Anatomy of the Pituitary Gland Flashcards
What makes up the diencephalon and what is it’s purpose?
The thalamus and hypothalmus
Central core of the cerebrum with connections to the right and left cerebral hemispheres and the midbrain
What are the 3 parts of the brainstem?
Midbrain
Pons
Medulla oblongata
What is the inferior continuation of the brainstem called?
Spinal cord
What connects the pituitary gland to the hypothalamus?
infundibulum
Where exactly does the pituitary gland sit?
Midline structure in the pituitary fossa of the sphenoid bone which sits in the sella turcica
Briefly describe what happens when light rays come from the nasal side of the right visual field.
- They are absorbed by the temporal retina
- Posterior to the retina is the optic nerve (ight changes to AP here)
- This AP goes posteriorly and crosses at the optic chiasm
- Now known as the optic tracts, they leave and synapse in the thalamus
- continue posteriorly as the optic radiation to the left vvisual cortex in the left occipital lobe
What is the clinical outcome of a pituitary tumour?
Bilateral hemianopia - loss of vision on the temporal side of visual field bilaterally
Give 3 options for gaining surgical access to the pituitary fossa.
Subfrontal
Transsphenoidal
le-Fort 1 down fracture
Which bones are involved in the nasal cavities?
Cribiform plate of ethmoid bone - roof
Perpendicular plate of ethmoid bone - superior part
Vomer - inferior part
What are the names of the 3 nasal conchae and which bones do they come from?
Superior nasal concha of ethmoid bone
Middle nasal concha of ethmoid bone
Inferior nasal concha (separate bone)
What are the nasal concha and paranasal sinuses lined by?
Mucous secreting respiratory mucosa
Name the 4 sets of paranasal sinuses.
Frontal sinuses
Maxillary sinuses
Ethmoidal air cells
Sphenoid sinuses
Where is dura mater and what is its function?
Adherent to the iternal aspects of ALL bones in the cranial vault
Functions to protect structures of the cranial cavity
What is tentorium cerebelli?
A tough sheet of dura mater “tenting” over the cerebellum within the posterior cranial fossa
It has a central gap which allows the brainste to pass through
What is the diaphragm sellae and where is it?
A tough sheet of dura mater forming a roof (diaphragm) over the pituitary fossa
What do dural venous sinuses drain?
Drains most of the venous blood from the cranial cavity (including the brain) into the internal jugular veina at the jugular formainae in the floor of the posterior cranial fossa
What is the pituitary gland surrounded by?
Cavernous ad intercavernous sinuses
What does the anterior intercavernous sinus connect?
The right and left cavernous sinuses anteroir to the pituitary gland
Where does the ophthalmic artery come from and what does it supply?
Branches off the internal carotid artery to supply the eye
What branches from the ophthalmic artery?
The central artery of the retina (end artery)
Give some potential functions of the paranasal sinuses.
Make mucous anddrain it into the nasal cavities via ostia
reduce the weight of the skull
Add resonance to the voice
Increase bouyancy in aquatic mammals
What do the left and right vertebral arteries become when they join?
Basilar artery (crossing anterior surface of Pons)
