Translation of the verse 7 from Surah AT-Tariq : Number of verses 17 - - page 591 - Part 30.
Proceeding from between the back-bone and the ribs,
Emerging from between the backbone and the ribs.
(86:7) emanating from between the loins and the ribs. *3
*3) "Sulb" is the backbone and "tara'ib"the breast- bones, i.e. the ribs. Since the procreative fluid in both man and woman is discharged from that part of the body which is between the back and the breast, it is said that tnan has been created from the fluid issuing out froth between the back and the breast. This fiuid is produced even in case the hands and feet are cut off. Therefore, it is not correct to say that it issues out from the whole body of man. In fact, the principal organs of the body are its source and all these are located in the trunk. The brain has not been mentioned separately because the back-bone is that part of the brain through which connection between the body and the brain is established. (Also see Appendix I).
Source : AT-Tariq Verse 7: Emerging from between the backbone and the ribs.