Anatomy of Space Occupying lesions Flashcards
What is a spce occupying lesion?
Abnormal tissue taking up space
What are the 5 layers of the scalp?
Skin Connective Tissue Aponeurosis Loose Connective Tissue Pericranium
Which artery courses over the deep parts of the pterion?
Middle Meningeal artery
What is meningitis?
Bacterial or viral infection of the meninges
What are the meninges?
Protective covering for the brain and spinal cord
What are the 3 layers of the meninges?
Dura Mater
Arachnoid Mater
Pia Mater
Where is the dara mater found?
Adherent to the internal aspect of the skull
What supplies the dura mater?
CN V
What is the diaphragm sellae?
A tough sheet of dura mater forming a roof over the pituitary fossa
What is the tentorium cerebelli?
Sheet of dura mater “Tenting” over the cerebellum
What is the falx cerebri?
Midline structure made of dura mater
Attaches to the deep aspecct of the skull
Seperates the right and left cerebral hemispheres
What contributes to the venous drainage of the brain?
Cerebral veins Superior sagittal sinus Confluence of sinuses Facial vein Opthalmic veins
What is the arterial supply to the brain?
Right vertebral artery
Right internal carotid
Right external carotid
What makes up the circle of willis?
Right anterior cerebral artery Right internal carotid Right posterior communicating Right posterior cerebral artery The basilar artery
Where is the circle of willis found?
Inferior to midbrain
Closely related to pituitary stalk and optic chiasm
Within subarachnoid space
What is contained in the subarachnoid space?
CSF
Where is CSF produced?
Choroid plexus of the ventricles
How is CSF reabsorbed?
Dural venous sinuses
How can CSF be accessed?
Via lumbar puncture at L3/4 or L4/5 disc levels
Where does the sub arachnoid space end?
S2 level
What are the ventricles of the bain?
Left and right lateral ventricle
3rd ventricle
4th ventricle
Where is the 3rd ventricle?
Midline within diencephalon
What connects the 3rd and 4th ventricles to the midline?
Cerebral aqueduct
What is the pathway of circulation for the CSF?
Secreted by choroid plexus
From the lateral ventricles via the foraminae of monro into the 3rd ventricle
Via the cerebral aqueduct into the 4th ventricle then mainly into the subarachnoid space then reabsorbed into the dural venous sinsues
What is hydrocephalus?
Excessive production, obstruction to flow or inadequate reabsorption leads to increased CSF volume
What is an extradural haemorrhage?
Between the dura and the bone
Ruptured middle meningeal artery
Trauma to the pterion
What is a subdural haemorrhage?
Separaes the dura from the arachnoid
Torn cerebral veins
Falls in the elderly
What is a subarachnoid haemorrhage?
Into the CSF of the arachnoid space
Berry aneurysm
Congenital aneurysm
What are different types of supratentorial herniatin?
CIngulate
Central
Uncal
Transcalvariial
What direction can infratentorial herniation occur in?
Upward
Downward or tonsillar
