AVIAN PHYSIOLOGY Meeting the demands of flight
Dec 24, 2015
FlightMost 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
FlightMost E-demanding type of locomotion (E/T)
Most efficient type of locomotion (E/D)
Hi metabolismRespiration
Circulation
Excretory System
Flight
Hi metabolismRespiration
Circulation
- BMR can increase (2-25)- Glucose levels 2 mammalian- Mean body Temp ~40°
- nerve impulse trans. - spd/strength muscle contrac.
Flight
Hi metabolismRespiration
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
Flight
Hi metabolismRespiration
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
Flight
Hi metabolismRespiration
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 H2OVerdin (9-10g): replaces 4.5g ml H2O/dy 100% H2O & 50% body mass
- Hyperthermia: higher body temp reduces loss of H2O
Evaporative water loss N turnover/loss
Flight
Hi metabolismRespiration
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 H2OVerdin (9-10g): replaces 4.5g ml H2O/dy 100% H2O & 50% body mass
- Hyperthermia: higher body temp reduces loss of H2O
Excrete N as Uric Acid crystals not Urea[0.5 ml H2O to flush 370 mg N as Uric Acidvs. 20 ml H2O to flush the same as Urea]
Evaporative water loss N turnover/loss
Excretory System
Flight
Hi metabolismRespiration
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
Air Post Air sacs lungs Ant Air sacs Out
(Inhale) (Inhale)(exhale) (exhale)
Excretion
No diaphragm, but spring-likeaction 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
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
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 exchangeHb efficiency: Duck [O2] gradient between venous and arterial ~ 60%
Humans ‘’ ‘’ ‘’ ‘‘ ‘’ ~ 27%
Temperature CO2 } help dissociation
Excretion
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