1/17 CSF, Vessels, & Higher Cortical Structure And Function Flashcards
What are the ventricles?
There are four interconnected ventricles
• Paired lateral ventricles (telencephalon)
• Interventricular foramen
• 3rd ventricle (diencephalon)
• Cerebral aqueduct (mesencephalon)
• 4th ventricle (metencephalon & myelencephalon)
What are the regions that the lateral ventricles supply?
Inferior horn – Temporal lobe
Posterior horn – Occipital lobe
Body – Parietal lobe
Anterior horn – Frontal lobe
Where do the lateral ventricles connect/where do they go?
Connected to 3rd ventricle through interventricular foramen (of Monro)
What is the third ventricle?
Flat ventricle between the two halves of the diencephalon
Where is the third ventricle?
Superior to the optic chiasm and midbrain
What are the openings to the third ventricle?
Two superior openings – interventricular foramen
One inferior opening – cerebral aqueduct
What are the boundaries of the fourth ventricle?
Anterior: pons and medulla
Posterior: cerebellum
What are the openings to the fourth ventricle?
Single superior opening – cerebral aqueduct
Inferiorly open to the central canal
What is the structure of the fourth ventricle?
Paired lateral apertures
Single median aperture
What are cisterns?
subarachnoid space that widens in several areas
What does the lumbar cistern consist of?
Cauda equina, filum terminale
What does the cisterna magna consist of?
Posterior inferior cerebellar and vertebral arteries, CN IX-XII
What does the prepontine cistern consist of?
Basilar and superior cerebellar arteries, CN VI
What does the interpeduncular cistern consist of?
Posterior cerebral and posterior communicating arteries, CN III
What does the quadrigeminal cistern consist of?
Pineal gland, great cerebral vein
How is CSF created?
The choroid plexus filters the plasma from the blood to create CSF
Where is choroid plexus found?
in most parts of the ventricles
What is the composition of CSF?
primarily composed of water (99%) with a small amount
of chemicals and nutrients including
– Sodium
– Chloride
– Potassium
– Calcium*
– Magnesium
– Small amounts of protein and glucose
What are the functions of CSF?
Physical support for the brain
Excretory functions allow for the removal of water-soluble metabolites
Channel for chemical communication
What are the chemicals that CSF allows to communicate?
Serotonin
Dopamine
Noradrenaline
Vasopressin
Oxytocin
How is CSF produced from choroid capillaries?
Choroid capillaries are permeable; however, they are surrounded by choroid epithelial cells that have very limited permeability.
This layer allows lipid soluble substances through (e.g. O2 and CO2)
Specialized transport selectively allows other substances through.
About 20 cc/hr are allowed through this barrier.
What is the order of flow/pathway of CSF?
Lateral ventricles
Interventricular foramen
Third ventricle
Cerebral aqueduct
Fourth ventricle
Median & lateral apertures
Subarachnoid space around spinal cord and brain
Absorbed by arachnoid granulations
What are the spaces in which CSF is produced by choroid plexus?
Lateral ventricles
Third ventricle
Fourth ventricle
How is CSF reabsorbed?
CSF passes through the arachnoid granulations (arachnoid villi)
Recent research has also shown that absorption happens through cervical lymphatics by way of the arachnoid surrounding the cranial nerves
Reabsorption usually matches production rate (20cc/hr)
What is hydrocephalus?
When there is more production than reabsorption it causes an increase in pressure
What are the causes of hydrocephalus?
There are over 100 causes
– Communicating
– Non-communicating
What are the symptoms of hydrocephalus?
headaches, nausea, motor or sensory disturbances
How is hydrocephalus traditionally treated?
With a ventroperitoneal shunt
What is non-communicating hydrocephalus?
Indicates a blockage within the ventricular pathway
What is communicating hydrocephalus?
(Non-obstructive) occurs outside of the ventricular system
What provides the blood supply to the anterior circulation to the brain?
Internal carotid artery
What provides the blood supply to the posterior circulation to the brain?
Vertebral arteries
What does the anterior cerebral artery supply?
Medial frontal lobe
Medial parietal lobe
What does the posterior cerebral artery supply?
Inferior & medial temporal lobe
Inferior & medial occipital lobe
Posterior thalamus
Cerebral peduncles
What does the middle cerebral artery supply?
(Travels between frontal and temporal lobe)
Lateral frontal lobe
Lateral parietal lobe
Lateral temporal lobe
Lateral occipital lobe
Insula
What does the lenticulostriate arteries supply?
Basal ganglia
Internal capsule
Amygdala
Anterior thalamus
How does the basilar artery arise and end?
formed by bilateral vertebral arteries
It bifurcates into the posterior cerebral arteries
What are the branches of the basilar artery?
Short and paramedian pontine branches
Long circumferential branches