Task 5 - Senosrimotor s

Question 1

hierarchially organized

Answer 1

information flows from highest level (association cortex) to the lowest level of system (muscles)

Question 2

efferent neurons

Answer 2

send impulses from the CNS to our limbs and organs

Question 3

afferent neurons

Answer 3

receive information from sensory organs (eye, skin) and transmit this input to CNS

Question 4

functional segregation

Answer 4

each neural structure performs a different functio

Question 5

motor output guided by sensory output?

Answer 5

-Our body has mechanisms to monitor what is coming in (sensory) and what it goes out in response (motor).

Question 6

Sensory feedback

Answer 6

feedback within sensory systems where info from sensory receptors is returned along afferent pathways -> so brain can monitor consequences of actions

Question 7

Ballistic movements

Answer 7

Occur too fast to be modified by feedback

Question 8

sensorimotor learning

Answer 8

when we first learn, each individual response is performed under conscious control -> after practice, responses become more organized and you do them without conscious regulation

Question 9

electromyography EMG

Answer 9

electrical recording of muscle activity

Question 10

fast twitch muscle fibers

Answer 10

• muscle that contracts rapidly but fatigues quickly

- quick movements like jumping ->contract and relax quickly

Question 11

slow twitch muscle fibers

Answer 11

muscle fiber that contacts slowly and weaker but able to sustain contraction longer
-movements like walking

Question 12

Sensorimotor association cortex

Answer 12

top of sensorimotor hierarchy and divided into two areas

1. posterior parietal association cortex
2. dorsolateral parietal association cortex

Question 13

posterior parietal association cortex

Answer 13

directing behaviour by providing spatial information

• directing attention ->receives input from more than one sensory input (visual, auditory and somatosensory system)
• most of the output goes to the secondary (non-primary) motor cortex or to the dorsolateral prefrontal association cortex

Question 14

what happens if we damage posterior parietal cortex?

Answer 14

a variety of deficits, deficts in the perception and memory of spatial relationships

• in accurate reaching and grasping
• in the control of eye movement
• attention

Question 15

Aprexia

Answer 15

difficulty making specific movements when they are requested to do so, if they don’t think about it they are able to move

Question 16

Contralateral neglect

Answer 16

Disturbance of ability to respond to stimuli on side of body opposite to side of brain lesion

Question 17

Dorsolateral prefrontal association cortex

Answer 17

location: frontal cortex, anterior to precentral gyrus
- identify and respond to objects
- iINTERACTS with posterior parietal to initiate voluntary movements
- METAMEMORY (self-awareenss of memo)

Question 18

Dorsolateral prefrontal a.c. input

Answer 18

receives info from posterior parietal cortex

Question 19

Dorsolateral prefrontal a.c.

output

Answer 19

sends info to areas of secondary motor cortex

Question 20

Dorsolateral neurons

Answer 20

send the info out

• their activation depends on location and characteristic pf objects and the combi of the two
• fire first in response

Question 21

what happens if we damage dorsolateral prefrontal cortex

Answer 21

Confabulation : unable to distinguish are true memory from a false or inappropriate for cortext (bcs dorsolat is important for meta memory)

Question 22

Secondary motor cortex

Answer 22

location: posterior part of frontal gyro
function: storage of programs of motor activity from past experience
- control of movement

Question 23

primary direction of information flow

Answer 23

in sensory systems, information mainly flows up the hierarchy
; in the sensorimotor system, information mainly flows down

Question 24

electrical stimulation of PPAC

Answer 24

causes patients to experience the intent to perform a particular action

Question 25

what causes apraxia?

Answer 25

unilateral damage to the left posterior parietal lobe or its connections; would have difficulty making specific movements

Question 26

what happens with contralateral neglect?

Answer 26

left side of their world down not exist. fail to appreciate that they have a problem

Question 27

three major areas of secondary motor cortex

Answer 27

premotor, supplementary, and cingulate

Question 28

supplementary motor area

Answer 28

wraps over the top of the frontal lobe and extends down its medial surface into its longitudinal fissue

Question 29

Primary motor cortex

Answer 29

``` location: precentral gyrus of frontal lobe function : execution of body movements (hand and mouth)t ```

Question 30

premotor cortex

Answer 30

runs in a strip from the supplementary motor area to the lateral fissure

Question 31

cingulate motor areas

Answer 31

three small areas in the cortex of the cingulate gyrus

Question 32

motor homunculus

Answer 32

motor cortex is organized in a somatotopic manner; according to a body map

Question 33

damage to primary motor cortex

Answer 33

small lesions often have minimal effects; large lesions may disrupt a patient's ability to move one body part independently of others

Question 34

Mirrorneurons

Answer 34

neurons that fire when an individual performs a particular goal-directed hand movement or when she or he observes the same goal-directed movement performed by another; neural basis of learning by imitation

Question 35

when are mirror neurons active

Answer 35

up to 50% of neurons in sensorimotor cortex are active when imagining or watches an action ; body does not move when mirror neurons fire because the overall level of activity is lower than needed

Question 36

basal ganglia and cerebellum

Answer 36

interact at many levels of the sensorimotor hierarchy; coordinate and modulate; may permit maintenance of visually-guided responses despite cortical damage

Question 37

cerebellum

Answer 37

- 10% of brain mass and 50% of brain neurons | - is organized stematically in lobes columns and layers

Question 38

cerebellum involved in

Answer 38

timing, fine-tuning, and motor learning

Question 39

basal ganglia

Answer 39

act as a filter, blocking plans that are inappropriate. | -Example – Inhibiting automatic, environment-triggered responses such as grasping food.

Question 40

BASAL GANGLIA input

Answer 40

primary motor cortex primary somatosensory cortex substania nigra- dopamine

Question 41

Basal ganglia output

Answer 41

Primary motor cortex supplementary motor area premotor cortex

Question 42

damage to basal?

Answer 42

- Parkinson’s disease – Problems controlling speech, movement and posture. - Huntington’s disease – Disorder in which nerve cells in certain parts of the brain waste away, degenerate. - Wilson’s disease – Disorder causing too much copper in the body’s tissues. - Dystonia – Muscle tone problems. - Progressive supranuclear palsy – Movement disorder from damage to certain nerve cells in the brain. - ->>Mostly movement disorders

Question 43

withdrawal reflex

Answer 43

- the contraction of a muscle when a painful stimulus is encountered - NOT monosynaptic and it takes longer - > does not go to the brain

Question 44

1.Dorsolateral corticospinal tract

Answer 44

direct contralateral distal muscle -> finger tips, fine momvement -towards the back and on the side

Question 45

2.Dorsolateral corticorubrospinal tract

Answer 45

indirect contralateral rubro= stop at red nucleus distal muscle -> finger tips, fine momvement

Question 46

1.Ventromedial corticospinal tract

Answer 46

-direct pathway -towards the belly and medial Ipsilateral -proximal muscles-> legs, arm, shoulders

Question 47

2.Ventromedial cortico-brainstem-spinal tract

Answer 47

``` indirect -stops at the brainstem -towards the belly and medial Ipsilateral -proximal muscles-> legs, arm, shoulders ```

Question 48

Tectum

Answer 48

receives auditory and visual info about spatial info

Question 49

vestibular nucleus

Answer 49

receives info about balance from receptors of inner ear

Question 50

reticular formation

Answer 50

contains motorprogams that regulate complex movements like walking swimming jumping

Question 51

motor nuclei

Answer 51

controls muscle of face

Question 52

similarity of the two pathways

Answer 52

- Both have two major tracts, 1.one whose axons descend directly to the spinal cord 2. another whose axons synapse in the brain stem on neurons that in turn descend to the spinal cord

Question 53

sensorimotor spinal circuits

Answer 53

- lowest level -> hierarchy - consisting of the spinal circuits and the muscles they control - circuits are capable of independent functioning

Question 54

motor unit

Answer 54

- also called moton neuron | - motor in the brain or spinal cord that transmits motor messages, stimulating a muscle or gland

Question 55

motor end plate

Answer 55

- Acetylcholine, which is released by motor neurons at neuromuscular junctions - >activates it on each muscle fiber and causes the muscle to contract.

Question 56

Flexors

Answer 56

act to bend or flex a joint (=biceps)

Question 57

Extensors

Answer 57

Act to straighten or extend a joint (=triceps)

Question 58

Synergistic muscles

Answer 58

-Two muscles whose contraction produces the same movement

Question 59

Antagonistic muscles

Answer 59

Two muscles that act in opposition (biceps – triceps).

Question 60

Isometric contradiction

Answer 60

Activation of a muscle that increases the tension that it exerts on two bones without shortening and pulling them together

Question 61

Dynamic contradiction

Answer 61

shortening the muscle and pulling it together | -muscle tension can be increased by increasing number of neurons in its motor pool that are firing

Question 62

skeletal muscles

Answer 62

are attached to bones by tendons, and they produce all the movements of body parts in relation to each other ->voluntary control

Question 63

smooth muscles

Answer 63

consists of narrow spindle-shaped cells with a single, centrally located nucleus -not voluntary