Question

Describe ventilation-perfusion matching in the lung. How might mismatch lead to hypoxemia?

physiology

Answer 1

answer) first we need to understand what is ventelation and what is perfusiion

VENTILATION: it is movement of air in the envrionment and the lungs via inhalation and exhalation.

PERFUSION: the amount of blood reach to alveoli is known as the perfusion.

it iscommonly known as V/Q ratio ehich measures the amount of air reaches to the alveoli and the amount of blood reaches to the alveoli by capilleries.

PHYSIOLOGY: the oxygen provided by the lung is adequate enough to saturate the blood fully. 1 litre of blood can hold 200ml of oxygen. because the lung is centered it is divided into lower and uper part that is apex and base respectivley. if a person standing the apex would show higher v/q ratio and base will show lower V/Q ratio.The main reason for lower V/Q ratios at the base is beacuse of both ventilation and perfusion increase when going from the apex to the base, but Q does it more strongly thus lowering the V/Q ratio and the whole ratio is decresed. the main factor invovled in this is gravity whch cause pressure in lungs.

mis match can lead to Type I respiratory failure in this the gas is not exchanged properly and the level of oxygen get down in blood which leads to a condition known as hypoxemia and rise in co2 condition and blood. in this lungs are not abe to absorb the oxygen present in the lungs..