Somatosensory System Flashcards
(42 cards)
What are the 3 types of somatosensory systems
Cutaneous (skin) sensation
Visceral (internal organs)
Proprioception (identity of limbs)
Which receptors in somatosensory system convert stimuli eg light into AP
Sensory receptors
What is a stimuli converted to in first step of sensory transduction
Receptor / graded potential
What happens if receptor/ grades potential reaches threshold due to large stimulus
AP can be fired
In AP initiation what suggests large stimulus
AP frequency
On the skin, what are the 2 layers called
Top epidermis and bottom dermis
Where are most receptors in skin found
In dermis (superficial)
What are the 4 skin receptors which are superficial
Merkels disk
Meissner corpuscle
Hair follicle receptor
Free nerve (no receptor)
What are the 2 types or deep receptors
Pacinian corpuscle
Ruffini’s corpuscle
What are the 3 nerve fibres connected to skin receptors
AB - large and myelinated (fastest)
A delta - small and myelinated
C - small and unmyelinated (slowest)
What is a receptive field
Area which a stimulus activates receptors and the nerve fibres
Which 2 receptors have small receptive fields
Meissner corpuscle and merkels disk
Which skin receptor detects stroking in a direction (large RF)
Ruffinis
What are slow adaptation receptors
Receptors which have a receptor potential and therefore fire AP all the way through a stimulus
What are fast adapting receptors
Receptors which have receptor potential / AP firing at start and end of stimulus not during
What are fast adapting receptors useful for
Identifying change Eg the slipping of an object
What on a pacinian corpuscle allows it to have a rapid adaptation
It’s capsule (bends during a stimulus, then pushes back at end of stimulus = rapid adaptation)
What are bare nerve endings for (superficial skin endings)
Detection of warm or cold temperatures
Which nerve is attached to bare nerve endings in skin to detect warm temp
C fibre (small and unmyelinated)
Which nerve ending defects cold in skin
A delta (small and myelinated)
Which receptors detect pain/ noxious stimuli
Nociceptors
What are 4 types of nociceptors
Mechanical (crushing pricking pain)
Thermal pain
First pain (stabbing)
Second pain (burning)
What detects sharp sensation (first pain)
A delta nerve endings
Which nerve detects second pain (burning)
C fibre
