Lecture 27 - Comparative Gas Exchange Flashcards
T/F: neither fish nor birds have alveoli
TRUE
why is the “cost” of breathing high to fish
high O2 extraction from water is essential
what factors affect oxygen desolvation in water
- temperature
- salinity
describe the anatomy of a fish heart
1 atrium and 1 ventricle
where is blood oxygenated in the fish
at the gills
describe gill anatomy
- 4-gill arches covered by operculum
- each gill has gill filaments
- each filament has lamella
what is unique about the anatomy of the gills
exponentially increased surface area
what pumps direct water over the gills
buccal and opercular
T/F: water ventilation cannot be supplemented
FALSE - can be supplemented by fast swimming
water and blood flow in the fish is ____ which allows for ____ extraction of O2
countercurrent; maximal
the avian respiratory system is designed for what
lightweight efficiency
pneumatic bones
filled with air
unlike the trachea of mammals, what is unique to birds
complete tracheal cartilage rings
birds have a unique trachea. describe how the length and diameter affect resistance
length = increased resistance
diameter = decreased resistance
*overall increased dead space
describe air sacs
acts as bellow system to move air through lungs and act a respiratory reserve
T/F: air sacs DO NOT participate in gas exchange
TRUE
describe the passage of air through the lungs in birds
- in trachea
- rear air sacs
- rear bronchi
- parabronchi in lungs
- front bronchi
- front air sac
- out trachea
T/F: it takes 1 cycle for air to move throughout the avian system
FALSE - 2 cycles
T/F: gas exchange occurs during both inspiration and expiration
TRUE
describe the gas exchange in birds
cross-current gas exchange mechanism air; capillaries 90* to parabronchus
what is the advantage of cross-current airflow
venous admixture helps maintain a concentration gradient
