Osmoregulation and Excretion Ainsley Lockhart and Emily Allyn

Osmoregulation: The Basics Osmoconformers – Isoosmotic with surroundings Osmoregulators- Control internal environment independently from environment Stenohaline – Animals that cannot tolerate large changes in external osmolarity Euryhaline – Animals that can survive large fluctuation in external osmolarity.

Osmotic Challenges: A Survey

Osmoregulation: Energy Cost and Other Mechanisms Energy is required for active transport and diffusion of solutes and water Transport epithelia is responsible for filtration and reabsorption

Nitrogenous Waste Ammonia Urea Uric acid Evolution of each mode

Excretion: The Basics How excretory systems maintain homeostasis. Bodily Fluids -> Filtrate -> Urine

Evolution of Excretory Systems: Protonephridia Organisms –Flatworms(acoelomates) –Rotifers –Some annelids –Mollusc larvae –Lancelets Functions –Metabolic waste excretion –Osmoregulation –Disposal of nitrogenous waste Mechanisms –Tubule network –Flame bulbs

Evolution of Excretory Systems: Metanephridia Organisms –Most annelids Functions –Metabolic waste excretion –Osmoregulation Mechanisms –Ciliated funnel –Collecting tubule –Transport epithelium

Evolution of Excretory Systems: Malpighian Tubules Organisms –Insects and other terrestrial arthropods Functions –Nitrogenous waste disposal –Osmoregulation Mechanism – transport epithelium

Evolution of Excrtory Systems: Kidneys Organisms –Vertebrates and some other chordates Functions –Osmoregulation –Metabolic waste excretion Mechanism: –Highly organized tubules –Ducts

Structure Of The Mammalian Excretory System Kidneys: renal cortex, renal medulla, nephron Renal veins and arteries supply blood Urine: Kidneys -> Ureter -> Bladder -> Urethra

Adaptations and Evolution of the Mammalian Kidney Gram-negative bacteria Hagfish and segmented kidneys

Pathway of Filtrate

From Blood Filtrate to Urine proximal tubule descending and ascending limb of loop of Henle distal tube collecting duct

Solute Gradients

Kidney Adaptations: Mammals The juxtamedullary nephron functions for water conservation Long loops of Henle

Kidney Adaptations: Birds and other Reptiles Birds –Juxtamedullary nephrons –Shorter loops of Henle –Uric acid Reptiles –Cortical nephrons –Transport epithelium in cloacas –Uric acid.

Kidney Adaptations: Freshwater Fish and Amphibians Freshwater Fish –Many nephrons –Transport epithelium for salt retention Amphibians –Water vs. land adaptations

Kidney Adapations: Marine Bony Fish Small nephrons with no distal tube Small or no glomeruli Divalent ions flushed out with kidneys, proximal tubules of nephrons Monovalent ions flushed out with gills

Contribution of Hormones to the Mammalian Excretory System antidiuretic hormones (ADH) hypothalamus and pituitary( osmoregulator cells in hypothalamus detects rising osmolarity of blood and produces the hormone. Hormone is stored in the pituitary gland) distal tubes and collection ducts (aquaphorons) (the ADH binds to aquaphorons in kidney to change the water pemeability of transport epithelial)

Renin-angiotensin- aldosterone system (RAAS) juxtaglomerular apparatus (JGA), afferent arteriol ( the afferent arteriol moitors blood volume/ artetiol tension and instructs the JGA which is close by to make angiotensin II) adrenal gland (makes aldosterone) aldosterone, angiotensin II

Homeostatic Regulation of the Kidney The renin-angiotensin-aldosterone system (RAAS) Antidiuretic hormones (ADH) Atrial natriuretic peptide (ANP)

Disorders of the Kidney Diabetes insipidus Affects of alcohol Gout

References 1."Gout: What You Should Know." American Family Physician 76.6 (2007): Science Full Text Select. H. W. Wilson. Wilson Web Science. 6 Apr < 2.Miller, Karen J., Eugene P. Kennedy, and Vernon N. Reinhold. "Osmotic adaptation by gram-negative bacteria: possible role for periplasmic oligosaccharides." Science 231 (Jan 3, 1986): 48(4). Student Resource Center - Bronze. Gale. PIEDMONT HIGH SCHOOL. 6 Apr < 3.Campbell, Neil A. “Biology.” Pearson, San Francisco

“Borrowed Photo” Credits 1. System.htmlhttp:// System.html BB/ ossM.htmlhttp:// BB/ ossM.html Campbell, Neil A. “Biology.” Pearson, San Francisco