Respiratory-4 Flashcards
at steep area of curve, a small reduction in po2 results in
large increase in unloading
areas of the body with lowest po2 are the most
o2 deprived
right shifts __ unloading
increase
left shifts __ unloading
decrease
left shifts __ loading
favor
when under conditions of low o2 (hypoxia) you produce more
dpg
dpg favors
unloading
right shift favors
unloading
anemia results in __ production
dpg
compound produced by rbcs in response to hypoxia
dpg
fetal hb __ shifted as compared to adult hb
left
can fetal hb bind dpg
no
when does adult hb production begin
at birth
where is total arterial o2 context found
dissolved in plasma & bound to hb
o2 bound to hb determined by
% saturation of hb X total # of binding sites
total # of binding sites depends on
hb content per rbc & # of rbcs
% saturation of hb affected by
ph, co2, temp & dpg
o2 dissolved in plasma influenced by
composition of inspired air, alveolar ventilation, o2 diffused between alveoli & blood, & adequate perfusion of alveoli
alveolar ventilation affected by
rate/depth breathing, airway resistance, & lung compliance
o2 diffusion between alveoli & blood affected by
SA & diffusion distance
diffusion distance affected by
membrane thickness & amount of interstitial fluid
S hb aka
sickled hb
cause of sickling
substitution of a single amino acid (valine for glutamate)
more sickling results in
lowered o2 delivery
sickle trait can be homozygous or heterozygous
t
muscle myoglobin similar to
hb
how many heme groups in muscle myoglobin
4
muscle myoglobin has __ affinity for o2 than hb
higher
o2 released only when po2 low or high
very low
o2 released during systole or diastole
systole
do2 hb has __ affinity for co2 than oxygenated hb
greater
co2 a bi-product of
metabolism
what are the forms in which co2 is transported
as carbonic acid & ultimately bicarb, as carbamino compounds, & as dissolved gas
how is co2 transported as carbonic acid & ultimately bicarb?
co2 enters rbc -> combines w h2o -> converts to carbonic acid -> carbonic acid dissociates into bicarb & a h ion
__% of co2 carried as carbonic acid & ultimately bicarb
70
co2 catalyzed by what enzyme which is found in huge quantities in rbc
carbonic anhydrase
__% of co2 binds to hb
23
co2 binds same site as o2
false; completely diff site
o2 & co2 do not compete w each other
t
what form of hb has affinity for co2
do2 form of hb
__% of co2 exists dissolved in plasma aka
7; pco2
co2 loading refers to
getting it out of tissues & bringing it to lungs to get rid of it
tissue fluid contains high amounts of
co2
most co2 reacts w
water to form bicarb & h ions
occurs slowly in plasma but quick in rbc due to presence of
carbonic anhydrase
antiporter (chloride-bicard exchanger) pumps __ out of rbc in exchange for __ in
bicarb; chloride
h ions buffered by
binding to deoxy hb
rate of co2 loading adjusted by need
t
person in high demands would have __ deoxy hb than person at rest
more
deoxy hb binds h ions __ than oxy hb
better
deoxy hb binds co2 __ than oxy hb
better
in the lungs, hb binds
o2
in the lungs, hb binding o2 results in
lowered affinity for h & co2
h binds bicard to form
carbonic acid
carbonic acid dissociates into
co2 & h2o
co2 diffuses from blood into alveoli & gets
exhaled
the co2 that was bound to hb when it was do2, gets __ once hb gets o2
dropped
the more co2 you have, the more __ you are
acidic
what system helps maintain proper acid-base bal by helping you get rid of co2 loads
respiratory
acidosis results in
hyperventilation
alkalosis results in
hypoventilation
bicarb is a
base
respiratory acidosis & alkalosis caused by
abnormal co2 levels
metabolic acidosis & alkalosis caused by
abnormal bicarb levels
metabolic acidosis bicarb too
low
metabolic alkalosis bicarb too
high
can get it from iv, antacid use, or vomiting (losing stomach acid)
metabolic alkalosis
can get it from being diabetic aka ketoacidosis or from diarrhea
metabolic acidosis
if you know someones bicarb & co2 levels you can calculate their
ph
resp component refers to
co2 blood concentration; regulated by lungs
metabolic component refers to
bicarb blood concentration; regulated by kidneys
