Chemicals that reduce or inhibit the transmission or perception of pain is

NHM UP Staff Nurse-2021 Shift-1st

Pharmacology

Easy

Appeared in: NHM UP Staff Nurse-2021 Shift-1st

Explanation

Endorphins are endogenous opioid peptides that function as the body's natural analgesics (pain relievers).
They are produced in the central nervous system and pituitary gland in response to stimuli like stress, exercise, or pain.
Endorphins bind to opioid receptors, primarily in the brain and spinal cord, which blocks the transmission of pain signals from the periphery.
This mechanism effectively reduces the perception of pain and can also induce feelings of euphoria, similar to the action of opioid medications like morphine.

Option A: Prostaglandins are inflammatory mediators that are synthesized at the site of tissue injury. They do not inhibit pain; instead, they sensitize nociceptors (pain receptors), lowering their threshold and increasing pain perception.
Option B: Leukotrienes are chemical mediators primarily involved in allergic and inflammatory processes, such as bronchoconstriction in asthma. They do not have a primary role in the direct inhibition of pain signals.
Option D: Serotonin has a complex, dual role in pain modulation. While it is part of the descending pathways that can inhibit pain, it can also facilitate pain in other contexts. Endorphins are the body's most direct and potent natural pain inhibitors.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Physiology of Pain Modulation and Endogenous Analgesics as background academic context rather than a clinical decision trigger.
Understanding the endorphin system helps nurses appreciate the effectiveness of non-pharmacological pain management techniques like exercise, acupuncture, TENS (transcutaneous electrical nerve stimulation), and even laughter, all of which are known to boost endorphin levels.
This physiological concept is the foundation for understanding how opioid analgesics (e.g., morphine, fentanyl) work. These drugs are exogenous agonists that mimic the body's natural endorphins to provide powerful pain relief.
Nurses can educate patients that engaging in pleasant and distracting activities can help manage pain by naturally stimulating the body's own pain-control system.

How to Approach the Question

First, analyze the question to identify the core concept. The keywords are 'reduce or inhibit' and 'perception of pain,' which points to an analgesic (pain-killing) substance.
Next, evaluate each option based on its primary physiological function related to pain.
Eliminate options that are known to cause or worsen pain. Prostaglandins are classic inflammatory mediators that increase pain sensitivity, so this can be ruled out.
Eliminate options with unrelated primary functions. Leukotrienes are mainly associated with allergies and asthma, not direct pain control.
Differentiate between the remaining options. Both Endorphins and Serotonin are involved in pain pathways. However, recall that 'endorphin' is short for 'endogenous morphine,' which directly highlights its primary role as the body's natural opiate for pain relief.
Select the option that is the most direct and potent inhibitor of pain perception, which is Endorphins.

Concept Tested & Keywords

QPMWQbq83o4mrajrHhnMOU

E6 Nursing Fundamentals Taylor p. 226-228

E6 Physiology Guyton 4SAE Part 3 p. 107-109

E6 Physiology Essentials Sembulingam 10e Part 3 p. 112-114