Pain Sensory Flashcards
Nociceptors are
Pain receptors, that have free nerve endings , respond to damage tissues, and are located on the surface of organ or skin or in the skin
Pain can be induced by
Chemo, thermal, and mechanical receptors
Fast pain
Aka sharp pain,pricking pain, acute pain , electric pain, has a short interval,and can be induced by thermal and mechano receptors
Slow pain
Aka slow burning, aching,throbbing, nauseous and chronic pain. It becomes less painful due to adaptation, induced by chemo, thermal , mechano receptors
Molecules that can induce pain due to the activation of the chemo receptors
Bradykinin , serotonin , histamine , Na levels, hydroids, ACTH , and proteolytic enzyme
Pain modulators
Can affect the intensity of the pain, chemical such as substance p and prostaglandins are modulators they enhance the the sensitivity of the pain but do not directly exite them
Some pain receptors are hyperalgeisa
Meaning increase sensitivity of pain
Ischemia
Sudden decline of blood flow to a certain organ, when blood flow to a tissue is blocked the tissue often become very painful due to anaerobic metabolic waste build up
Muscle spasms
It is involuntary contraction of the muscles, as the muscle contract involuntarily it squeezes the blood vessels and cause a resistance in blood flow, as resistance increase, metabolic waste will build up leading to an ischemic effect. Thus leading to pain due metabolic waste build up
Neospinothalamic tract
One of the pathways of pain which is used by fast pain receptors, the signal goes up the dorsal roots of the spinal cord synapses with the interneurons . The interneurons then synapses with the secondary sensor neurons.
Paleospinothalamic tract
Used by slow pain. It enter through the dorsal root
Acute (pathological pain)
Brief period of pain
Chronic pain( neuropathic pain)
Acute pain that lingers for years even after the tissue have been healed, the problem arise in the dorsal root, and it is associated with glial cels ( astrocytes and microglia)
Neurotransmitter that help to suppress pain are
Serotonin and natural opiates
Natural opiates
Binds to receptors and block off pain, there are 3 natural opiates that are peptide. They have 3 different precursor protein theatre cleaved to give rise to eukephalin , endorphin, dynorphins
Artificial suppression of pain
Is done by some drug as prostoglandins, glucosamine, and prostacyclin are used to block pain and NAIDs
NSAIDs
Mimics steroids drugs, blocks the formation of steroids, blocks the cox pathway therefore preventing the synthesis of 3 chemicals that cause pain
Cox pathway( cyclooxygenase)
Converts arachidonic acid into prostaglandins, prostacyclin a, thromboxin which are pain inducers
Lipooxygenase pathway
Converts arachidonic acid into eucotrienes which also induce pain
Sensitized molecules
Released by the glial cells due to the summation effect, can be growth factors or cytokines. It increases the responsiveness of post synaptic secondary neurons and recuit additional glial cells to release sensitizers, thus it heightens sensitivity and prolongs it therefore causing chronic pain
Neurotransmitters released by the pre synaptic neuron that can affect the glial cells that can eventually cause chronic pain are
ATP , nitric oxide, and glutamine
Endocannabonoids fatty acids
Two types produced in the brain that induce two different endocannabonoids receptor Cb1 and cb2
Cb1
Found in neuron and it deals with psychological effects
Cb2
Found in glial cells and it deal with pain suppression, the active ingredient in marijuana can inhibit cb2 receptors which stops chronic pain ( analgesic effect)
