Respiratory Flashcards
Respiration
exchange of respiratory gases - O2 and CO2
Why is there a constant need for O2
cellular respiration requires O2 to produce ATP, which most cells need a constant supply of
Anaerobic respiration
does not need O2
Aerobic respiration
needs O2
external respiration
transport of O2 and CO2 into and out of body
O2 comes from the environment into body
internal respiration
transport of O2 and CO2 into and out of cells
O2 gets to cells through the blood stream
Cellular respiration
reactions that convert stored energy to ATP
O2 used by mitochondria to produce ATP
gas exchange membrane
aka respiratory membrane
thin layer of 1 or 2 epithelia
separates internal tissue from environmental medium
diffusion
moves from high to low concentration - follows concentration or pressure gradient
Diffusion of O2 is sufficient for what
very small animals, as O2 moves through slowly
surface area to volume ratio
bigger the animal the smaller the ratio - they need respiratory organs with larger surface area
size increases ______ with surface area
proportionately
warm blood or cold blood need more O2?
warm blood to maintain body temperature
gas exchange membrane of birds and mammals
thinner for more efficient gas exchange
steps of respiration in large animals
breathing movements - ventilation
gas diffuses across respiratory epithelia
bulk transport of gases - perfusion
diffusion of gases across capillary walls
rate of diffusion of gas
proportional to partial pressure within total gas mixture
air characteristics at high altitudes
reduces pressure not % of O2
water vs air
water is more dense + viscous = harder to get O2 out
higher temperature water
has less oxygen in it
parts of gills
respiratory surfaces
they are branched and folded
increased area for diffusion
how water moves over gills
cilia beats and body muscles contract to create flow of water to ventilate gills
external gills
extend out from body, no protective coverings
internal gills
within body, protected by chambers of body, currents of water directed over gills
Ram ventilation
don’t have muscles to move water internally, have to keep swimming to be able to ventilate
filaments of gills
where gas exchange occurs
countercurrent flow
water and blood in capillaries move opposite directions - most efficient
gas exchange in insects
no lungs, air enters and leave through spiracles
O2 -> ECF -> cells
CO2 -> ECF -> tracheoles
large vs small insects
ventilation vs simple diffusion in tracheoles
respiratory system of birds
small lungs with additional air sacs not used in gas exchange
gas exchange in birds
blood flow branches into multiple streams which cross capillaries perpendicularly
high altitude adaptations
larger lungs
greater hemoglobin affinity for oxygen
mammalian lung components
trachea > divides into two primary bronchi > they branch into many bronchioles > they branch into alveoli
walls of lungs
two pleura make walls
pleural cavity with intrapleural fluid in between
lung inhalation
diaphragm contracts and moves down
air pressure in alveoli is below atmospheric pressure
lung exhalation
diaphragm returns to starting position
air pressure in alveoli is above atmospheric pressure
adult male lung capacity
5.7 L
Total lung capacity
max amount of air lungs can hold
tidal volume
volume of air entering or leaving lungs in a single breath
functional residual capacity
volume of air in lungs at the end of normal passive expiration
residual volume
minimum amount of air remaining in lungs after max expiration
vital capacity
maximum volume of air that can be moved out during a single breath following maximal inspiration
pressure gradient
necessary for O2 to diffuse across membrane into blood
most efficient gas exchange
cross current (avian) over tidal (mammalian)
peripheral chemoreceptors
located in aortic bodies within aortic arch
monitors pressure of CO2 and O2
information goes to respiratory centers in medulla and pons
how is oxygen carried in blood
bound to hemoglobin (98%)
dissolved in plasma (2%)
importance of hemoglobin
oxygen not very soluble in plasma
needs carrier protein
O2 transport
O2 moves from alveolar air into blood capillary - combines with hemoglobin in RBC
Hemoglobin + iron
oxygen binds to iron + hemoglobin, which can bind to 4 oxygens at once
hemoglobin + O affinity
binding of O2 in one site increases affinity for O2 at other sites
factors of hemoglobin affinity
temperature
pH
CO2
O2 diffusion into tissues
pressure of O2 in interstitial fluid and body cells lower than blood plasma
O2 goes from blood > IF > body cells
CO2 diffusion out of cells
pressure of CO2 higher in tissues than blood
forms of exiting CO2
combines with hemoglobin to form carbaminohemoglobin
combines with H2O to form HCO3 and H+
released into blood and combines with plasma
carbonic anhydrase (CA)
metalloenzyme - requires Zn
catalyzes conversion of CO2 and H2O to HCO3 and H+
CO2 transfer to lungs
pressure of CO2 higher in blood than alveolar air
moves from blood > alveolar air
