Nociceptor

Nociception After the initial insult, peripheral nociceptors are activated by transduction through thin myelinated Aδ and unmyelinated C-fibers to the dorsal root group and into the posterior horn of the spinal cord. The axon bifurcates into two branches with one branch continuing to the CNS, the other innervating peripheral tissues. Action potentials are generated and the nociceptive signals initiate excitatory neurotransmitters such as glutamate and substance P, neuromodulators including brain-derived neurotrophic factor. These bind with afferent nerves which activate corresponding receptors on the postsynaptic nerve terminals (Fishman et al., p. 29). Superficial lamina (laminae I and II) and deep laminae (lamina V and VI) receive primary afferent fibers in the dorsal horn. Projections from laminae I and V continue ventrally through the spinothalamic tract (STT) to the thalamus. The spinobulbar pathway receives input from the STT and continues to the hypothalamus, amygdala, periaqueductal gray…

ChanMee Bae Psych 421 Take-Home Exam Total 40 points with 2 One-Point Extra Credit 1. Where are the soma of the receptor cells for the sensation located? (1pt) Dorsal root ganglion of the spinal cord. (Students should state the spinal cord to get the point) 2. The pain receptors are called “nociceptors”, named one of the subtype of the nociceptors, and what are the one of four differences in those receptors? (2pts) 1) Mechanical. Thermal. or Polymodal. 2) Morphology of the peripheral ending.…

Response to Dr Foreman’s questions a. Discuss the nociceptive mechanisms, including the postsynaptic receptors of the spinal neurons, transmitters, pathways and nuclei that are activated when the injury occurs. Also include in your answer the explanation for the sharp pain and the long lasting pain that you experience with this injury. Nociceptors are specialized peripheral sensory neurons that are activated by noxious stimuli. These nociceptors are the free nerve endings of primary sensory…

This theory suggests that while pain does follow a specific pathway from the noxiuous stimulus to the brain via the spinal cord, there are gates in the spinal cord that can open and close which then control the flow of this information. When the gate is closed the information about pain can no longer reach the brain and therefore no pain is percieved. ( The open University 2017). Support for this theory comes from research that shows evidence of inhibitory interneurons in the spinal cord which…

DFQ #A. Explain in your own words everything you have learned about pain starting out with a definition. Pain is an unpleasant sensory and emotional experience caused by intense stimuli. Pain can range from dull, to extremely sharp, and even emotional. Pain can helps us survive by warning our bodies of potential danger, or can be an indicator that something is wrong. Pain is a feeling triggered by the nervous system. Our bodies are covered with millions of pain receptors called nociceptors.…

Work by Iggo and Perl had identified specific high threshold sensory neurons tuned to respond only to noxious stimuli, hence their name nociceptors , a term first coined by Sherrington based on his studies on noxious stimulus evoked flexion reflexes. Furthermore, first Perl and then others showed that nociceptor peripheral terminals could become ‘‘sensitized” after injury, reducing their threshold, mainly to heat stimuli, and only within the site of injury where the terminal was exposed to…

roaches feel little pain from the stimulation, which they quickly adapt to. Animal behavior scientist Jonathan Balcombe says that claiming that the insects aren’t seriously harmed by having body parts cut off is a blatant lie ("Cyborg Cockroach Sparks Ethics Debate"). Whether or not this impairment causes pain, however, is more debateable. Testing on insects is thought to be ethical because most insects do not have nociceptors, which most people refer to as pain receptors. Humans and most…

Visceral sensory receptors are located with the internal organs and blood vessels. Special senses receptors are located in the head. The five special senses are olfaction (smell), gustation (taste), vision (sight), hearing (audition), and equilibrium (head position and acceleration). Sensory receptors can also be classified by modality of stimulus. The five are chemoreceptors, thermoreceptors, photoreceptors, mechanoreceptors, and nociceptors. The chemoreceptors detect chemical, either molecules…

The alpha subunit has four different sections I - IV that have functions of different levels in voltage sensors, allowing the sodium to be able to pass through once they are in place. Sodium channels assist in forming the excitability of each distinct neuron. The gene of SCN9A has the specifications of forming a single section of the alpha subunit from the sodium channel named NaV1.7, which are precisely located in nociceptors. NaV1.7 creates and transmits action potentials and is essential for…

Pain that persists after the surgical wound has healed could be the result of somatic nociception, the consequence of ongoing inflammation (e.g. infection, haematoma), a manifestation of neuropathic pain from surgical injury to peripheral nerves (e.g. complex regional pain syndromes, neuralgias)3 , or from visceral nociception. chronic post surgical pain has been defined as “pathological pain that persists for longer than two months post surgery”. Recently, a mechanism of neuronal plasticity in…