Locomotion and propreoception Flashcards
- What is gait?
a. Repeating sequence of leg movement
b. Quadrupeds have 4
c. Each gait change how limbs move to give faster or slower pace
d. Repeating sequence set by group of neuroens in spinal cord called central pattern generator
e. Higher centres needed to initiate gait and refine, terminate as move but rhythmic movement = all spinal cord = keep happening until higher centres tell ti otherwise
- What determines speed?
Speed = stride frequency x stride length
- Name different gaits:
a. Walk, pace, trot, gallop
- What is proprioception?
a. A SENSE
b. AFFERENT information
c. Sensory input
d. Sense of the relative position of the body parts, whether moving and HOW they are moving
e. Used by the brain to integrate and influence motor output
f. Ensures posture is appropriate so you can maintain balance and position in the world
- What receptors does proprioception rely on and what do they tell the brain?
a. Proprioceptors
b. Inform CNS of body position, strength, speed etc so motor output can be modified as needed
c. Msucle spindles
d. Golgi tendon organs
e. Joint receptors = how bent and loaded joint
f. Skin receptors
g. Skin tactile and mechanoreceptors
h. Vestibular system
i. Hair cells
- What is key to remember with regards to proprioception and motor function? And why?
a. An animal can only demonstrate normal proprioception if have normal motor function
b. Can’t ask
c. P = only an input, it doesn’t imply awareness of it
d. When examining animal, can’t tell if know where legs are, unless putting legs in correct place which they can’t do if good motor function
- What are the types of proprioception?
a. Conscious
b. Subconscious
- What is conscious P to do with
a. Awareness of specific fine detail
b. Voluntary
c. 3 neurone system
- What is sub conscious P to do with
a. Rhythmic movements, subconscious
b. 2 neurone system
- How are conscious dan sub conscious P different anatomically?
a. Sub = 2 neurone system
b. Conscious = 3 and ends in somatosensory conscious for you to be conscious for it
- Conscious deficits
a. Stumbling, knuckling, intention tremor (animal tried to do something but can’t reach target)
- What is the anatomy of conscious proprioception
A 3 neuron system
a. Proprioceptor
b. Sensory neurone synpase in dorsal root ganglion
c. 2nd neurone to thalamus
d. 3rd neurone from T to contralateral somatosensory cortex (decussates)
e. Means that info on fine movement on LHS goes to right somatosensory cortex
- If animal lesion of left somatosensory cortex what conscious proprioception deficit signs might you expect?
a. Errors on RHS
b. Stumble, put foot wrong way up
c. Broadly will be able to navigate its way around the room.
- What is subconscious proprioception?
a. Rhythmic, innate, basic things you don’t think about: sitting, standing, scratching, chewing locomotion
b. Used to set postural platform (right way up)
c. Poor = stagger around, fall over, struggle to maintain appropriate strength
d. 2 neurone system
e. Input from head cranial nerves 5 and 8
- What is the anatomy of subconscious proprioception?
2 neuron system
a) Proprioceptors stimulate receptor and an axon with its cell body in a spinal ganglion (dorsal root ganglion)
b) second neuron runs as the spinocerebellar pathway bilaterally in the lateral funiculi of the spinal cord to the ipsilateral cerebellum. stays on same side.
c) Input from the head comes via cranial nerves V and VIII.
- Abnormalities/ deficits in sub conscious proprioception:
a. Called ataxia
b. Defined as alteration in the rate, range and force of movement
c) become inappropriate (too far/ not far enough, too strong of weak)
d. Swaying of trunk, wide base stance, cross legs, odd gait
e. May be a Non intention tremor = tremor occurring at rest as muscles can’t stabilise around a joint as body can’t tell where they are.
- Animals with lesion on left cerebellum, what subconscious proprioception deficits might you expect?
a. Signs on LHS
b. Un coordination – feet in wrong place
c. Cross legs over
d. Fall over
e. ataxia: swaying trunk, wide base stnace, non intention tremor
- Spinal tracts
a. Conscious P largely in dorsal funiculus
i. CP hindlimb = most medial part of this funiculus = Gracile fasiculus
ii. Thorax and thoracic limb = cuneate fasiculus = more lateral part of dorsal funiculus
- If lesion affecting the dorsal funiculus ONLY what would you expect to find and why?
a. Conscious P deficits for everything caudal to the lesion
b. Because tracts can’t travel forward
- Location of subconscious tracts
a. Lateral funiculus = spinocerebellar tracts (up spinal cord to cerebellum)
- If injury to lateral spinal cord what kind of proprio deficit would you expect as why?
a. Sub conscious as the sub conscious proprioceptors are located in the lateral funiculus = spinocerebellar tract
- What is Kinaesthesia?
a. Awareness of position of the movement of the body
b. Rather than just fact the input is happening
- How does kinaesthesia happen?
a. Info going into cerebellum from the subconscious proprioception ahs to go to the contralateral somatosensory cortex
b. Does by decussating
c. So although sub conscious P info goes to ipsilateral cerebellum it DECUSSATES to contralateral side for you to be aware of it
d. So to be functionally effective of the movement = only have to stay on one side
e. But to be aware it must decussate
- What type of proprioception is the cerebellum involved in?
a. Sub conscious
b. Comparing intended movement with actual
c. Input from muscle tendons, golgi, vestibular etc
- Where is the location of the vestibular cerebellum and what goes it coordinate
a. Bottom bit tucked under cerebellum
b. Balance and eye movement
- Where is location of spinocerebellum
a. Middle bit
b. Coordinates muscle tone and movement, general movement, posture
- Where is location of cerebrocerebellum?
a. Lateral hemispheres
b. Planning of movement
- Dog presents with: swaying, stumbling, deficits in awareness of body, strange gait, normal cranial nerve test, normal reflexes in all 4 limbs, deep pain sensation in all 4 limbs. Where might lesion be?
a. Spinal cord
b. All limbs affected so lesion must be in cervical spine somewhere
