Week 1 - E - Anatomy of EYE and raised ICP - & ventricles Flashcards
When testing the extra-ocular movements of the eye how do you do this?
So you move the index finger in an H shape Move medially for medial rectus Then move up for inferior oblique and down for superior oblique Move laterally for lateral rectus Then move up for superior rectus and down for inferior rectus
What nerves supply the extra-ocular muscles of the eye?
Medial rectus Inferior rectus Superior rectus Inferior oblique All supplied by the oculomotor nerve Superior oblique - trochlear nerve Lateral rectus - abducent nerve
What fills the anterior and posterior chambers of the eye?
The aqueous humour
What is the drainage of the aqueous humour of the eye?
Drains from posterior to anterior chamber and then through the trabecular network into the canal of schlemm which exists at the corneal iridocorneal junction
What are 4 examples of distrubances that may cause a raised intracranial pressure?
Head injury Intracranial lesion eg trauma or haemorrhage Hydrocephalus Meningitis
What are 3 signs of raised intracranial pressure?
A combination of headache, papilloedema and vomiting
When the photoreceptors are hit by light and convert the enrgy waves to neurones, they tavel to the ganglion cells of the retina via the bipolar cells What do the ganglion cell axons join to form? Where does it travel?
Forms the optic nerve which travel through the optic canal to converge at the optic chiasm
What is hyrdrocephalus?
It is the accumulation of CSF in the brain
What is the condition hydrocephalus better known as? Why can babies skulls grow large in hydrocephalus?
Better known as water on the brain Can grow as the cranial sutures have not closed yet therefore fluid can leak
On the left it shows hydrocephalus What colour is the CSF on MRI? If there is a hole in the skull where can CSF leak?
CSF is white on MRI CSF can leak into ears or nose
What are the three protective membrane layers surrounding the brain and spinal cord?
These are the meninges
What are the three meninges from outer to inner?
Dura mater Arachnoid mater Pia mater
The dura mater consists of two layers What are these? and which layer lines the inside of the cranium?
CO onsists of the endosteal layer and the meningeal later The endosteal layer lines the inside of the cranial cavity
What exists between the endosteal and meningeal layer of the dura mater?
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Where does the dural venous sinus drain? What space is located beneath the dura mater?
Drains into the internal jugular vein The subdural space separates the dura and arachnoid mater
What is the space in the arachnoid mater where the CSF flows?
This is the subarachnoid space - can have a pathological haemorrhage here sometimes