A 25-year-old pregnant female at 18 weeks gestation period presented to the Obstetrics OPD for routine ultrasound. Lab findings suggested severe anemia in the patient. Peripheral blood smear of the female is given. USG of the fetus showed an abnormality. Which of the following structures are responsible for the above abnormality: -

This is a case of antenatally diagnosed spina bifida cystica. 1st image shows megaloblastic anemia - which correlates that folate deficiency leads to neural tube disorders. 2nd image shows a cystic swelling in the lower spine of the fetus. Results from failure of fusion of neural tube dorsally during embryogenesis. There is a localized defect of the closure of caudal neuropore with persistence of neural placode (open spinal cord). Risk factors are in utero folate deficiency and in utero teratogen exposure. Antenatal USG may show evidence of an open neural tube defect with splayed or divergent posterior elements. Derivatives of somites: - Sclerotome Ventral sclerotome- Body of veebrae Lateral sclerotome - Pedicle, transverse process Dorsal sclerotome - Spinous process