1. AVIAN PHYSIOLOGY Meeting the demands of flight

2. Flight Most E-demanding type of locomotion (E/T) Most efficient type of locomotion (E/D) - An integrated physiology - Solutions and costs associated w/ meetings the demands of flight - Comparative physiology - largely with mammals - Basic

3. Flight Most E-demanding type of locomotion (E/T) Most efficient type of locomotion (E/D) Hi metabolism Respiration Circulation Excretory System

4. Flight Hi metabolism Respiration Circulation - BMR can increase (2-25  ) - Glucose levels  2 mammalian - Mean body Temp ~40° -  nerve impulse trans. -  spd/strength muscle contrac.

5. Flight Hi metabolism Respiration Circulation - BMR can increase (2-25  ) - Glucose levels  2 mammalian - Mean body Temp ~40° -  nerve impulse trans. -  spd/strength muscle contrac. In flight 2-25  BMR  CO 2 in blood; ~8 pH  Heat

6. Flight Hi metabolism Respiration Circulation - BMR can increase (2-25  ) - Glucose levels  2 mammalian - Mean body Temp ~40° -  nerve impulse trans. -  spd/strength muscle contrac. In flight 2-25  BMR  CO2 in blood; ~8 pH  Heat HOW??  Evaporative water loss  N turnover/loss

7. Flight Hi metabolism Respiration Circulation - BMR can increase (2-25  ) - Glucose levels  2 mammalian - Mean body Temp ~40° -  nerve impulse trans. -  spd/strength muscle contrac. In flight 2-25  BMR  CO2 in blood; ~8 pH  Heat - Intake of metabolic water: 1 g fat  1.04 ml H 2 O Verdin (9-10g): replaces 4.5g ml H 2 O/dy 100% H 2 O & 50% body mass - Hyperthermia: higher body temp reduces loss of H 2 O  Evaporative water loss  N turnover/loss

8. Flight Hi metabolism Respiration Circulation - BMR can increase (2-25  ) - Glucose levels  2 mammalian - Mean body Temp ~40° -  nerve impulse trans. -  spd/strength muscle contrac. In flight 2-25  BMR  CO2 in blood; ~8 pH  Heat - Intake of metabolic water: 1 g fat  1.04g ml H 2 O Verdin (9-10g): replaces 4.5g ml H 2 O/dy 100% H 2 O & 50% body mass - Hyperthermia: higher body temp reduces loss of H 2 O Excrete N as Uric Acid crystals not Urea [0.5 ml H 2 O to flush 370 mg N as Uric Acid vs. 20 ml H 2 O to flush the same as Urea]  Evaporative water loss  N turnover/loss Excretory System

9. Urea Uric acid

11. Flight Hi metabolism Respiration Extremely Efficient - Directional - 2 inhales/exhales per cycle - Complete refilling - unidirectional airflow (thru the lungs not into and out of lungs) - Efficiency reduces water loss through respiration AirPost Air sacs lungs Ant Air sacs Out (Inhale) (exhale) Excretion

13. No diaphragm, but spring-like action by the of the furula assists  and  of the chest cavity Increased Efficiency Compared to mammals: - Air breathed into lungs, mixes w/ stale air in alveoli, then out - 1 breath per cycle - Bi-directional - Refilling is incomplete - 20% or more is dead space  1 breaths birds: 3-4 in mammals

14. Respiration Circulation Flight Hi metabolism - 4-chambered heart (compared to single ventricle heart of Reptiles) - Dual circulation (separate pulmonary/systemic) - Avian hearts 50-100% (wt.) larger in birds - More mitochondria, muscle fibers -  pulmonary performance: 100-200 ml blood/kg more efficient - 14% of blood shunted to legs for heat loss As in mammals Excretion

15. Respiration Circulation Flight Hi metabolism - 4-chambered heart - Dual circulation (separate pulmonary/systemic - Avian hearts 50-100% (wt.) larger in birds - More mitochondria, muscle fibers -  pulmonary performance: 100-200 ml blood/kg more efficient - 14% of blood shunted to legs for heat loss Gas exchange Hb efficiency: Duck [O 2 ] gradient between venous and arterial ~ 60% Humans ‘’ ‘’ ‘’ ‘‘ ‘’ ~ 27%  Temperature  CO2 } help dissociation Excretion

16. Other sorts of changes: Digestive: lack teeth but use a gizzard for grinding (stones) Cloaca (Dig, Rep, Uro) Urogenital: All egg laying Single functional ovary/oviduct (left), most males lack phallus No bladder Misc: Females are heterogametic sex RBC nucleated Embryo nutrition is yolk-derived