Pain 1 Flashcards
Center surround structure of receptive field
Critical for lateral inhibition to occur
Lateral Inhibition
Perception of the Edges of stimulus
Center surround receptor field
Precise localization sensation (determining the location of the stimulus)
Dorsal Column- Medial Lemniscal pathway
Somatic Touch
- from peripheral to brain
In medulla
dorsal column nuclei, CROSSES midline and forms medial lemniscus
Medial Lemniscus Fibers
Travel up to the thalamus, synapsing in the ventral posterior nuclei
Thalamic Axons
Ascend to primary somatosensory cortex.
Primary Somatosensory Cortex divides into
3a, 3b, 1,2
3 a and 3b
Sends and receives info to 1 and 2
3b
Touch information
1
Texture
2
Size and Shape
Homunculus
Shows a mans body size proportional to cortical representation .
Secondary Somatosensory Cortex (SII)
- object Recognition
- Discern texture, shape, and size
- Sends projections to the posterior parietal cortex, premotor cortex, amygdala, and hippocampus.
Oral Somatosensation
Tooth Pulp and Periodontal ligament
Tooth Pulp
Pain Receptors
Periodontal Ruffini endings
- Sensory info about tooth position.
- Forces to facilitate reflex jaw activity during chewing.
Heat Pain Receptor
TRPV1 & TRPV2
- 1 is activated by capsaicin (Hot peppers)
Warm Receptor
TRPV3 & TRPV4
Cool Receptor
TRPM8
- Activated by menthol in mint oil
Cold Pain Receptor
TRPA1
- Activated by irritating compounds (Mustard Oil)
Nociceptive Substances
Substance P and CGRP Calcitonin gene related peptides
Substance P activates
immune cells
Mast Cells and Neutrophils release
PGE2, Bradykinin, histamine