Antepartum Normal Flashcards
Name the stages from sex to implantation?
Sex–>Fertilization–>zygote–>blastomeres–>morula–>blastocyst–>implantation
What period is the first 7 days after conception
Zygotic period (1-2 weeks)
What and when is the embryonic period?
week 3-7 after conception. 3 layers of cells (ectoderm, endoderm, and mesoderm) makes up all tissues and organogenesis at this time.
How does Teratogens affect this time period
May be lethal (cause SAB) or cause major congenital malformations.
Fetal development week 2 (after conception)
endo and ectoderm development
Fetal development week 3 (ac)
mesoderm development and notochord
Fetal development week 4 (ac)
heart beat begins, neural tube closes, beginning organ system, CRL 4-6mm
FD week 5 (ac)
rapid brain development, head enlarges, eyes, CRL 7-9mm
FD week 6 (ac)
nose, mouth, limb differentiation, ears, CRL 11-14
FD week 7 (ac)
Neck established, intestines herniated in umbilical cord, distinct human characteristics, CRL 16-18mm
FD week 8 (ac)
All structured present, eyelids closed, genitalia evident CRL 27-31mm
When does the fetal period begin
Week 9 (after conception) 11 weeks from LMP
FD week 9-12 (ac)
Body/limb growth accelerate, ears lowset, intestines back in abdomen, erythropoiesis shifts to spleen, swallows, breathe, urinates moves limbs (11-14 wks GA)
FD week 13-16 (ac)
Rapid growth, ossification of skeleton, ovaries differentiated, genitals recognizable, eyes/ears move to normal position, wt 3.5-4oz (15-18 wks GA)
FD week 17-20 (AC)
Movements stronger (mother feels now) Brown fat deposited, by 20wks body is covered in vernix; wt 1 lb (19-22 wks GA)
FD week 21-26 (ac)
Fetus gains wt, surfactant production, skin w/o SQ fat, lanugo present, crying and sucking, can make fist or grip, wt 1.25lbs (23-28 wks GA)
FD week 26 - 29 (ac)
Lungs capable of breathing air, CNS controls breathing, some fat storage begins, eyes open/shut, fingernails, wt 2.25 lbs (28 - 31 wks GA)
FD week 30-32 (ac)
Lanugo on face disappear, rhythmic breathing, can control body temp, wt 3.75 lbs (32-34 wks GA)
FD week 33-36 (ac)
Testes descended, more fat, less wrinkles, rounder body, wt 5.5 lbs (35-37 wks GA)
FD week 37 - 40 (ac)
Protuberant mammary glands, testes in scrotum, no lanugo, nails beyond fingers/toes, pulmonary, GI and renal permit extrauterine survival 7.5 lbs (39-42 wks GA)
Teratogens effect on weeks 1-4 after fertilization
either SAB or no reaction (all or nothing principle)
Teratogens effect of week 3-8 after fertilization
most critical for structural defects (during organogenesis)
Heart, arms/legs susceptible and neural tube defects w/o enough folic acid.
Teratogen effects what after 1st trimester
eyes, ears teeth CNS and genitalia
Which system has the longest sensitivity to teratogens? and how long
CNS and for a 16week window can be effected.