Receptors,Modalities And Spinothalamic Tract For Pain And Temperature Flashcards
What are the afferent signals for pain carried in?
Fast Pain -sharp and localized
Transmitted by small myelinated A delta fibers
Slow Pain-Duller and more diffuse
Carried on small unmyelinated C fibers
What are nociceptors?
Rapidly adapting receptors are sensitive to noxious or painful stimuli
Located at the peripheral terminations of lightly myelinated free nerve endings of A delta fibers or inmyelinatec type C fibers transmitting pain
What are the 3 types of nociceptors?
Mechanosensitive -Sencitibe to mechanical touch such as pinching with pliers
Temperature sensitive -Sensitive to heat or cold intensity
Polymodal -Mechanical,thermal or chemical
What are Thermoreceptors?
Sensitive to warmth or cold
Slow adapting receptors
What are the 3 types of thermoreceptors?
Cold -consists of A delta fibers that respond to cold Temp
Warmth -consists of free nerve endings of unmyelenated C fibers that respond to increase temp
Temperature sensitive -sensitive to excessive heat or cold
What are the sensory receptors for Pain?
Free nerve endings
Sensitive to touch or pressure
Situated between epidermal cells
Free nerve endings provide touch sensations are tonic Receptors with small receptive fields
What is the activation of nociceptors?
A variety of molecules released with tissue injury
Chemical mediators K,Histamine,Prostaglandin released from damaged cells and serotonin released from platelets activated by injury
What is Substance P?
It is a peptide released by primary sensory neurons and acts both as a Nt and a modulator that enhances the pain pathway
What is painful stimuli?
Carried by the lateral spinothalamic pathway to primary somatosensory cortex where it becomes conscious sensation
What are spinal reflexes?
Reflexes that dk not require integration in the brain
What are higher centers?
The ascending pathways for pain go in the limbic system and hypothalamus as well as the sensory areas of the cortex
What is Strong visceral pain?
Sensations arriving at a segment of spinal cord can stimulate interneurons that are part of the spinothalamic pathway And activity in interneurons lead to stimulation of primary sensory cortex so an individual feels pain in specific part of body surface
What is acupuncture?
Amanipulatiom of needles inserted in specific locations of the body and enhances a form of energy that promotes healing
The needle stimulates And triggers the release of endorphins
What are analgesic drugs?
Aspirin -inhibits prostaglandin and slows transmission of pain signals from site of injury
Opiates-act directly on opioid receptors In the brain and activates descending pathways that inhibit pain
