RESUMEN
Puncture of the cricothyroid membrane is a component of several clinical procedures. Among the several complications are the immediate risk of bleeding, long-term risk of subglottic stenosis and hoarseness of voice. Presence of blood vessels in the cricothyroid membrane has also been implicated in the extra-laryngeal spread of laryngeal cancers. Though various authors have described the attachments of the cricothyroid membrane, very few have studied its histology. We studied the histology of the cricothyroid membrane using hematoxylin and eosin, Mallory's trichrome and Verhoeff's special stain. The cricothyroid membrane was found to be continuous on its deeper aspect with the mucosa of the subglottic larynx and lined by pseudostratified ciliated columnar epithelium. The membrane was observed to be fibroelastic, containing equal proportions of collagen and elastic fibers and numerous fibroblast nuclei. Numerous blood vessels are seen traversing through the membrane, which probably connect intralaryngeal with other extralaryngeal vessels. These histological findings help to further understand the complications of cricothyroidotomy and spread of laryngeal cancer.
RESUMEN
BACKGROUND: Each kidney is supplied by a single renal artery and a single renal vein, which accounts for about 20% of the cardiac output. However, variations in the form of level of origin and arrangement of renal arteries are so frequent. AIM: The present study aimed to note the vascular anatomy of kidneys with respect to the variations in their origin, course and any aberrant vessels which were present. MATERIALS AND METHODS: The study material comprised of 15 formalin fixed human cadavers. During routine abdominal dissection for undergraduate students, the kidneys were exposed and the blood supply, along with its variations, were noted. RESULTS: The following anatomical findings are observed in this study: (i) Accessory renal arteries (ii) Presegmental arteries (iii) Upper polar arteries (iv) Lower polar arteries (v) Inferior suprarenal artery from accessory renal artery and (vi) Accessory renal vein. CONCLUSION: Awareness of the normal as well variational anatomy is mandatory for the surgeons, radiologists and urologists, for doing any uroradiological procedures or angiographic studies. Hence, this study will serve a useful guideline for the above mentioned procedures.