Meninges/CSF/Ventricles Flashcards
What are the major parts of the brain
- Brain stem
- Cerebellum
- Diencephalon
- Cerebrum
What are the 3 meninges from superficial to deep
- Dura mater
- Arachnoid mater
- Pia mater
True or False the meninges of the brain are continuous w/ spinal cord meninges
True
What is the space between the pia matter and the arachnoid mater
sub-arachnoid space
What is the difference between the cranial dura mater and the spinal dura mater.
Cranial dura mater=2 layers
Spinal dura mater=1 layer
What are the 2 cranial dura mater layers
- External periosteal layer=formed by periosteum covering the internal surface of the cranium
- Internal meningeal layer = layer that is continuous w dura mater of the spinal cord
What are the dural venous sinuses
An area where the external periosteal layer and the internal meningeal layer of the cranial dura mater are not fused allowing blood to drain from the brain into the internal jugular
What is the Falx cerebri
extension of the dura mater that separates the 2 hemispheres of the cerebrum
What is the Falx cerebelli
extension of the dura mater that separates the 2 hemispheres of the cerebellum
What is the Tentorium cerebelli
extension of the dura mater that separates cerebrum and cerebellum
What can disrupt the blood brain barrier
trauma, certain toxins and inflammation
What area of the brain lack a blood brain barrier
pineal gland, pituitary gland, hypothalamus, area postrema
What forms the blood brain barrier
tight junction of brain capillaries and astrocyte foot processes
What substances cross the blood brain barrier easy
Lipids and lipid soluble substances, O2, CO2, EtOH and anesthetic agents cross
What substances cross the blood brain barrier via active transport
Glucose and some other water soluble substances
What substances cross the blood brain barrier slowly
creatinine, urea, and most ions
What substances do NOT cross the blood brain barrier easy
proteins and most Abx
What is the function of the cerebrospinal fluid (CSF)
- Protect brain and spinal cord from mechanical injury (shock absorber)
- Circulation for the exchange of nutrients and waste products
- Chemical protection= provides optimal ionic composition for accurate neural signaling
What cells produce the CSF
ependymal cells, they produce it from blood plasma
What are the choroid plexuses
networks of capillaries of the ventricles covered in the ependymal cells
What compromises the 1st and 2nd ventricles
the lateral ventricles
Where is the 3rd ventricle located
between the R and L halves of the thalamus
Where is the 4th ventricle located
between the brain stem and the cerebellum
Describe the flow of CSF circulation
CSF formed in lateral ventricle flows to third ventricle=> then via the cerebral aqueduct CSF flows to the four ventricle=> then via the central canal CSF flows to the spinal cord and the subarachnoid spaces
-CSF is produced in all 4 ventricles
Where is CSF reabsorbed
the arachnoid villi
What are arachnoid villi
areas of projections from the subarachnoid space to the dural venous sinus
What is hydrocephalous
condition in which excessive CSF fluid builds in the brain causing increased cranial pressure
-can be present at birth or develop later in life
How is hydrocephalous treated
- shunt system that diverts CSF from CNS to the heart or abd cavity
- if a certain type of obstructive hydrocephalus then it maybe treated by creating a small hole in the floor of the 3rd ventricle via neuroscope
