In both syphilis and gonorrhoea, the infections are usually found in the following sites of human body except the _ _ _ _ which is infected only in gonorrhoea.

Step-by-step solution

Syphilis and gonorrhoea are sexually transmitted infections that share several common primary sites of infection due to the modes of transmission. The bacteria causing these infections (Treponema pallidum for syphilis and Neisseria gonorrhoeae for gonorrhoea) typically enter the body through mucous membranes during sexual contact. Therefore, the genital tract, rectum, and oral region are common primary infection sites for both diseases. However, Neisseria gonorrhoeae can also cause a primary infection in the eye, k