The Basics of Movement Flashcards
what two components are intertwined?
cognition and action
what are motor deficits often directly linked to?
cognitive problems
how many muscles does it take to make one step?
around 200
what is the strongest muscle in the human body?
Massester (Jaw)
what appendage occupies the least amount of area in our motor cortex?
Arm
^ more fine motor control needed, larger area needed in the motor cortex
What is the latin name for one of the muscles in your big toe?
Flexor hallucis longus
what is dystonia?
a movement disorder that is affected by the toning of the muscles (stiffness where the muscles are overcompensating)
what is pallidotomy?
a treatment for dystonia resulting in electric probes in the brain (baso-nuclei), allowing for better movement
what is the role of the motor cortex?
planning, initiating and directing voluntary movements
- range of reflexes coming out of the motor cortex, not only their coordination within this cortex, but it’s supplemented by the basal ganglia which helps starting and stopping movement and the cerebellum which helps you engage with smooth movement
what is the role of the brainstem centres?
basic movements and postural control
what is the role of the basal ganglia?
gating proper initiation of movement i.e. stopping and starting
what is the role of the cerebellum?
sensory motor cordination
what does the local circuit neurone do?
reflex coordination; help organise / shepard the lower motor neurones in order to enact a movement
* no need to involve higher brain regions in this case
what is also included in the brain system?
peripheral nervous system - signals coming in and out of your body / brain
what is the difference between the upper and lower neurone systems
upper motor neurones require a bit more fine-grained movements and can be supplemented by regions around them (i.e. basal ganglia and cerebellum)
+ other areas of delegation: brain stem centres which you require for basic movements (involuntary control)
whereas lower motor neurones generate movement more in terms of a reflex
what is meant by a ‘hierarchy’ system?
system kicks in as much and when it needs to
what about deficits in the lower and upper motor neurones?
specific deficits can happen
* lower motor neurones can get disrupted in your spinal column and brainstem
* while upper motor neurones (in your cortex) when disrupted will cause troubles with the lower motor neurones getting information out of the spinal column to the peripheral nervous system to the skeletal muscles
what happens if the upper motor neurone is disrupted?
no signal will be found outside the brain at all
the basics of movement
- simple reflex
- posture / postural changes
- locomotion
- sensory orientation
- species specific action patterns
- acquired skills
simple reflex
- stretch reflex, knee jerk
- mediated at the level of the spinal cord
posture and postural change
standing, balancing
locomotion
walking, running
* often doesn’t necessarily involve areas of the cortex -> central pattern generators in your spinal cord and brain stem that allow you to perform the movements without thinking about them
sensory orientation
head turning, eye fixation
species specific action patterns
Ingestion, courtship, escape/defence, grooming, gestures
acquired skills
dressing, painting, driving, sports, guitar hero, texting etc
how can you exert a degree of control over the same type of movement like breathing?
- can breathe in and out voluntary
- but this type of control is delighted and called rhythmic movement (timing and spatial organisation where it’s done automatically)
- then we have reflexive: if we’re underwater -> you will eventually breath in because of your reflexes
- different levels of control over the same muscle group dependent on how we need them and context/situation
PNS and Leprosy
- caused by a bacterium infection (which attacks nerve endings and the bodies ability to feel pain/detect heat)
- peripheral nerves thicken in leprosy, disrupting afferent (sensory inputs coming into local circuit neurones) and efferent (lower motor neurones sending information to skeletal muscles) signals
- thermal sensation is usually the first to go, followed by pain and touch
- inability to feel pain can result in severe limb damage over time
CNS -> PNS -> Muscles
all voluntary and reflex movements are brought about making striated muscles contract
There are three types of muscles, what are they?
cardiac, skeletal and smooth muscle
cardiac muscle
striated but relies on involuntary/rhythmic movements
smooth muscle
around blood vessel, glands, guts and bronchioles
skeletal muscles
- anchors somewhere onto bone and performs voluntary movements
-> at least one end (the origin) is connected to a bone through a tendon
Why are we interested in skeletal muscles?
- they are important for voluntary movements
muscle fibres
- striated because of regular bands composed of proteins: actin (thin filament) and myosin (thick filament)
- sarcomere: basic unit of striated muscle tissue (functional unit of contraction -> contraction makes it shorter)
how do actin and myosin work?
- Actin and Myosin overlap slightly.
- Myosin has a long fibrous tail and a globulus head which brings to actin and allows it to pull itself along [lots of them do this at once]
- Electrochemical reaction, pulls actin over myosin which releases calcium binding to actin and causing it to change configuration (provides an anchor site for the myosin to pull itself along, pulling it along)
myosin
has a long fibrous tail and globules head