PSYB32H3 Lecture Notes - Gonorrhea, Lanugo, Toxoplasmosis
Document Summary
The 9 months are characterized in two ways: trimsters: periods of 3 months, zygote, embryo, and fetus. Proximal-distal: growths first occurs in central areas (internal organs) then in more distal areas (such as arms and legs) Teratogens: an environmental agent that may cause developmental deviations in a growing human organism. Teratogens can exert their effects on prenatal development in specific ways: It effects only during critical periods: each has their own effects, either maternal or fetal genotypes may counteract its effects, the effect of one may intensify the. Cephalo-caudal: downward from head to trunk effect of another. Tendrils of zygote penetrate the blood vessels in the wall of the uterus. The embryo: (beg of 3rd week to end of 8th week) Most important physiological systems and structures become differentiated. Amniotic sac: thin membrane around embryo for protection from temp, ph
