Nervous system Flashcards
(27 cards)
How can you test the function of the hamstrings/ L5 – S2?
Ask patient to flex the knee
How can you test the function of the deep perineal nerve/ L5?
Ask patient to dorsiflex the foot or big toe
How can you test the function of the superficial peroneal nerve L5/S1?
Ask patient to evert the foot
Describe an upper motorneurone
Contained entirely within the CNS
e.g. corticospinal (pyramidal)
Describe a lower motorneurone
Cell body in CNS gives off axon that passes into a peripheral nerve to innervate a skeletal muscle
e.g. spinal nerve
Anterior/ ventral root
Myotone
Motor
General visceral efferent
General somatic efferent
Posterior/ dorsal root
Dermatome
Sensory
General visceral afferent
General somatic afferent
What does somatic refer to?
Musculoskeletal
What does visceral refer to?
Organs = autonomic
Briefly explain how a muscle cell is stimulated
ACh bind to receptor on muscle cell
Opens Na+ channels and Na+ moves in
Causing AP
ACh esterase degrades the transmitter
What determines the firing rate?
Strength of contraction required
What are medullary, pontine and reticulospinal and lateral vestibulospinal pathways?
Medial system pathways (medial - proximal muscles)
Contribute to balance and posture
Control proximal limb muscles
What is the corticospinal tract?
Lateral system pathway (lateral - distal muscles)
Influences reflex arcs that control fine movement of distal ends of limbs
What’s the difference between postural and goal directed movements?
Postural control •Active process •Unconscious •Accompanies voluntary movements •Relies on reflexes
Goal directed movements
•Voluntary
•Conscious
What are the 3 categories of movement?
- Reflexive
- Rhythmic
- Voluntary
Do reflex arcs often contain interneurons?
Yes
Do stretch reflexes contain interneurons?
No they are mono-synpatic
Describe the flexor crossed extensor reflex
polysynaptic
Reflex inhibits the motor neurone to extensor muscle and stimulates the flexor muscle on side that felt pain
Stimulates motor neurons in spinal cord to extensor muscle and inhibits flexor muscle in opposite leg
What’s responsible for control of distal musculature and control of fine skilled movements?
Primary motor cortex
What’s responsible for the initiation and planning of movement and bimanual coordination?
Supplementary motor area (SMA)
What’s responsible for the control of proximal musculature and control of movement sequence and preparation for movement?
Premotor cortex (PMC)
What’s responsible for motor sequence learning
e.g. learning to walk during infancy?
Basal ganglia
Basal ganglia
Primary concerned with with control of movement
Masses of grey matter
Largest mass of grey meter - corpus striatum
What does the corpus stratum consist of?
Caudate nucleus
Putamen
Globus pallidus