1. Controlling the Internal Environment
Thermoregulation
Osmoregulation
Excretion

2. Thermoregulation
Ectothermic
Endothermic
Poikilothermic
Homeothermic

3. Heat Exchange

4. Heat Exchange Conduction - direct transfer of heat
Convection - transfer of heat by the movement of air or water across a surface
Radiation - emission of electromagnetic waves
Evaporation - loss of heat from changing a liquid into a gas

5. Body Temp vs. Ambient Temp

6. Thermoregulation Adjustments
Adjusting the rate of heat exchange
vasodilation/vasoconstiction
countercurrent heat exchange
Cooling by evaporation
Behavioral responses
Changing the rate of metabolic heat production

7. Endothermic Animals
Invertebrates
Large flying insects
Honeybees

8. Endothermic Animals Fish Countercurrent heat exchange Bluefin tuna
Swordfish
Great white shark
Countercurrent heat exchange

9. Amphibians and Reptiles
Most are ectothermic
regulate temperature by behavior

10. Mammals and Birds Contraction of muscles Nonshivering thermogenesis
moving
shivering
Nonshivering thermogenesis
triggered by hormones

11. Feedback Mechanisms High body temperature Low body temperature
hypothalamus activates skin blood vessels to dilate and the sweat glands to produce sweat
Low body temperature
hypothalamus activates skin blood vessels to constrict and the skeletal muscles to shiver

12. Temperature Range Adjustments
Slow changes
acclimatization (enzymes and membranes)
Fast changes
heat-shock proteins

13. Metabolic Cycles
Torpor
Hibernation
Aestivation

14. Osmoregulation
Osmoconformers vs. Osmoregulators

15. Osmoregulation Marine Fish Freshwater Fish hypoosmotic
lose water to environment
must excrete salt
small amounts of urine
Freshwater Fish
hyperosmotic
gain water from environment
must take in salt
large amounts of urine

16. Functions of the Excretory System
Filtration
Reabsorption
Secretion
Excretion

17. Excretion of Nitrogenous Waste
Ammonia
Urea
Uric Acid

18. Invertebrate Structures
Protonephridia (flame cells)
network of closed tubules
used mostly for osmoregulation
found in platyhelminthes, some annelids, mollusk larvae

19. Invertebrate Structures
Metanephridia
Open tubules surrounded by a nephrostome
Osmoregulation and excretion
Found in annelids

20. Invertebrate Structures
Malpighian Tubules
Open into the digestive tract
Osmoregulation and excretion
Insects and terrestrial arthropods

21. Excretory Systems Origins in Vertebrates
Pronephros, Mesonephros, Metanephros

22. Vertebrate Excretory Systems
Pronephros
adult hagfish, embryonic fish, amphibians, reptiles, birds, mammals
Mesonephros
adult lamprey, fish, amphibians, embryonic reptiles, birds, mammals
Metanephros
adult reptiles, birds, mammals

24. The Human Excretory System
Kidneys
Ureters
Urinary Bladder
Urethra

26. Blood Filtrate to Urine
Bowman’s Capsule and the Glomerulus
(filters the blood)
Proximal tubule
reabsorbed (NaCl, Potassium, Water, Nutrients)
secretes ( ammonia)
regulates (pH)

27. Blood Filtrate to Urine
Loop of Henle
Descending loop
reabsorbed (water)
Ascending loop
reabsorbed (NaCl)

28. Blood Filtrate to Urine
Distal tubule
reabsorbed (NaCl, Water)
secrete (potassium)
regulate (pH)
Collecting duct
reabsorbed (NaCl, Water, Urea)

30. Control of the Kidney Antidiuretic hormone (ADH)
water reabsorption
Renin-angiotensin-aldosterone system (RAAS)
Atrialnatiuretic Factor (ANF)
inhibits the release of renin