Charge maintained by chloride entering RBC (chloride shift) Hydrogen ions combine with haemoglobin to form haemoglobonic acid. Hydrogencarbonate ions Releasing oxygen The partial pressure of oxygen (also called oxygen tension) of respiring tissues is lower than the lungs.
Screening is a process for evaluating the possible presence of a particular problem. The outcome is normally a simple yes or no. Assessment is a process for defining the nature of that problem, determining a diagnosis, and developing specific treatment recommendations for addressing the problem or diagnosis.
A screening by definition has to be relatively quick, easy to implement and have to have relative good sensitivity and specificity to try to identify those individuals who are potentially at risk for the problem. And the diagnostic evaluation has multiple components.