Anatomy of Space Occupying Lesions Flashcards
From which cranial nerve does the dura mater receive its sensory nerve supply?
CNV
What is the function of the arachnoid granules within the arachnoid mater?
Reabsorb CSF (into the dural venous sinuses)
What is the tentorium cerebelli?
Tough sheet of dura mater over the cerebellum - central gap for brainstem
Where does the tentorium cerebelli attach?
To the ridges of the petrous temporal bones
What is the diaphragm sellae?
Tough sheet of dura mater which forms a roof over the pituitary fossa
What is the faux cerebri?
Sheet of dura mater in the midline which separates the right and left hemispheres
Where do the dural venous sinuses ultimately drain?
Internal jugular vein at jugular foramen
What veins join at the confluence of sinuses?
Superior sagittal sinus
Inferior sagittal sinus
Straight sinus
What arteries supply the brain?
Vertebral
Internal carotid
What artery does the vertebral artery branch from?
Subclavian artery
What arteries make up the circle of Willis?
Anterior cerebral Posterior cerebral Internal carotid Anterior communicating Posterior communicating
(middle cerebral are NOT part of the circle)
What does the subarchnoid space contain?
CSF
Where is CSF produced?
By epithelial cells in choroid plexus of ventricles
Where does the subarachnoid space end?
L2
Where can the subarachnoid space be accessed? Via lumbar puncture
L3/L4
L4/L5
Describe the circulation of CSF (8 steps)
- Secreted by epithelial cells in choroid plexus
- From right and left ventricles via right and left foramen of Monroe
- Into 3rd ventricle
- Via cerebral aqueduct
- Into 4th ventricle
- Mainly into subarachnoid space but some into central canal
- Reabsorbed by arachnoid granulations
- Into dural venous sinuses
What is hydrocephalus?
Increased CSF volume
What is the management of hydrocephalus?
Ventricular peritoneal shunt
What are the 3 types of haemorrhage that can occur in cranial cavity?
Extradural
Subdural
Subarachnoid
What is an extradural haemorrhage and a likely cause?
Bleeding between bone and dura
Ruptured middle meningeal artery - usually due to trauma
What is a subdural haemorrhage and a likely cause?
When blood causes dura to separate from arachnoid
Torn cerebral veins - usually due to falls in elderly
What is a subarachnoid haemorrage and a likely cause?
When blood haemorrages into CSF of subarachnoid space
Ruptured circle of Wills - berry aneurysm
