ABSTRACT
Introduction The pituitary (Latin for ‘phlegm’) or hypophysis (Greek for ‘undergrowth’) sits in a bony indentation of the skull base called the sella turcica. Its superior surface is covered by dura called the diaphragma sella, through which passes the pituitary stalk connecting the pituitary gland with the hypothalamus (Fig. 10.1). The diaphragm sella is pain-sensitive; its nerve supply is from the ophthalmic division of the
trigeminal nerve. In about 20% of individuals, the diaphragma sella is incompetent, potentially allowing cerebrospinal fluid (CSF) from the suprasellar cistern to enter the sella turcica. Lateral to the pituitary gland are the paired cavernous sinuses, which contain the carotid artery, the nerves to the extraocular muscles (oculomotor-cranial nerve III; trochlear-cranial nerve IV; and abducens-cranial nerve VI) and the first division of the trigeminal nerve-cranial nerve V. Below the floor of the sella is the
sphenoid sinus. Above the diaphragma sella and within the suprasellar cistern is the optic chiasm, which contains crossing fibers of the optic nerve from each of the retinas. Above the optic chiasm is the hypothalamus, that secretes the releasing factors that regulate pituitary function and are transmitted to the pituitary gland via the stalk.
