Infant Lecture 4

Infant Lecture 4 - Infant Lecture 4 January 29, 2007 1-4...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Infant Lecture 4 January 29, 2007 1-4 days Zygote- cleavage - 20 hours [every 20 hours the number of cells double] Blastomere [each resulting cell called this]- 16 cells then called a morula 4 day – uterine cavity- blastocyst [trophoblast-supporting structures & embryoblast- becomes embryo ] 5-6 days – blasto hatches- implants 7-12 day - Trophoblast begins to develop capillaries and placenta 13 day - Chorionic villi Blood system in placenta Narrow streak cells Ectoderm, mesoderm, endoderm Down syndrome born to women younger than 35 Use ultrasound to get data on down syndrome In Europe 80% terminate pregnancies with down syndrome Male could also contribute to 21 st chromosome About 50% of all pregnancies [we assume a pregnancy means a fertilized ovum] end in miscarriages. Only 15% of recognized pregnancies Most miscarriages occur in first trimester Cause not entirely known Chromosomal abnormalities are on the list [including down syndrome] Mother may have infection There may be hormonal problems D+C when tissue is remained – 10-25% Healthy women 15-20% miscarriage Older you are more likely miscarriage Underage 35 15%, 1 out of 7 Btwn 35-45 years of age- 20-35% chance Over again 45 50% of pregnancies end in miscarriage If a women has a miscarriage once then future has 20% chance it will happen again Embryonic Stage: week 3 [brain, sc, and heart and GI tract]; weeks 4-5
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

Infant Lecture 4 - Infant Lecture 4 January 29, 2007 1-4...

This preview shows document pages 1 - 2. Sign up to view the full document.

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