2012 Group Project 2

From Embryology
Revision as of 20:00, 29 August 2012 by Z3331951 (talk | contribs) (Pressure)


Somatosensory Development

--Mark Hill 12:23, 15 August 2012 (EST) This is a better project title.

- Touch, Pain, Hot/Cold, Pressure Reception


Introduction

History of Discoveries

Central Somatosensory Differentiation

This is just preliminary work and will be edited later:


Making Connections between Afferent Sensory Fibres and the Central Nervous System (CNS)

Stage 23;

  • Axons of primary afferent neurons extend to the spinal cord. When these afferent neurons reach the CNS, axons of these afferent neurons bifurcate and begin to extend into the Primordium of the dorsal funiculus


Stage 24:

  • the afferent axons have extended 1 segment rostrally and 1 segment caudally relative to the axons' point of entry
  • the afferents start to grow within the white matter (periphery of Spinal Cord)

Stage 28 –

  • unbranched afferent axonal fibres invade gray matter at the border of Dorsal horn
  • axonal fibres extend rostrally and caudally and start sending fine collateral fibres into the gray matter of spinal cord (the cellular, central region of spinal cord)

Stage 29:

  • afferent fibres have extended 100-200μm into gray matter of the Dorsal Horn

Reference: <pubmed>2918087</pubmed>


Adult Central Somatosensory Pathway

Touch

Pain

Hot/Cold

Pressure

Thermoreceptors(1)

- Convey information regarding the temperature of the nerve ending in the tissue o Free nerve endings o Ion channels responsible for action potentials are called Transient Receptor Potential channels. Their activity is modulated by temperature - Two type, warm and cold - Warm- 30-45 - Cold – 20 – 30 - Frequency of action potentials codes for the relevant temperature o As temperature increases, the frequency of warm thermoreceptors increases o As temperature decreases, the frequency of cold thermoreceptors increases. - Receptors o Warm – TYPV1 to V4 o Cold – TRPM8 and TRPA1 From: 1. Stanfield, C. L., and W. J. Germann. 2011. Principles of human physiology. Pearson/Benjamin Cummings, San Francisco, CA.

Current Research

Glossary

References


External Links

External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.

--Mark Hill 12:22, 15 August 2012 (EST) Please leave the content listed below the line at the bottom of your project page.


2012 Projects: Vision | Somatosensory | Taste | Olfaction | Abnormal Vision | Hearing