CSF And BBB Flashcards
List some functions of CSF
- protect cranial contents
- modulate pressure changes
- chemical buffer (homeostasis)
- transport
List the 3 parts of the meninges
- pia matter
- arachnoid
- dura matter
The dura covers what in the brain?
Cortex and cerebellum
Which part of the meninges plays a role in clearing CSF?
Dura
An accumulation of blood outside a vessel in an organ or tissue or body space is a:
Hematoma
What are the 2 types of hematomas associated with the brain?
Epidural and Subdural
A localized, homogenous bright signal hematoma associated with arterial blood where the blood is outside the dura is a ?
Epidural hematoma
Describe a subdural hematoma
Associated with venous blood
Under dura
Widespread
Has dark spots in CT bc of blood cell degradation
Which structure specifically produces the CSF?
Choroid plexus - ependymal cells
Define CSF
Normally clear fluid in ventricles, central canal of spinal cord and subarachnoid space in brain/SC
Describe rate of formation, flow, and absorption of CSF
It is sufficiently high to completely be replaced several times daily
CSF circulation is due to:
- respiratory inspiration
- blood pulsation in choroid plexus
- ependymal cell pulsation
What type of fibers can be found in the arachnoid?
Collagen and elastic
Inside the arachnoid granulation, you can find ?
Arachnoid villi
Absorption of CSF occurs through protusions in the _______________ into arachnoid granulations (venous sinuses)
arachnoid membrane
Impaired CSF circulation or resoabsorption would lead to what condition?
Hydrocephalus
What can be installed to treat Hydrocephalus that goes into the abdomen?
Shunts
List 2 things that regulate the balance of CSF pressure
- absorption rate
- formation rate
A subarachnoid hemorrhage (blocks absorption) will increase/decrease CSF pressure?
Increase
The inflammation of meninges is called ___________
Meningitis
Meningitis causes:
- viral
- bacterial
- parasitic
- fungal
- toxin exposure
Define encephalitis
Brain inflammation
What is the most common cause of neurological disease in dogs?
Encephalitis
T/F there is epidural space in the skull
false
What creates an epidural hematoma ?
False space in a trauma
What separates the spinal cord dura from the periosteum lining the vertebral canal?
Vertebral column
Where do you insert the needle for a lumbar tap/CSF collection and why?
At level of cauda equine to prevent spinal cord damage
In small animals, describe where you can collect CSF from.
Atlantooccipital space (cerebellomedullary)
CSF is composed of what ratio of glucose?
2/3
List the 3 structures that make up the Blood brain barrier
- astrocytes
- pericytes
- endothelial cells
In a brain capillary, _________ junctions aid to reduce pinocytosis.
Tight
T/F brain capillaries have fenestrations
false
What is present around a brain capillary that is unique to that?
Astrocyte foot processes and pericytes
Which molecules cross the blood-brain barrier?
Lipid-soluble
Which charged molecules cross more freely than the other ?
Negatively charged
What can decrease the resistance of the Blood-brain barrier?
Injury or inflammation
BBB leakage can be induced by:
- seizures
- stroke
- traumatic brain injury
Which areas of the brain are not protected by the blood-brain barrier?
Circumventricular organs
List circumventricular organs
- Neurohypophysis
- pineal gland
- area postrema
-subfornical organ
Describe the reason why some areas of the brain may not be protected by the BBB
To allow brain to monitor humoral signals
Define edema
Swelling caused by fluid accumulation in body tissue
List the 2 types of edema
- vasogenic
- cytotoxic
Which type of edema is characterized by an increase in ICP, brain volume, and interstitial volume?
Vasogenic
Define cytotoxic edema
Intracellular swelling of neurons, glia, and endothelial cells
