02c: CNS Cells Flashcards
CSF exists in (X) space, between which meningeal layers?
X = subarachnoid;
Arachnoid and pia
List the two potential spaces associated with meninges, where blood can collect during hemorrhage.
Epidural and subdural
Tearing of (X) vessel where it meets dural venous sinus likely results in subdural hemorrhage.
X = cerebral vein (where it meets dural venous sinus)
Tearing of (X) vessel likely results in epidural hemorrhage.
X = meningeal artery of skull
(Like/unlike) other regions of body, fluid in blood (can/cannot) have unrestricted access to brain.
Unlike; cannot
T/F: BBB exists in all regions of brain.
False - most, except for few small regions
T/F: There’s only one mechanism by which substances are transported across BBB.
False - diverse mechanisms
Neuroglial cells are divided into which categories? They’re divided based on (X).
X = size
Microglia and macroglia
Astrocytes are in which specific category of (X) cells?
X = neuroglial
Macroglia
Oligodendrocytes are in which specific category of (X) cells?
X = neuroglial
Macroglia
(Astrocytes/oligodendrocytes) have more compact nucleus.
Oligodendrocytes
Which cells responsible for immuno surveillance/patrol in brain?
Microglia
T/F: Brain does not have a lymphatic system.
True
Localized damage in brain will initially activate fast directional movement of (X) cells in attempt to do (Y).
X = microglia Y = contain injury
(X) form myelin in CNS.
X = oligodendrocytes
Each process of (X) cell contacts and myelinates (Y) number of CNS axons.
X = oligodendrocyte Y = one
Each (X) cell contacts and myelinates (Y) number of CNS axons.
X = oligodendrocyte Y = multiple
T/F: Oligodendrocyte cell size depends on size of axon/amount of myelin.
True
T/F: Amount of myelin on axon depends on number of processes of oligodendrocyte.
False
T/F: There is notable loss of neurons with age.
False
T/F: Normal aging affects myelination/axons.
True
Star-shaped macroglia, aka (X), include which types?
X = astrocytes
Protoplasmic and fibrous
A (X) astrocyte is found near cell body, aka (grey/white) matter.
X = protoplasmic;
Grey
A (X) astrocyte is found near cell axon, aka (grey/white) matter.
X = fibrous;
white
Astroctye general functions:
- Regulate ionic composition
- Provide metabolic support
- Recycle NT
- GFAP (intermediate filaments) provide structural support
- Insulation of synapses/nodes of ranvier
GFAP stands for (X).
Glial fibrillary acidic protein
Parts of neuron that aren’t covered by synapses are covered by:
Astrocytes
(X) processes have end feet which cover (Y).
X = astrocytes Y = blood vessels and brain/SC surface
End feet of (X) that form membrane around (Y) is formally called (Z).
X = astrocytes Y = brain/SC Z = glia limitans
Large populations of astrocytes are connected by:
Gap junctions
Neuron is damaged. How do astrocytes respond?
- Strip synapses (isolate damaged neuron)
- Physical barrier to regeneration
- Proliferate and wall off area of injury (astrocytic scar)
Substance can pass into extracellular space by which mechanisms?
- Paracellular (between cells)
- Vesicular transport (through cells)
- Fenestration (through pores in endothelium)
The BBB exists between which vessels/space?
Between capillaries and extracellular fluid
Which specific cells of which specific vessels form the BBB?
Endothelial cells of brain capillaries
T/F: BBB has few caveolae and few pores.
False - NO pores
T/F: The massive amount of gap junctions form the tight BBB seal.
False - massive amount of tight junctions
(X) surround capillaries and provide secondary protective mechanism to assist BBB.
X = astrocytes
(X) substances diffuse through BBB.
X = lipophilic (lipids, O2, CO2)
(X) substances undergo facilitated transport through BBB.
X = glucose
Most substances transported through BBB via:
Active transport
Pericytes exist in (X) and function to (Y).
X = basement membrane of BBB Y = contribute to structural integrity of vasculature
Which area(s) of brain allow for blood monitoring via contact with vascular space?
- Area postrema (floor of 4th ventricle)
2. Subfornical organ (near hypothalamus)
Initiation of vomiting reflex is done by (X).
X = area postrema
Subfornical organ functions to:
Detect osmolarity of blood
(X) area(s) in brain secrete hormones/prohormones into blood.
X = pineal gland and hypothalamus
Areas of brain that indiscriminately contact substances in blood are “walled off” from rest of brain via:
Tanycytes (modified astrocytes that form barrier)
T/F: Astrocytes provide structural support to brain that isn’t very good.
True
CSF makes brain weight feel (X) times lighter.
X = 30
T/F: CSF functions both to support brain weight and buffer external forces.
True
List the ventricles in the brain. Star those that produce CSF.
- Lateral ventricles (2)*
- Third ventricle*
- Fourth ventricle*
Where does CSF flow once it flows out of the (X), and last, ventricle?
X = fourth;
Into subarachnoid space
Cerebral ventricles are lined by (X) cells, formally called (Y).
X = epithelial Y = ependymal
T/F: The ependymal cells form multiple thick layers.
False - one thick layer
T/F: The ependymal cells are not strongly connected.
True
The cerebral ventricles are lined by (X) cells that contain which key projections?
X = epithelial (ependymal)
Cilia
(X) cells produce CSF. They’re derived from (Y) cells and contain which key projections?
X = choroidal Y = ependymal
Microvilli
Choroidal cells are (simple/cuboidal/columnar). They line (X) vessels that have which characteristic?
Columnar;
X = capillaries
Fenestrated (hole-y)
T/F: CSF is made from plasma, but has different ionic composition than blood.
True
The Blood-CSF Barrier is formed by what?
Tight junctions between the choroidal cells that surround capillaries
Apertures in (X) ventricle allow CSF to gain access to subarachnoid space. List these apertures.
X = fourth
- Foramina of Luskha (2) (lateral)
- Foramen of Magendie (median)
Drainage of CSF out of subarachnoid space and into (X) is through (Y) structures.
X = superior sagittal sinus Y = arachnoid granulations
The (X) provides insight into metabolic status of CNS.
X = CSF
