avery Flashcards
what are the main features of the avian bones compared to mammals
main features of avian bones:
The cortex of the avian bone is much thinner
Avian bones are long bones and hollow
Avian bones have a high mineral content
Within the bones lightweight struts which create a honey comb interior which reinfources the bones. They are pneumatised
what is the definition of pneumatised
bones filled with air contained in membranous air sacs that connect with the respiratory system. They are an extension of the air sacs
what is the purpose of Pneumatised bones
makes the bird lighter
what size of bones are Pneumatised
Pneumatised bones are usually larger
why are Pneumatised bones usually larger
the larger bones are generally heivier therfor the bird becoms lighter
what types of birds would not have Pneumatised bones?
flightless birds
diving birds
what bird does not have any Pneumatised bones?
waders
describe the sternum in avian skeletal systems
the sternum is extended to form a laterally flatterend keel to provide a large surface area for attachment of flight muscles. flightless birds do not have a keel
what is a keel
the sternum
describe the coracoid in avian skeletons
is a large bone that lies between the keel and shoulder bone. it counteracts the action of flight muscles and supporting wing.
desribe the joints in avian skelitons
there are a reduced number of joints in an avian to provide a rigid trunk and aid the action of flght muscles
how many cervicle vertibrate do avian necks have
between 11 and 24
why would an avian neck contain 7 more vertibrea than mammals
a long neck allows flexibility and aids vision for survival, preen and to catch food.
describe the beak
the beak replaces the teeth and reduces the weight of the skeliton. the shape of the beak redlects on the dies
descrive the quadrate bone
its between mandible and skull makes jaw dislocation unlikely.
