CSF, Ventricular System, Meninges: Flashcards
-within the ____ of the brain: _____ is producing the cerebrospinal fluid
ventricles,
choroid plexus
Cerebrospinal Fluid
- found in:
- function (3)
Clear liquid
Helps to cushion
Supplies nutrients
Helps to remove waste products
Produced continuously by the choroid plexus in the ventricles
Found in your ventricles, central canal, and the subarachnoid space
Cerebrospinal Fluid is found in your ventricles, central canal, and the subarachnoid space
-where is it made?
Produced continuously by the choroid plexus in the ventricles
choroid plexus
-where found?
-is it vascularized?
-made of?
-function
-develops from :
probs dont have to know all of this
Way understudied
Found in ventricles and next to the pia mater
Highly vascularized [lots of little blood vesels]
Made of epithelial cells [not neurons]
Also contains immune cells
*Makes your CSF
Develops from the dorsal neural tube
Too Much CSF
-causes
Hydrocephaly/Hydrocephalus: too much CSF
Causes include trauma, meningitis, infection, blockage in CSF drainage pathways, and birth defects
*Why do we not want it? It puts too much pressure on your brain and within your skull. I think causing you to get headaches
Hydrocephaly/Hydrocephalus in an infant vs an adult
probs dont need to know
-this is bad in adults: the head cannot grow but in a baby the head can enlarge – getting less tissue death
In an infant: can address hydrocephaly
Too Little CSF
- causation
- result
Usually means you sprung a CSF leak somewhere or are severely dehydrated
- Why do we not want it? Brain does not have enough cushion. It can also cause the brain to sag, stressing nerves and meninges
- can get nerve damage
-the brain and spinal cord are not as protected. Cannot supply enough nutrients
which ventricle(s) is choroid plexus found?
Choroid plexus is found in each lateral ventricle and the third and fourth ventricle. It is involved in the production of cerebrospinal fluid.
(so I think all of them but the cerebral aqueduct)
Choroid Plexus Pathologies
(tbh confused if need to know it but i guess try to learn them)
Cysts- common with certain disorders
*Hemorrhages- often due to birth trauma/stress/hypoxia
Tumors and Hyperplasia- often lead to hydrocephalus
*Microorganism infiltration- seen in children who have meningitis
{Having an infection in the choroid plexus}
Deficiencies in thyroid hormone carrier protein (thus depriving brain regions of thyroid hormone)
*Perhaps involved in Alzheimer’s disease- CSF helps to clear plaques and choroid plexus appears atrophied in those with the disease
Ventricular Changes Due to Pathology or Trauma
- Alzheimer’s and Dementia
- Brain overall is shrinking: trying to pump the brain back out with CSF but this is a temporary fix.
- the ventricles are changing (getting bigger?)
- the brain is “looser”
- hippocampus shrinking
- schizophrenia
- Enlargement of the lateral ventricles
*CTE: Chronic traumatic encephalopathy
-caused by hitting the head (athletes or military etc)
The primary physical manifestations of CTE include a reduction in brain weight, associated with atrophy of the frontal and temporal cortices and medial temporal lobe. The lateral ventricles and the third ventricle are often enlarged, with rare instances of dilation of the fourth ventricle.]
Main Functions of Meninges*
Provide asupportive frameworkfor the cerebral and cranial vasculature.
Acting with cerebrospinal fluid to protectthe CNS from mechanical damage.
The singular of meninges is
meninx
Dura Mater
- location
- also known as
The dura mater is theoutermostlayer of the meninges
- Directly underneath the bones of the skull and vertebral column
- Thick, tough, and inextensible
- Fits brain like a loose bag
- Also known as the pachymeninx
- Continuous with the periosteum
two layers of Dura Mater
right below the skull have the
1) endosteal (periosteal)
2) meningeal
which is thicker: the dura around the brain or the spinal cord
The dura around the brain is a bit more thick than the one that protects the spinal cord.. Has to do with the number of layers
two layers in skull, one in spinal cord
Within the cranial cavity, the dura contains two connective tissue sheets:
- Endosteal (Periosteal) layer– Lines the inner surface of the bones of the cranium; does not extend through foramen magnum
- Meningeal layer– Lines the endosteal layer inside the cranial cavity.
- The only layer present in the vertebral column
Between the two layers of the Dura, what is located?
Between the Endosteal (Periosteal) layer and the Meningeal layer, thedural venous sinusesare located.
Responsible for the venous vasculature of the cranium, draining into theinternal jugularveins
T/F
the dura layers: two layers in spinal, one in skull
FALSE
two layers in skull, one in spinal cord
The layers of the meninges
Three layers of membranes known as meninges protect the brain and spinal cord. The delicate inner layer is the pia mater. The middle layer is the arachnoid, a web-like structure filled with fluid that cushions the brain. The tough outer layer is called the dura mater.
Dura Mater additional notes
- innervation?
- vascularization?
In some areas within the skull, the meningeal layer of the dura mater folds inwards asdural reflections.
They partition the brain and divide the cranial cavity into several compartments.
The dura mater receives its own vasculature; primarily from themiddle meningealartery and vein.
It is innervated by thetrigeminal nerve(V1, V2 and V3)
Can feel pain
Unlike cranial dura mater, spinal dura mater only has one layer, known as the ____ layer. The potential space between these two layers is known as the _____ space.
dont need to know this i think
Unlike cranial dura mater, spinal dura mater only has one layer, known as the meningeal layer. The potential space between these two layers is known as the epidural space.
The tentorium cerebelli
i dont think you need to know
The tentorium cerebelli is the second-largest dural reflection
-is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.
thedural venous sinuses
Responsible for the venous vasculature of the cranium, draining into theinternal jugularveins
Dura Mater additional notes
vasculature?
innervated?
- In some areas within the skull, the meningeal layer of the dura mater folds inwards asdural reflections.
- They partition the brain and divide the cranial cavity into several compartments.
- The dura mater receives its own vasculature; primarily from themiddle meningealartery and vein.
- It is innervated by thetrigeminal nerve(V1, V2 and V3) –>Can feel pain
hematoma vs hemorrhage
daubt need to know- I think she considered them to be the same thing
A hematoma can result from an injury to any type of blood vessel (artery, vein, or small capillary). A hematoma usually describes bleeding which has more or less clotted, whereas a hemorrhage signifies active, ongoing bleeding. Hematoma is a very common problem encountered by many people at some time in their lives.
haematoma can cause?
A haematoma can cause a rapid increase in intra-cranial pressure. Death will result if untreated.
thedural venous sinuses
- Responsible for the venous vasculature of the cranium, draining into theinternal jugularveins
- Small projections of arachnoid mater into the dura(known asarachnoid granulations)allow CSF to re-enter the circulation via the dural venous sinuses.