Space-Occupying Lesions & Head Trauma Flashcards
What is a space-occupying lesion?
When abnormal tissue takes up space within the cranium
What is the Monro-Kellie hypothesis?
That a rise in intracranial volume causes an exponential rise in ICP
What are the five layers of the scalp?
Skin Connective tissue Aponeurosis Loose connective tissue Pericranium
What is found in the connective tissue of the scalp?
Scalp arteries forming an anastomotic network
What is the pterion?
An H-shaped suture between frontal, parietal, temporal and sphenoid bones
Why is the pterion significant clinically?
As it is the thinnest part of the skull and sits superficial to the middle meningeal artery
What are the three layers of meninges?
Dura mater
Arachnoid mater
Pia mater
What is found deep to the arachnoid matter and what does it contain?
Subarachnoid space - contains circulating CSF
Give three important folds of dura mater
Diaphragm sellae
Tentorium cerebelli
Falx cerebri
What projects through the diaphragm sellae?
Pituitary stalk
The brainstem passes through what part of dura mater?
Tentorium cerebelli
Where is the falx cerebri located?
In the sagittal plane in the groove between cerebral hemispheres
What sinuses are found in the falx cerebri?
Superior and inferior sagittal sinuses
The superior and inferior sagittal sinuses drain towards what?
Confluence of the sinsuses
Blood from the superior and inferior sagittal sinuses drains into what structures?
Sigmoid sinus which becomes internal jugular vein
What are the four main arteries supplying the brain?
Right and left internal carotids
Right and left vertebrals
The right vertebral artery passes through what cranial foramina to enter the cranium?
Foramen magnum
The right and left vertebral arteries anastamose to form which artery?
Basilar artery
The basilar artery bifurcates to give what branches?
Right and left posterior cerebral arteries
Which arteries connect the posterior cerebral arteries to the internal carotid arteries?
Right and left posterior communicating arteries
The lateral aspects of the cerebral hemispheres are supplied by what arteries?
Middle cerebral arteries
The medial aspects of the cerebral hemispheres are supplied by what arteries?
Anterior cerebral arteries
Where is CSF produced?
Choroid plexus
CSF is secreted by the choroid plexus into which ventricles?
Right and left lateral
From the lateral ventricles CSF passes into which ventricle?
Third ventricle
CSF passes from the third ventricle into the fourth via what structure?
Cerebral aqueduct
Where is CSF reabsorbed once in the subarachnoid space?
Arachnoid granulations
What is hydrocephalus?
When there is overproduction, obstruction or poor reabsorption of CSF
The middle meningeal artery is found between what structures?
Parietal bone and dura mater
An extradural haemorrhage results from damage to which artery?
Middle meningeal
What is the cause of a subdural haemorrhage?
Torn cerebral veins
A subarachnoid haemorrhage is caused by what?
Berry aneurysm
What ligaments does the needle pass through in a lumbar puncture?
Supraspinous and interspinous
Ligamentum flavum
At which level should a lumbar puncture occur to ensure safety?
L3/L4
An uncal herniation results in compression of which nerve?
CN III
