**2.1 Blood supply of pituitary gland**

The pituitary gland receives its blood supply from bilateral superior and inferior hypophyseal arteries. Superior hypophyseal artery (SHA) is a direct branch from the supraclinoidal segment of the ICA. In addition to supplying the pituitary gland and stalk, the SHA also supplies the optic nerve and chiasm. The inferior hypophyseal artery (IHA) branches from the cavernous segment of the ICA, but can also branch from the meningohypophyseal trunk. The IHA supplies the pituitary gland and to some extent the stalk (**Figure 2**). Truong et al. [4] found that the bilateral coagulation of IHA has minimal effect on adenohypophysis and neurohypophysis functions due to presence of rich intraarterial anastomosis between SHAs. However, injury to SHA branches supplying the visual apparatus may result in visual field defects or vision loss due to paucity of anastomosis in the optic nerves or chiasm.
