75 Questions
What is the extraction ratio at rest?
25%
Which term refers to keeping the environment around the cell constant?
Homeostasis
What happens when Po2 is decreased up to 40%?
It has no effect on oxygen amount
What is the dangerous effect of changing concentrations for H2 or Na+?
It's different from O2
What shape is mentioned in relation to the effect of decreasing Po2?
Sigmoidal
What happens to the partial pressure of oxygen (PO2) in the blood if a person breathes pure oxygen?
Decreases to 650 mmHg
How does breathing pure oxygen affect oxygen in the blood?
It turns oxygen into free radicals
What is the impact of free radicals formed from oxygen species on cells?
They destroy DNA, proteins, and cell membranes
What term is used to describe oxygen species that can destroy cellular components?
Oxygen radicals
Why is breathing pure oxygen potentially harmful to cells?
Due to the conversion of oxygen into damaging species
What is the minimum Po2 level needed in zone 3 for the content of O2 to be 18 or higher?
60
When the Po2 doubles to 200, what happens to the saturation of Hbs?
All Hbs are fully saturated
What is the amount of O2 needed for cells in relaxation when Po2 is 60 or higher in zone 3?
5 ml
What is the feedback type in the respiratory system regarding O2 levels?
Half tail
What happens to impulses from the respiratory centers when Po2 reaches 200?
They are not sent
What is the percentage of oxygen that is dissolved in plasma?
1.5%
What is the formula to calculate the oxygen concentration dissolved in plasma according to Henry's Law?
[O2] = PaO2 x SO2
How much oxygen can 1 gram of hemoglobin maximally bind reversibly?
1.34 ml
What is the average hemoglobin concentration in the blood for males?
14 g/dl
If we have 1 dl of blood, how much oxygen in total (in ml) is present (both dissolved and bound)?
20.3 ml
What happens when a baby takes their first breath?
Bone marrow releases 2α 2β
What is the role of bone marrow when a baby takes its first breath?
Releasing (2α 2β)
How many types of substances does the bone marrow release when a baby takes their first breath?
(2α 2β)
What initiates the release of (2α 2β) from the bone marrow in a newborn?
First cry
Which of the following substances is released by the bone marrow when a baby takes their first breath?
(2α 2β)
What percentage of saturation is achieved when hemoglobin binds to 2 molecules of O2?
50%
At what percentage of saturation is hemoglobin when it binds to 3 molecules of O2?
75%
How much saturation is achieved by hemoglobin when it releases all O2 molecules?
0%
If hemoglobin binds to 1 molecule of O2, what percentage of saturation does it achieve?
25%
What happens to hemoglobin saturation when it binds to 4 molecules of O2?
100%
Why is high apical PO2 unable to correct low PO2 (base) when mixed in the left ventricle or left atrium?
Mixing of high and low PO2 levels causes a decrease in overall oxygen content.
What effect does mixing high apical PO2 and low base PO2 have on oxygen content in the blood?
Decreases oxygen content
What is the consequence of having high apical PO2 mixing with low base PO2 in terms of oxygen delivery to tissues?
Less efficient oxygen delivery
How does the interaction between high apical PO2 and low base PO2 influence oxygen-hemoglobin saturation?
Decreases saturation levels
What role does the left ventricle or left atrium play in maintaining oxygen levels when high apical PO2 mixes with low base PO2?
Actively balances the mixed PO2 levels
What is the consequence of Po2 reaching 200 in terms of the respiratory centers?
Impulses are not sent
What is the oxygen content required by cells in relaxation when Po2 = 60 or higher in zone 3?
5 ml
What type of feedback is involved in the respiratory system regarding oxygen levels?
Half tail
What happens to the saturation of Hbs when Po2 doubles to 200?
Hbs are fully saturated
Which zone is defined by a Po2 range of 60-100 where the cells need 5 ml of oxygen?
Zone 3
What happens to ventilation when ascending to high altitudes?
It decreases gradually
At what point does hyperventilation occur during the ascent to high altitudes?
Po2 = 60
What is the relationship between altitude and partial pressure of oxygen (Po2) during ascent?
Po2 decreases gradually
How does ventilation change as one climbs to higher altitudes?
It decreases due to reduced Po2 levels
When ascending to high altitudes, what happens to the partial pressure of oxygen (Po2) as the altitude increases?
It decreases gradually
What is the Po2 value for the numbers discussed in the text?
50
In what zone does the content of O2 need to be 18 or higher when Po2 is 40?
Zone 3
What is the impact on O2 saturation of Hbs when Po2 doubles to 200?
Remains the same
When does the bone marrow release (2α 2β) in a newborn?
When they take their first breath
What is the extraction ratio when a person is at rest?
$\frac{1}{3}$
What type of curve is created by the phenomena of sigmoidal binding of oxygen to Hb?
Sigmoid curve
In which zone does hemoglobin find it most difficult to bind to oxygen?
First zone
At which point does the process of binding oxygen to hemoglobin get easier?
Second zone
What characteristic shape does the sigmoid curve exhibit due to the varying ease of binding oxygen to hemoglobin?
Convex
Which zone presents a challenge for hemoglobin to be fully saturated with oxygen?
Third zone
What is the main factor that causes the shift to the left in the oxygen-hemoglobin dissociation curve?
Low 2-3 DPG levels
In fetal hemoglobin (HBF), what prevents the binding of 2-3 DPG to hemoglobin?
Presence of 2 α and 2 γ chains
What is the consequence of having high 2-3 DPG levels in relation to the oxygen-hemoglobin dissociation curve?
Shift to the right (lower affinity)
What structural difference between adult and embryonic hemoglobin prevents 2-3 DPG binding in embryos?
Presence of 2 α and 2 γ chains
Which factor contributes to a right shift in the oxygen-hemoglobin dissociation curve?
Decreased H+ concentration
What is the maximum amount of oxygen in milliliters that 1 gram of hemoglobin can reversibly bind to?
2.5 ml
If the oxygen concentration dissolved in plasma is 0.3 ml/dl, and the oxygen bound to hemoglobin is 20 ml/dl, what is the total oxygen content for 1 dl of blood?
20.3 ml
What percentage of oxygen is dissolved in plasma?
3.5%
For males, what is the average concentration of hemoglobin in the blood in grams per deciliter?
15 g/dl
If a female's hemoglobin concentration in the blood is 13 g/dl, how much oxygen (in ml) can be bound by 1 dl of blood?
17.82 ml
What is the potential consequence of a person breathing pure oxygen, which leads to a decrease in PO2 in blood?
Generation of free radicals that can damage cellular components
In the context provided, what is the implication of PO2 in blood decreasing from 760 mmHg to 650 mmHg due to breathing pure oxygen?
Formation of oxygen free radicals
What is the primary effect of high apical PO2 in the presence of low base PO2 when considering oxygen utilization in tissues?
Ineffective oxygen delivery to tissues
When a person breathes pure oxygen and the PO2 in blood decreases, what is the likely impact on cellular components due to the generation of free radicals?
Damage to DNA, proteins, and cell membranes
What is the expected outcome when the PO2 in blood changes from 760 mmHg to 650 mmHg as a person breathes pure oxygen?
Generation of harmful oxygen species
What effect does an increase in temperature and binding to 2-3 DPG have on oxygen?
Increases the release of oxygen
How does binding to 2-3 DPG affect the saturation of hemoglobin with oxygen?
Decreases hemoglobin saturation
What role does 2-3 DPG play in the binding of oxygen to hemoglobin?
Decreases the affinity of hemoglobin for oxygen
How does a decrease in temperature affect the release of oxygen from hemoglobin?
Decreases the release of oxygen
What is the impact of binding to 2-3 DPG on the oxygen-hemoglobin dissociation curve?
Shifts it to the right
Test your knowledge on how oxygen is transported in blood through dissolved plasma and bound to hemoglobin. Learn about Henry's Law for calculating dissolved oxygen concentration and the role of hemoglobin in oxygen transportation.
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