There any many grooves in the stroma which is lined by the epithelium and these are the uterine glands which secrete a glycogen rich fluid that's essential for the developing embryo during early pregnancy.

基质中有许多由上皮细胞排列而成的凹槽；这些凹槽即子宫内膜腺体，能分泌一种富含糖原的液体，对孕早期的胚胎发育至关重要。