Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

understanding the brain > Control of movement > Flashcards

Control of movement Flashcards

week 7

1
Q

what is a neuromuscular junction?

A

A synapse between a motor neuron and a msucle fibre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what ar ethe 5 steps of a nuromuscular junction?

A
  1. AP in motor neuron
  2. resease of Ach
  3. EPSP in muscle fibre (endplate potential)
  4. AP in muscle fibre
  5. Contraction (twitch) occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are muscle spindals?

A
  • Fibrous capsules containing specialised muscle fibres
    • Detects change in muscle length
      ○ Contracts of spindles to keep axons within their working range
      ○ How quickly it is happening (is detected)
      ○ Keeps length under control
    • Contracts of spindle poles to keep 1a axons within working range
    • Fire rapid impulses to protect you
    • E.g.: rolling ankle- requires quick impulses to protect the ankle from over stretching
      → muscle contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are golgitendon organs?

A
  • Located at the junction of muscle and tendon
    • Tendon= when the muscle joins the bone.
    • Innervated 1b sensory axons
    • Monitors muscle tension (tendon stretch)
      ○ How much tension is the muscle under
      →muscle inhibition- protective mechanism to avoid the use of the injured joint
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are monosynaptic reflexes?

A
  • Only uses one synapse
    • Uses reflex arc
    • Patellar tendon= most common (stretch reflex)
      1. Activation of a receptor (in quads)
      2. Activation of a sensory afferent neuron
      3. Integrating centre and information processing (only in the cell body of the post synaptic cell- motor neuron)
      4. Activation of a motor or efferent neuron
        Response by the effector neuron (causes kicking neuron)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is a polysynaptic reflex?

A
  • Uses 2 or more synapses
    • Withdrawal reflex (touching something hot with hand)
      ○ At spinal cord (so it is quick)
      ○ Signal is sent to brain to prevent pain and aid correctly
    • Uses reflex arc (has modifications)
      1. Receptor
      2. Afferent neuron (synapses with the interneuron)
      3. Interneuron (sends impulse to the bicep to contract and move the hand away)
      4. Efferent neuron
      5. Effector
        Inhibitory neuron (sends impulse to triceps to ensure it doesn’t contract to lengthen arm)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are reflexes and why are they important?

A
  • muscular movements
  • they control human breathing, movements and other functions vital to life
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the cortical movements involved in the control of movement?

A
  • The primary motor cortex (M1)
  • Parts of Frontal association cortex:
    ○ Supplementary motor area (SMA)
    Premotor cortex (PMA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the primary motor cortex?

A

primary commander for movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

why is the primory motor cortex important?

A

involved in the execution of movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how is the primary motor cortex organised?

A
  • somatotopically: motor homunculus
    ○ Disproportional amount of cortical area needed for our hands and mouths as they do more complex movements.
  • Each part of the body is located with a specific region of the primary motor cortex.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where is the primary motor cortex located?

A

at the back of the frontal lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the inputs for the primary motor cortex?

A
  • Frontal association cortex
  • Primary somatosensory cortex (S1)
    ○ S1 neurons in particular location send info to primary motor cortex area responsible for muscles in that body part
    ○ Rapid feedback to the motor system.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the function of the primary motor cortex?

A

to generate signals to execute movement in a specific region of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the supplementary motor area?

A
  • Learning and planning of behaviours consisting of sequences of movements
    ○ E.g.: dancing
  • Damage disrupts ability to execute well-learned sequences of responses
  • Pre-SMA is associated with the (perception of) control of spontaneous movement
  • Stimulation of SMA and Pre-SMA provokes the urge to make a movement or the anticipation that a movement will occur
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the premotor cortex involved in?

A
  • learnign and executing of complex movements
  • guided by sensory information
  • contains mirror neurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are mirror neurons?

A
  • Motor command neurons: In front of brain (frontal lobe)
    ○ Neurons fire if someone preforms a specific action
    ○ Fire when someone does something Infront of us
  • Imitation of an act (requires brain to adopt other person’s point of view)
  • Depends on culture and civilisation
    ○ Sudden emergence of evolutionary brain system
    § Spread vertically and horizontally across people and generations.
  • Mirror neurons of touch: empathises if someone else is being touched (and if we are being touched)
    ○ Don’t feel touch sensation due to touch and pain receptors relaying to brain to tell us we aren’t being touched.
  • If arm is numbed and has no feeling- others touch is in your consciousness (joined by neurons)- believe you are being touched.
  • Imitations and immolations.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the basal ganglia?

A
  • part of the tenecephalon
  • important for the control of voluntary movement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

whci part of the basal ganglia recieves the input?

A

the striatal nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what does the striatal nuclei recieve input about?

A
  • primary motor cortex
  • primary somatosensory cortex
  • substantia nigra
    • other cortices
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where is the output information from the basal ganglia recieved?

A
  • primary motor cortex
  • supplementary motor cortex
  • premotor cortex
  • motor nuclei of the brainstem
22
Q

what is huntington’s disease?

A
  • Hereditary (passed on) disease caused by degeneration of the striatal neurons
    ○ Loss of inhibition exerted on globus pallidus (middle of the lentiform nucleus in the brain)
    ○ A cluster of neurons in the basal ganglia
23
Q

what are the symptoms of huntington’s disease?

A
  • Uncontrollable jerky limb movements
  • Impaired ability to cease movements
  • Cognitive and emotional change
    Slow processing
    Difficulty in learning new information
    Hard to pick up on others’ emotions
    Depression/lack of emotion
24
Q

between what ages are people ususally diagnosed with huntingtons disease?

A

30-50 years old

25
Q

what is mutant huntington protein?

A

causes neurons to die prematurely- causing huntingtons.

26
Q

what is the cerebellum?

A

part of the metencephalon
“little brain”

27
Q

how many hemispheres does the cerebellum control?

A

2

28
Q

how does the cerebellum function?

A

ipsilaterally- affects the same side of the body

29
Q

how is the cerebellum connexted to the brainstem?

A

via the cerebellar peduncles

30
Q

what percentage of brain neurons does the cerebellum accunt for?

A

50%

31
Q

what is the function of the cerebellum?

A
  • Involved in motor control functions
  • Smooths and integrates ongoing movement
  • Important for independent rapid skilled limb movements
  • Important for postural reflexes
  • Integrates movement sequences
  • Partly responsible for motor learning
32
Q

what inputs information to the cerebllum?

A
  • vestibular, auditory and visual systems
  • motor and somatpsensory cortices
33
Q

where does the cerebellum output its information to?

A

every major motor brain structure

34
Q

what happens to an individual if they have a dmagaed cerebellum?

A
  • Cerebellar Ataxia = lack of coordination of movements
    ○ Can manifest as difficulty walking, particularly with narrow base (one foot in front of the other)
35
Q

what are the possible causes of a damaged cerebllum?

A

stroke, haemorrhage, alcoholism, tumour, physical trauma, chronic degenerative conditions

36
Q

what is an intention tremor?

A
  • involuntary, rhythmic muscle contractions (oscillations) that occur during a purposeful, voluntary movement.
    ○ slow tremor of the extremities that occurs at the end of a purposeful movement (e.g., touching a finger to the tip of nose)
    ○ Jerky, poorly coordinated, exaggerated movements
37
Q

what is reticulr formation?

A

includes a large number of nuclei in the brainstem (midbrain, pons and medulla oblongata)

38
Q

what is reticular formation importnat for?

A
  • a variety of motor functions:
    ○ Regulates muscle tone (via gamma motor neurons)
    ○ Controls (semi)automatic responses (e.g. respiration, coughing, vomiting)
    ○ Controls posture
    ○ Plays a role in locomotion- ability to move from one place to another
39
Q

what are the two major descending motor pathways/ tracts?

A
  • lateranl pathways
  • ventromedial pathways
40
Q

what do lateral pathways control?

A

voluntary independent movement of distal muscles
(e.g.: forearm, hand, finger)

41
Q

where do lateral pathways originate?

A

in the cortex

42
Q

how many tracts are lateral pathways composed of and what do they control?

A

3 tracts:
1. Lateral corticospinal
lower leg and foot
2. Corticobulbar
Face, neck, eye, tongue
3. Rubrospinal
Fore arm, hands (independent from trunk movement)

43
Q

where do ventromedial pathways originate?

A

in the brain stem

44
Q

what does the ventromedial pathathways control?

A

automatic movements of proximal and axial muscles (e.g. movements related to posture and locomotion)

45
Q

how many tracts is the ventromedial pathway composed of?

A

4

46
Q

what are the 4 tracts of the ventromedial pathway?

A
  1. Ventral corticospinal tract- involved in controlling proximal muscles, like those of the trunk
  2. Vestibulospinal tract- maintain equilibratory reflexes from the input of the vestibular apparatus
  3. Tectospinal tract- involved in orienting the eyes and the head towards sounds as part of the auditory and visual reflex
  4. Reticulospinal tract- descending tract present in the white matter of the spinal cord, originating in the reticular formation
47
Q

What structures send sensory feedback to motor neurons?

A

muscle spindles

48
Q

Give an example of a monosynaptic reflex:

A

patella tendon reflex

49
Q

What body parts havs a larger area dictated to it as part of somatotopic organisation?

A

lips, hands (fingers) and feet (toes)

50
Q

What are mirror neurons are thought to be involved it?

A

contagious yawning

51
Q

What connects the cerebellum to the brainstem?

A

cerebellar peduncles

52
Q

A man attends a clinic with a series of symptoms. Which of his symptoms cannot be explained by damage to his cerebellum?

A

difficulty yawning

understanding the brain (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions