The Fetus Flashcards
Ovum
First 2 weeks
Embryos
From 3rd week to 10 weeks of gestation
And 8th week post conception
Crl
Up to 20th week
Of embryo: 4mm
Fetus
From 8th week post conception
Crown heel length
From end of 20th week
Gestational age in weeks in first trimester
CRL + 6.5mm
First heartbeats at
D 21
Notochord develops at
D14-D21 pc
Complete neural tube closure
Limb buds appear at
At D30
Recognisably human at
Week 6-8 post conception
Ext genitalia develops at
Week 8-12 pc
Skin is covered with lanugo and vernix caseosa is present
Week 20
Baby viable and testis descend to int inguinal ring
Week 28
Both testicles descend into scrotum and nails project beyond fingers tips and post fontanelle closes
Week 40
Fetus blood
Yolk sac till 14 day (2week)
Liver from 10 week
Near term from BM
Adult hb appears from
24 week
Between 5 and 8 weeks, fetal blood has hb
HB GOWER 1 and 2
HB PORTLAND
Only adult hb
> 6-12 months
Rh factor develops at
38 days pc
Life span of fetal rbcs
80 days
Leukocytes appear after
2 months of gestation
Maternal igG crosses placenta from
12 week onwards
Lanugo appears at
16th week
Sebaceous glands
20th week
Meconium appears at
20th week
Breathing movements identifies at
11 week
Breathing movements regular
At 20 weeks
Lung surfactant
24 week
Alveoli expand
28 week
Glucagon
8th week
Insulin
12 week
Ant pituitary hormones
10 week
Post pituitary hormones
12 week
Thyroxine
11 week
Distal parts of umbilical a become
Lateral umbilical ligament
Proximal parts of umbilical a become
Superior vesical a
Closure of umbilical v
Ligamentum teres
Ductus venosus become
Ligamentum arteriosum
Umbilical a closes within
2-3 months
Ductus arteriosus become
Ligamentum arteriosus
Ductus arteriosus obliterates at
1-3 months
Closure of Foramen ovale
Within 1 yr
Distal parts of umbilical a become
Lateral umbilical ligament
Proximal parts of umbilical a become
Superior vesical a
Closure of umbilical v
Ligamentum teres
Ductus venosus become
Ligamentum arteriosum
Umbilical a closes within
2-3 months
Ductus arteriosus become
Ligamentum arteriosus
Ductus arteriosus obliterates at
1-3 months
Closure of Foramen ovale
Within 1 yr