Topic
The Quran’s references to the human body are about God’s signs, and are not a textbook of anatomy.
What it means
The verse often raised is “God has not placed two hearts in a man’s body” (33:4). In context it introduces the rules on adoption and on a man’s calling his wife “my mother”: a person cannot hold two contradictory loyalties. Commentators take “heart” (qalb) as the seat of intention and belief, not the organ.
Often misunderstood as
That the Quran gets the body wrong, for example in counting 360 joints.
What the sources say
The 360 joints appear in a hadith (Sahih Muslim), not in the Quran. Muslim scholars describe it as an observation about the many places where the body can be given thanks, not a medical count. The Quran’s own verses on the body, such as those on creation from a drop (see Embryology), invite reflection rather than give a medical text.