Class Notes (835,008)
Canada (508,866)
Psychology (6,249)

Psych 2040- Chapter 4: Prenatal Development.docx

4 Pages
Unlock Document

Psychology 2040A/B
Michael G Mac Donald

Overview  from conception to birth  environmental influence on prenatal development o teratogens o environmental hazards o the mother PRENATAL DEVELOPMENT  period of the zygote/germinal period: conception to implantation in uterine wall o 2 weeks long  period of the embryo: major organs formed and heart begins to beat  week 3 to week 8  period of the fetus: major organ systems function, rapid development  week 9 to birth  grow inside  out, head  down Period of the Zygote  path to implantation  inner layer of blastocyst becomes embryo, outer layer forms tissues that protect and nourish embryo  support structures of the embryo formed by outer layer: o amnion: watertight sac filled with fluid from mother’s tissues  protects organism from external environment o chorion: surrounds amnion and becomes placenta o placenta: semipermeable barrier sustaining embryo o umbilical cord … develop once implantation has occurred Period of the Embryo  all major organs formed and some begin to function  three cell layers form rapidly  ectoderm: becomes nervous system, skin, hair  mesoderm: becomes muscles, bones, circulatory system  endoderm: becomes digestive system, lungs, urinary tract, other vital organs  during second month…  ears formed  rudimentary skeleton  limbs develop  brain develops rapidly  indifferent gonad appears  about 2.5 cm long and 7g Perird of the Fetus  3 month…  able to kick, twist— not felt by mother  can swallow, digest, urinate  testosterone secreted by testes of males  ultrasound can detect sex  7.5 cm long, under 28 g  2nd trimester (4-6 months)  movements begin in preparation for extrauterine life  kicking felt  visual and auditory senses function by 6 months  3rd trimester (7-9 months)  “finishing phase”  organ systems mature  weight gain  age of viability: survival outside of uterus possible  22-28 weeks th  moves to head down position in 9 month  48-53 cm, 3.2-3.6 kg ENVIRONMENTAL INFLUENCES  affect prenatal environment  teratogens: agents that harm a developing fetus  viruses, drugs, chemicals, radiation  most affects period of embryo  environmental hazards  lead paint  maternal characteristics  nutrition, emotional well-being, age Effects of Teratogens  each developing structure has a sensitive period  when it is particularly susceptible to damage from teratogens  during rapid development (embryonic period)  once fully formed, parts are less susceptible to damage Maternal Disease  rubella  most dangerous in 1 sttrimester  effects: blindness, deafness, cardiac abnormalities, mental retardation  ST
More Less

Related notes for Psychology 2040A/B

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.