Ventricular System Flashcards
What is the ventricular system?
A series of CSF-filled interconnected spaces which are continuous with the subarachnoid space and central canal.
In embryology, what is the brain and spinal cord derived from?
The brain and spinal cord come from the neural tube (which is formed from the neuroectoderm)
How many lateral ventricles are there?
2 (one for each hemisphere)
What are the parts of each lateral ventricle and what lobes do they correspond to?
- Body = Parietal lobe
- Anterior Horn = Frontal lobe
- Posterior Horn = Occipital lobe
- Inferior Horn = Temporal lobe
What separates the lateral ventricles?
Septum pellucidum
What sits on the roof of the lateral ventricles?
Corpus callosum
What separates the lateral ventricles and the third ventricle?
Interventricular Foramen (Foramen of Munro)
What sits on the floor of the inferior horn of the lateral ventricles?
Hippocampus
What sits in the lateral wall of the lateral ventricles?
Caudate nucleus
What is the shape of the third ventricle and what does it separate?
Slit like cleft which separates the thalami
What sits on the roof of the third ventricle?
Fornix
What separates the third ventricle from the fourth ventricle?
Cerebral Aqueduct (Aqueduct of Sylvius)
What surrounds the cerebral aqueduct?
Midbrain
What surrounds the fourth ventricle?
Hindbrain:
- Cerebellum = Posterior
- Pons and Medulla = Anterior
- Cerebellar Peduncles = Lateral
What are the three foramina exits in the fourth ventricle to the subarachnoid space?
- Formamen of Luschka x2 (lateral)
- Foramen of Magendie (middle)
Where is the choroid plexus present?
Throughout the ventricular system
Where is CSF produced?
Choroid plexus
What blood vessels does the choroid plexus filter?
Branches of the internal carotid arteries and basilar arteries
What type of epithelium surrounds the choroid plexus?
Cuboidal epithelium
How does CSF get produced?
1) Blood gets filtered through fenestrated capillaries
2) Components then get transported through the cuboidal epithelium and into the ventricles
What prevent macromolecules from entering CSF?
Tight junctions in the cuboidal epithelium
At what level are Lumbar punctures taken?
- L3/4 in adults
- L4/5 in children
Why can the ionic composition of CSF vary from that of the plasma?
Because the regulation via active transport differs
What is the purpose of a lumbar puncture?
To sample CSF
What are the two types of hydrocephalus?
Communicating and Non-Communicating
What is a communicating hydrocephalus?
When the movement of CSF into venous sinuses is impeded because of issues in absorption of CSF in the arachnoid granulations.
What is a non-communicating hydrocephalus?
When there is a blockage in the ventricles (e.g. a tumour or cyst)
