Respiratory System 4 Flashcards
what are the two ways that oxygen is transported in the blood
dissolved in blood plasma and chemically bound to hemoglobin
define hemoglobin
protein contained in the red blood cells
how many molecules of oxygen can a molecule of hemoglobin carry
4, one on each heme
what is a fully saturated hemoglobin
all four heme groups bound to oxygen
what is a partially saturated hemoglobin
1,2, or 3 oxygen molecules are bound to a hemoglobin molecule
explain loading of O2 onto hemoglobin
occurs in the alveolar capillaries
oxygen binds to heme to form oxyhemoglobin (HbO2)
explain unloading of O2 from hemoglobin
occurs in the tissues
oxygens unbinds from hemoglobin to form deoxyhemoglobin and oxygen
what determines the direction of the hemoglobin reaction
partial pressure of oxygen in the blood and the affinity of hemoglobin and O2
define the cooperative binding effect
each O2 that binds causes a conformational change in hemoglobin making it easier for next O2 to bind
produces a sigmoidal (S-shaped) curve
explain the oxygen-hemoglobin saturation curve
initial curve is steep because of cooperative binding effect
as PO2 goes up, saturation goes up (happens in the alveoli)
as PO2 goes down, saturation goes down because it is being offloaded to go to the tissues
define oxygen reserve
oxygen bound to hemoglobin after passing through the systemic circulation
what are the 5 factors that affect hemoglobin’s binding and release of oxygen
PO2
pH
concentration of CO2
temperature
2,3-biphosphogylcerate (2,3-DPG)
explain how PO2 affects hemoglobin’s binding and release of oxygen
as PO2 goes up, we have more binding of O2 to hemoglobin
as PO2 goes down, we have more releasing of O2 from hemoglobin
explain how pH affects hemoglobin’s binding and release of oxygen
as pH goes down, H+ ions increase which decrease the affinity of oxygen to bind to hemoglobin
as pH goes up, H+ ions decrease which promotes the binding of oxygen to hemoglobin
explain how concentration of CO2 affects hemoglobin’s binding and release of oxygen
CO2 concentrations and saturation are inversely related
when CO2 concentrations increase, O2 is released from hemoglobin
when CO2 concentrations decrease, O2 is bound to hemoglobin
explain how temperature affects hemoglobin’s binding and release of oxygen
temperature and saturation are inversely related
as temperature increases, hemoglobin will release oxygen
as temperature decreases, hemoglobin will bind to oxygen
explain how 2,3-biphosphoglycerate (2,3-DPG) affects hemoglobin’s binding and release of oxygen
inversely related
as 2,3-DPG levels goes up, oxygen will be released from hemoglobin
as 2,3-DPG levels go down, oxygen will bind to hemoglobin
what does a right shift in a oxygen-hemoglobin saturation curve mean and what can cause it
Bohr effect: means that the % of oxygen saturation goes down
PO2 down
pH down; H+ up
concentration of CO2 up
temperature up
2,3-DGP up
what does a left shift in a oxygen-hemoglobin saturation curve mean and what can cause it
Haldane effect: increase oxygen binding to hemoglobin
PO2 up
pH up; H+ down
concentration of CO2 down
temperature down
2,3-DGP down
how does altitude affect oxygen-hemoglobin saturation
as we go up in altitude, PO2 in atmosphere goes down which means our oxygen saturation also goes down
how does a pulse oximeter measure oxygen in the blood
goes on finger
special light passes through your skin into your blood
sensor measures the amount of light and % of red blood cells that are full of oxygen
determines amount of deoxyhemoglobin vs oxyhemoglobin
usually around 95%
what are the three ways in which carbon dioxide is transported
as CO2 dissolved in plasma
attached to amine group of the globin portion of hemoglobin
as bicarbonate dissolved in plasma
what is the equation for CO2 attaching to amine group of hemoglobin
CO2 + Hb <–> HbCO2 (carbaminohemoglobin)
what are the two ways in which CO2 can be transported as bicarbonate dissolved in plasma
systemic capillaries and pulmonary capillaries
explain how CO2 is transported as a bicarbonate dissolved in the blood plasma at the systemic capillaries
CO2 diffuses into red blood cell and combines with H2O to form carbonic acid - catalyzed by carbonic anhydrase
carbonic acid dissociates into bicarbonate and hydrogen ion
bicarbonate diffuses into plasma and chloride moves into red blood cell (chloride shift)
explain how CO2 is transported as a bicarbonate dissolved in the blood plasma at the pulmonary capillaries
bicarbonate moves into the red blood cell, chloride moves out
bicarbonate combines with H+ to form carbonic acid
carbonic acid dissociates into CO2 and water (catalyzed by carbonic anhydrase)
CO2 diffuses out of red blood cell and into alveoli to be breathed out
