In the brain, the Dura Mater has __ _____, spaces in between these create the ____ ____ which function in:
- 2 layers
- dural sinuses
- removing the blood from the brain and sending it back to the heart
The Dural Septa run down into the fissures and:
There are 3 major Septa:
limits excessive movement of the brain
- Falx cerebri (longitudinal)
- Falx cerebelli (Vermis)
- Tentorium cerebelli (transverse)
There are non-real 'potential' spaces in the dura mater where hematomas or tumors can occur. These are the _______ and _______ spaces.
Epidural (following head injury in adults)
Subdural (following head injury in children)
The arachnoid adheres to the dura mater, and
under this lays the __________ ______ which is filled with ____ and helps
transfer this fluid back to the __________
- subarachnoid space
- Cerebrospinal fluid (CSF)
The web-like extensions in the subarachnoid space
Arachnoid Trabeculae (villi)
The pia mater is the ______ layer and contains ______ _______.
- (this layer adheres to the brain's surface,
- following its every contour)
What are the differences between the cranial and spinal cord meninges (3)?
- double layer dura
- Single layer dura
- Epidural space 'potential'
- Epidural space is real
- Pia attached to Surface
- Pia attached to SC, but expands as dentate ligaments (serves to anchor layers together)
What is Meningitis?
What can it be caused by?
Which is fatal?
What are the long term effects of fatal meningitis?
- An inflammation of the meninges (mostly affects arachnoid to subarachnoid), can lead to tissue/vascular injury and increased intracranial pressure
- many forms of bacteria and viruses
- deficits in learning/behavior, speech/language, hearing and cognitive difficulties
What is cerebrospinal fluid?
How much is in the brain?
How much are in ventricles?
A clear, watery-like fluid that is produced by the choroid plexus. There are approximately 150 mL of CSF in/around the brain, of this, 25 mL are found in the ventricles
What are the ventricles?
- Spaces in the brain that are filled with CSF:
- Lateral ventricles (one in each hemisphere)
- 3rd ventricle (between the thalamic bodies)
- 4th ventricle (between the pons and cerebellum)
How are the ventricles connected?
Later - 3rd
3rd - 4th
4th - subarachnoid space
- foramin of Monro (inter ventricular foramina)
- cerebral aqueduct
- medial and lateral apertures
Where does CSF go after it's used?
The subarachnoid trabeculae pick up used CSF and then it is reabsorbed into the blood stream by the superior saggital sinus
What are the functions of the CSF (3)?
- Protection: shock absorption
- Buoyancy: to prevent the brain from crushing itself
- Chemical stability/excretion: waste removal
What is HydrOcephalus?
In children, this is a genetic, developmental disorder in which excess CSF is built-up within the ventricles. In adults, this results from a TBI, hemorrhage, or tumor (blockage). A shunt can easily drain excess fluid to the abdomen.
What is HydrAencephaly?
"water brain" A condition in which hemispheres are absent and replaced by CSF. Death generally occurs before 1 and treatment is palliative in nature.
What is Anencephaly?
Failure of the neural tube to close at the cranial end during neonatal development. Much of the brain, scalp, and skull are absent.