Proprioception. Definitions and Introduction. Flashcards
What is ataxia?
A loss of unconscious/conscious proprioception that leads to uncoordinated movements.
What is an autonomous zone?
The area of skin innervated by a plexus nerve.
What is a dermatomal map?
A map that highlights all of the different dermatomes in the body.
What is a dermatome?
The area of skin innervated by the dorsal cutaneous branches of the spinal nerves.
What is the dorsal column?
The spinal tract used for the flow of conscious proprioceptive information.
What is the dorsal cutaneous branches of nerves?
Small nerves that branch off a spinal nerve and travel to the skin to innervate a small area.
What are plexus nerves?
Nerves that branch off a plexus.
What is proprioception?
The perception/awareness of the positioning of various parts of the body.
What is sensory ataxia?
A loss of postural responses and/or gait without a loss in muscle strength.
What are spinal nerves?
Nerves that branch off the spinal cord.
What is the spinocerebellar tract?
The spinal tract used for the flow of unconscious proprioceptive information.
What is proprioception?
The ability to tell where parts of the body are in space and where certain body parts are in relation to the body.
What is proprioception essential for?
Co-ordinated and purposeful movements.
What kind of movements are unconscious?
Automated movements such as walking.
Unconscious movements can be described as what kind of motor skills?
As gross motor skills.
What characterises skilled movements?
They are very precise.
Are skilled movements conscious or unconscious movements?
Conscious.
Conscious movements can be described as what kind of motor skills?
Fine motor skills.
What does a loss of conscious and/or unconscious proprioception lead to?
Ataxia.
What 3 things are constantly monitored by sensory proprioceptive receptors?
Muscle length.
Tendon length.
Joint angulation.
What part of a muscle is used by sensory proprioceptive receptors to monitor muscle length?
Muscle spindles.
What part of a tendon is used by sensory proprioceptive receptors to monitor tendon length?
Various parts of the tendon.
What part of a joint is used by sensory proprioceptive receptors to monitor joint angulation?
Various receptors in the joint.
What kind of ion channels are found in the neurons are the sensory proprioceptive neurons that are found in muscles?
Mechanically gated ion channels.
What do the sensory proprioceptive neurons found in muscles prevent?
Over-stretching of muscles.
What muscle is the patellar reflex associated with?
The quadriceps muscle.
How do we initiate the patellar reflex?
We tap the patellar tendon and the quadriceps muscle is stretched.
The movement is picked up by the receptors in the muscle spindles.
What happens during the patellar reflex once movement of the patellar tendon has picked up by receptors in the muscle?
Mechanically gated channels open and the neuron depolarises.
If there is no inhibitory input onto the nerve fibres then there will be an exaggerated response.
What organs within a tendon monitor the degree of stretch and contraction of tendons?
Specific receptors called golgi organs.
Where in tendons are golgi organs found?
In specialised collagen fibres within the tendon.
How are the golgi organs within a tendon activated?
As the fibres are stretched they opening mechanically gated ion channels to trigger an action potential.
Why are golgi receptors likely to respond to the contraction of a muscle?
As muscle contraction puts the most strain on a tendon.
Where are golgi organs found in relation to the tendon and the muscle?
At the junction between the tendon and the muscle.
What are motion receptors?
The receptors in joints.
Where are motion receptors located?
Around joint capsules.
