Lecture 52 - Avian Anatomy Part. 2 Flashcards
the nares of some parrots are surrounded by
cere
what is the choana
opening in hard palate
describe the periorbital sinuses
soft tissue lateral borders around the nasal cavity and connects to the cervicocephalic air sac
T/F: operculum are within the nostril
TRUE
rupture of the cervicocephalic diverticula causes
periorbital emphysema
describe the trachea of birds
- long with no epiglottis
- complete tracheal rings
- increased dead space
what is the syrinx? why is it important?
bifurcation of trachea to the 2 primary bronchi which acts as the site of sound production and fungal granulomas
T/F: the lungs of a bird resemble those of small animals with distinct lobes, pleural space, and free in the thoracic cavity
FALSE
1. no lobes
2. no pleural space
3. affixed to ribs
ostia
connection to air sacs
primary bronchi travel to where
caudal air sacs
describe the flow of air once it enters the bird
- primary bronchi
- caudal air sacs
- secondary bronchi
- parabronchi
- air capillaries
where does gas exchange occur
air capillaries
T/F: birds do not have alveoli
TRUE
when will birds struggle to breathe
when pressure is placed on keel
T/F: breathing is active
TRUE
why do birds have the most efficient gas exchange among air-breathing vertebrates
- less ventilation to achieve the same oxygenation
- continuous unidirectional airflow
- counter-current exchange
- small diameter of terminal airways
describe the anatomy of air sacs
- thin membranous structures
- connected to lungs and pneumatic bones
- 9 air sacs
describe the 4 part breathing cycle
- inhale - trachea and/primary bronchus to caudal air sacs
- exhale - caudal air sacs to lungs with gas exchange
- inhale - lungs to cranial air sacs
- exhale - cranial air sac to trachea and expelled
T/F: inhalation and expiration cycles happen independently
FALSE
air sac cannula
obstruction in the respiratory tract cranial to the lungs
what is unique about the right AV valve in birds
no chordae tendinae
birds have a ____ QRS. why?
negative; ventricular depolarization starts subepicardially
Compared to mammals, birds have:
increased or decreased heart rate relative to body mass
increased
Compared to mammals, birds have:
increased or decreased heart size
increased
Compared to mammals, birds have:
increased or decreased stroke volume and cardiac output
increased
where are the kidneys located
renal fossa of synsacrum
each kidney is comprised what divisions
- cranial
- middle
- caudal
T/F: nerves from the sacral and lumber plexus pass THROUGH the kidneys
TRUE
T/F: there is a distinct cortex and medulla of avian kidneys
FALSE
the medullary cone contains
loops of henle and collecting ducts
how do avian kidneys compensate for their poor concentrating ability?
post renal modifications of urine
- lower GI tract and cloaca resorption
- nasal salt glands
uricotelic
- uric acid secretion requires little water but more energy/proteins
female reproductive organs are found on the ____ side of the body
left
the ____ can be surgically removed but the ____ cannot
oviduct; ovarian follicles
T/F: testes can increase in size during breeding season
TRUE
describe the avian brain
no neocortex, gyri, nd sulci with large venous sinus
instead of the cauda equina, what is in the lumbosacral spinal cord
glycogen body
the globes are supported by
scleral ossicles
the retina are _____ and have ____
avascular; pectin
T/F: tapetum lucidum is present in most birds
FALSE
complete decussation of optic nerve fibers at optic chiasm results in
no consensual PLR
instead of lymph nodes, the lymphoid organs are
thymus and bursa of fabricius
