446 



THE ORGANS 



peripheral ganglia. Some of these cells have been considered to be 

 afferent sympathetic cells. (Figs. 311 and 312.) 



te 



a.j. a.f. 



Fig. 312. — Sympathetic Nerve-cells and their Capsules. (Cajal.) .4 , Two-celled 

 glomerulus; B, cell surrounded with the pericellular terminal arborizations of two fibres 

 {a.f.) passing to the cell; a, axones; d, fibre, probably dendritic, with bulbous termina- 

 tion. (Cajal's silver stain.) 



The sympathetic cells receive fibres which form arborizations 

 around and within their capsules and also around the long dendrites. 



Many of these are terminations of the visceral 

 cerebro-spinal efferent neurones, ie., the pre- 

 ganglionic libers (Figs 310 and 312, B). 



As already noted, the axones of the efferent 

 sympathetic cells terminate in heart muscle 

 (cardio-motor), in smooth muscle of viscera 

 (viscero-motor), of blood-vessels (vaso-motor) 

 and of hairs (pilomotor), and in glandular 

 epithelia (secretory). In heart muscle (Fig. 

 313) and in smooth muscle (Fig. 314) the 

 nerves of the sympathetic system end in fine 

 Jeltworks of fibres, which are in relation with 



■^ 



Fig. 313. — Nerve End- 

 ings on Heart Muscle 

 Cells. (From Barker, 

 after Huber and De 

 Witt.) 



