Touch Flashcards
What does the somatosensory system do?
Provides information to the body to the brain.
What type of information is sent to the brain? (List)
Touch, pressure, vibration, pain, temperature, proprioception (body position)
What is discriminative information?
Specific details eg. shape, texture, colour, volume
What is non-discriminative information?
General information, eg. Hunger, fatigue, pain, anxious/stressed with no known trigger
Exteroception
Info about external world
Mechanoreception (tactile sensitivity)
Pressure/touch
Thermoreception (thermal sensitivity)
Temperature
Nocireception (noxious sensitivity)
Damage or potential damaging stimuli
PROPRIOCEPTION
Position, movement of limbs/body in space (works with balance system)
Interoception
Information from internal organs
Somatosensory receptors are…
Specialised endings of nerve fibres
How are somatosensory nerve endings specialised?
They have special ion channels and accessory structures
What forms accessory structures?
Connective tissue and fluid
Why don’t we need special accessory structures?
The skin is viscous and elastic and able to modify the way stimulus energy arrives at the somatic receptor
What are touch sensations?
Cutaneous discriminative mechanoreceptors - information coming from the skin
What are the main cutaneous mechanoreceptors?
Meissner’s corpuscles (upper layers)
Merkel’s disks (upper layers)
Pacinian corpuscles (deep in skin)
————
Hair follicles (replace Meissner’s, nerve endings wrap around base of hair follicles)
What is adaption rate?
If something is changing and how fast
What is receptive field size?
How precisely you can identify where the stimulus is
Form perception
Ability to identify form and shape of objects solely by touch
Texture perception
Ability to feel and discriminate the smoothness/roughness of an object
Vibration perception
Ability to distinguish something fluttering on our skin to something vibrating on our skin
What activates ion channels?
Pressure or membrane displacement
