Fetal Development Flashcards
Beginning day 15 through approximately week eight after conception
The embryonic period.
First two weeks after conception
Pre-embryonic.
The blastocyte is free-floating during this week
Week 1
Weeks two through three
The embryo is 1.5 to 2 mm in length. The long buds appear. Blood circulation begins. Heart is tubular and begins to beat. Neural plate becomes brain and spinal cord.
During week five of fetal development
The embryo is .4 - .5 cm in length. The embryo is .4 g. Double heart chambers are visible. Heart is beating. Limb buds form.
During week eight of fetal development
The embryo is 3 cm in length and 2 g in weight . The embryos eyelids begin to fuse. Circulatory system through umbilical cord is well established. Every organ system is present.
During week 12 of fetal development
The fetus weighs 9 g and is 6 to 9 cm in length. Limbs are long and slender. Kidneys begin to form urine. Spontaneous movements occur. The heartbeat is detected by Doppler transducer between 10 and 12 weeks. Gender is visually recognizable.
During week 16 of fetal development
The fetus weighs 100 grams it is also 11.5 to 13.5 cm in length. Active movements are present. Fetal skin is transparent. Lanugo hair begins to develop. Skeletal ossification occurs.
Week 16 of fetal development
The fetus weighs 300 g it is also 16 to 18.5 cm in length . lanugo covers the entire body. Fetus has nails. Muscles are developed. Enamel in Dentin are depositing. Heartbeat is detected by regular fetoscope.
Week 24 of fetal development
The fetus weighs 600 g. The fetus is 23 cm in length. Hair on head is well formed. Skin is Redish and wrinkled. Reflects handgrips functions. Vernix caseousa covers entire body. Fetus has ability to hear.
Week 28 of fetal development
The fetus is 27 cm in length and weighs 1100 g. The limbs are well flexed. The brain is developing rapidly. I live open and close. The lungs are developed sufficiently to provide gas exchange. If born, neonate can breathe at this time.
Week 32
The fetus is 31 cm in length and weighs 1800-2100 g. The bones are fully developed. Subcutaneous fat has collected. Lecithin to sphingomyelin ratios is 1.2:1.
Week 36
The fetus weighs 2202 2900 g and is 35 cm in length. The skin is pink and less wrinkled the body is rounded the lanugo is disappearing. L /S ratio is greater than 2:1
Week 40
The fetus is 40cm in length and weighs 3200g. Skin is pinkish and smooth. Lanugo is present on upper arms and shoulders. Vernix caseousa decreases. Fingernails extend beyond the fingertips. Sole creases run down the heel. Testes are in scrotum. Labia majors are well developed.
