The chloride shift is movement of `Cl^(-)`

Options

A. From plasma to RBC
B. From WBC to plasma
C. From RBC to plasma
D. From plasm to WBC

Answer

### Step-by-Step Solution:

1. **Understanding the Chloride Shift**: The chloride shift refers to the movement of chloride ions (Cl^-) in the blood. It is an important physiological process that occurs primarily in red blood cells (RBCs) and is closely associated with the transport of carbon dioxide (CO2).

2. **Identifying the Direction of Movement**: The question asks about the direction of movement of Cl^-. The chloride ions move from the plasma (the liquid component of blood) into the red blood cells (RBCs).

3. **Reason for the Movement**: This movement of chloride ions is a compensatory mechanism that occurs as CO2 is transported from the tissues to the plasma. When CO2 enters the RBCs, it reacts with water to form carbonic acid, which dissociates into bicarbonate (HCO3^-) and hydrogen ions (H+). To maintain electrical neutrality, chloride ions move into the RBCs from the plasma.

4. **Conclusion**: Therefore, the correct answer to the question is that the chloride shift is the movement of Cl^- from plasma to RBCs.