BIOL 2114 Lecture Notes - Lecture 1: Bleeding, Ectopic Pregnancy, Morula
Document Summary
Fertilization: joining of sperm & egg to form a zygote (46 chromosomes 2n = diploid) Originally was 23 chromosomes n = haploid. Takes place in last of fallopian tube. If fertilization occurs too low, it can result in placenta previa & Placenta abruption: placenta pulls away from uterus wall before delivery. Life threatening, major blood loss if it occurs. Pulled down by weight, especially w/ multiples. Ectopic pregnancy: fertilized egg (oocyte) implants in tube. Tube can rupture if not naturally aborted. Oocyte ovum: capable of being fertilized w/ in 12-24 hrs. Gestation: (after egg is fertilized) developement through birth. Embryo period: day of fertilization to week 8. Egg (m & f) split 2 cells (blastomeres) 3-4 days: (post fertilization) morula hollows & fills w/ fluid. 6-7 days: implantation begins (blastocyst embeds into uterus) Gastrulation: process of 3 germ/dermal layers being formed & developing. Teratogens: harmful substances an embryo can be exposed to after organs formed.
