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Water Regulation (=Osmoregulation)Organization of behavior and biological rhythmsI. MonotremataII. MarsupialsAfrotheria: a collection of 6 orders that all have their roots in Africa. An ancient basal split on the mammalian family treeI. Order Afrosoricida: Afro=evolved on the african continent, soricida = shrewsII. Order MacroscelideaIII. Order Tubulidentata : tubes in teethIV. Order Hyracoidea very closely realted to the elephantV. Order Proboscidea : elephantsVI. Order Sirenia: closely related to elephants and hyraxesSuperorder XenarthraI. Order Rodentia by far the most numerous of mammals, more than 2000 them and the most widely distributed (where ever humans have been, guaranteed to be a rodent there tooII. Order Lagomorpha: sister taxa to rodents with similar charactersits. Adapted to herbivory/ Very widely distributer. Special locomotive adaptationsIII. Order DermopteraIV. Order Scandentia sometimes sister taxa to dermopterans sometimes to primatesV. Order PrimatesI. Order Cetacea: know a lot from fossil recordA. Suborder Mysticeti (found in big oceans)B. Suborder Odontoceti (dolphins, beluga whales) found in big oceans but also inland, more widely distributedII. Order Artiodactyla group that cetacean sprung out ofIII. Order PerissodactylaIV. Order Pholidota all found in tropical areas.V. Order Carnivora. Common name: dogs, cats, bearsVI. Order ChiropteraGeneral characteristicsEvolution and phylogeneticsVII. Order Erinaceomorpha: used to be lumped with insectivoreVIII. Order Soricomorpha (moles and shrews): used to be lumped with insectivoraParasites and zoonosesExam IIIWater Regulation (=Osmoregulation)I. Introduction A. Life processes are carried out in an aqueous medium. Places where water is found:1. Blood serum 2. Cytoplasm of cells 3. Digestive reactions and other enzymatic processes 4. Interstitial water, outside cell membranes between cells.B. Water balance (water taken in: water lost) must be regulated fairly precisely. Component of homeostasis, gaining and losing water at a balanced rate.Water gain1. Drinking2. Eating3. Metabolic water (a product of oxidation of organic molecules) C6H12O6 + 6O2--> 6CO2 + 6H2O Product of basic cellular respirationWater loss1. Respiration: when you breathe, air dries out moist tissues. Exhaling, water vapor from lungs released.2. Urination: Kidneys filter blood and take out excess liquids, keeps balance. N2 byproducts flushed out from blood.3. Defecation: depending on species, 50-80% water4. Sweating: evaporative cooling5. Lactation: milk is mostly water, significant drainII. Dealing with, dry hot environments A. Desert conditions are stressful to the mammalian body, water not readily available. Can’t replace water loss.1. Water loss (sweating/respiration) =1-3 % of body weight/hr2. Death occurs when water loss=15-20% of body weight. Brain over heats, blood gets too thick, can’t circulate through bodyB. Dealing with very dry environments 1. Take in more water a. Drink more (not an option for most mammals)b. Eat moist food Moisture content of food depends upon  Type of food I. AnimalII. Plant: less than animal tissue, have a lot of defensesIII. Seeds: mostly carbohydrates, metabolic gain, and change in water content depending on environment they’re in. Animals burrow seeds to pick up moisture, more humid environment underground. Humidity: plants lose water when air is dry, humidity of air depends on time of dayI. Cold weather, water vapor will condense on external surface of plant. In warm weather, water will evaporate out of plant and will be lost to environment. Better to eat plant at night because it’s picking up extra water through condensation on surfaces with air is colder and can’t hold as much water. Time of day (hygroscopic plants): move water within tissues very dramatically. Change on daily basis from green and healthy to shriveled up and brown. Water contained in leafy greens during night, to roots during day.2. Reduce evaporative water loss (evaporative water loss: sweating and respiration)a. Heat loading: camels and desert animals, passively gain heat from environment so they don’t have to regulate temperature.b. Lower metabolic rate when hot: torpor (everything goes into slow motion, use less energy, take in less O2, breathe less frequently, lowers water loss) c. Cooler nasal mucosa: kangaroo rat, lives in the desert so if itexhales normally, loses moist air and inhales very dry air. As thehot air from the lungs moves through nasal passages, loses heatbecause nasal passages are cooler. Some of the moisture fromlungs condense on tissues respiratory passages, Sets up tempdifference between nasal passages and lungs. d. Be nocturnal e. Be fossorial: in the shade, cooler, very stable temperature,buffered from extremes, confined space so when water lostthrough respiration it stays in the space, not lost to environment.f. Summer estivation 3. Reduce water excreted in urine 1a. Urine: produced by kidney. Excretory product from filtering blood Carries nitrogenous wastes from the body (urea, uric acid) Carries other wastes (excess ions, vitamins, etc.) Vertebrate urine is normally hypotonic to blood (taking water from blood), but mammals(and birds) have the capability to make hypertonic urine (very concentrated waste, very little water)b. Basic anatomy and physiology of the kidney: composed of repeating tubules (loops of Henley) Tissues that surround loop of Henley have a varying concentration of ions. Longer the loop, better at drawing water out of urine, making it more concentrated Filtration of blood plasma through glomeruli  Active secretion of waste molecules  Reabsorption of solutes (glucose, amino acids) and water  Final urine concentration depends on the lengths of the loops of Henle  Facultative adjustment of the urine concentration depending on level of hydrationBats get rid of a lot of water so they can fly back to roost, higher concentration of protein and nutrients4. Reduce water in feces 5. Reingestion of infant wastes by lactating mothers female gains back water she lost through lactation (1/3 regained). Lick offspring to stimulate urination and defecation. C. Water budget for a desert animal Kangaroo Rat: do not drink free water25 degrees C, 20% humidityIII. Comparison to humans Human % Kangaroo Rat %GainsDrinking 48 0Free water in food 40 10Metabolic water 12 90Losses2Mammalian blood plasma 300 mosmols Human urine 1200 mosmolsBanner-tailed K rat

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UMD BSCI 334 - Exam III

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