Carbon dioxide is transproted from tissues to respirtatory surface by only

Options

A. plasma only
B. RBCs and WBCs
C. plasma and RBCs
D. Red blood corpuscles only

Answer

To answer the question "Carbon dioxide is transported from tissues to respiratory surface by only," we need to understand the different methods of carbon dioxide transport in the body. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Forms of CO2 Transport
Carbon dioxide (CO2) is transported in the blood from the tissues to the respiratory surface through three main methods:
1. Dissolved in plasma
2. Bound to hemoglobin as carbaminohemoglobin
3. As bicarbonate ions (HCO3-)

### Step 2: Quantify Each Method
- **Dissolved CO2**: Approximately 5% of CO2 is transported in a dissolved form in the plasma.
- **Carbaminohemoglobin**: About 10% of CO2 binds to hemoglobin to form carbaminohemoglobin (HbCO2).
- **Bicarbonate Ions**: The majority, around 85%, of CO2 is converted to bicarbonate ions (HCO3-) through a reaction with water, forming carbonic acid (H2CO3), which dissociates into H+ and HCO3-.

### Step 3: Conclusion
Given the question asks how CO2 is transported from tissues to the respiratory surface, the correct answer is that CO2 is transported through both plasma (dissolved CO2) and red blood cells (RBCs, where carbaminohemoglobin and bicarbonate formation occurs). Therefore, the statement "Carbon dioxide is transported from tissues to respiratory surface by only" is misleading as it implies a single method.

### Final Answer
Carbon dioxide is transported from tissues to the respiratory surface by both plasma (dissolved CO2) and red blood cells (as carbaminohemoglobin and bicarbonate).

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