Anatomy of the Pituitary Gland Flashcards
What comprises the diencephalon?
Thalamus and hypothalamus
The diencephalon cnnects which aspects of the brain?
Right and left hemispheres and midbrain
How is the hypothalamus connected to the pituitary?
Infundibulum
Into which two parts is the pituitary gland split?
Anterior and posterior
The pituitary gland sits within the pituitary fossa which is located in which bone?
Sphenoid bone
The pituitary fossa lies within what?
Sella turcica
What are the two types of retina within the eye?
- Nasal retina
- Temporal retina
The optic canal runs through which bone?
Sphenoid bone
The right and left optic nerves combine/cross over forming what?
Optic chiasm
The pituitary gland originates from which embryogenic tissue?
Ectoderm
Which aspect of the pituitary is most glandular?
Anterior
The optic chiasm gives off what?
Optic tracts
Where do the optic tracts synapse?
Thalamus
What happens after the optic tracts synapse in the thalamus?
The next axons in the chain pass via the optic radiation to the visual cortex in the occipital lobe
Optic nerves from the nasal retinae will _______ _______ at the optic chiasm
Optic nerves from the nasal retinae will switch sides at the optic chiasm
What is the name of the condition when a patient loses the ability to see bilaterally in the temporal side of their vision?
Bitemporal hemianopia
Which two surgical procedures can allow access to the pituitary gland?
- Transcranial approach (under frontal lobe)
- Transsphenoidal approach (via nasal cavities and sphenoid sinus)
Which nasal conchae bone is a bone in itself without joining another conchae bone?
Inferior nasal concha
Both the ________ and __________ nasal conchae are part of the _________ bone
Both the superior and middle nasal conchae are part of the ethmoid bone
How many types of paranasal sinuses are there?
4
What are paranasal sinuses?
Air filled spaces within bones surrounding the nasal cavity
What are the four different paranasal sinuses?
- Frontal sinuses
- Maxillary sinuses
- Ethmoidal air cells
- Sphenoid sinuses
Which type of mucusa lines the paranasal sinuses?
Respiratory mucosa (mucous-secreting)
What are some proposed functions for the paranasal sinuses?
- To make mucous and drain it into the nasal cavities
- Reduce weight of skull
- Add resonance to voice
Which type of fracture can be caused to allow for better surgical access to the pituitary via the transnasal approach?
Le fort I
Which artery crosses the anterior surface of the pons?
Basilar artery
What is the name of cranial nerve III
Oculomotor nerve
What is the name of cranial nerve IV?
Trochlear nerve
What is the name of cranial nerve VI?
Abducens nerve
What are the three branches of the trigeminal nerve (CN V)
- Opthalmic nerve
- Maxillary nerve
- Mandibular nerve
The floor of the cranial cavity is lined with what?
Dura mater
What is the name given to the tough sheet of dura mater forming a covering over the pituitary fossa?
Diaphragm sellae
What is the name given to the tough sheet of dura mater over the cerebellum?
Tentorium cerebelli
Why does the tentorium cerebelli have a central gap?
To allow passage of the brainstem
What is the name given to the vein-like structures which drain blood within the floor of the posterior cranial floor?
Dural venous sinuses
Where do the dural venous sinuses drain?
Jugular foraminae into internal jugular veins
Which arteries pass through the caverous sinuses?
Internal carotid arteries
What connects the left and right caverous sinuses anterior to the pituitary gland?
Anterior intercavernous sinus
What surrounds the pituitary gland?
Caverous and intercavernous sinuses
What is the function of the oculomotor nerve (CN III)?
Most movements of the eye and that to raise the eyelid
What does innervation of the trochlear nerve do?
Abducts, depresses and internally rotates the eye
Which muscle does the trochlear nerve innervate?
Superior oblique muscle of the eye
Which muscle does the abducens nerve innervate in the eye?
Lateral rectus muscle
What is the function of the lateral rectus muscle of the eye?
Lateral movement of the eyeball, specifically abduction
The internal carotid arteries enter the _______ _________ in the ___________ bones
The internal carotid arteries enter the carotid canals in the temporal bones
Damage to which structure after pituitary gland surgery may result in a dilated pupil?
Oculomotor nerve
Damage to which structure after pituitary gland surgery may lead to cerebrospinal fluid leak?
Dura mater
What are the contents of the canvernous sinus?
- Internal carotid artery
- Internal jugular vein
- CN III, IV, V1, V2, IV
- Periarterial sympathetic nerve fibres
