37a By way of example, the Pharaoh surrenders Egypt's last military fortification (5) RE?AN
(There may be a misprint in the defn or an extra letter in the wordplay)
Also wondering about the wordplay for these:
23d A woman's extensive recurrent issue with ruptured muscle tissue (6) HERNIA - i see "her" for "a woman's" and the defn but the rest??
36d It holds your nerves and turns my insides - GLIA