PSY-1200 Lecture Notes - Lecture 11: Secondary Sex Characteristic, Frontal Lobe, Pubic Hair
Document Summary
A single sperm cell (male) penetrates the outer coating of the egg (female) and fuse to form one fertilized cell. A zygote is a fertilized cell with 100 cells, which become increasingly diverse. At about 14 days the zygote turns into an embryo (a and b) At 9 weeks an embryo turns into a fetus (c and d). Teratogens are chemicals or viruses that can enter the placenta and harm the developing fetus. The placenta transfers nutrients and pxygen from mother to fetus and filters harmful substances from reaching the embryo or fetus. Teratogens are harmful substances such as viruses (hiv, rubella) and drugs (cocaine, alcohol, nicotine) that can slip through and cause abnormal development or birth defects. Fetal alcohol syndrome (fas) is marked by a small, disproportioned head, with unusual facial features and lifelong brain abnormalities. 9 weeks- formation of brain: differentiation of ovaries and testes. 12 weeks- can smile and frown; circulatory system working.
