In human beings, oblique fissures are associated with :

1. Right lung

2. Left lung

3. Both lungs

4. None of the above

Trachea divides into two right and left primary bronchi at the level of:

1. Seventh cervical vertebra

2. Third thoracic vertebra

3. Fifth thoracic vertebra

4. Seventh thoracic vertebra

The C-shaped cartilaginous rings around the trachea are open posteriorly to:

(1) allow for expansion of the esophagus during swallowing 

(2) allow the vocal cords to relax

(3) prevent food from entering the nasal cavity during swallowing

(4) prevent food from entering the trachea

The trachea is lined with

1. ciliated simple squamous epithelium
2. stratified squamous epithelium
3. pseudostratified ciliated columnar epithelium
4. pseudostratified squamous epithelium

The figure shows a diagrammatic view of human respiratory system with labels A, B, C

and D. Select the option, which gives correct identification and main function and/or

characteristic.

1. A-trachea-long tube supported by complete cartilaginous rings for conducting

inspired air

2. 8-pleural membrane-surround ribs on both sides to provide cushion against rubbing

3. C-alveoli-thin walled vascular bag-like structures for exchange of gases

4. D-lower end of lungs-diaphragm pulls it down during inspiration