POUL 4200 E1

What characteristics of archaeopteryx are like modern birds

feathers, wishbone (clavicle)

what characteristics of the archeopteryx is unlike modern birds

teeth, boney tails

atavism

reemergence of previous ancestoral gene

vestige and ex

retention of a structure or behavior over evolution even if its function is lost

ex.) goosebumps, we still get them even tho our hair isnt thick

why is talpid 2 mutation significant

it proves atavism with increased Hedgehog signaling causing limbs and teeth in chicken

6 uses of feathers

insulation

camouflage

social signaling

brooding

anti-predation

singing?

what order are chicken in

galliforms

what is the largest order of birds

passeriform

heartbeat and bird size relation/lifespan

inverse

average chicken heart rate

250-300

all airsacs of the bird

interclavicular (no pair)

cranial thoracic

caudal thoracic

abdominal thoracic

bird bone fusions (4)

carpometacarpus

synsacrum (fusion of pelvic girdle and many vertebrae)

metatarsus (foot bones fused)

pygostyle (last caudal vert fused)

muscle for downward force

pectoralis muscle

muscle for upward force

supracoracoideus muscle (pec minor)

pec major origin and insertion

origin keel of sternum (carnia sterni)

insertion: ventral surface of proximal humerus

pec minor origin and insertion

origin: carina (keel) of sternum

insertion: dorsocaudal surface of humerus

purpose (3) of uncinate process on ribs and what do they tell

provides mechanical support and strength for ribs, prevents crushing, where respiratory muscles and shoulder attach

tell metabolic demand - brids that fly higher have higher demand for bigger uncinate processes for deeper R cycles

adaptation of GI system to help birds fly

short lightweight LI for flight

how does birds stomach differ from humans

birds have multiple champers to compendate for not having teeth

crop - holding area

proventriculus - HCl and proteases

gizzard - grinding

passage rate for chicken and human

chicken : 3-4 h

human : 24-72 hours

what are hollowed bones called

pneumatic

how does fresh air move though lungs

birds move their sternum in and out

funcs of integumentary system (5)

protection and physical barrier

sensory organ

V-D syn at legs cuz no feathering

thermoregulation

coloring

why is chicken skin so thin

cuz of feathers and they dont wana have thick skin on muscle area to restrict movement

3 layers of epidermis (superficial to deep)

stratus corneum

stratus spinosum

stratus basale

what is W about dead keratinized skin layer of stratum corneum

resists abrasion, microbial penetration, water loss

what type of cells consist of the stratum basale

epidermal stem cells which divide —> karatinocytes that replace lost surface cells

what allows for tight structure of stratum spinosum (2)

desmosomes and tight junctions

what pigments are found in keratinocytes

melanin and carotenoids in stratum basale

peterylae

areas where feathers grow

apteria

areas where feather don’t grow

how does blood supply change for feathers

growing feathers have blood supplied to follicle and when they become mature theres no more blood supply (why they have a hollow end)