PHYSIOL previous exam Q's Flashcards
which brain structure inhibits muscle tone through out whole body?
basal nuclei
which brain structure initiates all voluntary movement?
cerebral cortex
which brain structure that damage to this structure results with a resting tremor?
basal nuclei
which brain structure contains centres for respiration, heart and blood vessel function, and many digestive activities?
brain stem
which brain structure helps monitor and coordinate slow, sustained contractions, especially those related to balance and posture?
basal nuclei
which brain structure is concerned with coordination of motor activity initiated by higher brain centers; compares the “intentions” of the higher centres with the “performance” of the muscles, and corrects any “errors”?
cerebellum
which brain structure accomplishes final sensory perception?
cerebral cortex
what lobes are responsible for initial processing of visual input?
occipital
somatosensory cortex is the site for initial cortical processing of sensory and proprioceptive input, where is it located?
parietal lobes
what serves as a relay station?
thalamus
what motor area/s are involved in simple motor task?
primary motor cortex - no planning
what motor area/s are involved in complex motor task?
primary motor cortex
supplementary motor cortex
what motor area/s are involved in imagined complex motor task?
supplementary motor area
- no movement, just thought(planning)
the venom of certain poisonous snakes binds to acetylcholine receptor sites on the motor end-plate membrane. what would the effect of the venom be on neuromuscular transmission?
- this would mean Ach could not bind to receptors
- so channels would no open
- blocking occurrence of action potentials in the muscle fibres
draw a fully labelled diagram of the length tension relationship of skeletal muscle. why does the muscle tension vary with a change in muscle length?
draw hill diagram haha
if it asks about firing signals what do you draw?
contractile pattern(eg. single, summation and tetanus) compared with action potential firing underneath
why does increase frequency of AP firing make contractions summate?
increased availability of Ca2+ in cytosol
what is a feedforward control strategy? provide an example of a feedforward task in everyday movements:
- rapid movement that takes place without feedback from sensory receptors involving change in centre of gravity
eg. reaching our to catch a falling object [before it is caught]
describe 5 different types of feedback(SENSORS) that contribute to the performance of voluntary movement. Include in your answer the receptor that is responsible for each type of feedback:
muscle length - muscle spindle muscle force - golgi tendon organ joint angle - articular receptor touch - cutaneous receptor vision - eye
what sensor senses muscle force?
golgi tendon organs
what sensor senses muscle length?
muscle spindal
what sensor senses joint angle?
articular receptor
what sensor senses touch?
cutaneous
what is the purpose of efferent gamma nerve in muscle spindle?
to alter sensitivity of the muscle spindle so that it can detect changes in length when shortened
define what is meant by central fatigue. describe 4 potential sites of central fatigue:
progressive reduction in voluntary activation of muscle
- input to motor cortex
- descending CNS drive
- activation of motor units/neurons
- neuromuscular transmission
true or false: damage to the parietal lobe can lead to visual neglect?
true
true or false: spinocerebellum plays role in planning and initiating voluntary activity by input to cortical motor areas?
true
a repeated bout of the same eccentric exercise results in reduced symptoms of damage and soreness compared with initial bout. Describe 3 theories that are thought to contribute to the repeated bout effect:
neural theory: increased motor unit activity through synchronisation of recruitment
cellular theory: strengthening of cell membranes and additional longitudinal sarcomeres to reduce descending limb of length-tension curve
connective tissue theory: increase of CT or filament remodelling = increased resistance to tears
damage to cerebellum:
- delay in initiating movement
- impaired coordination
- irregular movements
- action tremor
damage to basal ganglia:
- resting tremor
- slowness
- rigidity
- deficits in APAs
list 3 representations in the cortex that illustrate the concept of map strategies for the organisation of info flow:
somatosensory homunculus
retinotopic
tonotopic
whisker barrels
cerebellum uses sensory feedback to correct errors between:
intent and performance
T/F: lipid bilayers of the plasma membrane create a hydrophobic barrier that traps organic anions inside cell where they provide an osmotic counter balance to the high concentration of Na+ outside cell:
true
