Lecture 3-Conception and Prenatal Development

Lecture 3-Conception and Prenatal Development - Conception...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Conception and Prenatal Development Lecture 3 January 18, 2012 Lecture Overview • Goal: To describe the events that lead from the formation of a single cell (conception) to an amazing newborn baby • Stages of prenatal development • Germinal, Embryonic, Fetal • Focus on brain development • Video • Risks to fetal health • Ovulation – The moment during a woman’s monthly cycle when the ovum (egg) is expelled from the ovary. • Brief window for conception • Ovum survives 24-48 hrs. • Sperm cells survive 2-5/6 days • Fertilization - union of sperm & ovum; conception • Usually occurs in a fallopian tube Conception Genetics of Fertilization • Almost all human cells contain 46 chromosomes • Ovum and sperm each contain 23 • Fertilized egg contains a unique set of 46 (23 from each parent) Stages of Prenatal Development • Germinal period (0 to ~ 2 wks) - lasts from fertilization to full implantation (when the cell mass attaches to the uterus wall). § Zygote Ø Fertilized egg Ø Dividing cells Ø Takes 3 days to go down fallopian tube to the uterus Ø When it reaches the uterus, it becomes a blastocyst § Blastocyst - hollow, 100-cell ball Ø Forming layers Ø Cell mass moves down uterus and implants in wall Events of the Germinal Stage Ovary Fallopian tube Germinal Stage continued • Implantation – when the blastocyst becomes imbedded into the uterus wall • Only ~20-33% of fertilized eggs complete the journey from the fallopian tube to the uterus and implant in the uterine wall. • Embryonic disk - cells on inside – become new organism • Trophoblast - outer layer of cells- will develop into life- support systems Germinal Stage continued • Trophoblast - continued § Amnion - protective sac - encases organism in amniotic fluid, a cushion & temperature regulator § Placenta - partial filter - permits food and oxygen to reach organism and waste products to be carried away § Umbilical cord - Structure that connects placenta to developing organism through which nutrients are passed and waste is removed Period of the Embryo (2-8 weeks)...
View Full Document

This note was uploaded on 02/15/2012 for the course PSYCH 250 taught by Professor Ward during the Winter '08 term at University of Michigan.

Page1 / 22

Lecture 3-Conception and Prenatal Development - Conception...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online