ANATOMY - pituitary gland Flashcards
which gland is known as the ‘master gland’ that controls function of other glands by secreting hormones
pituitary gland
where is the hypothalamus in relation to the thalamus
inferior
how big is the hypothalamus
4cm
where is the hypothalamus in relation to the midbrain
superior
where is the pituitary gland in relation to the hypothalamus
inferior
where is the hypothalamus in relation to the pituitary gland
superior
what connects the pituitary gland and the hypothalamus
infundibulum (pituitary stalk)
what are the 2 segments of the pituitary gland
anterior and posterior
which bone does the pituitary gland sit in
sphenoid
which part of the sphenoid bone does the pituitary gland sit in
sella turcica (‘Turkish saddle’) in the pituitary fossa
what lines the entire inside of the skull
dura mater
what is the purpose of dura mater
protects structures of the cranial cavity
where is dura mater
on the inside of the skull
nerve supply of dura mater
CN V
where is the diaphragm sellae
over the pituitary fossa
what is the diaphragm sellae made of
dura mater only
what is the only thing thats made of dura mater only
diaphragm sellae
what is falx cerebri
dura mater between 2 cerebral lobes
what is the sheet of dura mater over the cerebellum and vertebral cortex in the posterior cranial fossa called
tentorium cerebelli
what does the tentorium cerebelli do
‘tents’ the cerebellum (goes over it)
what is the tenorium cerebelli made of
dura mater
what are the 3 structures you need to know that are made of dura matter
where are they
diaphragm sellae (over the pituitary fossa) tentorium cerebelli (over cerebellum) flax cerebri (between 2 cerebral lobes)
which space in the cranial cavity is the dura mater on top of
arachnoid space
what do the dural venous sinuses do
collect venous drainage of the brain
where does venous drainage end up after the dural venous sinuses
right and left cavernous sinuses
where are the cavernous sinuses (right and left)
lateral to the pituitary gland
where do the right and left cavernous sinuses drain
anterior intercavernous sinus
where is the anterior cavernous sinus
anterior to the pituitary gland
apart from going to the left and right cavernous sinuses, where else might the venous drainage from the brain end up after being in the dural venous sinuses
straight down internal jugular vein
what layer is internal to the dura mater
arachnoid mater
where is the subarachnoid space (2)
between pia mater and arachnoid mater
around brain and spinal cord
what is the purpose of subarachnoid space
contains CSF
cushions brain and spinal cord
where is the pia mater
between brain and subarachnoid space
what does pia mater contain
nerves, arteries and veins to/from the brain
what is the space in the sphenoid bone called
sphenoid sinus
which vessel passes above the sphenoid sinus and curves back on itself
internal carotid artery
where is the pituitary gland in respect to the sphenoid bone
above the sphenoid sinus
what are lateral to the pituitary gland
right and left cavernous sinuses
which vessels go through the right and left cavernous sinuses
internal carotid arteries
+ nerves
what are the inferior and superior structures of the pituitary gland
diaphragm sellae sphenoid bone (sphenoid sinus)
which nerves go through the cavernous sinuses (4 - easy to guess)
CN III
CN IV
CN V (V1 and V2)
CN VI
what is the posterior pituitary made of
neurones
what is the posterior pituitary also known as
neurohypophysis (bc its made of neurones)
what is the anterior pituitary also known as
adenohypophysis
which section of the pituitary is glandular
anterior pituitary
what does the anterior pituitary look like on histology
red and blue dots (cytoplasms)
what 2 cells are there in the anterior pituitary
acidophils and basophils
how do basophils in the anterior pituitary present on histology
blue cytoplasm
Basophils = Blue
how do acidophils in the pituitary present on histology
red cytoplasm
what is the pituitaries blood supply
circle of willis
what 2 arteries make up the circle of willis
internal carotid arteries
vertebral arteries
what do the vertebral arteries join together to form
basilar artery
where do the intercavernous sinuses drain into
internal jugular veins
why is the visual pathway important for the pituitary
optic chiasm is right above the pituitary tumour
what is the clinical significance of a pituitary tumour (pathophysiology and condition)
optic chiasm compression = bitemporal hemianopia
which optic nerve fibres are affected in a compression of the optic chiasm (side and location)
both nasal retina fibres
if there is a pituitary tumour (or any pituitary problem really) what are the 2 routes you can get to the pituitary gland
name and description pls
transcranial - under frontal lobe, under brain, through frontal sinuses
transsphenoidal - via nasal cavities, through sphenoidal sinuses
which 2 bones have to be broken in transspehnoidal access to pituitary gland
ethmoid bone and vomer (make up the nasal septum)
if someone had a sore nose (eg previous trauma) but you still wanted to do a transsphenoidal approach to get to the pituitary gland, how could you do this
stimulate a le fort I fracture - fracture of maxilla, easily fixed
if you damage the cavernous sinus in pituitary surgery what would happen
venous haemorrhage
if you damage the internal carotids in pituitary surgery what would happen
catastrophic haemorrhage
if you damage optic chiasm in pituitary surgery what would happen
bitemporal hemianopia
if you damage CN III (oculomotor) in pituitary surgery what would happen
cant move eye in some directions (can only move it laterally and inferiorly) on the affected side
if you damage CN IV (trochlear) in pituitary surgery what would happen
cant move eye inferiorly when looking inwards
if you damage CN V (trigeminal) in pituitary surgery what would happen
no facial sensation
chewing problems
if you damage CN VI (abducent) in pituitary surgery what would happnen
cant move eye laterally (outwards)
if you damage dura mater in pituitary surgery what would happen
CSF leak
