touch/pain Flashcards
(18 cards)
how many neurons are in touch?
4
how many neurons are in pain?
3
how many neurons are in nociceptive reflexes?
3
what is the difference between nociceptive reflexes and pain?
the difference is in the nociceptive reflexes the 2nd neuron does not go to the brain it talks directly to the muscle
Nociception vs. pain
Pain: “an unpleasant sensory and emotional experience associated with actual or potential tissue damage…”
Nociception was first coined to distinguish the physiological process from ‘pain’ (a subjective experience).
There are four major processes in pain name and explain them
Transduction refers to the processes by which tissue-damaging stimuli activate nerve endings.
Transmission refers to the relay functions by which the message is carried from the site of tissue injury to the brain regions underlying perception.
Modulation is a recently discovered neural process that acts specifically to reduce activity in the transmission system.
Perception is the subjective awareness produced by sensory signals; it involves the integration of many sensory messages into a coherent and meaningful whole. Perception is a complex function of several processes, including attention, expectation, and interpretation.
What are the three types of stimuli that can activate pain receptors in peripheral tissues?
mechanical (pressure, pinch), heat, and chemical. Mechanical and heat stimuli are usually brief, whereas chemical stimuli are usually long-lasting.A variety of pain-producing chemicals activate or sensitize primary afferent nociceptors.
Transduction needs what for it to happen?
It needs Noxious stimuli → electrical signals
What are mechanoreceptors?
(touch receptors) respond to blunt objects, but do not respond to pinpricks or pinches.
What are nociceptors?
(pain receptors) respond to pinpricks and pinches, but not blunt objects.
What are primary somatosensory neurons?
Known as pseudounipolar neurons
Only have one process coming off their cell body but they actually do have 2 processes. The cell body will only have a single process coming off the cell body but it then divides into two separate processes one axon will talk to the PNS and axon one will go into the CNS
There are 3 main neurons for pain
1st one is mechanoreceptor and it is the most myelinated and it sends information the fastest for sharp intense pain
the 2nd one is myelinated a well just not as much and primarily used for pain and temperature
the 3rd one is not myelinated and takes longer to send information to the brain about pain and the pain is usually dull and lasts a while.
define transmission
Neural events from the periphery to the brain
Ascending pain pathway
The nociceptive message is transmitted from the periphery to the central nervous system by the axon of the primary afferent nociceptor. This neuron has its cell body in the dorsal root ganglion and a long process, the axon, that divides and sends one branch out to the periphery and one into the spinal cord. The axons of primary afferent nociceptors are relatively thin and conduct impulses slowly
Define Modulation
Central nervous system can selectively inhibit or enhance pain signals
Abnormal Pain
-non-protective leads to chronic (Pain as Disease)
Normal Pain
-protective which can be either acute or prolonged. Acute reflexes and prolonged inflammation and repair.
Define Perception
Subjective interpretation by the brain
- Sensory component; Affective component
