Pituitary Gland Flashcards
List all the major endocrine glands
Hypothalamus Pituitary Parathyroid gland Thyroid gland Adrenal gland Pancreas Ovaries Testes
What is the role of the cerebrum?
Anterior part of the brain that controls voluntary activity in the body
What is the role of the cerebellum?
Posterior part of the brain that coordinates and regulates muscle activity
What is the diencephalon?
Central core of the cerebrum and connects hypothalamus to the midbrain
List the parts of the brainstem in order
Midbrain
Pons
Medulla oblongata
What structure connects the hypothalamus to the pituitary gland?
Infundibulum/ pituitary stock
Which bone is the pituitary gland located within?
Pituitary fossa of the sphenoid bone
The pituitary gland lies within the…
Sella turcica
The nasal retina supplies visual information from the ____ visual field
Temporal
The temporal retina supplies visual information from the ____ visual field
Nasal
Outline the visual pathway from the retina to the occipital lobe
Optic nerves Optic chiasm Optic tracts Thalamus Optic radiation Visual cortex of occipital lobes
The optic chiasm is located inferior to the ______
Pituitary gland
A pituitary tumour compresses what part of the visual pathway?
Optic chiasm
Name the visual field defect that arises from compression of the optic chiasm
Bitemporal haemanopia
Describe the mechanism behind bitemporal haemanopia
Transmission of AP from nasal retina is disrupted bilaterally
Lose ability to see structures in temporal side of visual field ONLY bilaterally
Name the two main surgical approaches to the pituitary gland
Transcranial subfrontal
Transphenoidal
Through which Le Forte fracture can the pituitary gland be accessed from?
Intranasal via Le Forte fracture 1 (surgical fracture of nasal septum and floor and roof of sphenoid sinuses)
What structure forms the superior part of the nasal septum?
Perpendicular plate of the ethmoid bone
What structure forms the middle part of the nasal septum?
Vomer
What structure forms the roof of the nasal cavity?
Cribiform plate of the ethmoid bone
Name the three nasal conchae. Which conchae are part of the ethmoid bone?
Superior, middle, inferior
Superior and middle, inferior is it’s own bone
What is meant by ‘paranasal sinus’
Air-filled space within a bone surrounding the nasal cavity
List the types of paranasal sinuses and their location
Frontal (right and left on frontal bone)
Maxillary (right and left, line each antrum)
Ethmoid air cells (3 groups between nasal cavity and orbit)
Sphenoid (connect in midline)
What type of epithelium lines paranasal sinuses?
Mucous-secreting respiratory epithelium
List the functions of the paranasal sinuses
Drain mucous into the nasal cavity via ostia
Reduce skull weight
Voice resonance
Which foramen do vertebral arteries pass through?
Foramen magnum
Define ‘Circle of Willis’
Anastomosis of internal carotid and vertebral arteries around optic chiasm and infundibulum
Define ‘tentorium cerebelli’
Tough sheet of dura over posterior cranial fossa
Define ‘diaphragm sellae’
Tough sheet of dura over pituitary fossa
What are the dural venous sinuses? What do they drain into, and where do they drain?
Venous channels within dura matter that drain blood from cranial vault into the internal jugular vein at the jugular foramen in floor of posterior cranial fossa
What structure do the cavernous sinuses surround?
Pituitary glands
List the structures located WITHIN the cavernous sinuses
Internal carotid arteries CN III CN IV CN V1, V2 CN VI
List the structures located in the LATERAL WALL of the cavernous sinuses
Internal carotid arteries
CN VI
What is the function of the intercavernous sinuses?
Anterior and posterior sinuses that connect the right and left cavernous sinuses anteriorly to the pituitary gland
List the structures at risk during pituitary gland surgery
Oculomotor nerve Trochlear nerve Trigeminal nerve Abducent nerve Optic chiasm Cavernous sinus Internal carotid artery Dura matter
What intracranial event can occur due to damage to the cavernous sinuses?
Ventricular haemorrhage
What fluid from inside the brain can leak due to damage to the dura matter?
CSF
