Human Anatomy Vol 1

LUNGS

Figs 16.8a and b: The bronchopulmonary segments as seen on: (a) The costal aspects of the right and left lungs. Medial basal
segments (no. 7) are not seen, and (b) segments seen on the medial surface of left and right lung. Later:al segment of middle lobe
(no. 4) is not seen on right side

Usually the infection of a bronchopulmonary

segment remains restricted to it, although

tuberculosis and bronchogenic carcinoma may

spread from one segment to another.

Knowledge of the detailed anatomy of the

bronchial tree helps considerably in:

a. Segmental resection (Fig. 16.10).

b. Visualising the interior of the brorrchi through

an instrurrient passed tfuough the mouth and

trachea. The instrument is called a bron-

choscope and the procedure is called bron-

choscopy.

Carina is the area where trachea divides into

two primary bronchi. Right bronchus makes an

angle of 25', while left one makes an angle of 45'.

Foreign bodies mostly descend into right bronchus

(Fig. 16.11) as it is wider and more vertical than

the left bronchus.

Carina (Latn keel) of the trachea is a sensitive area.

When patient is made to lie on her/his left side,

secretions from right bronchial tree flow towards

the carina due to effect of gravity. This stin'rulates

the cough reflex and sputum is brought out. This

is called postural drainage (Fig. 16.12).

Paradoxical respiration: During inspiration

the flail (abnormally mobile) segment of ribs are

pulled inside the chest wall while during expira-

tion the ribs are pushed out (Fig. 16.13).

Tuberculosis of lung is one of the commonest

diseases. A complete course of treatment must be

taken under the guidance of a physician.

Bronchial asthma is a common disease of res-

piratory system. It occurs due to bronchospasm

of smooth muscles in the wall of bronchioles.

Patient has difficulty especially during expiration.

It is accompanied by wheezing. Epinephrine, a

sympathomimetic drug, relieves the symptoms.

Auscultation of lung: Upper lobe is auscultated

above 4th rib on both sides; lower lobes are best

heard on the back. Middle lobe is auscultated

between 4th and 6th ribs on right side.

Apical segment of lower lobe is the most depen-

dent bronchopulmonary segment in supine

position. Foreign bodies are likely to be lodged

here.

Right

Upper lobe Middle lobe Lower lobe

1 Apical 4 Lateral^6 Superior

2 Posterior 5 Medial 7. Medial basal

3 Anterior 8. Anterior basal

9 Lateral basal

'10 Posterior basal

Upper lobe Lower lobe

1. Apical 6. SuPerior
   2, Posterior 7. Medial basal
   3 Anterior^8 Anterior basal


2. Superior lingular^9 Lateral basal
   5 lnferior lingular 10. Posterior basal