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Bibliography

Bartelmez, G.W., and Dekaban, A.S. 1962. The early development of the human brain. Contrib Embryol. Carnegie Institution of Washington. 37:13-32.

Bentin-Ley U., Horn T., Sjögren A., Sorensen S., Larsen J. F., and Hamberger, L. 2000. Ultrastructure of human blastocyst-endometrial interactions in vitro. J Reprod Fertil. 120:337-350.

Bentin-Ley, U., Sjögren, A., Nilsson, L., Hamberger, L., Larsen, J. F., and Horn, T. 1999. Presence of uterine pinopodes at the embryo-endometrial interface during human implantation in vitro. Human Reprod. 14:515-520.

Buster, J.E., Bustillo, M., Redi. I.A., Cohen, S.W., Hamilton, M., Simon, J.A., Thorneycroft, I.H., and Marshall, J.R. 1985. Biologic and morphologic development of donated human ova recovered by nonsurgical uterine lavage. Am J Obstet Gynecol. 153:211-217.

Davis, Carl L. 1927. Development of the human heart from its first appearance to the stage found in embryos of twenty somites. Contrib Embryol. Carnegie Institution of Washington. 19:245-284.

DeVries, P.A., and Saunders, J.B. deC.M. 1962. Development of the ventricles and spiral outflow tract in the human heart - a contribution to the development of the human heart from age group IX to age group XV. Contrib Embryol. Carnegie Institution of Washington. 37:87-114.

Gardner, E., and O'Rahilly, R. 1976. The nerve supply and conducting system of the human heart at the end of the embryonic period proper. Journal of Anatomy. 121:571-587.

Gasser, R.F. 1975. Atlas of Human Embryos. Harper and Row, Hagerstown, Maryland.

Gualtieri, R., Santella, L., and Dale, B. 1992. Tight junctions and cavitation in the human pre-embryo. Mol Reprod Dev. 32:81-87.

Hardy, K., Warner, A., Winston, R.M.L., and Becker, D.L. 1996. Expression of intercellular junctions during preimplantation development of the human embryo. Mol Hum Reprod. 2:621-32.

Hertig, A.T., and Rock, J. 1945. Two human ova of the pre-villous stage, having a development age of about eight and nine days respectively. Contrib Embryol. Carnegie Institution of Washington. 33:169-186.

Hertig, A.T., and Rock, J. 1949. Two human ova of the pre-villous stage, having a development age of about seven and nine days respectively. Contrib Embryol. Carnegie Institution of Washington. 31:65-84.

Hertig, A.T., and Rock, J. 1941. Two human ova of the pre-villous stage, having an ovulation age of about eleven and twelve days respectively. Contrib Embryol. Carnegie Institution of Washington. 29:127-156.

Hertig, A.T., Rock, J., Adams, E.C., and Mulligan, W.J. 1954. On the preimplantation stages of the human ovum: A description of four normal and four abnormal specimens ranging from the second to the fifth day of development. Contrib Embryol. Carnegie Institution of Washington. 35:199-220.

Heuser, C.H., and Streeter, G. L. 1941. Development of the macaque embryo. Contrib Embryol. Carnegie Institution of Washington. 29:15-55.

Heuser, C.H., Rock, J., and Hertig, A.T. 1945. Two human embryos showing early stages of the definitive yolk sac. Contrib Embryol. Carnegie Institution of Washington. 31:85-99.

Jirásek, J.E. 2001. An atlas of human embryos and fetuses. Parthenon Publishing, New York.

Lindenberg, S., Hyttel, P., Lenz, S., and Holmes, P.V. 1986. Ultrastructure of the early human implantation in vitro. Human Reprod. 1:533-538.

Lindenberg, S. 1991. Ultrastructure in human implantation: Transmission and scanning electron microscopy. Baillieres Clin Obstet Gynaecol. 5:1-14.

Lopata, A., Kohlman, D.J., and Kellow, G.N. 1982. The fine structure of human blastocysts developed in culture. Embryonic Development, Part B: Cellular Aspects. Alan R. Liss, Inc. New York. 69-85.

Lopata, A., Sathananthan, A.H., McBain, J.C., Johnston, W.I.H., and Spiers, A.L. 1980. The ultrastructure of the preovulatory human egg fertilized in vitro. Fertil Steril. 33:12-20.

Makabe, S., Naguro, T., Nottola, S.A., and Motta, P.M. 2001. Ultrastructural dynamic features of in vitro fertilization in humans. Ital J Anat Embryol. 106:11-20.

Menezes, J., Gunasheela, S., and Sathananthan, H. 2003. Video observations on human blastocyst hatching. Reprod Biomed Online. 7:217-8.

Ménézo, Y.J.R., Kauffman, R., Veiga, A., and Servy, E.J. 1999. A mini-atlas of the human blastocyst in vitro. Zygote. 7:61-65.

Müller, F., O'Rahilly, R, and Tucker, J. A. 1981. The human larynx at the end of the embryonic period proper: 1. The laryngeal and infrahyoid muscles and their innervation. Acta Otolaryngol. 91:323-336.

Nikas, G., Ao, A., Winston, R.M.L., and Handyside, A.H. 1996. Compaction and surface polarity in the human embryo in vitro. Bio Reprod. 55:32-37.

O'Rahilly R, Müller F., and Meyer, D.B. 1983. The human vertebral column at the end of the embryonic period proper: 2. The occipitocervical region. J Anat. 136:181-195.

O'Rahilly, R., and Müller, F. 1987. Developmental Stages in Human Embryos. Carnegie Institution of Washington.

O'Rahilly, R., and Müller, F. 1996. Human embryology and teratology, 2rd edition. Wiley-Liss, New York.

O'Rahilly, R., and Müller, F. 2001. Human embryology and teratology, 3rd edition. Wiley-Liss, New York.

O'Rahilly, R., and Müller, F. 1986. The meninges in human development. J Neuropathol Exp Neurol. 45:588-608.

O'Rahilly, R. 1966. The early development of the eye in staged human embryos. Contrib Embryol. Carnegie Institution of Washington. 38:1-42.

Pereda, J., and Croxatto, H.B. 1992. Human preimplantation development in vivo: Ultrastructural observations. Ann Acad Med Singapore. 21:480-8.

Sathananthan, A.H., and Chen, C. 1986. Sperm-oocyte membrane fusion in the human during monospermic fertilization. Gamete Res. 15:171-186.

Sathananthan, A.H., and Trounson, A.O. 2000. Mitochondrial morphology during preimplantational human embryogenesis. Human Repro. 15:148-159.

Sathananthan, A.H., and Trounson, A.O. 1985. The human pronuclear ovum: Fine structure of monospermic and polyspermic fertilization in vitro. Gamete Res. 12:385-398.

Sathananthan, A.H., and Trounson, A.O. 1982. Ultrastructure of cortical granule release and zona interaction in monospermic and polyspermic human ova fertilized in vitro. Gamete Res. 6:225-234.

Sathananthan, A.H., Menezes, J., Gunasheela, S. 2003. Mechanics of human blastocyst hatching in vitro. Reprod Biomed Online. 7:228-34.

Sathananthan, A.H., Trounson, A.O., and Wood, C. 1986. Atlas of fine structure of human sperm penetration, eggs and embryos culture in vitro. Praeger Publisher, New York.

Sathananthan, A.H., Wood, C., and Leeton, J. F. 1982. Ultrastructural evaluation of 8- to 16-cell human embryos cultured in vitro. Micron. 13:193-203.

Sathananthan, A.H. 1985. Maturation of the human oocyte in vitro: Nuclear events during meiosis. Gamete Res. 12:237-254.

Sathananthan, A.H. 2005. Video clips of embryos in vitro. Personal communication.

Sathananthan, A.H. 1984. Ultrastructural morphology of fertilization and early cleavage in the human. Trounson, A.O., and Wood, C. In Vitro Fertilization and Embryo. Churchill Livingstone, London.

Soupart, P., and Strong, P.A. 1974. Ultrastructural observations on human oocytes fertilized in vitro. Fertil Steril. 25:11-44.

Streeter, G.L. 1949. Developmental horizons in human embryos (fourth issue); A review of the histogenesis of cartilage and bone. Contrib Embryol. Carnegie Institution of Washington. 33:149-169.

Streeter, G.L. 1951. Developmental horizons in human embryos; Description of age groups XIX, XX, XXI,XXII, and XXIII being the fifth Isssue of a survey of the carnegie collection. Contrib Embryol. Carnegie Institution of Washington. 34:165-196.

Trounson, A.O., and Sathananthan, A.H. 1984. The application of electron microscopy in the evaluation of two- to four-cell embryos cultured in vitro for embryo transfer. J In Vitro Fert Embryo Transf. 1:153-165.

Veeck, L.L., and Zaninović, N. 2003. An atlas of human blastocysts. Parthenon Publishing Group, New York.

Weller, G.L. 1933. Development of the thyroid, parathyroid and thymus glands in man. Contrib Embryol. Carnegie Institution of Washington. 24:93-139.

Zamboni, L., Mishell, D.R. Jr, Bell, J.H., and Baca, M. 1966. Fine structure of the human ovum in the pronuclear stage. J Cell Biol. 30:579-600.

Zamboni, L. 1971. Fine morphology of mammalian fertilization. Harper and Row, New York.


Source: The Virtual Human Embryo.