Dural Venous Sinuses and Ventricular System Flashcards
What are the dural venous sinuses and where are the found?
Endothelium-lined spaces located between periosteal and meningeal layers of dura mater
Where do the sinuses receive tributaries from?
brain, diploe of skull, internal ear, orbit
What is the purpose of the dural partitions in the skull?
Restrict rotary displacement of the brain
Name the dural partitions.
Falx cerebri, falx cerebelli, tentorium cerebelli, diaphragma sellae
Describe the position of the different venous sinuses and where blood travels to.
- Sup. sagittal sinus - upper margin of flax cerebri - blood flows towards confluence of sinuses and then into R transverse sinus
- Inf. sagittal sinus - lower border of falx cerebri - flows into straight sinus, confluence, L transverse sinus
- R and L transverse sinuses - flow into R and L sigmoid sinuses
- Each sigmoid sinus - internal jugular vein at jugular foramen
- Sup. petrosal sinus - within margin of tentorium cerebelli attached to sup. border of petrous part of temporal bone
- Inf. petrosal sinus - within groove between petrous part of temporal bone and occipital bone
- Cavernous sinuses - either side of sella turcica and connected by intercavernous sinus
What is the confluence of sinuses?
Point where superior sagittal, straight, occipital and transverse sinuses meet
What is the confluence of sinuses?
Point where superior sagittal, straight, occipital and transverse sinuses meet
What is the clinical relevance of the cavernous sinuses?
Danger triangle of face
- facial veins communicate with cavernous sinuses via superior and inferior opthalamic veins
- infection can spread from face into cranial cavity
Which cell secretes CSF in the ventricular system?
Choroidal epithelial cells of choroid plexus (within lateral ventricles, third ventricle, fourth ventricle)
* majority of CSF produced in lateral ventricles
Where is CSF contained?
Ventricular system and subarachnoid space
What are the functions of CSF?
- cushions brain
- provides nutrients
- removal of waste products from brain
What are arachnoid granulations?
Prolongations of arachnoid mater - protrude through meningeal layer of dura mater and open into dural venous sinuses - involved with resorption of CSF
What is the clinical relevance of the ventricular system?
obstruction of flow of CSF can be caused by a tumour - leads to rise in fluid pressure that will cause hydrocephalus
symptoms include: headaches, unsteadiness, mental impairment
decompression of dilated ventricles may be achieved by inserting peritoneal shunt
