気管支の分岐

関

呼吸器の上皮の移行、肺区域、気管支

類	generation		Diameter	Length	Number	Total cross
			(cm)	(cm)		sectional arec
						(cm^2)
C	trachea	0	1.8	12	1	2.54
C	bronchi	1	1.22	4.8	2	2.33
C	bronchi	2	0.83	1.9	4	2.13
C	bronchi	3	0.56	0.8	8	2
C	bronchioles	4	0.45	1.3	16	2.48
C	bronchioles	5	0.35	1.07	32	3.11
C		↓	↓	↓	↓	↓
R	terminal bronchioles	16	0.06	0.17	6x10^4	180
R	respiratory bronchioles	17	↓	↓	↓	↓
R	respiratory bronchioles	18	↓	↓	↓	↓
R	respiratory bronchioles	19	0.05	0.1	5x10^5	10^3
R	alveolar duct	20	↓	↓	↓	↓
R	alveolar duct	21	↓	↓	↓	↓
R	alveolar duct	22	↓	↓	↓	↓
	alveolar sacs	23	0.04	0.05	8x10^6	10^4

C: Conducting zone~ R: Transitional and respiratory zones