Morphology of the structural elements of the uterine wall at a higher magnification. Stratum compactum (a,e,i) and spongiosum endometrii (b,f,j), circular (c,g,k) and longitudinal (d,h,l) layers of the myometrium at the end of gestation months 1 (a-d), 3 (e-h), and 8 (i-l). Note the increasing height of the surface epithelium (SE), the increasing thickness of the subepithelial mesh of connective tissue fibres (*), the increasing diameter of deep uterine glands (DG) and myometrial smooth muscle cells, while superficial uterine glands SG did not show significant changes with ongoing pregnancy. The decreasing nucleus:cytoplasm ratio of myometrial smooth muscle cells is evident when comparing g,h vs. k,l. C: chorion.