Human Anatomy Vol 1

THORAX

Lobes

A. Upper

B. Middle

C. Lower

A. Upper

. Upper division
. Lower division

B. Lower

Branch of

terminal

bronchiole

Respiratory

bronchiole

Segments

1. Apical


2. Posterior


3. Anterior


4. Lateral


5. Medial


6. Superior


7. Medial basal


8. Anterior basal


9. Lateral basal


10. Posterior basal
    Left lung


11. Apical


12. Posterior


13. Anterior


14. Superior lingular


15. lnferior lingular


16. Superior


17. Medial basal


18. Anterior basal


19. Lateral basal


20. Posterior basal

Fig. 16.6: Bronchial

Segmental bronchus

Cartilaginous plate

Division of segmental

bronchus

Line separating the

conducting part and

respiratory part of

the bronchopulmonary

segment

Terminal bronchiole

(no smooth muscles

and glands)

Alveolar sacs

with alveoli

tree

Smooth muscle

Elastic fibres

Alveoli

Alveolar sac

lnteralveolar

septum

Respiratory

bronchiole

and alveolus

Alveolar duct

Atria

Fig. 16.7: Parts of a pulmonary unit

2 Each one is aerated by a tertiary or segmental

bronchus.

3 Each segment is pyramidal in shape with its apex

directed towards the root of the lung (Fig. 16.8).

4 Each segment has a segmental bronchus, segmental

artery, autonomic nerves and lymph vessels.

5 The segmental venules lies in the connective tissue

between adjacent pulmonary units of bronchopul-

monary segments.

6 During segmental resection, the surgeon works

along the segmental veins to isolate a Particular

segment.

Relation lo Pulmanary A{tety

The branches of the pulmonary artery accompany the

bronchi. The artery lies dorsolateral to the bronchus.

Thus each segment has its own seParate artery

(Fig. 16.e).

ftelaliontoFulmonary fn

l'he pulmonary veins do not accomPany the bronchi

or puhnonary arteries. They run in the intersegmental

planes. Thus each segment has more than one vein and

each vein drains more than one segment. Near the

hilum the veins are ventromedial to the bronchus.

It should be noted that the bronchopulmonary

segment is not a bronchovascular segment because it

docs not have its owtt veitr,