![This is blank.](https://digitalhistology.org/wp-content/themes/histology-unified/imgs/trans.png)
Bronchial vessels
In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x
![Bronchus <p>In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x</p>](https://digitalhistology.org/wp-content/uploads/2018/06/O.R.B.B.03.P01.png)
Bronchus
In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x
![Cartilage plates <p>In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x</p>](https://digitalhistology.org/wp-content/uploads/2018/06/O.R.B.B.03.P02.png)
Cartilage plates
In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x
![Bronchial vessels <p>In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x</p>](https://digitalhistology.org/wp-content/uploads/2018/06/O.R.B.B.03.P03.png)
Bronchial vessels
In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x
![Macrophages <p>In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x</p>](https://digitalhistology.org/wp-content/uploads/2018/06/O.R.B.B.03.P04.png)
Macrophages
In order to supply tissues that form the walls of respiratory passageways, bronchial vessels must lie within the wall, making their diameter smaller than the thickness of that wall. 200x