Renal artery located above the renal vein. Supernumerary renal arteries (two or more arteries to a single kidney) are the most common renovascular anomaly, occurrence ranging from 25% to 40% of kidneys. Renal artery stenosis, or narrowing of one or both renal arteries will lead to hypertension as the affected kidneys release renin to increase blood pressure to preserve perfusion to the kidneys. RAS is typically diagnosed with duplex ultrasonography of the renal arteries. It is treated with the use of balloon angioplasty and stents, if necessary. Atherosclerosis can also affect the renal arteries and can lead to poor perfusion of the
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,