Neuromotor L2 Flashcards
1
Q
What are the 4 reasons why posture adjustment is needed?
A
- Balance
- Stabilize- Eye tracking
- Alignment of head and body WRT gravity
- Protective
2
Q
What are 4 systems used? (sensory input to brainstem motor centre) Drive coordinated activity
A
- Proprioceptors
- Vision (eyes connecting to recticular formation)
- Vestibular apparatus
- Inner ear to lateral vestibular nucleus
3
Q
What are the 2 mechanisms of postural adjustment?
A
- Feed Forward (anticipatory) pre-programmed -experience -unlike reflexes - scale of response refined with experience- Motor movements become refined as you get experience (from a baby- not coordinated –> adult- coordinated)
- Feed Back (compensatory) - like reflexes = rapid, stereotyped & show a space time organisation- Disturb something want to come back to original position (homeostasis)
4
Q
What is feed forward?
A
(anticipatory) pre-programmed -experience -unlike reflexes - scale of response refined with experience
Motor movements become refined as you get experience (from a baby- not coordinated –> adult- coordinated)
5
Q
What is feed back?
A
(compensatory) - like reflexes = rapid, stereotyped & show a space time organisation
Disturb something want to come back to original position (homeostasis)
6
Q
What are 6 things that postural adjustment relies on?
A
- Afferent (sensory) input to trigger responses
- Proprioceptive
- Vestibular
- Eyes
- Sensory cutaneous
- Experience
7
Q
What are 3 examples of postural adjustments?
A
- MOVABLE PLATFORM (1st trial, and Repeated trials)
- Coordinated Arm and Leg movements during a voluntary movement
- Falling forward while walking up steps
8
Q
What are the automatic postural responses change with biomechanical conditions?
A
9
Q
What does movable platform (1st trial, and repeated trials)?
A
10
Q
What is the 3 activity from source of disturbance up (caudal to rostral) for feed backwards ?
A
- Ankle (gastroc)
- Hamstrings
- Spinae rectus
11
Q
What are 3 characteristics of feed forward?
A
- If done 7 times –> body sways least –> don’t want to fall forward and knows whats goingt to happen (anticipating)
- Activation of these muscle potentials are activated quicker but less of them (because not going as forward eg. sway)
- Can also get antagonist activity. Why? Bracing –> co-contract –> freeze like a statue
12
Q
What makes feed backward and forward worst?
A
- blindfold –> loss of vision
- Viral infection to inner ear
13
Q
What does falling forward while walking up steps?
A
- Motor output to the brachial region
- Hands will go out and alignment with head and neck with gravity
- Always try to keep their head still to the rest of their body. Why?
- As part of a learned behaviour that is now integrated into their motor control –> done as a reflex Aging parent with infection in inner ear = stumbling all over the place
14
Q
What are the 2 key points illustrated about postural mechanisms?
A
- Feed Forward to anticipate a loss of posture
- When loss of posture - feed back mechanisms produce a rapid corrective response (Feedback) Another example – where feed forward mechanism is operating
15
Q
What are the 2 characteristics which the Head- Neck - Eyes are controlled by Vestibular & Neck Reflexes?
A
- Vestibular Reflexes triggered by changes in head
- Neck Reflexes triggered by bending-turning of Neck 1 & 2 produce coordinated effects in limb muscles
16
Q
What are the 4 centres Brain Stems Motor Centers involved in Posture-Movement?
A
- Vestibular Nuclei (4 parts)
- Reticular Formation (2 parts)- Information from eyes and other systems –> control eye movements
- Superior Colliculus- Neuromotor sensory intergrator —> input from other brainstem motor centres and output to motor neurons (particularly in head, neck and eyes)
- Red Nucleus- Helps control lower motor neurons in the hands and feet
17
Q
What is the function of the Reticular Formation?
A
Information from eyes and other systems –> control eye movements
18
Q
What is the function of the superior colliculus?
A
Neuromotor sensory intergrator —> input from other brainstem motor centres and output to motor neurons (particularly in head, neck and eyes)
19
Q
What is the function of red nucleus?
A
Helps control lower motor neurons in the hands and feet
20
Q
What are 4 characteristics of the vestibular nuclei (Vestibulo-spinal Tract)?
A
- Receive Vestibular Afferent inputs - signal position of Head WRT Gravity
- Lateral = maintaining stance – proximal muscles of limbs- Also get Purkinje neurons from the cerebellum Also via III, IV and V crainal nerves – eye movts that can maintain fixation on a target. (Lateral vestibular tract)
- Medial &Superior - coordination of eye with head movts (neck muscles) Medial vestibular tract
- Inferior - integrates afferents and cerebellum to higher centers
21
Q
What are 5 functions of reticular formation (reticulo-spinal tracts)?
A
- Collection of inter-neurons in Brain stems 2 parts
- Helps in maintaining posture
- Important in the feed forward mechanisms of postural control
- Receives connections from pre-motor cortical regions.
- Premotor coordination of lower motor neuron pools
22
Q
What are 2 characteristics of reticular formation (reticulo-spinal tracts)?
A
- Medullary (Lateral) Reticular Formation (Lat. Reticulo-spinal tract) = inhibitory to Extensor Muscle tone
- Pontine (Medial) Reticular Formation (Medial Reticulo-spinal tract) = facilitates extensor muscle tone
23
Q
What are 4 characteristics of superior colliculus?
A
- Sensorimotor integrator centre - Many inputs
- Role in Eye-Head and Orientation movements - Many Outputs
- Sensor-motor intergrator - Inputs = Visual, Afferent (priopceptor - Muscle Spindle, Golgi T.O , Joint Rs) and Cortical. Outputs = Reticular formation to motoneurons of ocular motor nucleus) and Cervical motoneurons of head and neck.
- It controls saccadic eye movements thought to be under control from the cortical inputs.
24
Q
What does red nucleus (Rubro spinal tract)?
A
Role in Motor learning in Humans function is minor
25
What are 2 characteristics of cerebellum?
* 10% Brain vol. 50% of CNS neurons
* \* Functions as a COMPARATOR = intended movt with performance of movt &makes adjustments
26
What do the tracts look like?
27
What does the cerebellum act as?
COMPARATOR = intended movt with performance of movt , & makes adjustments
28
What are 3 mechanisms for function of the cerebellum?
1. Internal feedback (corollary discharge)
2. External feed back (reference)
3. Input to lower motor neurons 1 & 2 allow for comparisons, & 3 for correction.
* Gross appearance.
29
What does the cerebellum look like?
30
What are the 3 cortex functional subdivisions?
1. Cerebrocerebellum (lateral hemisphere) Function initiation, planning of movts, and timing of movts Input - cortical afferents Output - Dentate Nucleus to Motor and Pre-motor cortices.
2. Spinocerecellum (2 parts)
1. Vermis Function control of axial and proximal muscle, ongoing execution of movt. Input auditory, visual & vestibular Output Fastigal Nucleus.
2. Intermediate part of hemisphere Function control of distal muscles, ongoing execution of movt. Input Spinal afferents (distal parts) Output Interposed Nucleus Outputs via the Reticular Formation - to motor execution in the spinal cord.
3. Vestibulocerebellum Function axial control & Vestibular reflexes (balance and eye movements). Input Vestibular apparatus Output Lateral Vestibular N.
31
What is Cerebrocerebellum (lateral hemisphere)?
Function initiation, planning of movts, and timing of movts Input - cortical afferents Output - Dentate Nucleus to Motor and Pre-motor cortices.
32
What are the 2 parts of the Spinocerecellum?
1. Vermis Function control of axial and proximal muscle, ongoing execution of movt. Input auditory, visual &vestibular Output Fastigal Nucleus.
2. Intermediate part of hemisphere Function control of distal muscles, ongoing execution of movt. Input Spinal afferents (distal parts) Output Interposed Nucleus Outputs via the Reticular Formation - to motor execution in the spinal cord.
33
What is the Vestibulocerebellum?
Function axial control & Vestibular reflexes (balance and eye movements). Input Vestibular apparatus Output Lateral Vestibular N.
34
The activity out of neurons within a deep cerebellar nucleus is governed by a combination of both excitatory ____ and ____ fiber inputs and inhibitory Purkinje neuron inputs. What does this look like?
Climbing; mossy
35
What are the 3 Cerebellar Dysfunction?
1. Hypotonia - a diminished resistance to passive limb displacements. Eg after a knee jerk produced by a tap of reflex hammer, the leg normally comes to rest after the jerk. In patients who has cerebella disease the leg may oscillate up to 6 to 8 times before coming to rest.
2. Ataxia or lack of coordination. - delay in initiating responses - errors in the range of movement (dysmetria), and errors in the rate and regularity of movements. Dysdiadochokinesia an irregular pattern of alternating movements
3. Tremor. Most marked at the end of a movement, when the patient attempts to stop the movement by using antagonist muscles.
36
Vestibulocerebellum Receives input from ______ And projects directly To Vestibular Nuclei (lat and medial) Lesions Seen on the same (ipsilateral) side. What does that look like?
Vestibular apparatus
37
Vestibulocerebellum Receives input from _____ And projects directly To _____ Vestibular Nucleus then to Motor neurons – antigravity muscle (extensors) Lesions to Vestibulocerebellim Seen on the same (ipsilateral) side SpinoCerebellum – (Vermis) to _____ N. then to brain Stem (e.g. Medullar Ret formation) Lesions ipsilateral
Vestibular apparatus; Lateral; Fastigal
38
CerebroCerebellum and Lateral SpinoCerebellum Lesion will affect motor performance on the\_\_\_\_\_ (ipsilateral/contralateral) of the body – even though their projections From their respective Deep Cerebellar Nuclei are Contralateral (to Motor Cortex and Red N respectively)
Ipsilateral
39
What are 4 symptoms of Lowe Motor Neurons lesions?
1. Weakness or Paralysis
2. Muscle tone reduced or absent
3. Muscle mass is lost
4. Myostatic reflexes reduced or absent
40
What are 5 causes of lower motor neurons lesions?
1. Poliomyelitis (viral infection of CNS)- A small foot drop --\> progressive weakness (3-5 yrs after diagnosis = death)
2. Motor Neuron Disease
3. Spinal cord injury at segmental level- Budging discs, injury to peripheral nerves = muscle weakness
4. Nerve Trauma (compression, deymelination)
5. Muscle disorders (MG, Dystrophies)- Effect organs (skeletal muscles) = weakness and atrophy
41
What are 5 symptoms of an upper motor neuron lesion?
1. Weakness or paralysis- But spinal cord circuits are still in place
2. Muscle tone increases (except acutely)
3. Myotatic reflexes increases (except acutely)- When stimulating peripheral inputs --\> not getting modification of high centres
4. Muscle mass is maintained
5. Babinski's sign (upper plantar reflexes)
42
What are the 2 causes of upper motor neuron lesion?
1. Stroke
* Can affect larger blood vessels in the brain --\> in M1 region (primary motor cortex region) = loss of muscle tone; altered posture
2. Cord lesion
* Because it is encases in the vertebral column --\> has a shock phase and then everything looks normal
* Inflammatory response is actually causing the damage
* Need axons to grow again --\> astrocytes to build a glial scale (brick wall)
* Axonals cant get through the brick wall --\> Need to destroy the brick wall OR Work way around the brick wall to reconnect
* Get neurons to re-grow or use electrical device to get around the lesions
43
What is a cord lesion?
* Because it is encases in the vertebral column --\> has a shock phase and then everything looks normal
* Inflammatory response is actually causing the damage
* Need axons to grow again --\> astrocytes to build a glial scale (brick wall)
* Axonals cant get through the brick wall
* Need to destroy the brick wall OR
* Work way around the brick wall to reconnect
* Get neurons to re-grow or use electrical device to get around the lesions
44
What is a stroke?
Can affect larger blood vessels in the brain --\> in M1 region (primary motor cortex region) = loss of muscle tone; altered posture
45
What does a motor neuron lesion look like?
46
What does a transplanted peripheral nerve look like? What is it?
Favourable environment for the regeneration of central axons
