Identify the incorrect statement

Options

A. External nostrils leads to nasal chamber.
B. Inner pleural membrane is in contact with thoracic lining.
C. Rights from the lateral boundary of thoracic chamber.
D. Exchange of gases in alveoli occurs by simple diffusion

Answer

To identify the incorrect statement regarding the respiratory tract, we can analyze each of the provided statements step by step:

### Step 1: Analyze the First Statement
**Statement**: External nostrils lead to nasal chamber.
**Analysis**: The external nostrils, also known as nares, are indeed the openings that lead into the nasal cavity or nasal chamber. This statement is true.

### Step 2: Analyze the Second Statement
**Statement**: Inner pleural membrane is in contact with the thoracic lining.
**Analysis**: The inner pleural membrane (visceral pleura) is actually in contact with the lungs, while the outer pleural membrane (parietal pleura) is in contact with the thoracic cavity lining. Therefore, this statement is incorrect.

### Step 3: Analyze the Third Statement
**Statement**: The ribs form the lateral boundary of the thoracic chamber.
**Analysis**: The ribs do indeed form the lateral boundaries of the thoracic cavity, providing structure and protection to the organs within. This statement is true.

### Step 4: Analyze the Fourth Statement
**Statement**: Exchange of gases in alveoli occurs by simple diffusion.
**Analysis**: Gas exchange in the alveoli occurs through the process of simple diffusion, driven by differences in partial pressures of oxygen and carbon dioxide. This statement is true.

### Conclusion
After analyzing all four statements, we conclude that the incorrect statement is:
**"Inner pleural membrane is in contact with the thoracic lining."**