anatomy of SOL Flashcards
Wh y can’t the brain afford to have a space occupying lesion?
What is meant by an SOL?
- no spare room in the skull
—an SOL: ABNORMAL tissue taking up space; can be ACUTE or SUB-ACUTE intracranial pathologies
Risk of raised icp?
- herniation
What is the skull capable of holding?
- coping with SLOW-rate expansion
What are the layers of the scalp?
S- SKIN C- Connective tissue A- Aponeurosis L- Loose Connective Tissue P- Pericranium
What holds the arteries of the scalp?
- connective tissue
What gives rise to the Scalp branches?
- external carotid artery
What is significant about the sutures of your skull?
- help PREVENT skull fractures from spreadin
What is the pterion?
- H-shaped
- —lateral aspect of the head; where the frontal, parietal, temporal and sphenoid bones meet.
- —THINNEST part of the skull
What is blood vessel is the pterion a.w?
- middle meningeal artery, course over the DEEP aspect of the pterion
Label the image of the skull found at the end of the NEURO IMU teaching
WHat is the dura mater? What is it also known as?
- aka the “hard mother”
- –TOUGH/FIBROUS; outer-most meningeal layer
Which nerve supplies the DURA mater?
CNV Sensory supply
What does the dura mater enclose?
- encloses the DURAL venous sinuses
What is significant about the arachnoid mater?
- —has arachnoid granulations (to reabsorb CSF)
- –aka Spidery mother
What circulates within the subarachnoid space?
- CSF
What is the PIA mater?
- —the “faithful” mother
- —adheres to the brain and the blood vessels and nerves entering/ leaving the brain
What is the diaphragm sellae?
- tough sheet of DURA mater forming a ROOF over the pituitary fossa
What is the tentorium cerebelli? What lies in its centre?
- –sheet of DURA tenting over the cerebellum
- –has a central gap to allow the brainstem to pass through
WHere does the tentorium cerebelli attach to?
- the ridges of the PETROUS temporal bones
What is the falx cerebri made of?
What does it attach to>
- dura mater
- attaches to the DEEP aspect of the skull -crista galli of the ethmoid - ANTERIORLY
- —internal aspect of the Sagittal suture, mediallu
- –internal occipital protuberance posteriorly
What does the right common carotid artery split into?
- Right internal carotid artery
- Right external carotid artery
Through what foramen does the R internal carotid artery enter the cranium?
- the CAROTID canal
Which artery predominantly supplies the scalp, neck and face
- right EXTERNAL carotid artery
Describe the course of the R vertebral artery.
- passes through TRANSVERSE foraminae in the cervical vertebrae
- to enter the cranial cavity, enters trough the foramen magnum
What supplies the MEDIAL aspect of the cerebral hemisphere?
anterior cerebral artery
What supplies the POSTERIOR aspect of the cerebral hemisphere?
—–posterior cerebral artery
What supplies the lateral aspect of the cerebral hemisphere?
- middle cerebral artery
Where is the circle of willis found?
- inferior to the MIDBRAIN
- closesly related to the PITUITARY stalk and the OPTIC chiasm
- —-found within the subarachnoid space
How much CSF is made in a day?
400-500ml
Where is csf produced and reabsorbed?
- produced by the choroid plexus in the LATERAL ventricles
- —reabsorbed into the DURAL venous sinsuses via the subarachnoid granulations
At what levels can LP be performed?
- L3/L4
OR - L4/L5 IV discs
Describe the course of CSF circulation.
- CSF is produced by the choroid plexus (lateral and 3rd V)
- Flows through Foraminae of Monro to the 3rd ventricles
- passes through the cerebral aqueduct to the 4th ventricle
- passes to the subarachnoid space around the brain and the spinal cord, through 3 small foraminae.
Where are the lateral ventricles located?
- within the cerebral hemispheres
Where is the 3rd ventricle found?
- midline WITHIN the diencephalon
Where is the 4th ventricle found?
- between cerebellum and the pons
When may hydrocephalus occur?
- with excessive prodn. obstruction to flow, or INADEQUATE reabsorption
Which space is the circle of willis found?
in the SUBARACHNOID space
How does subdural hemmorrhage occur?
- with TORN cerebral veins
occurs with FALLS in elderly
What causes a subarachnoid haemorrhage?
- RUPTURED CIRCLE of WILLIS
- -congenital
