Anatomy of the Pituitary Gland Flashcards
what is the diencephalon formed from
thalamus and hypothalamus
what does the diencephalon form
cental core of cerebrum with connections to right and left cerebral hemispheres and the midbrain
what connects the pituitary gland to the hypothalamus
infundibulum
what is the pituitary gland divided into
anterior and posterior
where is the pituitary gland located in the skull
midline structure in the pituitary fossa of the sphenoid bone
where does the pituitary fossa lie
within the sella turcica (Turkish Saddle)
where does the pituitary gland lie in relation to the optic chiasm
inferior
optic chiasm
x shaped structure formed by the crossing of the optic nerves (CNII) in the brain
R and L optic tracts pass posteriorly from the chiasm
synapse in the thalamus and then the axons pass via optic radiation to the visual cortex in the occipital lobe
what is this
optic canal
what is vision divided into
temporal and nasal fields
what is the early clinical effect of a pituitary tumour of the visual pathway
bitemporal hemianopia
- tumour disrupts the transmission of AP from the nasal retina bilaterally
- patient loses ability to see structures in the temporal side of the visual field bilaterally
sphenoidal sinus - part of the paranasal sinuses
transcranial approach to pituitary fossa
under the frontal lobe (subfrontal)
transphenoidal approach to pituitary fossa
via nasal cavities and sphenoid sinus
pituitary fossa (blue dot)
sphenoidal sinus
what are the superior and inferior parts of nasal septum
superior - perpendicular plate of ethmoid bone
inferior - vomer
what is the roof of the nasal cavity
cribriform plate of ethmoid bone
cribiform plate of ethmoid bone
what is the hard palate formed of
mainly maxilla
what is the function of the nasal conchae
increase the surface area of the nasal cavities - rapid warming and humidification of air as it passes into the lungs
what is another name for nasal conchae
turbinates
also frontal, sphenoid and ethmoid sinus
what are the paranasal sinuses
air filled spaces within the bone surrounding the nasal cavities
ethmoid is between the eyes
sphenoid is behind the eyes
what are the paranasal sinuses lined by
mucous secreting respiratory mucosa
what is the function of the paranasal sinuses
make mucous and drain it into the nasal cavities through ostia
reduce the weight of the skull
add resonance to the voice
what is a singular ostia called
ostium = bony drainage hole
how are the frontal sinuses connected
often in the midline
what bone are the sphenoid sinuses in
body of the sphenoid bone (sometimes in the midline)
what are the maxillary sinuses known as clinically
antrum (pleural= antra)
where are the ethmoid air cells located
3 groups located between nasal cavity and orbit
what bone are the nasal concha formed from
ethmoid bone
apart from the inferior one
le fort fractures
what surgical procedure can provide better surgical access to nasal cavities etc in more complicated cases
le fort 1 down fracture
name the meninges from external to internal
waht is the cranial vault
the space in the skull occupied by the brain
what is the cranial cavity lined by
the entire cavity is lined by dura mater
what is the tentorium cerebelli
tough sheet of dura mater
separates the cerebellum from the inferior portion of occipital lobes
where in the cranial fossa is the TC located
posterior
what does the central gap in the TC permit through
brainstem
diaphram sellae
tough sheet of dura mater forming a roof over the pituitary fossa
has a hole that allows the vertical passage of the pituitary stalk (infundibulum)
what are the dural venous sinuses
lie between the layers of dura mater
best thought of as collecting pools of blood, that drain most of the venous blood from the cranial cavity (including brain) into the internal jugular veins
where do the dural venous sinuses drain into the IJV
at the jugular foraminae in the floor of the posterior cranial fossa
what sinuses are the pituitary gland surrounded by
cavernous and intercavernous sinuses
(these are part of the dural venous sinuses)
what arteries pass through the cavernous sinuses
internal carotid arteries
carotid canal
the passageway in the temporal bone which the internal carotid artery enters the middle cranial fossa from the neck
trigeminal nerve function
sensory to most of face
motor to muscles of mastication (CNV3)
functional deficit of CNV
sensory symptoms on face
difficulty chewing
functional deficit of cavernous sinus
venous haemorrhage
function of internal carotid artery
supplies arterial blood to brain and orbit
functional deficit of internal carotid artery
catastrophic haemorrhage
function of dura mater
protects the structures of the cranial cavity
what is located anteriorly and posteriorly to the pituitary fossa
intercavernous sinuses
name the contents of the cavernous system
internal carotid artery, cavernous sinus, CN III, IV, VI, V1, V2
carotid canal
