1162 



PHYSIOLOGY 



the epidermis is moulded. These papillae contain for the most part capillary 

 vessels ; a few contain touch corpuscles, special organs of tactile sensation. 

 The blood-vessels of the skin form a close capillary network immediately at 

 the surface of the cutis, sending up loops into the papilla?. All parts of the 

 skin, except the palms of the hands and the soles of the feet, are beset with 

 hair-follicles. The hair-follicles are small pits which extend downwards into 

 the deeper part of the corium, being down- growths of the rete mucosum. 

 The hair grows from a small papilla of cells at the bottom of the follicle, the 



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FIG. 542. Vertical section through the skin of the palmar side of the finger, showing 

 two papillae (one of which contains a tactile corpuscle) and the deeper layer of 

 the epidermis. Magnified about 200 diameters. (SCHAFER). 



part of the hair lying within the follicle being known as the hair-root. The 

 hair itself consists of long tapering, horny cells, the nuclei of which are 

 still visible, though the cell substance has been almost entirely converted 

 into keratin. 



In order to keep the cuticle supple and preserving it from the drying 

 effects of the atmosphere, it is kept constantly impregnated with a fatty 

 material known as sebum. This material is formed by the sebaceous glands, 

 which are distributed all over the surface of the skin wherever hair- follicles 

 are to be found, the mouths of the glands opening into the hair- follicles. A 

 sebaceous gland is a pear-shaped body, consisting of a secreting part and a 

 short neck, opening into the follicle. The gland proper is composed of a 

 solid mass of cells. The outermost cells are flattened and generally show 



