Term
| List 3 layers of Meninges and their related pathological processes |
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Definition
1. dura matter
2. arachnoid matter
3. pia matter
trauma, hemorrhages, infection, inflammatory diseases, neoplasia |
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Term
| What is dura matter comprised of? |
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Definition
| 2 layers of collagenous connective tissue with large veious sinuses |
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Term
| What are arachnoid villi? |
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Definition
| structures that penetrate the sinuses that coduct CSF back to ciculation |
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Term
| what is the leptomeninges? |
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Definition
| the Pia-arachnoid which are often considered a single covering. |
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Term
| what is the functional periosteum of the inner table? |
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Definition
| dura tightly adherent to the skull |
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Term
| How does an epidural hemotoma occur? |
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Definition
| Middle Meningeal Arterial bleeding (most commonly from fractures of the temporal bone that injure the artery), may go into the space between the duram matter and the intter table of the skull. |
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Term
| What is arachnoid matter comprised of? |
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Definition
| arachnoid matter is a thin membrane made of a mixture of fibroblasts and arachoidal cells |
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Term
| what are meningothelial cells |
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Definition
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Term
| does the arachnoid matter and the dura often form a single layer/ |
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Definition
| yes--which is why blood can accumulate in subdural spaces |
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Term
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Definition
cells mostly concentrated over the arachnoid villi. they have small, multicellular clusters and sometimes psammoma bodies
***thought to form the basis for a slow growing tumor seen in OLDer adults, MENINGIOMA |
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Term
| what forms the basis of meningiomas? |
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Definition
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Term
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Definition
a layer of cells tightly affixed to brain itself.
normally, it's clear, but it becomes dark with age |
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Term
| what do arachnoid trabeculae do? |
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Definition
| they connect the arachnoid to the pia matter |
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Term
| why does the arachnoid get opacified with age? |
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Definition
| Deposition of collagen in subarachnoid space |
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Term
| pathalogical reactions involving the SA space? |
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Definition
| meningitis, (infections), neoplastic infiltrations, hemorrhages |
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Term
| what is the Virchow-Robin space? |
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Definition
| space between the pia and the vessels. continuous with the SA space. can be filled with anything that fills the SA space (hemorrhage, inflammatory cells, infection). can be a route for spreading tumors (Scherer's secondary structures) |
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Term
| what are Scherer's secondary structures? |
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Definition
| routes for spread of infiltrating tumor cells through the Virchow-Robin space |
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Term
| what are neurons responsible for? |
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Definition
| the reception, transmission, and processing of stimuli; triggering of cell activities; release of neurotransmitters |
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Term
| what features are appreciated in the perikaryon of the neuron? |
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Definition
| nucleus, RER with Nissel bodies, golgi, mitochonidria, synaptic boutons, axon hillocks |
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Term
| how can you recognize an axon hillock? |
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Definition
| presence of neurofilaments and absence of RER and ribosomes (Nissl Substnace |
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Term
| where are the largerst number of neurons? |
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Definition
| neocortex of the cerebral hemispheres |
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Term
| name the 6 layers of the neocortex, outside to in |
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Definition
acellular molecular layer
2. external graular layer
3. external pyramidal layer
4. internal granular layer
4. internal pyramidal layer
6. multiform layer (mixed neurons, including large pyramidal type cells) |
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Term
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Definition
| large pyramidal cells of layers 3 and 5 of the neocortex |
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Term
| what is a normal aging change seen in neurons? |
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Definition
| accumulation of lipofuscin |
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Term
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Definition
| neurons that have experienced irreversible ischemic injury---shrunken cell body, intense cytoplasmic eosinophilia with complete loss of Nissl basophilia |
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Term
| what are 2 signs of inclusions; and what are the indicative of? |
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Definition
Inclusions are indicative of neurodegenerative disase:
1. neurofibrillary tangles in AD
2. Lewy bodies in PD |
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Term
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Definition
| astrocytes and oligodendrocytes |
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Term
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Definition
| have an important structural role and fuctional role as mediators of metabolic exchange between neurons and blood as they are situated in non-synaptic regions of neurons. |
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Term
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Definition
| glial fibrillary acidic protein. contained in astroncytes |
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Term
| what are the 2 components of astrocytic response to brain injury? |
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Definition
1. Hypertrophy (accumulation of GFAP, increased numbers of astrocytes and their processes)
2. hyperplasia |
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Term
| what are key features of astrocytomas? |
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Definition
| GFAP expression (defining a non-neoplastic astrocyte) |
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Term
| where are astrocyes and oligodedrocytes found? |
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Definition
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Term
| what do Oligos look like? |
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Definition
| fried eggs/halo. little cytoplasm |
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Term
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Definition
| they give structural and metabolic support to neurons and thus are close in proximity to them. |
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Term
| what type of features do ependyma and choroid plexus cells have? |
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Definition
| epithelial-meaning they line up in an orderly manner, with cell polarity and close cell to cell connections. |
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Term
| where is deep gray matter found? |
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Definition
| in the BG, Thal, hypothal |
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Term
| what do all deep gray matter structures have in common? |
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Definition
| non-laminar architecture containing a mixed populations of neurons and myelinated fibers |
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Term
| where is superficial gray matter found? |
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Definition
| medial temporal lobe/hippocampus/amygdala |
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Term
| what is the cornu ammonis (CS) |
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Definition
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Term
| what is the CA1, and what's its relevance? |
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Definition
aka: Sommer sector.
It is the most sensitive to ischemia, seizures, and degen relating to AD |
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