Touch Flashcards
What are the four different types of stimulus?
MTNP
Mechanoreceptor- force, touch, pressure, vibration, stretch
Thermoreceptors- changes in temperature
Nociceptors- pain
Pruriceptors- itch
What are the three location of stimulus receptors?
EIP
Exteroceptors- outside body {touch, pressure, pain, special senses}
Interoceptors (visceroceptors)- inside body {chemical changes, stretching tissues, temperature} typically aware when hungry, thirsty, experiencing discomfort
Proprioceptors- internal stimuli {located only in skeletal muscle, tendons, joints, ligaments}
Cutaneous sensory system contain?
Skin, nerves, receptors Spinal cord Brain network Cognition-emotion Grooming and affiliative bhvrs
Proprioreceptors of skeletal muscles
Axon type
Diameter
Conduction speed
Aa
13-20
80-120
Mechanoreceptors of skin
Axon type
Diameter
Conduction speed
AB
6-12
35-75
Pain temperature receptors
Axon type
Diameter
Conduction speed
Ad
1-5
5-30
Temperature, pain, itch
Axon type
Diameter
Conduction speed
C
- 02-1.5
- 5-2
Two types of skin, what are they?
Glabrous
Hairy
What are first order neurons?
Cell bodies in DRG or cranial nuclei
Conduct impulses from receptors/propioreceptors to the cord or brain stem to synapse
What are second order neurons?
Transmit impulses to the thalamus or cerebellum where they synapse
What are third order neurons?
Located in thalamus & conduct impulses to the somatosensory cortex of the cerebrum
What are two pathways?
Spinothalamic pathway- carries most info about skin, temp and pain (slower)
Dorsal-column medial lemniscal pathway- carries signals about touch, pressure and position (fast)
What is posterior column pathway?
Fasciculus gracilis
Fasciculus cuneatus
Carries sensations from highly localised touch, pressure, vibration and proprioception
What is anterolateral pathway?
Ascend within what?
What do anterior spinothalamic tracts carry?
What does the lateral spinothalamic tracts carry?
Sensations of crude touch, pressure, pain and temp
Anterior or lateral spinothalamic tracts:
Crude touch and pressure sensations
Pain and temp sensations
What is topographic organisation?
What is homunculus?
Similar to somatosensory map in brain area of touch corresponds with area in brain
A map-like representation of regions of the body in the brain
