Somatic sensation Flashcards
What are the somatic and visceral sensations
Touch
Pain
Temperature
Body position
What are the special senses
Vision Hearing Taste Smell (pheromones) Vestibular (balance)
What are the 4 types of information that describe a sensory stimulus
Modality
Intensity
Duration
Location
Describe modality
Type of sensory receptor activated (light, sound, taste, temperature, pressure, smell)
Describe intensity
Frequency of action potential firing (the stronger the sensory input the more the AP’s)
Describe duration
Duration of the AP firing. How long the sensation presents (onset and offset)
Describe location
Location of sensory receptors activated. Where on body ‘mapped’ in primary somatosensory cortex
How do we experience touch
Touch receptors have a receptive field. (Nerve endings are in tissue) Specific receptor will be associated with specific area of skin
Describe a specialised form of receptor
Associated with the skin stretching around joints.
Some sensory axons associated with single hair
Describe effect of stimulus intensity
The stronger the stimulus (further above the threshold) the stronger the action potential. Can activate more receptors.
Describe the affect of stimulus duration
often show adaptation - decrease output over time in response to continuous stimulation. (some touch receptors and vibration. Thermoreceptors and change in temp)
describe affect of location (receptive field)
Small fields and dense innervation gives good discrimination.
How can a receptive field send a stronger message
When they overlap or when a stronger stimuli activates more than one
What is transduction
When a stimulus is converted into an action potential
Describe the process of conscious sensation
Transduction to sensory receptors to
Afferent neurons to
Integration (cerebral cortex - conscious sensation)
