BIOL 1361 1nd Edition Lecture 20Outline of Last Lecture I. Negative FeedbackII. Regulation of blood glucoseIII. Figure 33.19IV. Retrieval of Store Glucose for UseV. Hormonal Regulation of Blood GlucoseVI. ThermoregulationVII. ThermogenesisOutline of Current LectureI. ConductionII. ConvectionIII. RadiationIV. EvaporationV. Regulating Heat ExchangeVI. BioenergeticsVII. OsmoregulationVIII. OsmolarityIX. Osmotic ChallengesX. Marine AnimalsThese 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.XI. Terrestrial AnimalsXII. Metabolic WasteCurrent LectureI. Conductiona. When two substances are in visible contact with each otherb. Direct transfer of heat between objects in contactc. Ex. leaning against a warm brick wall on a cold dayII. Convectiona. Heat transfer by moving fluidb. Heat transfer by fluid flowi. Ex. Breeze, water flowIII. Radiationa. Electromagnetic radiation coming from objects warmer than absolute 0i. Ex. Snakes use thisii. Most animals: infraredIV. Evaporationa. Liquid molecules with enough kinetic energy to escape as gasb. Departing high energy molecules remove heatc. Ex. sweatingV. Regulating Heat Exchangea. Behaviori. Seeking or avoiding environmental heatii. Ex. regulating body temp by how the animal acts1. Basking to warm2. Seeking shade to coolb. Insulationi. Feathers of hair1. Increase or decrease thickness by fluffing2. This will trap warm air next to bodyii. Blubber1. Subcutaneous fat in marine mammals2. Not easily changeablec. Circulation of body fluidsi. Vasodilation1. Superficial (near surface) blood vessels widen2. There’s more opportunity for heat exchange here 3. A way to increase heat exchange with environment4. Not about changing the body temp, it changes the exchangeii. Vasoconstriction1. Superficial blood vessels become narrower2. Decreases heat exchange with environment3. Helps reduce heat gain from the environmentiii. Counter-current Exchange1. Fluid flow in opposite directions maximizes concentration difference between fluidsa. Equilibrium does NOT developb. Therefore, exchange of a substance between fluids is maximizedd. Evaporationi. Body water:1. Sweating 2. Pantingii. External water source:1. Bathing VI. Bioenergeticsa. The overall flow and transformation of energy in an animalb. Greater SA: Volume i. More exchange of:1. Heat 2. Water 3. Solutesii. Have higher maintenance costVII. Osmoregulationa. Controlling solute concentration and water gain/loss from body fluidsb. Purpose: to maintain cell function through requiring specific, stable solute concentrationVIII. Osmolaritya. Moles solute particles/Lb. Units: mosm/Lc. M = mol/Ld. Not the same as molarity because some solutes dissociate in aqueous solutione. Ex. 100 mM MgCl2i. 100 mM = 100 mmol/Lii. 100 mmol Mg2+ + 100 mmol Cl- + 100 mmol Cl- per literiii. = 300 mosm/LIX. Osmotic Challengesa. Conformers and regulatorsb. Conformer – internal conditions can be stable for them if and only if external conditions are stablec. Regulator – hypoosmotic animal looses water, gains saltX. Marine Animals Fig 32.15?a. Bony fishi. Body fluid 300 mOsm v. seawater 1000 mOsmii. Challenge:1. Water loss and salt gainiii. Solution:1. Drink salt water2. Excrete Na+ and Cl- by active transport3. Net Result: water conservationb. Freshwater animali. Body fluid 300 mOsm v. water 0.5-15mOsmii. Challenge: 1. Water gain and salt lossiii. Solution1. Import Na+ and Cl- by active transport2. Excrete dilute urine3. Net result: solute (salt) conservationXI. Terrestrial Animals a. Like us and roadrunnersb. Challenge: i. Dehydrationc. Solution:i. To reduce dehydrationii. Nocturnal activityiii. Keratinized skin – waterproof their skin iv. Waxy coating on exoskeleton (insects)XII. Metabolic Wastea. Protein and nuclei acid breakdown NH3i. NH3 + H+
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