8 Which of the following is not one of the tissue layers of

8 Which of the following is not one of the tissue layers of the respiratory tract? a. Muscularis b. Mucosa c. Adventitia d. Submucosa 9 What three structures constitute the respiratory membrane? 10 hich of the following is not a trend we find within the respiratory tract? a. The epithelium gets progressively shorter in the lower passages b. The amount of hyaline cartilage gradually increases as we move to smaller passages c. The amount of smooth muscle increases in the smaller pa d. The amount of elastic fibers increases in the smaller passages

Solution

8 a. Muscularis is not one of the tissue layer of respiratory tract.

The tracheal wall is made up of three distinct tissue layers, the mucosa, submucosa, and adventitia (internal to external).Mucosa: composed of goblet cell which contains pseudostratified ciliated epithelium.Submucosa: a connective tissue that contains seromucous glands,produces mucous within the trachea. Adventitia:outermost connective tissue which is strengthened internally by 16-20 C- shaped rings of hyaline cartilage.

9. The three structures that constitute the respiratory membrane are
a squamous epithelial lining of alveolus
b endothelial cells lining of adjacent capillary
c fused basal laminae between alveolar  and edothelial cells
The respiratory membrane is made up of the alveolar and capillary walls and their fused basal laminae, which acts as a air-blood barrier. It is also called the alveolar-capillary membrane. In the lungs gase exchange occurs across the respiratory membrane by simple diffusion, as it has gas on one side and blood flow on the other side of

10. Within the respiratory tract we do not find
b. The amount of hyaline cartilage gradually increases as we move to the smaller passages.

Rather the smaller passages or the bronchioles do not have the hyaline cartilage and they have club cells in their epithelial lining.

5. Goblet cells are more numerous in the upper respiratory passage than in the lower respiratory passages because more dust and debris are present in the upper respiratory passage and they are needed to be removed and since the goblet cells secrete mucus, which traps these and the ciliated cells help in removing it out of the respiratory tract . The goblet cells are present in a ratio of 1:6 ciliated cells. In the lower respiratory passages these dust and debris decreases and hence the number of goblet cell also decreases.