PHYSIOL previous exam Q's

Question 0

which brain structure inhibits muscle tone through out whole body?

Answer 0

basal nuclei

Question 1

which brain structure initiates all voluntary movement?

Answer 1

cerebral cortex

Question 2

which brain structure that damage to this structure results with a resting tremor?

Answer 2

basal nuclei

Question 3

which brain structure contains centres for respiration, heart and blood vessel function, and many digestive activities?

Answer 3

brain stem

Question 4

which brain structure helps monitor and coordinate slow, sustained contractions, especially those related to balance and posture?

Answer 4

basal nuclei

Question 5

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”?

Answer 5

cerebellum

Question 6

which brain structure accomplishes final sensory perception?

Answer 6

cerebral cortex

Question 7

what lobes are responsible for initial processing of visual input?

Answer 7

occipital

Question 8

somatosensory cortex is the site for initial cortical processing of sensory and proprioceptive input, where is it located?

Answer 8

parietal lobes

Question 9

what serves as a relay station?

Answer 9

thalamus

Question 10

what motor area/s are involved in simple motor task?

Answer 10

primary motor cortex - no planning

Question 11

what motor area/s are involved in complex motor task?

Answer 11

primary motor cortex

supplementary motor cortex

Question 12

what motor area/s are involved in imagined complex motor task?

Answer 12

supplementary motor area

- no movement, just thought(planning)

Question 13

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?

Answer 13

• this would mean Ach could not bind to receptors
• so channels would no open
• blocking occurrence of action potentials in the muscle fibres

Question 14

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?

Answer 14

draw hill diagram haha

Question 15

if it asks about firing signals what do you draw?

Answer 15

contractile pattern(eg. single, summation and tetanus)
compared with action potential firing underneath

Question 16

why does increase frequency of AP firing make contractions summate?

Answer 16

increased availability of Ca2+ in cytosol

Question 17

what is a feedforward control strategy? provide an example of a feedforward task in everyday movements:

Answer 17

• 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]

Question 18

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:

Answer 18

muscle length - muscle spindle 
muscle force - golgi tendon organ
joint angle - articular receptor 
touch - cutaneous receptor 
vision - eye

Question 19

what sensor senses muscle force?

Answer 19

golgi tendon organs

Question 20

what sensor senses muscle length?

Answer 20

muscle spindal

Question 21

what sensor senses joint angle?

Answer 21

articular receptor

Question 22

what sensor senses touch?

Answer 22

cutaneous

Question 23

what is the purpose of efferent gamma nerve in muscle spindle?

Answer 23

to alter sensitivity of the muscle spindle so that it can detect changes in length when shortened

Question 24

define what is meant by central fatigue. describe 4 potential sites of central fatigue:

Answer 24

progressive reduction in voluntary activation of muscle

1. input to motor cortex
2. descending CNS drive
3. activation of motor units/neurons
4. neuromuscular transmission

Question 25

true or false: damage to the parietal lobe can lead to visual neglect?

Answer 25

true

Question 26

true or false: spinocerebellum plays role in planning and initiating voluntary activity by input to cortical motor areas?

Answer 26

true

Question 27

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:

Answer 27

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

Question 28

damage to cerebellum:

Answer 28

• delay in initiating movement
• impaired coordination
• irregular movements
• action tremor

Question 29

damage to basal ganglia:

Answer 29

• resting tremor
• slowness
• rigidity
• deficits in APAs

Question 30

list 3 representations in the cortex that illustrate the concept of map strategies for the organisation of info flow:

Answer 30

somatosensory homunculus
retinotopic
tonotopic
whisker barrels

Question 31

cerebellum uses sensory feedback to correct errors between:

Answer 31

intent and performance

Question 32

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:

Answer 32

true