The anterior lobe manufactures its hormones via endocrine cells. The pars intermedia lies between the pars distalis and the posterior lobe, whilst the pars tuberalis wraps the pituitary stalk. The pars distalis is found in the most anterior portion of the anterior lobe and forms much of the anterior lobe. The anterior lobe (adenohypophysis) is formed of glandular tissue split into three regions: 1ДЄntidiuretic hormone (ADH) helps to control homeostasis of fluid in the body via increasing water reabsorption in the kidneys, this forms a negative feedback loop. It is also necessary for the milk ejection reflex and thought to contribute to parent-neonate bonding. Oxytocin stimulates uterine contractions and dilation of the cervix with a positive feedback loop from cervical stretching. In response to signals from the hypothalamus, these hormones are released into the bloodstream.

Instead, the posterior pituitary stores and secretes the hormones produced by the hypothalamus, specifically oxytocin (produced by the paraventricular nuclei) and antidiuretic hormone (produced by the supraoptic nuclei). The posterior pituitary does not manufacture hormones.

The posterior lobe (neurohypophysis) is formed from neural tissue and is an extension of the neurosecretory fibres of the paraventricular and supraoptic nuclei of the hypothalamus. This can be performed with a microscope or endoscope.

One method of treatment involves surgery, approaching through the nose, and through the sphenoid sinus and sphenoid bone, a transsphenoidal approach (Figure 3). This can cause visual field defects, notably bitemporal hemianopia, which if left untreated can lead to permanent visual field loss. These tumours can manifest clinically secondary to the secretion of excess hormone and compression of local structures.ДЄs these tumours grow, they can compress the optic chiasm which lies superior to the pituitary gland. 4ДЄnterior lobe adenomas comprise about 10% of all intracranial tumours (posterior lobe adenomas do not occur). The pituitary gland within the pituitary fossa.

Posteriorly: posterior intercavernous sinus, dorsum sellaeДЇigure 2.

Anteriorly: anterior intercavernous sinus.

Laterally: cavernous sinus containing the internal carotids, oculomotor nerve, trochlear nerve, ophthalmic and maxillary divisions of the trigeminal nerve, and abducens nerve.

Superiorly: hypothalamus, pituitary stalk, optic chiasm, circle of Willis, diaphragma sellae (a fold of dura matter that covers the pituitary stalk).

Inferiorly: sphenoid bone and the sphenoid sinus.

3Дue to the pituitary glandвЂ™s location, it has important and complex anatomical relations: It is connected to the hypothalamus via the pituitary stalk (infundibulum), which serves not only to connect them physically but also allowing passage of nerve fibres from the hypothalamus. The pituitary gland is located within a depression of the sphenoid bone, called the pituitary (hypophyseal) fossa or sella turcica. Location of the hypothalamic-pituitary complex.

рџ«ЃДЄnatomical location and relations Figure 1. You might also be interested in our Anatomy Flashcard Collection which contains over 2000 anatomy flashcards in addition to advanced features such as spaced repetition.

Pituitary gland hormones