Gas Transport Flashcards
(30 cards)
How is oxygen carried in the blood?
Oxygen is carried in two forms;
1. Dissolved oxygen(2%)
2. Bound to Hb. (98%)
State Henry’s Law
The amount of Dissolved oxygen in the blood is directly proportional to its partial pressure (P02).
How many mls of oxygen is contained in a 100ml of arterial blood with normal PO2?
O.3mls of Oxygen ND only about 90ml of oxygen delivered to tissues per minute.
Oxidized form of iron in Hb will results to the formation of what compound?
Methemoglobinemia…..
It does not bind oxygen and thus has no role in gas Transport.
Why is Hb conc. in men greater than women?
Because RBC production is stimulated by both EPO and Androgen
How many mls of O2 is bound to 1g of Hb?
1.34mls of oxygen.
What is the normal oxygen capacity in 100mls of RBC in males and females?
Males, about 20.8mls
Females, about 19.8mls
What is the oxygen saturation of both arterial and venous blood?
Arterial blood– 97.5% (PO2=100mmHg)
Venous blood— 75% (PO2=40mmHg)
Describe the O2-Hb dissociation curve.
It is a fundamental tool in understanding how O2 is picked up in the lungs and released to the body tissues.
What does a flatten O2-HB curve indicate?
An increase in PO2 can only have a minimal effect in Hb saturation.
What tool is used to measure the HB’s affinity for Oxygen?
P50 O2-HB dissociation curve.
What does a Right shift of the O2-HB dissociation curve indicate?
Decrease affinity of Oxygen by the Hb and Increase Oxygen release to tissues.
What are the factors responsible for a Right shift?
- Increased Temperature
- Decreased pH
- Increased PCO2
- Increased 2,3-BPG
What does a left shift in the O2-HB dissociation curve indicate?
Increase in HB’s affinity for oxygen, and decreased Oxygen release to tissues.
What are the factors responsible for a left shift?
- Decreases temperature
- Increased pH
- Decreased PCO2
- Fetal HB
- Decreased in 2, 3-BPG
- CO poisoning.
What compound stabilizes the HB in its T-state?
2, 3-BPG
T-state——-Deoxygenated state.
In what forms is CO2 transported to tissues?
In 3 forms;
- Dissolved CO2 (10%)
- Bound to HB as Carbamino HB. (5%)
- As Bicarbonate (about 85%)
What is the chloride Shift?
The chloride Shift involve chloride ions moving out of the RBC that is undergoing the carbonic Anhydrase catalysed rnx between water and CO2 in other to maintain electrical neutrality in the cell.
HCO3 is soluble to the cell membrane and thus can move freely outside. But H+ ion cannot, thus increase the positivity in the cell. Chloride entering the cell neutralizes the acidity and maintains the cells integrity.
Some of the H+ bind sto HB molecule.
What is the Haldane Effect?
A situation where deoxygenation of the blood increases its ability to carry CO2.
What happens when the Alveolar PO2 drops?
If PO2 drops, then the amount of Dissolved oxygen in blood drops.
What is Anemia?
Anemia is the reduction of Oxygen Carrying capacity of a RBC below normal for age, sex and race.
What are the various classifications of Hypoxia?
- Hypoxic Hypoxia
- Anemic Hypoxia
- Ischaemic Hypoxia
- Histotoxic Hypoxia
What are the effects of Hypoxic Hypoxia?
It decreases the Arterial PO2.
Effect of Anemic Hypoxia
It decreases the oxygen carrying capacity (HB)
