Reproduction and the Backbone

A man's semen is produced in the backbone, the spinal column, and women too produce semen, in the upper ribs.

S 86:6-7 He was created from water pouring out. Coming out from between the backbone {sulb} and the upper ribs {tara'ib}.

Ibn Abbas says:

(He is created from a water gushing forth.) meaning, the sexual fluid that comes out bursting forth from the man and the woman. Thus, the child is produced from both of them by the permission of Allah. Due to this Allah says,يَخْرُجُ مِن بَيْنِ الصُّلْبِ وَالتَّرَآئِبِ(Proceeding from between the backbone and the ribs.) meaning, the backbone (or loins) of the man and the ribs of the woman, which is referring to her chest. Shabib bin Bishr reported from `Ikrimah who narrated from Ibn `Abbas that he said,يَخْرُجُ مِن بَيْنِ الصُّلْبِ وَالتَّرَآئِبِ(Proceeding from between the backbone and the ribs.) "The backbone of the man and the ribs of the woman. It (the fluid) is yellow and fine in texture. The child will not be born except from both of them (i.e., their sexual fluids).'' https://quranx.com/Tafsir/Kathir/86.1

Narrated Anas:

The Prophet (ﷺ) said, "Allah will say to that person of the (Hell) Fire who will receive the least punishment, 'If you had everything on the earth, would you give it as a ransom to free yourself (i.e. save yourself from this Fire)?' He will say, 'Yes.' Then Allah will say, 'While you were in the backbone of Adam, I asked you much less than this, i.e. not to worship others besides Me, but you insisted on worshipping others besides me.' "

https://sunnah.com/bukhari:3334

Narrated Anas bin Malik:

The Prophet (ﷺ) said, "Allah will say to the person who will have the minimum punishment in the Fire on the Day of Resurrection, 'If you had things equal to whatever is on the earth, would you ransom yourself (from the punishment) with it?' He will reply, Yes. Allah will say, 'I asked you a much easier thing than this while you were in the backbone of Adam, that is, not to worship others besides Me, but you refused and insisted to worship others besides Me."'

https://sunnah.com/bukhari:6557

Egyptian Beliefs about the Bull's Spine: An Anatomical Origin for Ankh on JSTOR

For taribah, singular of tara'ib: Lanes Lexicon Almaany:

تَرِيبَة : - عِظَامُ الصَّدْرِ مِمَّا يَلِي التَّرْقُوَتَيْنِ

- thorax; rib; breast; chest

تريبة In English - Translation and Meaning in English Arabic Dictionary of All terms Page 1