Scar tissue is where severe damage has occured, usually during sex, so that the repairing collagenous fibers have been laid down haphazardly in the healing process, cross-linking has occured, and the longitudinal aspects of the tunica are no longer continuous.
In a normal tunica, without scar tissue, even with a large curve, the longitudinal aspect of the tunica is continuous. If you place stress on the end of the tunica, all of the fibers along the tunica wil receive the stress, if no other factors intervene. If the stress is great enough, the fibers will fail in turn, weakest first, strongest last.
I hope that helps.
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