Somatic Sensation Flashcards
What is sensation?
A physical feeling from stimulation of a sense organ
What is somatic sensation?
Feeling detected by a body wall
What is visceral sensation?
Feeling detected by an organ
What is special sensation?
Feeling detected by a specialised cranial nerve
What is a modality?
The stimulus that a specific receptor is sensitive to
List 4 sensory modalities
Temperature Pain Stretch Vibration 2-point discrimination Pressure
Give an example of a tonic modality
Pain
What is a tonic receptor?
A receptor which is slowly adapting to a stimulus. The stimulus is felt continuously at the same pressure so the person is constantly aware of the stimulus
What is a phasic receptor?
A receptor which quickly adapts to the stimulus so the stimulus is felt initially and then although it remains present, is not felt over time
Give an example of a phasic modality
Pressure
What is a receptive field?
The area that 1 sensory nerve supplies
When is receptor acuity at its best?
When there is a high density of sensory neurones and the receptive fields are very small
Why can dermatomal boundaries overlap?
Receptive fields can overlap so on the edges of dermatomal boundaries the edges blur
What is lateral inhibition?
More than 1 nerve is stimulated but the brain wishes to know which is stimulated more. The lateral nerves to the most stimulated nerve are inhibited by a inhibitory interneurone.
What is the function of lateral inhibition?
Enhance receptor acuity
