General Embryology: Development & Reproduction

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GENERAL EMBRYOLOGY By Dr. Ann Mwangi SPHS, USIU Outline 1. Definition of general embryology 2. Developmental periods 4. Terminologies used in embryology 5.Germitogenesis 6.Fertilization 7.Ectopic pregnancies 8. 1 st -4 th week of Intra-uterine life Embryology -is a branch of science that is concerned with the formation and development of the embryo and the fetus. • Embryology helps in developing knowledge concerning the beginning of human life, and the changes occurring during prenatal development. • It also helps in understanding causes of variations in human structure (how abnormal relations develop). NB >Development does not stop at birth. Important changes, in addition to growth, occur after birth (e.g., teeth, female breasts....). Developmental Periods • Human development is usually divided into two broad periods: 1. Prenatal developmental period -Is the developmental period before birth -Is further divided into three stages; Stage 1; Pre-embryonic stage -First 2 weeks; Fertilization to formation of the bilaminar germ disc Stage 2:- Embryonic stage; -From week 3 to week 8 (day 56) • Most visible advances occur during this period. - Is the most susceptible period to teratogenic...