Sensory Receptors Flashcards
What do sensory receptors do
Inform the brain about internal and external environment
What are sensory receptors
Nerve endings
Many have specialised non-neural endings
What do sensory receptors do with stimuli
They are also ____ in regards to stimuli
Converts into frequency of netve action potentials
They are also transducers (change stimuli from one form of message to another)
Name three types of receptors
Mechano receptors
Proprioceptors
Noicoceptors
Which receptors are peripheral sensory processing
Mechanoreceptors and proprioreceptors
What is receptor transduction
Take energy and change into electrical signals and nerves
Involves ion channel opening or closing. Graded potential change
What is sensory modality
Stimulus type that activated particular reception, touch pressure, joint angle, pain
Sensory receptors
Adaptation.
Some mechanoreceotirs adapt to maintained stimulus
What senses vibration
Pacinion corpuscle
What sense steady pressure and texture
Merkel receptors
What responds to flutter and stroking movement
Meissners corpuscle
What responds to noxious stimuli
Free nerve ending of NOCICEPTOR
What carries signals to spinal cord
Sensory nerves
What responds to skim stretch
Ruffini corpuscle
Two point discrimination test depends on what 2 things
Receptive field size
Neuronal convergence
What is adequate stimulus in cutaneous mechanoreceptoea and proprioceotis called
Membrane deformation
Explain adaptation
Mechanoreceptors adapting to maintained stimulation and actio potential fires again once released
What receptors do not adapt
Nocioceptors
Properties of proprioception
- Send sensory into spinal cord -> to brain control voluntary movement
- Muscle spindles and golgi tendon organ provide sensory information to spinal cord neurones which generate spinal reflex movements
- Provide sensory information to perceive limb and body position in space =kinaesthetia
Where are most contactile muscles
In extrafusall fibres
Where are soecialed muscle fibres that have own sensory and motor innervation
Intrafusal fibres
What are intrafusal muscle fibres
Specialised
What is convergence
Individual neurones come together
What is divergence
Input from one neurone separated into multiple neurones
What is function of Golgi tendon
Monitors muscle tension
What is term for when muscles are kept same length
Isometric
What is the function of gamma neurone
Fires -> exttafusal muscles contract/shorten
(Without, would stay same length, spindle becomes slack - no longer report muscle length to brain?
What would happen if no gamma neurones
(Without, would stay same length, spindle becomes slack - no longer report muscle length to brain)
What us inverse stretch reflex
1b afferent neurones from golgi tendon organs
Collapse resistance spring loaded knife protective mechanism
Flexor withdrawal reflex with cross extension
Use from nocioceptor
Ipsilateral flexion antagonistic extensor inhbited
