movement Flashcards
what are the three muscle categories and their movements
smooth muscles: digestive, skeletal muscles (movement of body in relation to environment) cardiac muslces (both skeletal and smooth)
each _____ receives information from one _____ but one _____ may innervate many _____
msucle fibre, axon
what is a neuromuscular junction
a synapse between a motor neuron axon and a muscle fibre
release of what at the neuromuscular junction causes the muscle to contract
acetylcholine
movement requires the alternating contraction of opposing sets of muscles called ______
antagonistic muscles
what are the two contracting skeletal muscles
flexor (flexes or raises), extensor
when you want to bend what happens to antagonist muscles
bicep contacts flexor muscle, tricep relaxes
skeletal muscles can be fast or slow..whats the difference
fast twitch: fribres produce fast contractions but fatigure rapidly…fast moving, jumping
slow twitch: fibres profuce less vigurious contraction without fatigue..gradual movements such as walking
what are proprioceptors
recptors that detect the position or movement of a part of the body and regulate muscle contraction
what are the two kinds of proprioceptors
muscle spindles and the golgi tendon organ
what do muscle spindles do
they are parralel to the muscles and respond to stretch and can cause contraction if the length of that muscle stretches too far . like when stretching arm back for baseball pitch bicep will contract
what do tendons do
connect muscle to bone
what does the gologi tendon organ do
located in tendons, act as a break against excessivley vigorous contaction by sending an impulase to the spinal cord where motor neurons are inhibited, senses muscle tenstion, inhibits muscle activation
does muscle spindles or gogli tendon organ result in efferent signals
muscle spindles
describe reflexes
involuntary, consistent, automatic responses to stiumi
what kind of reflex requires one synapse between sensory input and movement
monosynaptic reflex
describe the patellar tendon reflex
tap on the tendon stretches the quadriceps muscle, the sensory nerve responds to the muscle stretch; by sending a signal to the spinal cord, where it connects to a motor neuron through a signal synapse; the motor neuron stimulates the quadricep muscle to contract and reduce the stretch; the quadriceps contracts, extneding the lower leg
true or false: most movements are a combination of voluntary and involuntary: reflexive and non reflexive
true
describe how some movements vary with respect to feedback
some are ballistic and cannot be changed once initiated, others guided by feedback to allow for percision
what are central pattern generators
neural mechanisms in spinal cord or elsewhere that generate rythmic patterns of motor output in absence of sesnory feedback…both interconnected inhibitory and excitiroty neurons..breathing, swimming locomotion
what is a motor program
a fixed sequence of movements that is either learned or built into the nervous system, once begun, the sequence is fixed from beggining to end. automatic. thinking or talking about it interferes with action …yawning
understanding how btain controls movement offers hope for spinal cord damage because can use
brain computer interface (BCI) , use brain signals to direct computured controlled deivces such as neuro prosthetics
describe 5 major parts of the motor system
cerebrum: in forebrain, consious control of movement
brain stem + spinal cord ; direct movements
subcortical basal ganglia: help produce the appropriate amount of force for grasping
the cerrebulum helps regulate the timing and accuracy of movement
what is the role of the cerebral cortex
initiating a motor sequence..most motor learning is mastering sequences of action so that while one sequence is being activated the next is being prepared
explain 3 parts of the frontal lobed involved in movement
prefrontal cortex: plans complex behavior, the complex movements
premotor cortex: produces the appropriate complec movement sequences
primary motor cortex: in the precentral gyrus, specifies how each movement is carried out, axons connect brain stem spinal cord and generate impulses , excecutes actions
what does damage to posterior parietal cortex result in
difficultiy in coordinating visual stimuli with movement
what part of brain keeps track of the position of the body relative to the world
posterior parietal cortex
what is a saccade
voluntary eye movement from one target to another
performing an inti saccade tasj requires activity in what parts of the brain before seeing the moving stimulis
prefrontal cortex and basal ganglia
when are mirror neurons active
during preperation of a movement and while watching someone else do the same movement
do mirror neurons cause or result from social behavior
unknown
messages from brain are sent to the ____ and spinal cord to control the muscles
medulla
what are the paths from the cerbral cortex to spinal cord
corticospinal tracts
what are the two tracts from cerebral cortex to spinal cord
lateral corticospinal tract
medial corticospinal tract
describe the lateral corticospinal tract
set of axons ffom the primary motor cortex surrounding areas and red nucleus to the spinal cord. controls movement in peripheral areas (hands and feet) ….axons corss ar rhw pyramids of medualla
where is the red nucleus
in the midbrain area, output mainly to the arms
describe medial corticospinal tract
set of axons from many persts of the cortex: reticular formation, midbrain tectum and vestibular system,,,controls musclrs of the neck, shoulders trunk, on same side. responsible for bilateral movements like walking turning bending etc
what is the bestibular nucleus
brain area that receives information from vestibular system ..inner ear,,, sense balance spatial
what are symptoms of cerbral palsy and whats it caused by
voluntary movements difficult to make, consious behavior controlled by cortex may remain in tact. casued by brainstem traauma usually in pregnancy lack of oxygen to the brain
what is locked in syndrome what is it caused by
patient aware and awake but cannot move or communicae verbally, complete paralysis nearly all voluntary muscles except the eys….mesagges cant come from cortex to spinal cord…due to brainstem damage
two example of brianstem damage?
cerebral palsy and locked in syndrome
where was christopher eeves spinla cord sevvered
near upper end c1-c2 level..brain and psinal cord no longer connected..completlety paralyzed unable to breathe without assistance
whata are the two plegias of spinal cord
quadriplegia :loss sensation amrs and legs…upper spinal cord damage
paraplegia: sensation legs + lower body…dmaage lower body
there mor neurons in the _____ than anywhere else combined
cerebellum
the cerrelbelum is often associated with _____ and _____
coordination
what else is cerrebelum responsible for
excecution of a sequence (that requires timing), responds to sensory information, espcially violations of sensory info like going to touch an object and not feeling anything, important certain aspects of attention like shifitng attention
the _____ is the first area affected by alcohol which causes ____ and why they do finger to nose
cerebellum, clumsiness
how does the cerrebelum improve motor control
cortex sends motor instructions to the spinal cord, sends same instructions to the cerrebelum. the sensory receptors code the actual movement and report tot the cerrebelum. it now has information about bothe versions…what you intended to do vs what you actually did, calculates error and tells cortex how to correct
the bassal ganglia is a group of large subcortical structures in the _____ ..comprises these three…what is it important for
forebrain, …. caudate nucleus, putamen, globus pallidus……self initating behaviors, not guided by stimulus,,,, a monkey deciding which time to start
the cerbral cortex sends input to the _____ and ____ which send info to the ____ which then sends info to the _____ and _____.
putamen and caudete nucleus…globus pallidus,,,,thalamus and motor areas and the prefrontal cortex
what are the 2 pathways of the basal ganglia
direct: promotes behavior
indirect: inhibits unwanted movements
basal gangling selects a movement by ceasing to
inhibit it
tourette syndrome is a result of abnormality in the
basal ganglia
learning of new skills requires multiple areas but basal ganglia are critical for
learning motor skills, organizing sequences of movement, automatic behaviors and new habits…driving a car
describe readiness potential and when does it occur
activity in the motor cortex that occurs at least 200ms before voluntary movement, we become consious decision to move after process has already begun
brain disorders like parkinsons disease and huntingtons disease not only affect movement but also
impair mood, memory and cognition
describe parkinsons disease
involuntary muscle contractions, tremors/shaking in hands, righty/stiffness, slow movements, difficulty initiation physical activity….impairment initationg spontaenous movement without stimulus..also depression memory and reasoning..
what is parkinsons disease caused by
- gradual and progressive death of neurons, especially in the substantia nigeria as it usually sends dopemaine releasing axons to caudate nucleus and putamen
- loss of dopamine leads to less stimulation of motor cortex and slower onset of movements
in parkinsons its more thought to be genetic if
its early onsent
what is the main treatment for parkinsons and what is the downside
l-dopa….often ineffective in later stages and cause other side effects
other treatments for parkinsons?
-drug to directly stimulate dopamine receptors, implementing electrode to stimulate deep areas of brain,
experminetal stem cells
what is shown in the photo that shows huntingtons disease
the ventricles that contain spinal fluid are expanded and cause death to those surrounding brain areas
what is usual onsent of huntingtons disease
age 30-50
what areas are damaged in huntingtons disease
basal ganglia and cerebral cortex
what are physical cognitvie and emotions symptoms of huntingtons
weight loss, arm jerks, involuntary movements, difficulty walking…….focus, planning, insight….depression, apathy, irritbiailty, obsessive behavior
huntingtons diseased controlled by what….more likely to develop it earlier if higher number of what
an autosomal dominant gene on chromosome # 4, consecutive repeats of the combonation C-A-G
