RUSVM Physio Neuro Part 3 Flashcards
T/F ependymal cells form a selective tight-junction barrier
True
Where is most of the CSF formed?
at the choroid plexus of the ventricles.
What is the choroid plexus joined by?
Tight junctions
T/F CNS Accounts for 20% of the body weight but has disproportionately high metabolic rate and receives 2% of the total cardiac output
False- CNS = 2% body weight and receives 20% of total cardiac output.
What ventricle is oriented longitudinally in each hemisphere and connected with the 3rd ventricle
Lateral ventricles
What forms a perivascular end feet around the entire outer surface of the capillary endothelium?
Astrocytes
What ventricle is connected with the subarachnoid space?
4th ventricle
The BBB is highly permeable to what?
water, CO2, O2 and most lipid soluble substances such as OH and anesthetics
Where is the blood CSF barrier and BBB located
Located both at the choroid plexus and at the tissue capillary membranes in all areas of the brain.
T/F Interaction between astrocytes and endothelial cells is important for the maintenance of the BBB
True
How is the manner in which the cells are joined together in the BBB
Membranes of the adjacent endothelial cells are tightly fused rather than having large slit pores between them
Most of the CSF is absorbed from the subarachnoid space into the venous sinuses through what?
Arachnoid villi
What causes the low permeability of the barrier ?
The manner in which the cells are joined to one another.
What contains CSF?
the ventricular system and the subarachnoid space. CSF is also in the central canal that runs through the core of the spinal cord.
T/F Absorption of CSF appears to be pressure independent and multidirectional
False- pressure DEPENDENT and UNIdirectional
What ventricle surrounds the interthalamic adhesion and connected with the 4th ventricle
3rd ventricle
The neuraxis and meninges are drained by what?
veins and sinuses
What glucose transporter is used in the BBB
GLUT 1
White or Grey matter receives more blood?
Grey matter receives more blood than white matter.
What is the BBB slightly permeable too?
to electrolytes such as Na, Chloride and K.
What are the functions of the CSF
- Cushion the brain, protection against hard blows
- Maintain a consistent extracellular microenviornment for the neurons and glia
- effective waste control system that can remove potentially harmful cellular metabolites
- Act as a brain distribution system for some peptide hormones and growth factors.
What is the BBB almost totally impermeable too?
Plasma proteins and non-lipid-soluble large organic molecules.
The ventricular system comprises 4 expanded regions forming ventricles interconnecting what?
Foramens and tubes
What cells cover the choroid plexus?
thin layer of ependymal cells (glial cell)
