Birds 3 Flashcards
What are the 2 parts of the beak?
tomia (maxillary and mandibular parts) and rictus (caudalmost part)
How are bird beaks shaped?
vary depending on diet
What material is the beak made of?
Exterior = keratin Interior = foam-like material
T/F: Birds have a complete hard palate
False; it is incomplete with a choanal slit
Why will birds sometimes get seeds in their nose?
Their hard palate is incomplete and there is no barrier between the oropharynx and the nose
What do birds lack in the oropharynx/mouth region that mammals have?
True salivary glands
What are some reasons that the choanal papillae can become blunted?
Vitamin A deficiency or chronic respiratory infections
What is the only spp to have intrinsic tongue muscles?
parrots
What can you use to open the beak during a physical?
speculums
What is the woodpecker tongue like?
wood-like; no instrinsic muscles; begins in infraorbital area and wraps all the way around the head to the mouth
What side is the bird esophagus on?
right
What is the crop?
Diverticulum associated with the esophagus that serves as a storage area; not present in all spp
What do some birds (i.e. pigeons) secrete from the crop?
Nutritive regurgitation AKA “pigeon milk”
What are the 3 parts of the avian stomach?
- Proventriculus
- Isthmus of the stomach
- Ventriculus (gizzard)
What is the glandular part of the avian stomach?
proventriculus
What is the function of the ventriculus?
Proteolysis and mechanical digestion
What does the ventriculus have on the inside that protects it?
cuticle (koilin) layer
What is the shape of the duodenum and what is associated with it?
U-shaped, has the pancreas in the middle
What is the Meckel’s diverticulum and why is it important?
Remnant of yolk sac on the antimesenteric side of the intestines; orad to it is jejunum, aborad to it is ileum
How many ceca do birds have?
2
What determines size of the ceca?
Bird’s diet; birds that eat roughage have enlarged ceca, birds that need minimal fermentation (i.e. raptors) have smaller ceca
What is the coprodeum?
First portion of the cloaca, where fecal material is stored (part of GI)
What is the urodeum?
2nd portion of cloaca, part of urogenital tract into which urine is excreted (common opening for urinary and repro systems)
What is the proctodeum and what structures are associated with it?
3rd portion of the cloaca; have the phallus, cloacal bursa, and then opens into the vent
How many lobes does the liver have?
left and right
Does the bird have a gall bladder?
Yes but it is not present in all spp
What is the major bile pigment in birds and what color is associated?
Biliverdin; reason that birds turn green instead of yellow when jaundiced
Where is the kidney located?
In the renal fossa of the ilium
What does the testicle look like?
Like a mammalian kidney
What are the parts of the kidney and how are they supplied?
Cranial, middle, caudal; each have their own blood supply
Where are the testes found?
near cranial lobe of the kidney
What are the 2 nephron types in birds and which is prominent?
cortical (prominent) and medullary
What is the waste product from the cortical nephrons?
uric acid
What is the waste product from the medullary nephrons?
Urine, but is not as concentrated as mammalian urine because their medulla isn’t as large as in the mammal
What are the 3 types of bird droppings?
feces, urates, urine
Where can venous blood from the pelvic limb drain into?
caudal vena cava and renal portal veins –> renal parenchyma
Why do you want to avoid the pelvic limbs if giving a nephrotoxic injection?
Bc the pelvic limbs drain into the renal system; want to go into the pectorals instead
What is the order of the 3 main nerves we need to know from cranial to caudal?
femoral, obturator, sciatic
What is a pretty tell-tale sign that a bird has an abdominal tumor?
Paralysis of the sciatic nerve causing leg dysfunction/paralysis
How many eggs can a kiwi bird lay and what does it weigh?
Only lays one, can be up to 25% of its body weight
Which side of the repro tract in females regresses?
right
Where does the female repro tract open into?
urodeum
What are the parts of the oviduct, starting where the egg first travels?
- Infundibulum
- Magnum
- Isthmus of the oviduct
- Uterus
- Vagina
What are the two parts of the infundubulum?
Proximal (“funnel”) and distal (“tubular”)
What is the function of the proximal or funnel infundibulum?
captures the egg
What is the function of the distal or tubular/chalaziferous infundibulum?
helps keep the yolk centered
What is the longest and coiled part of the oviduct?
magnum
What does the magnum secrete?
Majority of albumen
What is the isthmus of the oviduct made up off and what is its function?
Has sulfur-containing proteins and produces inner and outer shell membranes
What happens in the uterus?
It “plumps” the egg by secreting water and adds the majority of the shell
Where is the spermatic fossulae and what is its function?
At the uterovaginal junction; some spp can store sperm for up to a year depending on the environment the bird lives in
What potential systems are affected if a bird is egg bound?
Kidneys, nerves, and GI (cannot get rid of waste)
How do the testes differ in size and when?
During breeding season are often larger/hypertrophied compared to non breeding season
What is the shape of the ductus deferens during breeding season?
More coiled and hypertrophied compared to non breeding season
What is the rete epididymis?
Attachment that connects with the adrenal gland; can still secrete androgens if the bird is caponized
How can you sex a bird?
By looking at the ceres color, but if no distinct difference then can scope thru abdominal air sac or by genetic testing
Where does the ductus deferens run?
Next to the ureter
What is a phallus?
Found in males, not the same as a penis and has no urethra but is more of a groove on which secretions from the ductus deferens runs allowing for the cloacal kiss
What is unique about the phallus of water fowl?
They can go outside of the cloaca; enlarges during breeding season but otherwise kept coiled up in the proctodeum
Why are vaginas convoluted?
Males can be aggressive during breeding so this adaptation helps to deter males and slow the breeding process
What % of the bird’s body weight are its eyes?
11-15%
Why does the bird eye not move much?
They have poorly developed extraocular muscles so have to move their heads more to see things
What are the features of the 3rd eyelid?
It is not passive, has a skeletal muscle that pulls it across, and originates from dorsomedial
What is unique about the iris of the bird?
It has voluntary control of the iris with variable amounts of striated muscle so can control pupil size
Does atropine cause mydriasis in birds?
No because of the voluntary control of the iris
What are characteristics of the avian vitreous chamber?
Well developed choroid, no tapetum, and avascular retina
What is the pecten?
Pigmented, pleated, vascular structure of the eye that projects from the rear surface near the optic nerve; function is unclear but is thought to provide nourishment to the retina
What covers the optic disk?
pecten
