lecture 6 Flashcards
what are the partial pressures of atmospheric gases
78% N2, 21% O2, 0.03% CO2
what is the atmospheric pressure and what are the conditions
0% humidity, includes vapour pressure, 760 mmHg
what is hyperoxia, hypoxia, normoxia
-Hypoxia (decreased inspired O2), hyperoxia (increased inspired O2), normoxia (normal inspired O2)
what is hypocapnia, hypercapnia, normocapnia
Hypocapnia (decreased inspired CO2), hypercapnia (increased inspired CO2), normocapnia (normal inspired CO2)
what are the characteristics of air
30x more O2 than water, O2 diffuses 10,000x better in air than water
what are the characteristics of O2 in water
water is 1000x denser than air, 50x more vicous than air, more energy needed to move through water
what are the general forms of respiration
active ventilation, passive ventilation, tidal ventilation (uni-directional and non-directional)
what are external gills found on
tadpoles and octopus
tadpoles have external gills early on, lose them for internal gills, lose gills altogether
how do external gills work
passive and unidirectional
structures or tentacles flap around, tubes pumping water in and out
what are internal gills found on
aquatic invertebrates (squid)
how do internal gills on squid work
gills inside mantle cavity that expands to suck water in through opening at bottom, ventilate the gills - cavity contracts to push water out bottom and propel squid
how do internal gills on crustaceans work
gills at legs between carapace and body wall - scaphognathite at head that propels water forward, negative pressure in body cavity sucks water in to ventilate gills
how do external gills in spiders (terrestrial) work
book lungs have epithelium - air flow between them to ventilate gills, air comes back out
how do internal gills on fish that use exclusively internal gills work
water goes in through mouth - buccal cavity - through gills - operculum cavity - opercular opening/gill slit
where are the gills positioned in the fish
under operculum
what are the structures associated with fish gills
gill arch - each has gill 2 gill filaments - each filament has secondary lamellae (site of gas exchange)
how many gills are on each side of a fish
4
how do blood vessels run on the gills and what is this mechanism called
blood vessels pass through the lamellae, water flows through in b/t lamella
crosscurrent exchange
what are the types of breathers
obligate and facultative breathers
what is a swimbladder
gas in it for buoyancy - fish goes to surface to get air, perform gas exchange, let g of a little gas at a time, sink at the same time
how do catfish breathe
swallow air into oral cavity into gut - gas exchange - flatulent to signal predators
the die without water because they dry out not because they do not have water
what are the arapaima gigas (piaruchu) and what type of breather are they
obligate in newborn, facultatuve in juvenile, obligate air in adult
describe how mudskippers are facultative breathers
tide goes out - burrow filled with water - gas exchange in water - O2 lowers - breathe pockets of air - O2 pressure is <40torr - come out to breathe air - tide comes in - fills burrow with O2 again - go back into the burrow
what type of breathers are lungfish and how do their lungs look
obligate water breathers
they have many chambers in lungs to increase SA for effective gas exchange, blood vessels on walls
how do amphibian lungs work
bags of air, no divisions, partitions that do not increase SA, no trachea or diaphragm
breathe through nares/gills - new air into buccal cavity - old air in lungs are at higher pressure than buccal cavity - open glottis - lungs collapse - old air exit through upper buccal cavity and nares - nares close - raise floor of mouth - push air into lungs - close glottis - open nares
what is it called when amphibians raise the floor of their mouth to push new air into the lungs
buccal force pump
how do reptilian lungs work
small chambers, similar to lungfish, have trachea and larynx leading to mouth, no diaphragm
suction lungs - negative pressure cause new air to be sucked in
reptiles use the same muscles to breathe and to run
they still breathe when they are running, supplementary mechanisms are used
what is the evolutionary history of birds
from dinosaurs, lungs should resemble closely
what are the characteristics of bird lungs
rigid, not like other vertebrates, modified bags of air, do not change volume, have air sacs
what are the bird lungs made out of
bronchi or parabronchi
describe how a bird breathes
1st inspiration - air - trachea - posterior sacs
1st expiration - air - posterior sacs - lungs
2nd inspiration - air - lungs - anterior sacs
2nd expiration - air sacs contract - push air out of trachea
1st and 2nd inspiration happen at the same time
how does crosscurrent gas exchange work in bird lungs
blood vessels run parallel to bronchi, air capillaries run perpendicular to bronchi
describe the mammalian/human lung
air - nose/nouth - pharynx - larynx - epiglottis - glottis - trachea (rigid) - bronchi - bronchioles - terminal bronchioles - respiratory bronchioles - alveolar sacs - alveoli - lined with blood vessels
what makes up the human chest wall
ribs, sternum, thoracic vertebrae, internal and external intercoastal muscles
where is the diaphragm located
primary respiratory muscle in mammals, between thoracic and abdomen cavity
