Cells Of The Nervous System Flashcards
What is a neuron
A cell that transmits nerve impulses
Give an example of a neuron
Pyramidal neuron, multipolar, cerebral cortex
Name a glial cell and its function
Oligadendrite- makes myelin and wraps around the axon in CNS
Schwann cell - myelin sheath wraps around axon in PNS, insulation and increase speed of message
Astrocyte - provide protection and support, clean up ions from synapse, exchange nutrients at the blood brain barrier
Microglia cells - immune cells of CNS, surround and digest invading cells.
What is Fields (2020) critical period referring to
The critical period of adolescence when there is synaptic pruning, plasticity and myelination happening
How to Xing et al 2016 refer to plasticity
Restorative plasticity - axonal sprouting reconnects pathways
Compensatory plasticity - another region takes over function
What is hemi special neglect?
When there is trauma, tumour or stroke in the r parietal lobe, the somatosensory cortex, the pt. Cannot identify their left side,
eat only their dominant side of food plate, drawing, high risk of falls,
1/2 of people who have a stroke have it for a period of time so not always in the r parietal only. Less awareness of the world.
Rehab:- constrained induced therapy (Page etal.2005)
VR, focussed effort, eye tracking
What is the cerebral cortex
The grey matter on the outside layers of the cerebrum, with gyro and sulci folds, two hemispheres consists of 6 layers of neocortex containing neurones. There are 4 lobes,
frontal lobe for decision making, conscious thought, planning, executive function
Parietal lobe for somatosensory input, touch, pain, pressure and temp.
Temporal lobe for auditory, speech production
Occipital lobe for disseminating information received from the retina.
What is VBLSM
Vocal based lesion symptom mapping is a way of seeing which part of the brain is damaged and comparing this damage to cognitive function using cog tasks. Need to be experienced and trained for accuracy.
4 stages,
Delineate lesion
Normalise scan to size of 3d vocal box
Loop the voxels, dividing with and without lesion on scans
Compare pts with and without using cog tests
Use ANCOVA as volume of lesion can be calculated
No 2 people are the same
Diaschesis can happen with symptoms, a brain damaged region away from the lesion may affect symptoms
Describe fear conditioning
Pavlovian response - US = shock
UR = fear
NS = sound
CS = fear with sound
Brain associates and reinforces events, used to guide directed behaviour
What does the amygdala do?
The amygdala is part of the limbic system, it is a cluster of neurones in an almond shape in both hemispheres deep within the temporal lobe. It is part of the fear response network.
A threat is seen, spider, aargh, message to amygdala via the occipital lobes visual cortex, this triggers a body response: thalamus, amygdala, periaquaductal grey, decides how to respond, triggering the HPA axis, hypothalamus, pituitary gland releases hormones to the adrenal gland which releases norad, adrenaline and cortisol. Fight or flight response. it is thought the pre frontal cortex hijacks the amygdala when it perceives a threat, that may not be there. Research has focused on fear as other emotions are subjective, pos emotions are also induced by the amygdala. LeDoux 2016
What does good sleep before and after learning do
Increases information transfer from hippocampus to the cortex (Rasch and Bom, 2013)
What does the pineal gland do
Produces melatonin, released at dusk
What is glymphatic flow
The waste that is taken away by the astrocytes and is done when sleeping (Liffe et al. 2012)
What effect does sleep have on myelin , Cirelli (2004)
Increases synthesis and maintenance of myelin and cell membranes
Matt walker (2018) says what about his study findings on sleep deprivation
Sleep correlations reduce memory when sleep deprived.
Natural killer cells 70% are depleted on less than four hours sleep
Short sleep is an all cause mortality
Less sleep more beta amyloid and tau build up, causes of alzheimers
