QS Study

Gross Anatomy of Pituitary Gland

Pituitary Gland is a small endocrine gland situated in the hypophyseal fossa in relation to the base of the brain. It is a part of our endocrine system. Its major purpose is to emit hormones into your bloodstream. It secretes hormones that control the actions of other endocrine organs and various tissues around the body.

  • Shape: Oval.
  • Size: Anteroposteriorly – 8mm and transversely – 12mm.
  • Weight: 500 mg.

It is located within the cranial vault. It lies just inferior to a part of the diencephalon called the hypothalamus and inferioroposteriorally to the optic chiasma. The fully developed pituitary gland is pea-sized and weighs approximately 0.5 g.

Subdivision

It has two main parts:

(A) Adenohypophysis – It is highly cellular and occasionally presents intra-glandular cleft. The part behind the cleft is known as pars intermedia.

  • Anterior lobe or pars anterior.
  • Intermediate lobe or pars intermedia.
  • Tuberal lobe or pars tuberalis.

(B) Neurohypophysis – It is continuous above with the infundibulum. It consists of three parts:

  • Posterior lobe (pars posterior).
  • Infundibular stem.
  • Median eminence.

Pituitary Gland 1

Fig: Gross Anatomy of Pituitary Gland

Relations

(A) Superiorly – optic chiasma, anterior communicating artery and the floor of the third ventricle separated by the diaphragm sellae, which has a central aperture that allows the passage of the infundibulum

  1. Diaphragm sellae.
  2. Optic chiasma.
  3. Tuber cinerum.
  4. An infundibular recess of 3rd ventricle.

(B) Inferiorly – The body of the sphenoid, with its sphenoid air sinuses.

  1. Irregular venous channels between the two layers of dura mater lining the floor of the hypophyseal fossa.
  2. Hypophyseal fossa.
  3. Sphenoidal air sinuses.

(C) On each side: The cavernous sinus with its contents.

Related Study: