938 



HUMAN ANATOMY. 



Fat 



Capsule 

 Lymph-sinus 



Cortical follicle 



Trabecula 



Lymph-sinus 



Lymph-sinus 



Medullary cord 



the cortical nodules ; those within the communicating central compartments form a 

 net-work ot irregular cylinders, the medullary coras, which are continuous with one 



another and with the deeper 

 Fig. 790. p^j-j- Qf ^^ cortical nodules 



(Fig. 789). 



The intervals between 

 the tracts of lymphoid 

 tissue and the trabecular 

 frame- work constitute a 

 system of freely intercom- 

 municating channels, the 

 lymph - shmses, through 

 which passes the lymph 

 brought to the node by the 

 afferent lymphatic vessels. 

 The latter pierce the capsule 

 on the convex surface of 

 the node and empty into 

 the sinuses that surround 

 the outer and lateral surfaces 

 of the cortical nodules. 

 After traversing the periph- 

 eral sinuses, the lymph 

 passes into the irregular 

 channels of the medulla 

 and towards the point at 

 which the efferent lymph- 

 vessels leave the nodule. 

 The position of this exit is 

 usually indicated by a more 



or less pronounced indentation, known as the hihim, on the surface of the node 



opposite the entrance of the 



afferent lymph-vessels. 



The lymph-sinuses, there- 

 fore, are bounded on one side 



by the capsule or the trabeculae 



and on the other by the masses 



of dense lymphoid tissue. The 



lumen of these channels, however, 



is not free, but occupied by a 



delicate wide-meshed reticulum 



consisting of fine strands of 



connective tissue where most 



marked, or of the processes of 



stellate cells where very delicate 



(Ebner). The sinuses are lined 



by an imperfect layer of flattened 



plate-like cells, that represent 



the endothelium of the adjoining 



lymphatic vessels and also cover 



the more robust trabeculae cross- 

 ing the channels. The reticulum 



occupying the sinuses is continu- 

 ous with the closer and more 



delicate net-work within the adja- 

 cent dense lymphoid tissue. 



Although both the afferent and 



efferent lymphatics are provided 



with valves, the lymph-channels 



Portion of periphery of Ivmph-node, showing relation between trabecula, 

 sinus, and lymphoid tissue. X 50. 



Fig 



Trabecula 



Lympl 



Lymph-sinus 



<*■* 



Portion of medulla ot lymph-node, showing details of lymph-sinub 

 and medullary cords. X 250. 



