RESUMO
Background: Sciatic nerve is a mixed nerve which provide sensory and motor supply for skin and muscles of the lower limb by tibial and common peroneal nerve. Anatomical variations of sciatic nerve at high division have been reported by various authors. The path of the sciatic nerve is important while administration of intramuscular injection to prevent nerve injury and nerve blockage failure during anesthesia. This knowledge of high division helps in different surgical approach for sciatic nerve injury or hip dislocation. Aims and Objectives: The aim of the study was to describe incidences of high division variation of Sciatic nerve and different types in cadavers during routine dissection schedule. Materials and Methods: The study was conducted during routine dissection schedule in anatomy department for first MBBS students to observe sciatic nerve course in 30 gluteal regions from 15 adult cadavers fixed by formalin. Location of sciatic nerve in relation to piriformis muscle and its division whether in single nerve sheath or separate sheath and types was recorded. Results: In 12 cadavers (80%), sciatic nerve course found normal which leaves pelvis at inferior border of piriformis muscle and bifurcate in terminal branches tibial nerve and common peroneal nerve as it approaches at the apex of popliteal fossa. In 3 cadavers (20%), two male and one female, we found high division of sciatic nerve where terminal branches, tibial nerve, and common peroneal nerve leave the pelvis below piriformis separately in different sheaths. Conclusion: Knowledge of variations-related high division of sciatic nerve would help surgeons during different interventions related to sciatic nerve and for preventing further complications.
RESUMO
Background: Airway formation is one of the earliest events in development of respiratory system. However, maturation of airway continues well in post-natal life. The trachea has framework of incomplete ring of hyaline cartilage united by fibrous tissue and smooth muscle through which air conduction takes place. The trachea-bronchial mucosa is target for host of airborne toxic agents; bacterial and viral agents, allergens, reactive gases, aerosols, and irritant particles. This fascinates many workers for detailed study of epithelium or lining air passage. Aims and Objectives: The present study was undertaken to document normal developmental microscopic structure of tracheal cartilage in fetuses of different age group (gestational ages between 12th and 40th weeks) and to compare the difference between different age groups. Materials and Methods: Tissues from trachea of various age group fetuses were collected, processed, and stained with H and E and Masson’s trichrome. Results: Development of tracheal cartilage was observed into three trimesters. The 2nd and 3rd trimesters were further divided in the early 2nd (13th–16th weeks), mid-2nd (17th–20th weeks), late 2nd (21st–24th weeks), early 3rd (25th–28th weeks), mid-3rd (29th–32nd weeks), and late 3rd (33rd–40th weeks) phases. Conclusion: Perichondrium of cartilage had shown well-marked outer fibrous layer with increased vascularity by late 2nd to early 3rd trimester. Well-marked inner cellular layer of perichondrium was noticed by 3rd trimester, while cartilage had shown active chondrocytes by late 2nd to early 3rd trimester. At the late 3rd trimester, typical hyaline cartilage had shown chondrocytes in cell nest surrounded by territorial matrix.