Motor Systems Flashcards
Where are motoneurones innervating AXIAL muscles located in the motorpool?
Medially
What is a motorpool?
Somatotropic organisation of motoneurones
In a cross section of the VENTRAL HORN
At the CERVICAL level
Where are motoneurones innervating DISTAL muscles located in the motorpool?
Laterally
Recruitment of motor units: what kind of fibres fire first?
Low threshold
What kind of muscles are spindle fibres?
Intrafusal
What does spindle detect?
Changes in muscle length
Degree of stretch in muscle
Spindle fibres lie _____ to extrafusal muscles
Golgi tendon organs are _____ with extrafusal muscles (and load)
Parallel
In series
Extrafusal fibres form bulk of muscle and generate _____?
Tension
Extrafusal fibres are innervated by ____ motor neurones?
Alpha
Intrafusal fibres (spindle) have a ______ function?
Sensory
Intrafusal fibres are innervated by _____ motor neurones?
Gamma
When spindle are slackened are they sensitive to stretch?
No
Only when contracted
What does the Golgi tendon organ detect?
Changes in muscle tension
Which sensory afferents:
1) sense stretch and rate of stretch
2) stretch only
3) are from tendon organs ?
1) group Ia (primary afferents)
2) group II (secondary afferents)
3) group Ib
The Renshaw cell is involved in what pathway?
Recurrent inhibition
