Birds 2 Flashcards
What is the name of the fused clavicles
Furcula
Describe which eyelids of the chicken shut during sleeping and blinking
3rd eyelid blinks
1st and 2nd shut during sleeping
How does the chicken eye differ to mammals?
Thinner cornea
Softer lens
Thick, avascular retina
No tarsal glands
The beak doesn’t chew food, but breaks it to make it smaller. It also reduces weight, as it has no teeth. What are the upper and lower beaks called?
Upper - rhinotheca
Lower - gnathothetca
The cere is a waxy substance at the beak base. Which birds have this?
Raptors, parrots, owls, budgies
Used for sexing in budgies
Are the nares at the proximal or distal cere? Which species is the exception?
Proximal
Owls distal
What side of the body is the oesophagus one? What is this lateral to?
Right
Glottis
What is used for swabbing in the chicken? What is this?
Choanal slit
Opening that connects oral to nasal cavity
Do chickens have a pinna? What protects their ears?
No
Auricular feathers
How many chambers are in the chicken heart? How does their CO compare to mammals and why?
4
Higher CO - large amounts of blood pumped to head, wings and flight muscles
What is the HR and BP of a chicken? Do they have nucleated or non-nucleated red blood cells?
Both high
Up to 800bpm
BP = 180/140
Nucleated
Do chickens have a diaphragm? How does the thoracic cavity expand?
No
Expands via thoracic/abdominal muscles
(Lungs are fixed and don’t expand - but air sacs do)
What is the syrinx? What does it do?
Last few tracheal rings, first few bronchial rings and central tympanic membrane
Allows vocalisation
Where does air go when breathed through chicken nares?
Rostral, middle and caudal conchae (turbinates - warms/filters) Trachea Trachea bifurcates Primary/secondary bronchi Parabronchi Air capillaries (no alveoli)
How many air sacs do birds have? Where are they?
9 1 interclavicular 2 cervical 2 anterior thoracic 2 posterior thoracic 2 abdominal
What are air sacs? Where do some extend to?
Mucoserous extensions of secondary bronchi
Pneumatic bones
Do chickens have lymph nodes? Where are immune cells produced?
No lymph nodes
Immune cells produced in embryonic liver, yolk sac ad bone marrow
Where are B cells produced in birds? Where are T cells produced?
B - Bursa of fabricus (dorsal cloaca)
T - thymus
What is the primary lymphatic organ in birds? When does this take over B/T cell production?
Bone marrow
After thymus/bursa of fabrics have receded (rudimentary/absent in adults)
What are the secondary lymphoid tissues in a chicken?
GALT - gut RALT - respiratory CALT - conjunctiva Spleen Harderian gland
Describe the order of the bird GI tract
Oesophagus Crop Proventriculus Ventriculus (gizzard) SI Caeca and LI
What is the crop? Is it present in all birds?
Elastic muscular structure in oesophagus
Temporary food storage
Not all birds
How can the crop be used to help feed young? What do pigeons have that is significant?
Fat filled epithelial cells - sloughed off and regurgitated to feed young
Pigeons have double sack that produces crop milk
What is the proventriculus?
Glandular stomach
Secretes digestive enzyms
What is the ventriculus? Which birds may it be reduced in? Why may it contain grit?
Muscular stomach
Birds that have liquid diet or eat whole prey
Avoid grinding
The SI of a bird is highly coiled, or short and simple in meat eaters. What is found at the junction between the jejunum and ileum? What is this?
Meckel’s diverticulum
Remnant of yolk sac attachment
What are caeca? Which birds have large caeca?
Outpouches of GI
Galliformes (chickens, turkeys)
Where is the liver found in birds? Describe it
Caudal to heart (no diaphragm)
Bilobed
Right lobe larger
Do chickens have a gall bladder?
Yes
Where is the pancreas located in a bird? What does it produce?
Within the duodenal loop
Exocrine - digestive enzymes
Endocrine - insulin, glucagon, somatostatin
How do seed eaters GI differ from fruit eaters GI? (birds)
Seed - well developed crop, proventriculus and ventriculus, long GI and distinct caeca
Fruit - shorter intestines, less distinct caeca
Describe the GI of meat/fish eating birds
Rudimentary caeca and ventriculus
Well developed pancreas and proventriculus
What separates the coprodeum and urodeum?
Coprodeal fold
What is the site of haemotpoiesis in birds? Where is this?
Bursa of fabricus
Dorsal cloaca
How many lobes does each bird kidney have?
3 per kidney
Cranial middle caudal
Do chickens have a renal portal system? Do they have a bladder?
Yes
No bladder
What type of nephrons do chickens have (mammal or reptilian)?
Mix
Lots of water is lost through bird kidneys. How is it reuptaken?
Via colon
What is in bird urine?
Uric acid mixed with copious mucus
Where is uric acid produced and excreted?
Produced in the liver
Excreted in urine (white precipitate)
What are the parts to normal bird droppings?
Green part - faeces
White part - urates
Clear - urine
Where are the testes in a bird? When does spermatogenesis take place?
Abdominal cavity
During the night - lower body temperature
Do birds have an epididymis? Do they have accessory sex glands?
Short epididymis - little sperm storage
No accessory glands
Phallus is present in some birds. Which birds have an intromittent phallus? How do non-intromittent and birds with no phallus fertilise?
Intromittent - ducks, geese, ratites
Non-intromittent - fertilise by touching
Psittacines - no phallus, fertilise by everting cloaca containing papillae
Which ovary and oviduct is more functional in birds? Why? Where are ovaries located?
Left - functional
Right not fully developed
Cranial to kidneys
After laying, when do chickens next ovulate?
30 mins after laying
Continuous layers
Chickens are continuous layers. What may other birds be?
Indeterminate layers - produce clutches, can replace lost eggs
What is the female repro tract of a chicken?
Ovary Infundibulum Magnum Isthmus Uterus Vagina
Describe egg production and how long each takes?
Infundibulum - catches ovulated follicle, site of fertilisation (15 mins)
Magnum - egg white/albumin develops around follicle (3 hrs)
Isthmus - shell membrane produced (1 hr)
Uterus/shell gland - calcification of shell (20 hrs)
Vagina - adds cuticle and stones egg
What is crop impaction?
Failure of food to leave crop and enter proventriculus
What is sour crop?
Yeast infection of crop, causes thickening
Yeast infections often due to weak immune system
What is Macaw wasting disease?
Proventricular dilation
Due to weak muscle contractions and nerve damage
What is papillomatosis?
Viral infection affecting mouth/cloaca
Looks like a prolapse
Worstened by stress
What parasites affect birds?
Giardia spp
Trichomonas spp
Tapeworm (rare)
What is follicular stasis?
Inappropriate follicle maturation without ovulation
What is air sacculitis?
Inflammation of air sacs
Secondary to bacterial infection
What can fractures/trauma to pneumatic bones cause?
Subcutaneous emphysema
