Gland
Pituitary gland (hypophysis)
Sellar endocrine organ linking brain signals to hormone output
High-yield
The nearby optic chiasm, cavernous sinuses and sphenoid sinus explain many effects of sellar disease. Their exact relationships vary, especially with enlargement or altered sinus anatomy.
Overview
The pituitary lies in the sphenoid's sella turcica and connects to the hypothalamus through its stalk. Oral ectoderm forms the glandular anterior component; neural ectoderm forms the posterior component. These tissues use different mechanisms to transfer hypothalamic information into the circulation.
Reference facts
- Location
- Within the hypophyseal fossa, beneath the diaphragma sellae and between the cavernous sinuses; the sphenoid sinus is usually inferior.
- Hormones
- Anterior tissue produces GH, prolactin, ACTH, TSH, FSH and LH. Posterior tissue releases hypothalamic vasopressin and oxytocin.
- Blood supply
- Hypophyseal branches of the internal carotid system feed direct and portal networks; posterior communicating branches may contribute superiorly.
- Innervation
- Anterior hormone output responds mainly to blood-borne signals; posterior release follows activity in hypothalamic axons.
- Function
- Coordinates growth, reproduction, lactation, thyroid and adrenal activity, water balance and reproductive smooth-muscle responses.
Clinical correlation
A mass can affect visual fields or cavernous-sinus nerves, but the pattern depends on its direction and extent. Sudden hemorrhage or infarction can cause pituitary apoplexy, with acute headache, visual disturbance and potentially dangerous hormone deficiency.
Frequently asked questions
Where is the pituitary gland (hypophysis) located?
Within the hypophyseal fossa, beneath the diaphragma sellae and between the cavernous sinuses; the sphenoid sinus is usually inferior.
What does the pituitary gland (hypophysis) secrete?
Anterior tissue produces GH, prolactin, ACTH, TSH, FSH and LH. Posterior tissue releases hypothalamic vasopressin and oxytocin.
What does the pituitary gland (hypophysis) do?
Coordinates growth, reproduction, lactation, thyroid and adrenal activity, water balance and reproductive smooth-muscle responses.
What is the blood supply of the pituitary gland (hypophysis)?
Hypophyseal branches of the internal carotid system feed direct and portal networks; posterior communicating branches may contribute superiorly.