respiration 6 Flashcards
co2 must leave body…
-poisonous for body
-cause blood pH to drop
-small organisms diffuse it out, large ones must carry it out of circulatory system
23% in the form of carbaminohemoglobin, 70% is bicarbonate (HCO3- and H+), made via carbonic anhydrase with zinc
CO2 transport in blood
at resp surface it is released from carbanimohemoglobin heme, and bicarbonate converts back to carbonic acid, then CO2 to diffuse out
CO2 equilibrium curve
buffering capacity of blood allows for more HCO3 to be formed beyond normal limits
haldane effect
deoxy blood can carry more HCO3, and therefore promotes its uptake of it at tissues and unloading at resp surface
RBC and CO2 transport
- separates reactants and products of CA equil to increase CO2 carrying capacity
- carbonic anhydrase, which synthesizes HCO3 is in RBC
- hemoglobin also have CO2 bound to form carbaminohemoglobin
- Hb acts as a buffer by binding H+ to itself
- HCO3 is exchanged for Cl- to prevent build up of HC)3 in RBC (this is a metabolon)
- at resp surface co2 diffuses out, causing Cl- to be traded out for HCO3, which is converted back to co2 and diffused out of the RBC thru the resp surface
davenport diagram
pH-bicarbonate plots
-tell you how changes in one parameter (CO2, HCO3, pH) in a system changes the other factors under normal conditions
hyperventilation causes…
decrease in co2 conc, and thus increase in pH, aka respiratory Alkalosis
hypoventilation causes…
increasing in co2 conc, decrease in pH, aka resp acidosis
regulation of respiratory systems
-ventilation depth and rate, oxygen carrying capacity and affinity, and perfusion all must be regulated
regulation of vent depth and rate
rhythmic firing of central pattern generators in medulla initiate vent movements via interneurons, then nerve signals to somatic motor neurons
- medullary chemoreceptors sense increases in CO2, while carotid and aortic body chemoreceptors sense decrease in pH, both of which are processed at the medulla
- negative feedback of increased rate and depth of vent reduces co2 conc and increases pH
primary regulators
oxygen in water breathers, CO2 in air-breathers; both central and peripheral chemoreceptors
- aortic and carotid bodies sense oxygen conc in mammals
- mechanoreceptors are conscious controlled
hyper/hypooxia vs hyper/hypocapnia
high or low levels of o2/co2
-hypoxia due to high altitude, burrows, hypoventilation, or anemia
high altitude hypoxia
low O2 conc can increase ventilation rate and depth, causes hypocapnia, increases lung blood pressure, and loss of unconscious ventilation drive, which will conflict with sleep
- increased pH in blood (alkalosis) due to carbonic anhydrase equilibrium leads to higher kidney excretion of HCO3 to regulate pH (have to pee a lot)
- long term: increased RBC volume, increased blood O2 transport