Week 8 - Sensory Feedback Flashcards
how is voluntary movement created ?
motor neurons bring signals out from the spinal cord to the muscles
define perception
the processes of obtaining information about the internal / external environment from sensory stimulation
define sensory neurons
(afferent) enter the spinal cord via the dorsal root
define interneurons
sit within the CNS
define motor neurons
(efferent) exit the spinal cord via the ventral root
what are the components of a sensory neuron ?
- cell body
- axon
- peripheral fibre
- central terminal branches
- dendrites
define cell body
- contains nucleus and cell machinery
- lie in the dorsal root ganglia
define axon
- carries impulses away from cell body into spinal cord
- can continue up spinal cord to brain
define peripheral fibre
carries impulses from dendrites to cell body
define central terminal branches
make connection with motor neuron dendrites or connector neurons in spinal cord
define dendrites
carries impulses from sensory receptors to peripheral fibre
define sensory receptors
cells or organs that are selective in their response to different types of stimuli
define exteroceptors
- located at / near a body surface
define interoceptors
- visceroceptors: impulses from internal organs
- proprioceptors: impulses related to movement
define photoreceptors
sensitive to light
define mechanoreceptors
sensitive to mechanical inputs
define chemoreceptors
sensitive to chemical substances
define thermoreceptors
sensitive to thermal energy
define sensory adaptation
- the stronger the stimuli, the higher the firing rate in the afferent axon
- response tends to decrease over time if stimulus stays constant
what are the 2 types of muscle proprioceptors ?
- muscle spindles
- golgi tendon organ (GTO)
define muscle spindles
- lie parallel and between muscle fibres
- sensitive to change in length
- stimulate muscle to produce force to resist stretching
