The pituitary gland Flashcards
What is the other name for the pituitary gland
The hypophysis
what does the pituitary gland do?
It secretes hormones that control the actions of other endocrine organs and various tissues around the body.
Describe the anatomical relations of the pituitary gland
Anteriorly – sphenoid sinus (the pituitary gland is accessed surgically via the sphenoid sinus, known as a trans-sphenoidal approach).
Posteriorly – posterior intercavernous sinus, dorsum sellae (posterior wall of the sella turcica), basilar artery and the pons.
Superiorly – diaphragma sellae (fold of dura mater that covers the pituitary gland), optic chiasm.
Inferiorly – sphenoid sinus
Laterally – cavernous sinus.
Describe the embryological derivation of the anterior pituitary gland
The anterior part is derived from an upgrowth from the oral ectoderm of the primitive oral cavity called Rathke’s pouch.
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
wwwwwwwwwwwwwwwwwww
What is another name for the anterior pituitary gland?
adenohypophysis
What is another name for the posterior pituitary gland?
neurohypophysis
What type of epithelium is the anterior pituitary gland composed of
Glandular epithelium
The anterior lobe of the pituitary gland is divided into which three parts
Pars anterior – the largest part, responsible for hormone secretion.
Pars intermedia – a thin epithelial layer that separates the pars anterior from the posterior lobe.
Pars tuberalis – an upwards extension of the pars anterior that surrounds the anterolateral aspect of the infundibulum.
Describe the hormone secretion process?
The release of hormones is under the control of the hypothalamus, which communicates with the gland via neurotransmitters secreted into the hypophyseal portal vessels. These vessels ensure that the hypothalamic hormones remain concentrated, rather than being diluted in the systemic circulation.
Describe the posterior pituitary gland embryonic origin
The posterior lobe (neurohypophysis) consists of nervous tissue. It arises from the embryonic forebrain it originates from neural ectoderm
What two substances does the posterior pituitary gland secrete
-ADH (responsible for the control of blood osmolarity), –Oxytocin (involved in parturition and milk secretion).
ADH and oxytocin are produced and stored where?
Both of these substances are produced in the supraoptic and paraventricular nuclei of the hypothalamus and then subsequently stored in the posterior pituitary gland, ready for release.
State the blood supply of the anterior pituitary gland?
The anterior pituitary gland receives arterial supply from the superior hypophyseal artery (a branch of the internal carotid artery).
State the blood supply of the posterior pituitary gland?
The superior hypophyseal artery
infundibular artery
inferior hypophyseal artery.
