Kidney structure with a convex and a concave border. A recessed area on the concave border is the renal hilum, where the renal artery enters the kidney and the renal vein and ureter leave. The kidney is surrounded by tough fibrous tissue, the renal capsule, which is itself surrounded by perirenal fat, renal fascia, and pararenal fat. The anterior (front) surface of these tissues is the peritoneum, while the posterior (rear) surface is the transversalis fascia. The superior pole of the right kidney is adjacent to the liver. For the left kidney, it is next to the spleen. Both, therefore, move
Posterior ethmoidal artery Posterior ethmoidal artery The posterior ethmoidal artery is an artery of the head which supplies the nasal septum. It is smaller than the anterior ethmoidal artery. Once branching from the ophthalmic artery, it passes between the upper border of the medial rectus muscle and superior oblique muscle to enter the posterior ethmoidal canal. It exits into the nasal cavity to supply posterior ethmoidal cells and nasal septum; here it anastomoses with the sphenopalatine artery. There is often a meningeal branch to the dura mater, while it is still contained within the cranium. This artery supplies the posterior ethmoidal air sinuses,