Resp Physiology Flashcards
1
Q
Dalton’s Law at MSL
A
2
Q
Describe the oxygen cascade
A
The oxygen cascade describes the transfer of oxygen from air to mitochondria.
In each step of the cascade the PaO2 falls. It demonstrates that oxygen delivery to tissues relies on the passive transfer of gas down partial pressure gradients.
The steps of the cascade are:
Dry atmospheric gas
Humidified tracheal gas
Alveolar gas
Arterial blood
Mitochondria
Venous blood
3
Q
Atmospheric partial pressure of oxygen
A
160mmHg
4
Q
A-a gradient
A
The difference in partial pressure of oxygen between alveolar and arterial blood.
It occurs due to:
1. Shunt/VQ scatter (small shunt is normal due to blood from the bronchial circulation and veins
2. Diffusion abnormality
5
Q
Functions of the respiratory system
A
- Gas exchange
- Heat exchange
- Blood reservoir
- Immunological function
- Hormonal / enzyme functions
