REGULATING THE INTERNAL ENVIRONMENT

1. REGULATING THE INTERNAL ENVIRONMENT

2. Thermoregulation Q10 effect- there is a 2-3 times increase for metabolic reactions for each 10°C rise in temperature. Conduction-direct transfer Convection-movement of air or water past a surface Radiation-between objects not in contact through electromagnetic waves Evaporation-removal of heat from the surface of a liquid by losing molecules as a gas Can all of these be a source of gain or loss?

3. Ectotherm-low metabolic rate does not generate enough heat to effect body temperature. Endotherm-High metabolic rate generates heat to maintain body temperatures higher than the environment

4. Thermoregulation • Adjusting the rate of heat exchange between the animals and surrounding. Vasodilation--- vasoconstriction--- Countercurrent heat exchangers • Cooling by evaporative loss. Panting and perspiration- only way to lose heat if environment is warmer than the body temperature • Behavioral responses. Positioning; hibernation; migration • Changing the rate of metabolic heat production. Shivering; Nonshivering thermogenesis-hormones cause mitochondria to increase their metabolic rate; special tissue called brown fat

7. acclimatization- stress-induced proteins which include heat-shock proteins torpor-general term for a physiological state in which activity is low and metabolism decreases hibernation- estivation- daily torpor-

8. Belding’s ground squirrel hibernates to conserve energy

9. Osmoregulation can drink seawater Involves some type of transport epithelium that have selectively permeable membranes for the transport of specific solutes. Many tight junctions between cells. Use large amounts of ATP for active transport. Purpose is to maintain the composition of the cytoplasm of the body’s cells. Accomplished indirectly by maintaining the interstitial fluid and blood

10. Less toxic-Higher conc. less water Most toxic-Low concentrations more water released Least toxic-Highest conc. least water

11. osmoconformer-does not actively adjust its internal osmolarity because it lives in an isoosmotic environment osmoregulator-must control its internal osmolarity because it internal fluids are not isoosmotic with its environment stenohaline-cannot tolerate substantial changes in external osmolarity and thus are usually osmoregulators euryhaline-can tolerate substantial changes in external osmolarity

14. Anhydrobiosis- tardigrades (water bears) inhabit temporary ponds; can go from 85%-2% water and survive for ten years

16. Key functions of Excretory Systems

17. Protonephridia of planarian flame-bulb system-fluid is filtered into the bulb; produces very dilute urine but there is some reabsorption of solutes by the tubules.

18. Metanephridia-take in coelomic fluid (filtration) and then reabsorb the nutrients; produces a dilute urine that allows them to get rid of excess water absorbed from damp soil

19. Malpighian tubules of the insects; nitrogenous wastes are secreted into the lumen of the tubes from the hemolymph and then it passes into the rectum; nitrogenous wastes are converted to insoluble nitrogenous wastes and are released with the solid waste

21. vasa recta

22. Adjustments on NaCl, K+ and pH Filtration Reabsorption & Secretion permeable to water but impermeable to NaCl interstitial fluid is more hyperosmotic Active transport permeability to water is affected by ADH Passive transport impermeable to water permeable to NaCl

26. ADH-increases the permeability of the collecting ducts to water Juxtaglomerular apparatus near the afferent arteriole secrete renin when the BP drops; renin converts angiotensinogen to angiotensin IIthat increases BP in several ways Aldosterone-causes distal tubules to reabsorb more NaCl and water thus increasing blood volume and pressure Atrial natriuretic factor lowers BP by opposing renin and aldosterone