APE 7: The endocrine system Flashcards
What’s another name for the pituitary gland?
The hypophysis
Describe the structure and position of the pituitary gland
The pituitary gland is a pea-sized structure, suspended from the underside of the brain by the pituitary stalk (the infundibulum). It sits in the hypophyseal fossa on a small depression in the sphenoid bone known as the sella turcica
What’s the name of the reflection of the dura mater through which the infundibulum passes?
The diaphragma sellae
What is anterior to the pituitary gland?(The gland can be accessed via this structure in surgery)
The sphenoid sinus
What 4 things are found posterior to the pituitary gland?
The posterior intercavernous sinus, the dorsum sellae, the basilar artery and the pons
What sinus is lateral to the pituitary gland?
The cavernous sinus
What are the names of the 2 lobes of the pituitary gland?
The anterior lobe is called the adenohypophysis. The posterior lobe is called the neurohypophysis.
What are the names of the 3 parts of the anterior lobe?
Pars anterior, Pars intermediate and Pars tuberalis
What is pars anterior responsible for?
Pars anterior is responsible for hormone secretion.
Via what vessels does the hypothalamus communicate with the pituitary gland to control hormone release?
The hypophyseal portal vessels
What is the importance of the hypophyseal portal vessels?
These vessels ensure that the hypothalamic hormones remain concentrated, rather than being diluted in the systemic circulation
What tissue type does the posterior lobe of the pituitary consist of?
Nervous tissue
Upon stimulation, which 2 hormones does the posterior pituitary secrete?
ADH and oxytocin
What is the function of ADH?
Regulation of blood osmolarity
What is the function of oxytocin?
Parturition and milk secretion
How many bones make up the cranium?
There are 8 bones
What does the sphenoid bone consist of?
A body, paired greater wings and lesser wings, and 2 pterygoid processes
What sinuses does the body of the sphenoid bone contain?
The sphenoid sinuses
With what bone does the sphenoid bone articulate with anteriorly and where do the sphenoid sinuses open up into ?
The sphenoid body articulates anteriorly with the ethmoid bone. Here, the sphenoid sinuses open into the nasal cavity
What structure is found on the superior surface of the sphenoid body?
The sella turcica, where the pituitary gland sits