Term
|
Definition
It is described as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. |
|
|
Term
What specialized receptors perceive pain and where? |
|
Definition
*Dorsal horn by A-delta and C-fibers
*Dorsal horn contains complex circuitry of neurons
*6 Laminae (Rexed's)
*Substantia Gelatinosa (Lamina II)
*Interneurons or 2nd neurons
|
|
|
Term
Where is the first and second neurons in the pain pathway located? |
|
Definition
*1st is located in the spinal ganglia or ganglia of CNs
*2nd is located in dorsal horn or the rhombencephalon |
|
|
Term
What effect does pain have on perfusion? |
|
Definition
*Direct activation of autonomic sympathetic neurons by the processing of nociceptive information of the segmental spinal level can lead to immediate changes in the perfusion of defined areas. |
|
|
Term
Where are the high concentrations of opioid receptors in the spinal cord? |
|
Definition
*In the dorsal horn in the periaqueductal gray area
*Greatest abundance is substantia gelatinosa |
|
|
Term
Where do opioid receptors have the highest affinity for opioids but do not have the greatest number? |
|
Definition
|
|
Term
What is the endogenous pathway for pain? |
|
Definition
Periaquaductal gray matter-->Nucleus raphe magnus--> substantia gelatinosa-->APs stimulate enkephalin release OR exogenous given ligands-->Decreases APs to lateral spinothalamic tract |
|
|
Term
What is the exogenous pathway for pain? |
|
Definition
*AP stimulate enkephalin neurons-->enkephalin released or exogenous given-->decreases action potentials to lateral spinothalamic tract. |
|
|
Term
How do opioids effect presynaptic receptors? |
|
Definition
*Presynaptic receptors inhibit th release of substance P, glutamate and other neurotransmitters and postsynaptic receptros decrease the evoked excitatory postsynaptic potential (EPSP). |
|
|
Term
Where are first order and second order receptors found? |
|
Definition
*First order found outside of the cell
*second order found on the inside of the cell |
|
|
Term
What are the natural ligands for opioid receptors? |
|
Definition
*Enkephalins
*Endorphins
*Dynorphins |
|
|
Term
What are the most clinically relevant pharmacodynamic measures? |
|
Definition
*Potency
*Speed of Onset
*Duration of Action |
|
|
Term
What is used as the benchmark analgesic opioid? |
|
Definition
|
|
Term
|
Definition
*Fentanyl
*Sulfentanyl
*Alfentanil
*Remifentanil
*Methadone |
|
|
Term
What are important pharmacologic characteristics? |
|
Definition
*Metaboism
*Bioavailability
*Protein binding
*Lipid solubility |
|
|
Term
What do all opioid receptors have common? |
|
Definition
They all are G-protein coupled receptors |
|
|
Term
What are the MOA when G-protein coupled opioid receptors are activated? |
|
Definition
*Potassium ion channels open causing hyperpolarization and decreased neuronal firing
*Reduction of calcium ion influx and subsequent neurotransmitter release
*Glutamine and substance P release is inhibited |
|
|
Term
Why can muscle rigidity result with opioid use? |
|
Definition
*Inhibition of dopamine release and GABA pathways in the striatum and substantia nigra. |
|
|
Term
How can muscle rigidity be treated |
|
Definition
With a partial antagonist such as Nubain or Stadol. Allows delta and kappa receptors to have opioid agonist on board but removes Mu agonist only. |
|
|
Term
What nerve fibers and neurotransmitters are associated with acute pain? |
|
Definition
*A-delta nerve fibers
*Glutamate |
|
|
Term
What nerve fibers and neurotransmitter are associated with chronic pain? |
|
Definition
*Unmyelinated C fibers at the dorsal roots and free nerve endings
*Substance P |
|
|
Term
What does substance P do to vessels? |
|
Definition
It increases vasodilation and permeability |
|
|
Term
Describe Superficial somatic pain, where receptors are located, and what to use for treatment |
|
Definition
*Superficial Somatic pain is characterized by sharp, throbbing, pricking and is well localized
*Nociceptive receptors in skin, sub Q tissue, mucous membranes
*Treat with opioids |
|
|
Term
Describe deep somatic pain, location of receptors and treatment |
|
Definition
*Deep somatic pain is characterised by dull, aching, quality more diffuse
*Arises from muscle, tendon, joints, and bones
*NSAIDS such as Torodol, good drug |
|
|
Term
What is radicular pain caused by? |
|
Definition
*Irritation of nerve roots ie disc herniation |
|
|
Term
|
Definition
*Weakness, numbness, tingling or loss of reflexes in the distribution of the nerve. |
|
|
Term
What does neuropathic pain result from? |
|
Definition
*Injury to the nervous system either central or peripheral.
*Occurs after trauma and many disease |
|
|
Term
What is the first line therapy in cancer pain treatment? |
|
Definition
|
|
Term
Why does cancer pain arise? |
|
Definition
*Arises when a tumor presses on bone, nerves, or body organs.
*Tumor cells lie between capillary and nerve causing inflammation when the chemo destroys the cells. |
|
|