Movement At Joint

A single muscle can only contract
one muscle can bend a joint or straigtthem but cannot do both,.

• Bicep muscle contracts (flexor)
• Tricep muscle relaxes extensor
• stiff joint by tensioning both extensors and flexors at same time

Central Pattern Generators

• Spinal Cord manage rythmic movement
• horses natural trot, ipsilateral legs move in opp. direc
• genetic mutation in icelandic horses, natural is pacing, those legs move in same direction

Dev and Reflex

Most reflexes don't change

• child reflexes are inhibited when age matures
• Stroking bottom of foot in baby causes toes to curl outward
• stroke food of adult cause it to curl down
• nerve damage can make it reappear

Descending Control of Movement

Originates in pmc or red nucleus of midbrain
Controls fine, voluntary movements of outerlimbs
ventralmedial; pathways originate in brainstems

• Name origin first and target second of pathways
• Tectospinal pathways origininates in tenctum part of midbrain
• connects motor neurons in spinal cord

The Cerebellum and the Basal Ganglia.

Cerebellum does sequential movements
trial by error, making nessesary adjustments

• Basal Ganglia act as voluntary gateway
  • unwanted behaviors are supposed to be inhibited
• parkinsons, ocd, and adhd interfere with basal ganglia

The Motor Homunculus

PMC located in precentralgyrus
most caudal area of frontal lobe just infront of central sulcus, dividing frontal and parietal lobe
amount of brain space is not at all correlated with actuaal sixe of body part
more space for fine movement

Planning and impelementing movement

brain imaging can watch progressioon

• planoing in frontal and parietal
• evaluated, steps lined uo
• basal ganglia check off final plan,
• msg go to PMC
• what gives us sense of agency or free will
  • occurs when outcome of movement is congruent with original plan
  • movement caused by external circumstance

Conscious intnet to move

• Movement occurs way before we know we gonna move
• Conscious awareness of movement helps us interpret and make sense of movement without guiding it

Movement Vectors

• single cell recordings show very specific connections between stim like a dot of flight of the isual field in a particular cell response
• when lpooking in that part of pmc
• single cell coding of part move can be studied by recording brai nactivity when monkey moves joystick, in a partiuclar direction rinforced to doing
• single cell in pmc respond more to some movements more than others
• response of whole pop. of cells determines direction of movements

Mirror Neurons

Cells that respond for part. movement regardless of who does it
We think they are not built in, but learnd
support immitation
cant characterised ASD as a result of broken mirror
(they show normal, if not better than neuriotyoical)