PHYSIOLOGY OF GONADS 



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Fig. 9.16. An area of the normal implantation 

 site of a developing ovum. (From Carnegie Institu- 

 tion, No. C467.) 





Fig. 9.17. An experimentally induced implanta- 

 tion reaction in a castrated monkey showing condi- 

 tion 6 days after mechanical traumatization of the 

 endometrium. 



blast. Rossman (1940j made an extensive 

 morphologic study of these epithelial pro- 

 liferations and concluded that they should 

 be regarded as typical metaplasias \vith an 

 embryotrophic function. 



VI. The Cervix Uteri 



The cervix uteri of the rhesus monkey is 

 remarkable for its size and complexity. It 

 forms a large segment that is set off from 

 the fundus by a conspicuous constriction at 

 the level of the internal os (Fig. 9.1). A 

 sagittal section (Fig. 9.18) shows the cervi- 

 cal canal not straight but thrown into sev- 

 eral sharp turns by colliculi that extend 

 from its walls into the lumen. The largest 

 of these projects from the midventral wall. 

 The functional advantage of such tortuosity 

 of the cervical canal is not obvious but 

 since the cervix probably serves as a barrier 

 between the bacterial flora of the vagina and 

 the corpus uteri, this may be a useful adap- 

 tation. 



The physiology of the cervix has received 

 much less attention than has been given the 

 uterus. This is regrettable in view of the 

 consideration it must receive in practical 

 obstetrics and gynecology, as well as the 

 possibility that physiologically the monkey 

 cervix may be homologous with that of the 

 human regardless of morphologic difTer- 

 ences. Recent observations indicate that 

 this is indeed quite probable. 



Fig. 9.18. Sagittal section of the cervix from a 

 normal monkey. The vagina and the external os of 

 the cervix are shown at the left and the entrance 

 to the fundus is at the right. 



