T1 L9: Organisation of the CNS Flashcards
What does the Telencephalon comprise of?
The cerebral hemispheres/cerebral cortex, components of the basal ganglia, and the limbic system
Where is the Central Sulcus?
It divides the frontal lobe from the parietal
Where is the Lateral Sulcus?
It divides the temporal lobe from the parietal
What is the precentral gyrus for?
Motor skills
What is the Postcentral gyrus for?
Somatosensory
What is the Gustatory cortex for?
Taste. It’s part of the insula
What is the name of the structure that links the left and right hemisphere?
The Corpus Collosum
What is the basal ganglia for?
Control of posture and movement
What are the subdivisions of Corpus Striatum?
Corpus striatum into Lentiform nucleus and caudate nucleus. The Lentiform nucleus then splits into the Putaman and Globus Pallidus
What is the corpus striatum?
A collective name given to the caudate nucleus and lentiform nucleus within the basal ganglia. Its connected to the motor cortex and the substantia nigra in the midbrain
What are the symptoms of disorders of the basal ganglia?
Abnormalities in movement, muscle tone, and posture
Which is more lateral, the caudate nucleus or the lentiform nucleas?
The lentiform nucleus
What is the nucleus accumbens for?
It’s the rewards centre
Where are the cerebral capsules found?
Either side of the lentiform nucleus, there is an internal and external one
What is the Claustrum?
An area lateral tot he lentiform nucleus. It’s function is unknown
What is the limbic system for?
Emotion and memory
What structures are included in the Limbic system?
Hippocampus, Amygdala, Cingulate cortex, Fornix, Thalamus, and Mammillary bodies
What is the Hippocampus for and where is it?
It’s for memory and is found in the floor of the lateral ventricle
What is the function of the Fornix?
It connects the Hippocampus to the Mammillary bodies. Its made out of white matter
What is the function of the Amygdala and where is it found?
Involved in processing of fear and anger and is found at the tip of the inferior horn lateral ventricle
What are the 3 layers of the meninges?
Dura mater, Arachnoid Mater, and Pia mater
What is the function of the meninges?
Creates a cushion for the brain and supports a network of blood vessels
What separates the Arachnoid mater and Pia mater
CSF
What is the Dura Mater?
A dense fibrous membrane
Which 2 layers make up the cranial dura?
The endosteal layer and Meningeal layer
How many layers does the spinal dura have?
A single meningeal layer only
Which artery supplies the cranial dura mater?
The middle meningeal artery, a branch of the maxillary artery from the external carotid. It sits within the endosteal layer of the dura
Through which foramen does the middle meningeal artery enter the cranium?
Through the foramen spinosum
What is the innervation of the dura mater?
The trigeminal nerve (CN5) mainly but also vagus (CN10) and spinal nerves C1,C2,C3
Which is the only part of the CNS with a sensory supply?
The dura
What does the Falx cerebri separate?
The cerebral hemispheres
What does the Tentorium cerebelli seperate?
Separates the cerebellar hemispheres from the cerebral hemispheres
What is the difference between cerebellar hemispheres and cerebral hemispheres
Cerebellar relates to the cerebellum and the cerebral is the rest of the brain
What does the Falx Cerebri separate?
The cerebral hemispheres
What is the Falx cerebri attached to?
Christa galli at the ethmoid bone, midline of cranium, and tentorium cerebelli
What is the Tentorium cerebelli attached to?
Occipital, temporal, and sphenoid bones
What is the Falx cerebelli attached to?
Occipital bone and tentorium cerebelli
What is an extradural haemotoma?
When blood collects above the dura because there has been trauma to the middle meningeal artery
What is an subdural haematoma?
When blood collects in the subdural space because there has been trauma to the cerebral veins
What is the subdural space?
A space that can be created by blood when it pools there
What is transtentorial herniation?
When brain injury or a tumour causes the brain to be displaced through an opening in the tentorium cerebelli
What is the Arachnoid mater?
A thin avascular translucent layer lining the dura. Vessels pass through it
What is the subarachnoid space?
A space filled with CSF that contains cerebral vessels
What are arachnoid granulations?
Herniations of arachnoid into the venous sinuses
What is a subarachnoid haemorrhage?
A bleed into the subarachnoid space caused by major trauma
What are arachnoid granulations?
Structures filled with cerebrospinal fluid (CSF) that extend into the venous sinuses through openings in the dura mater
What are the projections of arachnoid called?
Trabeculae
What is the Pia mater?
A very thin membrane that very closely invests the brain
What is the leptomeninges?
Arachnoid and pia dura together
What is leptinomeningitis?
Also known as meningitis, it’s the inflammation of the leptomeninges
What do the dural venous sinuses drain?
Blood and CSF from the brain into the internal jugular vein
What are the dural sinuses closely associated with?
The dural folds
Where do Dipolic veins drain from?
The cranium
Where do emissary veins drain from?
The extracranial spaces
Where do cerebral veins drain from?
the cranium
Which veins provide a route of infection into the cranial space?
The Emissary veins
What is the cavernous sinus?
A paired sinus located against the sphenoid bone
Which structures pass through the cavernous sinus?
CN3-6 (Oculomotor, trochlear, trigeminal, and abducent) and the internal carotid arteries
Why does the cavernous sinus affect the ability to move eyes during infection?
It gets inflammation of the structures around it which restrict movement
Which structures does the cavernous sinus receive blood from?
Sphenoparietal sinus, cerebral, aphthalmic, and emissary veins (all in the infratemporal fossa region)
