PSYC 250 1st Edition Lecture 5 Outline of Last Lecture I. The evolutionary perspectiveII. Genetic foundations of developmentIII. Reproductive challenges and choicesIV. Heredity and environment Interactions: The Nature-Nurture debate Outline of Current Lecture II. The course of prenatal development III. Prenatal developmentIV. BirthCurrent LectureII. The course of prenatal development- The Germinal Periodo Takes place in first 2 weeks after conceptiono It includes the creation of the fertilized egg, cell division, and attachment of zygotto uterine wallo Rapid cell division continueso Differentiation of cells take placeo Cells are now formed into blastocyst-an inner mass of cells that will eventually develop into the embryoo The trophoblast, an outer layer of cells that later provides nutrition and support for the embryoo Implantation occurs 11-15 days after conception- The Embryonic Periodo Occurs 2-8 weeks after conceptiono Rate of cell differentiation intensifieso Support systems for cells form and organs appearo The blastocyst attaches to the uterine wallo Mass of cells now called an embryoo Endoderm, mesoderm, ectoderm form o Life support systems develop rapidly: amnion, umbilical cord, placenta- The Fetal Period o Between 2 months up until birtho Growth and development continueThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Fetus is 3 inches long and weighs 3 ounceso Structures of the skin formo Eyes and eye lids are completely formedo Can survive outside the womb at 26 months without technological interventions III. Prenatal development- The braino Babies have 100 billion neurons when borno Basic architecture of the human brain is assembled the first two trimesters of development. o At 6-24 weeks neuronal migration occurs o Once a cell has migrated to its target destination, it must mature and develop a deeper connectiono At 23rd week, connections between neurons begin to occuro Two birth defects related to a failure of the neural tube to close: anencephaly and spina bifida - Teratology and hazards to prenatal development o Teratogen: any agent that can potentially cause a birth defect or negatively alter cognition o Does, genetic susceptibility, and time of exposure to a teratogen influence both the seveity of the damage to an embryo and the type of defect - Psychoactive drugso Act on nervous system to alter states of consciousness, modify perceptions, and changes moods. Examples- caffine, alcohol, nicotine, illegal drugs- Environmental hazards o Radiationo Toxic wasteso X-ray radiationo Environmental pollutants - Maternal diseases and infections: can produce defects in offspring by crossing the placental barrier or they can damage during birtho Rubella, syphilis, genital herpes, AIDS, diabetes o Maternal diet and nutritiono Maternal ageo Emotional states and stressIV. Birth- Birth process occurs in three stages- First stage is the longest of the three stages- Uterine contractions are 15-20 minutes apart at the beginning and last up to a minute each- Contractions cause the woman’s cervix to stretch and open- As the first stage progresses, the contractions come close together, appear every two to five minutes- By the end of the first stage, contractions dilate the cervix to an opening of about 4 inches, so that they baby can move from the uterus to the birth canal. - Second stage begins when the baby’s head moves through the cervix and ends with the baby’s complete emergence- Afterbirth is the third stage at which time the placenta, umbilical cord, and other membranes are detached and