Infant and Child Development Exam 1 Chapters 1-6 Complete Exam Questions With Correct Detailed Answers.

When does prenatal development begin? When does it end? How many weeks does it typically last? - correct answers Begins with fertilization Ends with birth Lasts 38-40 weeks What are the 3 periods of prenatal development? What is the term for the developing organism in each period? What's the time period for each? - correct answers1. germinal period -developing organism: zygote -time period: conception to 2 weeks 2. embryonic period -developing organism: embryo -week 3-8 3. fetal -developing organism: fetus -time period: week 9 - birth GERMINAL PERIOD When does the germinal period begin? What is fertilization? - correct answersbegins with conception fertilization: process by which sperm and egg unite in a fallopian tube What is the zygote? What does it do after fertilization? - correct answerszygote: fertilized egg that has a full complement of human genetic info (1/2 from each parent) after fertilization: moves toward uterus (which can take up to a week) What are the sex differences in conception, for miscarriage, and through the life span? About what age is the proportion of males to females about equal? - correct answersin conception: sperm with the Y chromosome are lighter and swim faster to the egg than those bearing an X chromosome for miscarriage: male embryos are miscarried at higher rates than female embryos, and boys are more vulnerable to developmental disorders throughout the life span: males are more vulnerable what age proportion of males = females? What is the blastocyst? What does the inner layer eventually become? What is the trophoblast and what does it later provide? - correct answersblastocyst: 4th day after conception Inner layer eventually becomes embryo trophoblast: the other layer of the blastocyst that later provides nutrition and support for embryo What is implantation? About when does it take place? - correct answersimplantation: the attachment of the zygote to the uterine wall that ends the germinal period takes place 11-15 days after conception EMBRYONIC PERIOD What weeks does it include? - correct answersweek 3-8 What is an embryo? What are the 3 layers of cells? What will each layer develop into (generally and specific systems and parts of the body)? - correct answersembryo: the mass of cells when the blastocyst attaches to the uterine wall 3 layers of cells: -endoderm: inner layer of cells ~will develop into the internal body parts ~digestive and respiratory systems -mesoderm: middle layers of cells ~will develop into the parts that surround the internal areas ~becomes circulatory system, bones, muscles, excretory system, and reproductive system -ectoderm: outermost layer ~will develop into the surface parts ~becomes the nervous system and brain, sensory receptors, and skin parts (hair/nails) every part of body eventually develops from these 3 layers What are the 2 patterns of development (terms and definitions)? - correct answers1. cephalocaudal development (Head-to-body): -areas near the head develop earlier, faster than those farther away ~head develops before the body ~hands develop before the feet 2. proximaldistal development: development starts in the center areas, such as the internal organs, and proceeds to more distal areas, such as legs and arms What are: the amnion, the umbilical cord, the placenta? - correct answersamnion: a bag or envelope containing a clear fluid in which the developing embryo floats -amniotic fluid provides an environment that is temperature and humidity controlled as well as shockproof umbilical cord:tube that contains the blood vessels that travel from the placenta to the developing organism and back again -contains two arteries and one vein and connects the baby to the placenta placenta: disk-shaped group of tissues in which small blood vessels from the mother and the offspring intertwine but don't join -permits the exchange of materials between the bloodstream of the fetus and that of the mother Why is the placenta semipermeable? What passes from mother to developing baby? What does not pass from mother to developing baby? What passes from developing baby to mother? - correct answersthe placenta is semipermeable because it allows nutrients and gasses to pass through Passes from mother to developing baby: very small molecules -oxygen, water, salt, nutrition -any drug of chemical substance to some degree that is not metabolized, not altered during passage, and that is small enough Passes from developing baby to mother: very small molecules -carbon dioxide, digestive wastes -any drug of chemical substance to some degree that is not metabolized, not altered during passage, and that is small enough Does not pass from mother to developing offspring: large molecules -red blood cells, most bacteria, maternal wastes What is organogenesis? - correct answersthe process of organ formation during the first two months of prenatal development. organs are especially vulnerable to environmental changes while they are being formed What are 2 important developmental milestones of the embryonic period and at what week does each occur? - correct answers3rd week: neural tube 4th week: heart beat What is the neural tube? What will it eventually become? - correct answersneural tube: u-shaped groove that forms out of the ectoderm. tube closes at top and bottom at ~day 24 becomes brain and spinal cord FETAL PERIOD What weeks does it include? - correct answersweek 9 - birth How big is the average North American baby at birth (length and weight)? - correct answers20" long and weighs 7.5 lbs What are 5 important developmental milestones of the embryonic period and at what week(s) does each occur? What is viable? - correct answers9th week: all internal organs present (but not fully developed) 12th week: sex is distinguishable 18th-20th week: mother can begin to feel baby move and can hear baby's heart through a stethoscope 24th-25th week: viable -brain and lungs sufficiently developed so that if born at this time, has a chance of surviving, but will likely need help breathing 32nd week: prenatal learning -responds to sounds -CNS developed enough so that learning and memory can occur How are periods of prenatal development associated with trimesters (i.e., in which trimester does each period occur)? - correct answersFirst trimester: Zygote, embryo, fetus Second trimester: Fetus Third trimester: Fetus What were the results of The Cat in the Hat Study? What does this demonstrate? - correct answersexperiment: -mothers read aloud last 6 weeks of pregnancy -as newborns, first measured sucking baseline rate -experimental condition: ~half needed to suck faster to hear the story ~half needed to suck slower to hear story results: adjusted rate to hear the story (Even when condition was switched on them) demonstrates that newborn infants recognize rhymes and stories presented before birth What is: a teratogen, teratology, behavioral teratology? - correct answersteratogen: any agent that can potentially cause a birth defect or negatively alter cognitive and behavioral outcomes -some mother has no control over (i.e. pollution) -others mother can control (i.e. alcohol and drugs) teratology: the field of study that investigates the causes of birth defects behavioral teratology: the field of study that investigates teratogens that do not caused physical birth defects but can alter developing brain and influence cognitive and behavioral functioning What are effects of teratogens? What are 4 general principles concerning effects of teratogens? - correct answerseffects of teratogens: -physical birth defects -alteration of the developing brain and can influence cognitive and behavioral functioning -long-term effects depend on postnatal environment -some effects not apparent until later in life ~only about half of the potential effects appear at birth 4 general principles concerning effects of teratogens 1. genetic susceptibility: type or severity of abnormalities caused by a teratogen is linked to the genotype of the pregnant woman and the genotype of the embryo or fetus 2. nature of teratogen: different agents have different effects 3. dose-response relation: longer exposure/higher dose of teratogen = more harm -amount varies by teratogen 4. timing of exposure: teratogens do more damage when they occur at some points in development than at others Can teratogens influence development before conception? Both men and women? - correct answerswomen: study found that taking folic acid for at least 1 year prior to conception was linking to lower risk of early delivery men: exposure to lead, radiation, certain pesticides, and petrochemicals may cause abnormalities in sperm that lead to miscarriage or diseases such as childhood cancer Concerning exposure to teratogens during prenatal development: during which prenatal period is the developing organisms usually not susceptible to teratogens, and if they do have an effect, the effect is more likely miscarriage? During which prenatal period is the probability of a structural defect the greatest? During which prenatal period is the effect more likely to be to stunt growth or create problems in the way organs function? - correct answersduring the germinal period, the developing organisms are usually not susceptible to teratogens, and if they do have an effect, the effect is more likely miscarriage during the embryonic period the probability of a structural defect is greatest because this is a time of rapid structural development/organogenesis during the fetal period the effects is more likely to be to stunt growth or to create problems in the way organs function BIRTH What has research shown about many aspects of the birth experience for the baby? - correct answersthey have adaptive values and increase the likelihood of survival for the newborn What are the 3 stages of labor? Which is the longest stage of labor? Which is the shortest? - correct answers1. regular uterine contractions: contractions open cervix -longest stage