

THYMUS BODY 121 



THYMUS BODY 



The thymus body (frequently and im property called a gland) is 

 an adjunct to the lymphatic system of in man foetal and infatiF 

 tile life, disappearing by an atrophic process at or before the age 

 of puberty. 



It is enveloped by a fibrous capsule, partitions from which sub- 

 divide the organ into lobes and lobules. The lobules are generally 

 subdivided into follicles, which are irregularly sized and shaped, 

 while tending to an ovoid form. 



It is in connection with the general lymphatic system by efferent 

 vessels which emerge from the hili of the lobes the lymph having 

 meanwhile traversed the mesh -like structure of adenoid tissue 

 composing the follicles. 



The blood- vascular system is in the form of a nutritive supply; 

 the larger vessels occupying the fibrous framework, and sending 

 branches into the follicles. The capillary plexuses are more abun- 

 dant in the peripheral portion of the follicles. The blood is col- 

 lected in the venous channels of the central or medullary area, and 

 emerges from the organ by the veins which accompany the efferent 

 lymphatics. 



PRACTICAL DEMONSTRATION 



The organ should be obtained from a still-born infant, divided in small 

 pieces, and hardened rapidly in strong alcohol. Sections may include an entire 

 lobe, and be stained with haematoxylin and eosin. 



SECTION OF THE THYMUS BODY FROM AN INFANT AFTER 



DEATH ON THE SIXTEENTH DAY 

 OBSERVE: 



(L.) 



1. The fibrous capsule. 



2. Division by prolongations of 1 into somewhat spherical lobes. 



3. Subdivision of 2 into lobules. 



4. Subdivision of 3 into follicles. (Note that these are not 

 uniformly outlined \)y the connective tissue.) 



5. The subdivision of the follicles into an outer, deeply stained 

 cortex, which completely surrounds a light center, the medulla. 



6. The larger lymph-spaces and arteries of the capsular and 

 trabecular tissue. 



(H.) 



7. The cortex of the follicles. (a) The numerous deeply- 



