Case 5 - Extra

Question 1

what does the anterior cerebral artery supply

Answer 1

medial portions of the frontal lobes
superior medial parietal lobes
anterior four fifths of the corpus callosum
anterior portions of the basal ganglia an internal capsule
olfactory bulb and tract

Question 2

where does the anterior cerebral artery pass

Answer 2

passes forward to travel in the inter hemispheric tissue as it sweeps back and over the Corpus callosum

Question 3

what are the two main branches of the ACA

Answer 3

pericallosal artery - this forms an anastomosis with the PCA
callosmomarginal artery

Question 4

where does the middle cerebral artery travel

Answer 4

turns laterally to enter the depths of the Sylvian tissue. within the Sylvia tissue, it usually bifurcates into the superior and inferior divisions

the branches of the MCA form loops as they pass over the insula and then around and over the operculum to exit the Sylvia fissue onto the lateral convexity

Question 5

what does the superior division supply

Answer 5

the cortex above the Sylvian fissure, including the lateral frontal lobe and usually the peri-rolandic cortex

Question 6

what does the inferior division supply

Answer 6

the cortex below the Sylvian fissue, including the lateral temporal lobe and a variable portion of the parietal lobe

Question 7

where does the posterior cerebral artery travel

Answer 7

curves back after arising from the top of the basilar and sends branches over the inferior and medial temporal lobes and over the medial occipital cortex

Question 8

what does the PCA territory therefore include

Answer 8

the inferior and medial temporal and occipital cortex

Question 9

what are the three things that cause ischaemic damage:

Answer 9

neurotransmitters - glutamate
ions - sodium and calcium
free radicals - abnormal oxygen molecules egg superoxide

Question 10

excitotoxicity explanation

Answer 10

• hypoxia leads to inadequate supply of ATP which in turn leads to failure of membrane pumps
• this causes an increased release of the excitatory neurotransmitter glutamate into the extracellular fluid
• this causes a rapid influx of calcium and sodium ions into the cells in the immediate area
• the calcium overload in the cells triggers a wide range of processes including, eventually leading leading to the formation of free radicals.
• the processes that occur inside the cell, leading to free radical formation ate:
  mitochondrial injury
  increased production of nitric oxide
  protease activation
  phospholipase activation

Question 11

what is free radical formation

Answer 11

this is induced in the brain
there is formation of superoxide and nitric oxide, which combine together to form superoxynitrate

Question 12

what does the formation of these radicals result in

Answer 12

lipid periodisation
protein oxidation
DNA damage

Question 13

what is apoptosis

Answer 13

excitotoxicity results in necrosis at the onset of injury
apoptosis is programmed cell death that occurs much later than the onset of the injury

Question 14

how does apoptosis occur

Answer 14

oxidative stress causes mitochondria injury
this causes release of cytochrome C from the mitochondria
cytochrome C activates the paracaspases into caspases
this leads to DNA damafe and cell death

Question 15

what is central inflammation

Answer 15

occurs in the brain and involves the microglia

Question 16

what does central inflammation cause

Answer 16

the degradation of the extracellular matrix in the brain, leakage of the BBB and the activation of the endothelial cells in the brain

Question 17

what is peri inflammation

Answer 17

the liver becomes activated due to the release of chemokine from the brain
it causes the liver to expresses acute phase proteins and other chemokine and cytokines
these cause an increased production of neutrophils which contain IL-1
due to the leakage of the BBB the neutrophils infiltrate the brain

Question 18

when is the outcome of a stroke pore

Answer 18

if you already have an inflammatory condition like obesity and arthritis

Question 19

what are watershed infarcts

Answer 19

the term watershed refers to those areas of the brain that receive dual blood supply from the branching ends of two very large arteries

the. the blood supply to two adjacent cerebral arteries is compromised, the regions between the two vessels are the most susceptible to ischaemia and infarction

Question 20

where are the bilateral watershed infarcts usually

Answer 20

in both the ACA-MCA and MCA-PCA watershed zones and can occur with severe drops in systemic BP

Question 21

what can watershed infarcts cause

Answer 21

in the dominant hemisphere, they can cause transcortical aphasia syndromes
MCA-PCA watershed infarcts can cause dsturbances of higher order visual processing

Question 22

what is transient global amnesia sully due to

Answer 22

posterior circulation ishcameia

Question 23

what is memory

Answer 23

the mental capacity to store and later recall or recognise events that were previously experienced

Question 24

what does learning emphasise

Answer 24

what is retained

Question 25

what does memory emphasise

Answer 25

what is forgotten

Question 26

what are the three stages of memory

Answer 26

perception
storage
retrieval

Question 27

facts about the short term memory

Answer 27

lasts seconds to minutes
capacity is limited to 7+/- 2 pieces of information: rule of 7

Question 28

which part of the brain is essential for consolidation learning

Answer 28

the hippocampus

Question 29

what is the mutlistore model of memory

Answer 29

information is detected by the sense organs and enters the sensory memory

this information is attended to, enters the short term memory, around 20 seconds

information from the STM is transferred to the long term only if that information is rehearsed

if rehearsal does not occur, then information is forgotten, lost form STM through the processes of displacement or decay

Question 30

where does conscious processing take place

Answer 30

the STM

Question 31

what is the model of working memory

Answer 31

in this model instead of all the information going into one single store, there are different systems for different types of information

Question 32

what does the working memory consist of

Answer 32

a central executive which controls and co ordinates the operation of two subsystems; the phonological loop and the visuospatial sketchpad

Question 33

what is the central executive

Answer 33

drives the whole system and allocates data to the sub systems

it also deals with cognitive tasks such as mental arithmetic and problem solving

Question 34

what is the visuo-spatial sketchpad

Answer 34

stores and processes information in a visual or spatial form

the VSS is used for navigation

Question 35

what is the phonological lop

Answer 35

it deals with spoken and written material.

Question 36

what are the two parts the phonological loop consists of

Answer 36

phonological store - linked to speech perception. hold information or speech based form for 1-2 seconds

articulatory control process - linked to speech production. used to rehearse and store verbal information from the phonological store

Question 37

what is the phonological loop responsible for

Answer 37

the manipulation of speech based information whereas the visuospatial sketchpad is assumed to be responsible for manipulating visual images

Question 38

what does this model propose

Answer 38

that every component of working memory has a limited capacity and also that the components are relatively independent of each other

Question 39

what is the episodic buffer

Answer 39

this is dedicated to linking information across domains to form integrated units of visual , special and verbal information and chronological ordering

Question 40

what is the difference between stroke and bells palsy

Answer 40

you get forehand spearing in a stroke unlike bells as It is a low motor neurone lesion