Morphology and Histology of Thoracic Sympathetic Ganglia in Fetus: A Medicolegal Aspect

Introduction: The thoracic sympathetic trunk possesses 12 ganglia,one corresponding to each thoracic nerve ,it lies anterior to head of ribs or side of the body of thoracic vertebrae.Splanchnic nerves arise from the thoracic ganglia and supply thoracic and abdominal viscera. Material and method: The present study included 50 preserved fetus specimens sent for routine autopsy in Department of Anatomy ,Government medical college and hospital,Chandigarh.The thoracic and abdominal wall of the fetus was incised ,then all organs were removed to expose the sympathetic chain .Morphological observations were noted.Next the thoracic ganglion was removed and fixed in paraffin for the histological processing in different gestational ages. Observation: The fetus were divided into 4 age group (Group A=11-15weeks,Group B=15+_20weeks,Group C=20+_25weeks and Group D=25 weeks onwards) Morphological observation: The length of thoracic chain was noted which was directly proportional to gestational age.The number of ganglia showed variability 12 in 22 cases,11 in 18 cases and 10 in 7 cases.The origin of splanchnic nerves from thoracic ganglia was quite variable. Histological observation: In group A the neuroblast cells were observed with eccentric nucleus. Presence of satellite cells was noticed in group B surrounding neuroblasts. In group C, some neuroblasts were seen undergoing mitosis whereas others slowed more differentiation.In group D mature adult like neuroblasts were seen with processes, satellite cell sheath and perinuclear halo.