S3C5 (2.0) Flashcards
(101 cards)
What is a UMN lesion?
Lesion along the descending motor pathways
Typically before the anterior horn cell of the spinal cord or motor nuclei of the cranial nerves
What is a LMN lesion?
Lesions anywhere along the nerve fibres between the ventral horn of the spinal cord and relevant muscle tissue
Which motor neuron lesion would lead to atrophy and fasciculations?
Lower motor neuron
What are fasciculations?
A twitching of muscle caused by involuntary, asynchronous contraction of muscle fascicles within a single motor unit
What are the characteristics of UMN lesion?
Central paresis (spastic paresis): pyramidal tract signs
Increased tone, spasticity and clonus
Decreased power
Increased reflexes Increased muscle tone
What are the characteristics of LMN lesion?
Peripheral paresis (flaccid paresis): absent pyramidal tract signs
Decreased tone
Decreased power in single muscle fibres
Decreased reflexes / areflexia
What effect does a UMN lesion have on the bladder?
Detrusor hyperreflexia and detrusor/external sphincter dyssynergia (A disturbance of muscular coordination that causes uncoordinated and abrupt movements)
What effect does a LMN lesion have on the bladder?
Overflow incontinence - An involuntary leakage of urine secondary to overfilling of the bladder
Which motor neuron lesion would lead to the babinski sign and pronator drift?
Upper motor neuron
What is clonus?
Involuntary contractions and relaxations of muscles in response to stretching
What causes spasticity?
Removal of inhibitory influences exerted by the cortex on the postural centres of vestibular nuclei and reticular formation
What is memory?
The mental capacity to store and later recall or recognise event that were previously experienced
Memory is an active mental system the received, encodes, modifies and retrieves info
What is recall?
Reproducing info to which you were previously exposed to without linked stimulus
What is recognition?
Uses a stimulus to retrieve something you have seen or heard before (cue dependent)
What did Bartlett say on the constructive nature of memory?
Serial reproduction of stories
People who perform a memory task do no simply repeat what they have learned but actively reconstruct what they remember
What are the main models of memory?
Multistore model
Working memory theory
Levels of processing model
What are the 3 types of memory in the multistore model?
Sensory
Short term
Long term
What is sensory memory in the multistory model?
Lasts about 0.1 to 0.5 of a second
Holds quite an accurate and complete representation
Encoding is sense-specific - different sensory memory stores for the different sensory modalities
What is short term memory in the multistory model?
Lasts seconds to minutes
Involves frontal and parietal lobes
Capacity is limited to 7 (the rule of 7) - chunking can improve capacity
Uses an acoustic engram
What is long term memory in the multistory model?
Duration potentially unlimited
Much greater capacity
Activity spread throughout brain but hippocampus is essential to consolidation
Sleep essential to consolidation and especially 7 days for emotional processing involving the amygdala
Mainly semantic encoding
What are the different elements of the working memory theory?
Central executive
Phonological loop
Visuo-spatial sketchpad
What is the central executive of the working memory theory?
Allocates limited attention resources to other components of working memory. Performs cognitive tasks such as problem solving
What is the phonological loop of the working memory theory?
Stores auditory info by silently rehearsing sounds and words in a continuous loop - the articulatory process
What is the visuo-spatial sketchpad of the working memory theory?
Stores visual and spatial info -engages when performing spatial tasks and visual ones