Bird 2 Flashcards
Common features of avian anatomy
o Shaped and constrained by flight
o High metabolism
o Physiologically extreme
o Birds are reptiles, some similarities are expected
avian beak structure
Avian beak: Keratin layer = ramphotheca (rhinotheca + gnatotheca)
>2 parts
funny things birds have on their heads
-knob
-casque
-comb
-wattles
-snoot
-creast
types of bird feet
Cursorial - ostrich (2 toes in front)
Raptors
Perching
Webbed
different bird feet toe configurations (that are important to us)
anisodactyl - 3 front, 1 back (almost all species)
zygodactyl - X-shape: 2 front, 2 back (almost all the parrots)
important pads on bird foot and why its important
-metatarsal pad - common site for dermatitis
-digital pads
> many foot issues in practice
main roles of feathers
o Flight
o Insulation
o Communication o Sensitive
types of feathers
o Contour feathers (flight and covert feathers)
o Down feathers (includes powder down)
o Bristles
o Filoplumes (simplified covert feathers)
feather anatomy
ranchis in the middle, vanes radiate out
calamus at base (quil)
> each vane has small barbs and hooks of distal barbules
types offeathers
tail, flight, semiplume, filoplume, bristle, down
flight feathers - where they attach, anatomical division
attach to periosteum of the bone
Primary remiges > 10 feathers inward from wing tip
Secondary remiges > on caudal wing aspect
apteric areas
have no feathers
plumage maintenance
o Molting
- Frequency varies
- Pattern varies
o Preening
- Use uropygial gland on the rump
- Use beak
- Use powder down feathers
o Water and dust bath (+ rain)
‘preening gland’ real name and purpose
uropygial gland - make feathers nice and waterproof
structure of bird skeleton - main adaptations for flight
- Pneumatization of most bones by the air sac system
o Except distal wing and legs
o Species variation - Fusion of bones
o Carpometacarpus
o Tibiotarsus
o Vertebral column (notarium, synsacrum, pygostyle)
what bones are fused in birds
o Carpometacarpus
o Tibiotarsus
o Vertebral column (notarium, synsacrum, pygostyle)
bones of the pectoral girdle
-scapula
-coracoid bone
-clavicle
> different from mammals
spring mechanism for flight: components - muscles, bones
m. supracoracoideus - goes through triosseal canal
- sternum
- coracoid
- clavicle
- humerus
m . pectoralis
what is cranial kinesis? who can do it
forward motion in beak, esp. in parrots
important flight muscles
-M. supracoideus > goes through hole, inner
-M. pectorlais, outer
Coelomic Cavities: what ones are present
- Extremely complex in birds
o Pleural and pericardial cavities - Lungs
o 4 hepatoperitoneal cavities - Liver
o 1 intestinoperitoneal cavities - All abdominal organs
- Abdominal air sac
o Cranial group of air sac are in subpulmonary cavity (not a coelomic cavity)
subcavity devisions of celomic cavity, and what they contain
-Subpulmonary cavity (contains cranial air sacs)
-Hepatoperitoneal cavities (contain liver)
-Intestinoperitoneal cavity (contain organs + abd air sac)
a very different system in birds compared to mammals, and why important
respiratory - important for anesthesia and treatment of resp disease
differences in bird resp system
- complete tracheal rings
- sound produced by syrinx
- presence of large air sacs
- respiratory system pneumatizes most bones and cavities
- cross-current gas exchange
anatomy of upper respiratory system - components
o Nares
o Nasal cavities
o A single paranasal sinus
- Infraorbital sinus
Lateral wall is made of soft tissues
Many diverticula
Pneumatizes the skull
simplified lanrynx structure of birds
oNo epiglottis or vocal cords
oCrista ventralis in some species
difference in birds trachea vs mammals
Complete and overlapping tracheal rings
purpose and location of syrinx
o Sound production
o At bronchial bifurcation inside thorax
how many air sacs in most birds
9 air sacs in most birds
1. infraorbital sinus
2. cervicocephalic diverticulum
3. cervical
4. interclavicular
a) intrathoracic diverticulum
and b) extrathoracic diverticulum
5. cranial thoracic
6. caudal thoracic
7. abdominal
resp system flow in bird
Trachea. > primary bronchi > mesobronchi > parabronchi > atrium > infundibulum > Air capillaries
microscopic nature, flow, and exchange of bird resp system
- Highly efficient lungs
o Cross-current gas exchange
o Thinner air-blood barrier
o Very large exchange surface
o Unidirectional flow (in most of the lungs)
breathing mechanism in birds - how many breaths for full cycle, what muscles used
- Inspiration and expiration are both active
- Two inspirations / exhalations required for a full cycle
- Mainly use intercostal muscles
o Other muscles can be recruited- Tail bobbing
major clinical implications of birds resp system for anesthesia
- use uncuffed endotracheal tubes
- air sac perfusion anesthesia possible
- fast induction and recovery
major clinical implications of birds resp system for surgery
- some surgeries require penetration into the air sac system
- wound irrigation may cause fluid aspiration (eg. pneumatized bone fracture, abdominal surgery, sinusotomy)
major clinical implications of birds resp system for disease pathogenesis
- highly succesptible to airborne toxins
major clinical implications of birds resp system for diagnostics
- air sac system allows coelioscopy
- decreased ultrasound windows throught the body
major clinical implications of birds resp system for therapeutics
- nebulized particles should be below 1 - 2 microns to reach air capillaries
avian heart structure and important differences from mammals
- Heart larger than in mammals o Especially in falcons
- 4 chambers
o Left AV valve > standard anatomy
o Right AV valve > muscular flap with its own nerve - Some important differences from mammals
o Higher stroke volume, heart rate, and blood pressure o Right ascending aorta
o Different ECG
biird GI system basic flow to gizzard
esophagus > crop > esophagus > proventriculus > gizzard
no crop in what birds?
No crop in owls, ducks, ratites
proventriculus and ventriculus tissue and structure
- proventriculus more flicced, has glandular tissue
- ventriculus/gizzard is muscular
ceca structure in birds
o Birds have 2 ceca (vestigial in parrots and passerines)
liver, tolk sac remnant, and pnacreas structure in birds
o Liver has 2 lobes and 1 gallbladder (no gallbladder in Psittaciformes except cockatoos)
o Remnant of yolk sac is called Meckel’s diverticulum o Pancreas is within duodenal loop
cloaca structure in birds
- Cloaca has 3 chambers
o Coprodeum
- Rectal opening
o Urodeum
- Ureteral openings
- Vaginal opening
- Vas deferens openings
o Proctodeum
- Bursa of Fabricius
- Phallus of some birds (ostrich, duck)
urinary system in birds structure and location. what dont they have?
- Several kidney lobes- typically 3 (cranial, middle, caudal)
> Located dorsally in the synsacrum - Ureters run ventrally on kidneys and open into the urodeum
- No bladder in any bird
internal anatomy of kidney, and differences from mammals
- No gross demarcation between cortex and medulla, no pelvis
o Renal lobules - Two types of nephrons
o 70% loopless “reptilian” nephrons (cortical)
o 30 % looped “mammalian” nephrons (medullary) - Lower concentrating ability
Uricotelism in birds; what is it, how is it produced
o Uric acid is the primary nitrogenous waste product in birds
o Producedintheliver
o Uric acid is relatively non-toxic, does not diffuse, but has decreased solubility
o 90% eliminated by tubular secretion
advantages of Uricotelism vs ureotelism
o Uric acid is non toxic
o UA does not diffuse through membrane (useful in eggs)
o UA excretes more nitrogen
o Can be excreted with little water
disadvantages of Uricotelism vs ureotelism
o Poorly soluble, may produce gout
o More costly to produce
osmoregulation in birds vs mammals and in general
- Lower renal concentrating ability
- But,
o Birds can modulate their GFR and urine output in response to hydration status
o Renal portal system perfuses renal tubules
o Post-renal handling of urine by cloaca, colon, and ceca
o Some species have salt glands
bird feces components
urine, feces, urates
components of and peculiarity of bird female repro system
ovary > infundibulum > magnum > isthmus > uterus > vagina > cloaca
-Only left ovary and oviduct (a few exceptions)
Function of the 5 parts of the oviduct
o Infundibulum
- Picking up oocyte during ovulation
- Site of fertilization
- Deposition of chalazae
o Magnum
- Deposition of albumen
o Isthmus
- Deposition of shell membranes
o Uterus (shell gland)
- Shell formation and deposition of calcium
- Where egg spends most of its time
o Vagina
- Sperm storage
- Muscles for laying
how long does process from ovulation to egg laying take?
about 24h
Oviposition, important hormones, and laying
oSmall end first
oHormones induce laying:
- Arginine vasotocin
- Prostaglandins E2 and F2α
> can be used to treat egg binding
egg incubation; important considerations and timing
o Natural or artificial
- Humidity
- Temperature
- Turning (unlike reptiles)
o Lots of diseases associated with improper incubation parameters
o Duration of roughly 24-32 days
components of the male avian reproductive system
- Two testicles
> Internal
> Can get huge during reproductive activity (not in parrots) - deferent duct
- urodeum
what birds have a phallus? what is the erectile mechanism?
ducks, ratites
Erectile mechanism is lymphatic
bird brains: differences and similarities to mammals in macroscopic structure
- Different organization and terminology than mammals
- Hindbrain, midbrain, thalamus, and cerebellum are similar to mammals
o But no cortex, replaced by a “nidopallium” - Birds have a nuclear brain organization
o Whereas mammals have a layered organization
bird neuron and cranial nerve differences from mammals
o Birds have more neurons than mammals
o 12 cranial nerves (like mammals)
bird spinal cord differences from mammals
o Spinal cord extends to the limit of vertebral column
o No cauda equina
o Glycogen body in lumbosacral sinus
Main differences with mammals for bird eye
Large eyes
Minimal motion
Striated iris muscles > control dilation
Scleral ossicles
Avascular retina
Pecten
