Which of these statements are fasle regarding the human respiratory regarding the human respiratory system ?
(a) The nasal chamber opens into the pharynx .
(b) Trachea, bronchus and initial bronchioles are supproted by complete cartilaginous rings.
(c ) The branching network of bronchi, bronchioles and alveoli comprises the lungs.
(d) Pleural fluid increase friction on the lung surface.

Options

A. a & b
B. b & c
C. b & d
D. only d

Answer

To solve the question regarding which statements are false about the human respiratory system, we will analyze each statement one by one:

### Step-by-Step Solution:

1. **Statement (a)**: "The nasal chamber opens into the pharynx."
- **Analysis**: This statement is correct. The nasal cavity does indeed open into the pharynx, which serves as a common passage for both air and food.

2. **Statement (b)**: "Trachea, bronchus, and initial bronchioles are supported by complete cartilaginous rings."
- **Analysis**: This statement is false. The trachea and primary bronchi are supported by C-shaped (incomplete) cartilaginous rings, while the smaller bronchioles do not have cartilage support. Thus, this statement is incorrect.

3. **Statement (c)**: "The branching network of bronchi, bronchioles, and alveoli comprises the lungs."
- **Analysis**: This statement is correct. The lungs are indeed made up of a branching network of bronchi, bronchioles, and alveoli, where the alveoli are the sites of gas exchange.

4. **Statement (d)**: "Pleural fluid increases friction on the lung surface."
- **Analysis**: This statement is false. The pleural fluid actually reduces friction between the lungs and the thoracic cavity during breathing movements. Therefore, this statement is incorrect.

### Conclusion:
The false statements regarding the human respiratory system are:
- **(b)**: "Trachea, bronchus, and initial bronchioles are supported by complete cartilaginous rings."
- **(d)**: "Pleural fluid increases friction on the lung surface."

### Final Answer:
The false statements are (b) and (d).

---