2O2 Examination of Chest 



consolidation, for condensed lung-tissue is a good conductor (p. 189). 

 Bronchophony is a lesser degree of pectoriloquy. 



Sometimes the voice sounds cracked, or like the bleat of a goat (m|, 

 aiyos, goat ; (frwvrj, voice) aegophony. It is due to a break-up of the 

 sound-waves as they come splashing through a thin layer of fluid 

 probably of pleural effusion. 



Dyspnoea. When the free entry of air is prevented, as in laryn- 

 geal diphtheria, or oedema glottidis, the inspiratory muscles work with 

 great energy, diminishing the intra-thoracic pressure ; and, as the 

 balance cannot be restored by air entering through the trachea, the 

 equilibrium is partially restored by the jugular, intercostal, and epi- 

 gastric regions falling in with each inspiratory effort. 



THE MAMMA 



The mamma in the female reaches from about the third to the 

 sixth rib. The nipple is over the fourth space, and points slightly 

 outwards and upwards for the convenience of the infant in the mother's 

 arms. As the ribs ascend in inspiration more than the breast, the 

 nipple which lay over the fourth space on expiration will be over the 

 fifth rib on inspiration. In emphysematous patients the nipple is 

 considerably higher than in the phthisical, for in the latter the chest 

 represents the type of expiration. 



The developing breast at puberty is often tender and tingling. 

 With old age the gland becomes wasted, and, when this retrogressive 

 physiological change sets in, cancer is especially apt to invade the 

 tissue. 



The breast is placed within the superficial fascia, and is connected 

 with the skin and with the deep fascia over the pectoralis major by 

 slender ligamentous fibres. 



The nipple may be absent in the virgin, its future site being 

 surrounded by a pinkish zone, but in the second month of pregnancy 

 it begins to grow, and the areola darkens and extends until it forms a 

 deeply pigmented circle two inches in diameter. After parturition and 

 weaning, the pigmentation does not entirely clear away, so that 

 darkening of the areola is important as evidence of the first pregnancy 

 only. 



The skin of the nipple is somewhat leathery, on account of the 

 fibrous tissue which it contains ; it is, moreover, rich in sebaceous 

 glands, which increase during pregnancy, to diminish the risk of 

 cracking and tenderness during suckling. Along the centre of the 

 nipple the milk-ducts (fifteen to twenty in number) ascend, and around 

 them are pale muscular fibres, to the contraction of which under 

 stimulation 4 erection ' of the nipple is due. 



Structure. The breast is surrounded by a fibrous capsule from 



