PSY2003 W3 Sensorimotor System - (L) Flashcards
What does motor control involve?
A dynamically chaning mix of conscious and uncousious regulation of muscle force by complex and continous sensory feedback
What types of motor control are there?
Voluntary, Goal-directed, habit, involuntary
What are some examples of voluntary motor control?
Running, walking, talkin gplayin gguitar
What are goal-directed motor control?
concious explicit automatic
What are habit based motor control?
unconcisous, implicit automatic
What are some examples of involuntary motor control?
eye movemen, facial expressions, jaw, tongue, postrual muscles, digestive tracts etc.
What does the learned threat affect?
Cortex and limbic system (avoidance)Being able to assess dangerous situations from our knowledge
What does looming threat trigger?
Sensorimotor midbrain (avoidance) coordinated response
What does pain trigger?
Spinal cord (escape)
What governes motor control?
Upper nad lower motor neurons
Where are the lower motor neurons?
begin in the brainstem or spinal cord and prokects to the muscle
Where are the upper motor neurons?
hiher centres and project down to meet the lower motor neurons
How do individual muscle fibers act?
in a all or non manner and so control of muscle force ependes on the way in which lower motor neurons activate different types of muscle fibres
How much of our body weight is muscle?
around 40%
What are the three types of muscles
Cardiac, smoot and skeletal
Where can the smallest and largest be found?
stapedius (inner ear), gluteus maximus (hip/bottom)
What do muscles do?
Contract and relax only
How do you achieve such a range of movement and forces?
antagonisit carragement combined with co-ordinated action
How do muscle contract?
Interlockig filaments, muscle fibres are pulling towards each other or relax by extending
How is the release of acetylcholine help contract a msucle?
actin and myosin filament The release of acetylcholine leads to release of calcium from inside the muscle cell (fibre). This causes the myosin head to change shape, enabling it to bind with the actin filament. ATP (provides energy for cells) is required to break the bond between the myosin head and the actin filament
What does neurotransmitters have to do with muscle contraction
Neurotransmitter is the one causing the process.
How do enzymes help a muscle to relax
ATP is produced by oxidative metabolism, which stops upon death. So the muscle become contracted and remains that way until enzymes begin to breakdown the actin/myosin.
What is requirment of a muscle for it’s normal functioning
Level of control and strenght
What is the Size principle ?
Units are recruited in order of size, fine control typically require at lower force
What are slow muscle fibres?
sitting, relatively still they don’t get tired
What are fast fatigue resistant muscle fibers?
fast, large amount of force, quite quickly they can maintain for a while but not forever
What are fast fatiguable msucle fibres?
tired quickly but more force
How can training affect muscle fibres?
Training and exercise lead to changes in the thickness of muscle fibres and the proportion of different muscle fibre types
What does fewer fibres mean?
greater movement resolution (finger tips/tongue)
What are motor units
a single alpha motor neuron and all the muscle fibres it innervates
What is the final common pathway for motor control?
motor unit
What happens when alpha motor neuron is activated?
depolarisation and casues contraction of all muscle fibres in that unit
Why are muscel units distributed throughout the muscle
to provide evenly distributed force
What happens when more motor units fire?
more fibres cnotract more power
What is a motor pool?
all the lower motor neurons that innervte single muscle, the pool contrain both alpha and gamme motor neurons, often arranged in a rod like shpae