MSK physiology

Question 1

What is the function of the cerebellum?

Answer 1

ensures movements are smooth

Question 2

What are the parts of the cerebellum?

Answer 2

1) vestibulocerebellum (equilibrium and eye movements)
2) spinocerebellum (receives info on what brain wants body to do and ensures this is what happens)
3) cerebrocerebellum (movement planning and accuracy)

Question 3

What are the tracts descending from the motor cortex?

Answer 3

Medullary nucleii
corticospinal tract
- ventral
- lateral/pyrimidal

Question 4

What is the function of the medullary nuclei?

Answer 4

serve function of balance, posture & basic locomotion

Question 5

What is the function of the corticospinal tracts ?

Answer 5

fine motor function & posture

Question 6

What are Upper motor neurones?

Answer 6

neurones which descend from the motor cortex within the spinal cord

Question 7

What are lower motor neurones?

Answer 7

neurones directly innervating muscles, come directly from spinal cord

Question 8

Symptoms of LMN lesion?

Answer 8

• localised muscle weakness
• flaccid paralysis
• areflexia
• atrophy of muscle (due to lack of stimulation)
• Fasciculations/fibrillations (due to hypersensitivity and damage potentials

Question 9

Symptoms of UMN lesion?

Answer 9

• contralateral muscle weakness
• loss of skilled muscle activity
• hyperreflexia (no longer any inhibition of reflexes)
• spastic paralysis
• less atrophy
• pos Babinski sign

Question 10

What is Brown Sequard syndrome?

Answer 10

damage to spinal cord on one side causing ipsilateral loss of vibration, motor function, deep touch and proprioception
and contralateral loss of pain, temp and light touch

Question 11

What do lesions in the cerebellum result in?

Answer 11

vestibulocerebellum - broad and unsteady gait & nystagmus

Spinocerebellum or cerebrocerebellum - intention tremor, dysdiadochokinesia , dysarthria, slow reflexes & reduced tone

Question 12

What is dysdiadochokinesia (DDK)?

Answer 12

inability to perform rapidly alternating movements

Question 13

What is the function of the basal ganglia?

Answer 13

initiation of complex pre-programmed movement & setting baseline tone and posture before movement

Question 14

What does abnormalities in basal ganglia result in?

Answer 14

• reduced and slow voluntary movement (akinesia and bradykinesia)
• increased tone
• DDK
• Dyskinesia (resting tremor, chorea and hemiballismus)