Avian anatomy Flashcards
patagium
wing from shoulder to wrist
completes airfoil of wine
alula
thumb
allows slowing of flight (flare- nose up wheels down on airplane)
Adaptations for flight
- Lightweight, rigid airframe
- Hollow bones
- High metabolic rate
- Feathers
- External embryonic development
- Highly efficient respiratory oxygen exchange system
bird bones
- Hollow
- Medullary bone laid down as pullet (young female).
- Allows for flux of calcium for egg production
- Can become depleted
- strengthened with criss cross struts
feathers function
- Insulate
- Waterproof
- Aerodynamic and Provide Airfoil
- Courtship, Display and Mating
- Camouflage
- Sensory
what are feathers, beaks and claws composed of?
**β-Keratin **
Mammal hair, hoof and horn is α-Keratin
apterylae
area with no feathers
pterylae
area with feathers
pigment based feather colors
Melanins – Tiny granules.
Black, reddish brown, pale yellow
Also add strength to feather, why tips of wings are black
carotenoids
feather color
Red, yellow, pink
Carotenoids are ingested and incorporated into the feather
once grown, doesnt change color
ex: flamingos eat carotenoids when young and turn pink
porphyrins
feather colors
Modification of Amino Acids
Reds, greens, browns, etc.
structural feather colors
Iridescent feathers – light strikes the feather and is reflected from the microscopic structure, similar to a prism.
Tiny air pockets in barbs results in the blues of jays.
Ultraviolet reflection
Uropygeal gland
waterproofs feathers
pectoralis muscle
adduct limbs
power stroke down
supracoracoideus muscles
abduct wing, raise wing
bird hearts
High HR (large species differences)
high heart weight to body weight ratio
left ventricle»> R ventricle
bird heart valves
R AV valve is muscular, not tendinous
L is tendinous
torpor
Profound hypothermia
Mechanism for small birds to conserve energy during cold weather
avian respiratory system
Lungs are rigid, fixed and non-expandable, air sacs expand instead
No diaphragm
Lungs continually bathed in fresh, Oxygen rich air via a 4-stroke respiratory pattern.
The **trachea has solid rings **and a proportionally greater diameter than mammals.
Larger tidal volume than mammals.
4 stroke respiratory pattern
- Inspiration 1: Our nitrogen molecule is inhaled and finds itself in the caudal air sacs.
- Expiration 1: The bird exhales. Our nitrogen molecule finds itself in the lungs.
- Inspiration 2: The bird inhales again. The nitrogen molecule passes from the lungs to the cranial air sacs.
- Expiration 2: The bird exhales and the nitrogen molecule is freed into the atmosphere once again.
syrinx
makes bird voice
bird RBCs
nucleated
bird digestive system
Copious salivary secretions
Crop for food storage, pigeon milk
Proventriculus ≈ stomach (pepsinogen, HCL)
Great digestive efficiency
Paired cecal pouches (helps break down cellulose) cecal dropping ~ 1 in 10 voids
bird renal system
Urecotelic: Protein metabolism: Uric Acid
Urine may be liquid and urate.
May pass urine and feces together
