Osmoregulation and Excretion 22 April 2015 Osmoregulation.ppt

Animal Life Multicellular organisms Internal circulation Coordination, information transfer Structural maintenance Movement Maintenance of homeostatic internal environment Excretion of N waste Regulation of pH 22 April 2015 Osmoregulation.ppt

How neurons conduct impulses: Membrane potential (in neurons, muscle cells, etc.) K+ diffuses out, Na+ diffuses in, Na-K pump moves Na+ out & K+ in. Cl-, phosphate, protein anions balance cations “Resting potential” = - 70 mV Imbalance of electrolytes results in serious disorders 22 April 2015 Osmoregulation.ppt

Osmoregulation Maintaining osmotic homeostasis Balancing water and electrolyte concentrations Maintains cell integrity Maintains enzyme function etc. 22 April 2015 Osmoregulation.ppt

Osmosis Diffusion of water from high water concentration to lower water concentration. Water loss Water gain 22 April 2015 Osmoregulation.ppt

Osmosis Marine fish lose water by osmosis Actively excrete salt to maintain homeostasis Freshwater fish gain water by osmosis Excrete excess water 22 April 2015 Osmoregulation.ppt

Nitrogenous wastes Produced from metabolism of amino acids and nucleic acids Ammonia Urea Uric acid Guanine Arachnids 22 April 2015 Osmoregulation.ppt

Nitrogenous wastes Produced from metabolism of amino acids and nucleic acids Uric acid from birds 22 April 2015 Osmoregulation.ppt

Nitrogenous waste & Osmoregulation Same systems balance water and dispose of nitrogenous wastes Protonephridia & “flame bulbs” in flatworms Metanephridia in annelids Malpighian tubules in arthropods 22 April 2015 Osmoregulation.ppt

Humans Body Water 75% of body weight in infant 60% of body weight in adult male 55% of body weight in adult female Reasons for differences ?? 22 April 2015 Osmoregulation.ppt

Osmoregulation Fluid compartments” Intracellular fluid Extracellular fluid Interstitial (tissue) fluid Blood plasma Lymph 22 April 2015 Osmoregulation.ppt

Osmoregulation Exchanges among compartments Intracellular – interstitial Diffusion, facilitated diffusion, osmosis, active transport Interstitial fluid (excess)  lymph Lymph  blood plasma Plasma  interstitial fluid Filtration from capillaries carries electrolytes & nutrients to cells 22 April 2015 Osmoregulation.ppt

Osmoregulation Regulation of blood plasma regulates all body fluids Parts of osmoregulation Filtration Reabsorption Secretion Excretion (disposal) 22 April 2015 Osmoregulation.ppt

Kidney Nephron Renal corpuscle Tubule Glomerulus Bowman’s capsule Proximal convoluted tubule Loop of Henle Distal convoluted tubule 22 April 2015 Osmoregulation.ppt

Nephron Filtration in renal corpuscle Afferent arteriole Glomerular capillaries Podocytes of Bowman’s capsule Efferent arteriole 22 April 2015 Osmoregulation.ppt

Osmoregulation Reabsorption in proximal convoluted tubule Active transport of Na+ Co-transport of glucose, amino acids, etc. Cl- follows Na+ Osmosis of water Diffusion of non-polar molecules Diffusion of urea 22 April 2015 Osmoregulation.ppt

Osmoregulation Loop of Henle Concentration of salts in medulla of kidney 22 April 2015 Osmoregulation.ppt

Osmoregulation Reabsorption and tubular secretion in distal convoluted tubule Recovery of NaCl, water, Reabsorption of HCO3- Secretion of H+, K+ pH regulation Sources of metabolic H+ 22 April 2015 Osmoregulation.ppt

Osmoregulation Collecting duct Filtrate/urine makes one more pass through medulla Final reabsorption (or not) 22 April 2015 Osmoregulation.ppt

Osmoregulation Antidiuretic hormone (ADH) Causes recovery of water Absence  excretion of water Important for water homeostasis 22 April 2015 Osmoregulation.ppt

Osmoregulation Diuretics Ethyl alcohol Beer, wine, liquor Inhibits ADH release Water NOT recovered Caffeine Coffee, tea, Coke, etc. Inhibits Na+ transport Sodium, water, etc. NOT recovered 22 April 2015 Osmoregulation.ppt

Urine Drainage Collecting ducts to Minor calyx Major calyx Renal pelvis Ureter 22 April 2015 Osmoregulation.ppt

Urine Drainage Ureter to Urinary bladder Detrusor muscle Urethra Smooth muscle of bladder Urethra internal sphincter external sphincter 22 April 2015 Osmoregulation.ppt

Urine Drainage Urethra internal sphincter external sphincter Female 3-4 cm Anterior to vagina Male 15-20 cm Passes through prostate and penis 22 April 2015 Osmoregulation.ppt