Avian Anatomy 1 Flashcards
What are three things that makes birds different to other vertebrates
- flight
- Feathers
- Egg laying
What are the musculoskeletal adaptations (4)
- Pneumatic bones
- Bone fusions
- Strong pectoral girdles
- Pectoral limb and wing structure
Name the 3 bones in the pectoral girdle
- Coracoid - very strong
- Scapula - mighty bound to rib cage
- Clavicle - fuses midline
Function of the pectoral girdle
forms stable support for wind
What does the humerus articulate with
Scapula and coracoid
What three systems are the head divided into
- Neurocranium
- Splanchnocranium
- Mandibula
What bone holds the upper beak
Incisive bone
How many bones of fusion are the mandibula
6 bones
What animal does the neck of a bird replicate
Reptile
What does the neck of a bird lack
Fibrocartilage discs
Modification of the sternum
- Large
- Large attached flight muscles
What shape is the thorax
Triangulated bone structure
Function of the pectoral girdle
Stabilises the cranial thorax
Function of the cranial sternum
articulates from coracoid
What action does the crania sternum have
Hinge action
Where do the ribs flex
Vertebrosternal rib junction
What is the thoracic movement
Cranio-caudal
Name the two parts of the sternum
- Lateral plates
2. Ventral plates
What is the triosseal canal
Junction between clavicle, coracoid and scapula. Passage for tendon of supracoracoideus m elevator wing
What muscle causes the down beat
Pectoralis
What muscle causes the up beat
Supracoracoideus
Purpose of fusion bones in limb (4)
- Reduce muscle weight
- Restrict ranges of movement
- Reciprocal apparatus
- Radius/ulna act as pantograph
Where is the caudal axis fusion
vT5 - vL - vS - vC
Which way does the pelvic girdle open
Ventrally to allow eggs to pass
Which bones do air sacs extend into (3)
- Scapula
- Femur
- Humerus
How do birds perch with minimal muscular effort
Tendon of the digital flex muscle passes caudal to the tarsal joint before running into each digit
What does ratites refer to
Flat sternum
Epidermis of birds
Thin, lightly keratinised, no sebaceous glands
What do brood patches do
Promote heat transfer from the hen to her eggs
What do claws enclose
Phalanx
What are ornamental structures made of
Sexual attraction and heat exchange
What do uropygial glands do
water proofing of feathers
Name the 3 types of feathers
- Contour feathers
- Filoplume feathers
- Down feathers
Describe contour feathers
- Firm barbs, barbules and hooklets
Describe filopxme feathers
No or little vane at each contour feather
Describe down feathers
Soft barbs, no hooklets, fluffy and insulating
What are pterylae tracts
Symmetrical tracts over the body in which contour feathers follicles are distributes
What are apteria tracts
Bare spaces between the tracts and perfect place for surgery
What does the process of moulting do
- Replace worn out feathers and usually happens after the breeding season
- Provides brightly coloured feathers for courtship and mating
