Avian Anatomy Flashcards
Uncinate process
Extensions of bone that project caudally from the vertical segment of each rib.
Prevents excessive compression of the thorax.
Choanal slit
Connects the oropharynx with the nasal cavity.
Coracoid
Short bone extending from the sternum (acts as a wing strut).
Calamus
Proximal shaft.
Hollow inner portion of the feather shaft that lacks barbs and attaches to the skin.
Opening at the tip is the pathway for blood vessels.
Synsacrum
Fusion of the bones to decrease flight stress and wind resistance.
Usually consists of ilium, ischium, lumbar, sacral, and first 6 caudal vertebrae.
No ventral pelvic symphysis.
Rachis
Distal shaft. Vane and barb attach to it.
Furculum
Pair of clavicles; ”wishbone”.
Acts as a strut to brace the wings apart.
Preen gland
Surface gland found at the base of the tail that functions to secrete a mixture of waxes, lipids, and other organic compounds which the bird applies to its feathers.
Pygostyle
Fusion of the last few coccygeal vertebrae.
Acts as an anchor for the main tail feathers.
Cecal tonsil
Lymphoid tissue present at the most proximal part of the cecae.
Tibiotarsus
The largest bone in the leg.
Fusion of the tibia and proximal tarsal bones (drumstick).
Cloaca
The colon.
Receives waste from the large intestine and materials from the urinary and reproductive systems.
Syrinx
Muscular structure found at the tracheal bifurcation.
Responsible for vocalization.
Bursa of Fabricius
Where B-cells are programmed.
Off-white, fleshy structure.
Dorsal to the cloaca/colon.
Prominent in juvenile birds.
Involutes in sexually mature birds.
Crop
Out-pocketing of the esophagus that provides storage for consumed food.
Foodstuffs moistened and softened.
Lined with simple columnar epithelium.
Thin tunica muscularis.
Located on the right side of the neck.
Proventriculus
Glandular stomach where the first significant amount of digestive juices are added.
Mucosal ridges (look like papillae).
Simple columnar epithelium.
Large submucosal glands.
One type of glandular cell.
Gizzard
Mechanical stomach. A muscular organ used to grind and break up food.
May contain grit eaten by animal.
Lined by a thick keratinized layer but is not a keratinized epithelium.
Simple cuboidal to columnar epithelium. Amorphous substance is the pellicle.