning Objectives 1 Be able to Describe the structures and process of blood filtration to urine formation in kidney nephrons Describe a kidney regulation process Excretory System Function Overview a Filtration Hydrostatic pressure blood pressure pushes bodily fluids blood hemolymph coelomic in contact with a selectively permeable membrane transport epithelium Diffusion depends on the concentration of solutes b Re absorption These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute III IV Recovering useful molecules and water from the filtrate water and solutes and then returning it to the bodily fluids c Secretion The discharge of wastes from the bodily fluids to the filtrate d Excretion 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 a Filtration of blood flows to the Bowman s Capsule as active transport lots of energy b In the proximal tubule the filtrate goes through reabsorption before heading down the Loop of Henle i The longer the loop the more the organism can conserve water c The descending part of the Loop of Henle contains many aquaporins in order for water to reabsorb back into the kidneys more hyperosmotic d As the loop ascends salt solutes are being pulled out of the filtrate through passive transport i This part of the Loop of Henle is impermeable to water and contains no aquaporins ii The higher the filtrate travels the more diluted it gets e At the distal tubule the diluted filtrate controls body pH through reabsorption active transport f 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 V Regulation a Pituitary gland produces endocrine hormones to signal out kidneys i Releases Antidiuretic hormone to reduce urination if water in blood is low b Hypothalamus regulates water content in blood
View Full Document
Unlocking...