Ventricles & CSF Route Flashcards
Define ventricles
Cavities/spaces within the brain
What is contained within the ventricles
CSF, which is produced by a vascualr structure choroid plexus which lies inside the ventricles
Where do ventricles lie
One is bilateral (a pair with 1 in each hemisphere) and the others are singular structures along the midline with varying shapes/dimensions
What does the prosencephalon (forebrain) become
Telencephalon
Diencephalon
What does the mesencephalon (midbrain) become
Stays as the mesencephalon
What does the rhomboencephalon (hindbrain) become
Metencephalon & myelencephalon
Adult brain structures of the telencephalon
CEREBRUM - cerebral hemispheres (cortex, white matter, basal nuclei)
Adult brain structures of the diencephalon
Thalamus
Hypothalamus
Epithalamus
Retina
Adult brain structures of the mesencephalon
BRAIN STEM - midbrain
Adult brain structures of the metencephalon
BRAIN STEM - pons
Cerebellum
Adult brain structures of the myelencephalon
BRAIN STEM - medulla oblongata
Adult neural canal regions of the cerebrum
Lateral ventricles
Adult neural canal regions of the diencephalon
3rd ventricle
Adult neural canal regions of the brain stem (midbrain)
Cerebral aqueduct
Adult neural canal regions of the brain stem (including the pons and medulla oblongata) and the cerebellum
4th ventricle
Adult neural canal regions of the spinal cord
Central canal
Overview of development of ventricles
What cells line the ventricles
Ependymal cells, which specialise to form choroid plexus
Where does the choroid plexus receive an arterial blood supply from
The choroidal arteries
What area does CSF fill first
Fills the ventricles first and then proceeds to flow to fill a layer surrounding the brain and spinal cord
Where do the lateral ventricles extend through
Each lobe of the cerebrum - the interventricular foramen
Where is the 3rd ventricle
In the diencephalon - a single unpaired midline space
How does CSF flow into the 3rd ventricle
from the lateral ventricles through the interventricular foramen into the 3rd ventricle
What is the cerebral aqueduct
Where does CSF flowing into the cerebral aqueduct come from
A narrow canal through the midbrain of the brainstem
The 3rd ventricle
Where is the 4th ventricle located
A singular space posterior to the brainstem and anterior to the cerebellum
How does CSF reach the 4th ventricle
CSF flows from the cerebral aqueduct
Where does CSF go when it leaves the ventricular system
2 ROUTES
- Central canal of the spinal cord
- Exit into the layer between the coverings (meninges) of the brain
3 core locations of the choroid plexus
- The floor of the lateral ventricle
- The roof of the 3rd ventricle
- The 4th ventricle
Lateral view of ventricular system
Anterior view of ventricular system
Summary of CSF route
What is hydrocephalus
- Overproduction of CSF, failure to drain or obstruction of flow
- Dilates ventricles
- Separates the calvaria in infants
- Hydrocephalus occurs with congenital abnormalities, head injury, meningitis and episodes of bleeding into the brain (rupture of pia)
At wk 3 of development what happens to the neural tube
Pinches in places to form 3 compartments
Direction of flow of CSF is from top to bottom
Hollow prosencephaly
The forebrain fails to develop
What happens in wk 5
Secondary brain vesicles are formed
- Telencephalon (hemispheres are forming)
- Diencephalon
- Mesencephalon
- Metencephalon
- Myelencephalon
Horns of the lateral ventricles
Anterior
Posterior/occipital
Inferior/temporal
Exit point of CSF from lateral ventricles
Interventricular foramen
2 major components of the diencephalon
3rd ventricle
Thalamus
Periaqueductal grey
Grey matter near the aqueduct
Pathways that relay our PAIN sensations
How can CSF exit the 4th ventricle
- Via apertures - median and lateral - flows into SAS - ascends and exits via arachnoid villi (features of meninges)
- Central canal of spinal cord
