1 50 The Thorax 



stellate and info-articular ligaments, and by a capsule with two 

 synovial membranes. 



The neck of the rib is connected with the front of the transverse 

 process by a strong interosscous ligament, and also with the trans- 

 verse process next above it by the anterior costo-transvcrse band, 

 which is continuous externally with the intercostal aponeurosis. The 

 tubercle is connected with the tip of the process by a capsule and 

 synovial membrane, and by the posterior costo-transverse ligament. 



Pig-eon-breast is produced in rickety, soft-boned children when 

 inspiration is obstructed, as by enlarged tonsils the contraction of 

 the diaphragm causes a partial vacuum in the chest which the pressure 

 of the external air helps to efface by thrusting inwards the weak costal 

 ends of the ribs, with the effect of making the sternum project. 

 Strengthening the child, removing the obstruction, and instituting 

 respiratory gymnastics, gradually diminish the defect ; no compression 

 of the prominent sternum should be used. 



The Prussian army surgeons have been ordered to measure 

 narrow-chested recruits every four weeks. All are to be regarded as 

 narrow-chested the circumference of whose chest is less than half the 

 length of their bodies. Narrow-chested men whose chests are not 

 widened by drill are regarded as predisposed to tuberculosis. 



The dorsal nerves, twelve on each side (the twelfth emerging 

 below the last dorsal vertebra), divide into an anterior and a posterior 

 trunk ; the former becomes the intercostal nerve, with the exception of 

 the first, the chief part of which passes up for the brachial rjlexus, only 

 a small intercostal branch being sent forward from it. 



As the anterior divisions of the upper dorsal nerves run between 

 the intercostal muscles, and are half-way in their course, they give off 

 lateral cutaneous branches which pierce the outer intercostals and the 

 serratus magnus in the axillary line, and then divide ; the posterior 

 division supplies the skin over the region of the latissimus dorsi and 

 the scapula, and the anterior winds round the pectoralis major for the 

 mamma and the neighbouring integument, or, in the case of the lower 

 nerves, for the skin over the front of the abdomen. 



The continuation of the intercostal nerve runs on and leaves the 

 space by the side of the sternum, piercing the origin of the pectoralis 

 major, and ending in the anterior cutaneous twigs. 



The small, first intercostal nerve gives no lateral cutaneous branch, 

 but from the second a large undivided offshoot runs across the arm-pit 

 to end in the skin of the inner and back part of the arm. This is the 

 intercosto-numeral nerve, and it is often joined by the lesser internal 

 cutaneous. When the intercosto-humeral nerve is stretched by sup- 

 puration in the arm-pit, or is caught in the enlargement of axillary 

 glands which follows mammary scirrhus, neuralgia occurs in the area 

 of its distribution, down to the internal condyle. 



In their course the intercostal nerves supply the parietal pleura ; 



