The classical substances that increases the sensitivity of pain receptors by enhancing the pain-provoking eff… - ESIC Nursing Officer - 2019 (Shift-2)

ESIC Nursing Officer - 2019 (Shift-2)

Pharmacology

Easy

Appeared in: ESIC Nursing Officer - 2019 (Shift-2)

Explanation

Prostaglandins are hormone-like lipid compounds released during tissue inflammation and damage.
They do not directly cause significant pain but act to sensitize peripheral nociceptors (pain receptors), lowering their activation threshold.
This sensitization makes the receptors hyper-responsive to other chemical mediators like bradykinin, as well as to thermal or mechanical stimuli.
This process leads to hyperalgesia, which is an increased sensation of pain from a stimulus that is already painful.

Option A: A nociceptor is the sensory receptor (nerve ending) that detects painful stimuli. It is the biological structure that is being acted upon, not the chemical substance causing the change in sensitivity.
Option B: Endorphins are endogenous opioid peptides that act as natural analgesics (pain relievers). They bind to opioid receptors in the central nervous system to inhibit the transmission of pain signals, thereby reducing the perception of pain.
Option C: Encephalin, also known as enkephalin, is a specific type of endorphin. Like other endorphins, it is an endogenous opioid that functions to reduce pain by inhibiting pain signaling pathways.

Visual 1: Diagram: Illustrating the process of peripheral sensitization at a nociceptor terminal. The visual should show tissue injury leading to the release of inflammatory mediators like bradykinin and prostaglandins, and how prostaglandins make the receptor more sensitive to bradykinin.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pain Physiology and Chemical Mediators as background academic context rather than a clinical decision trigger.
Understanding this mechanism is fundamental to pharmacological pain management. Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and aspirin work by inhibiting the cyclooxygenase (COX) enzyme, which blocks the synthesis of prostaglandins. This reduces nociceptor sensitization and provides analgesia.
A nurse administering NSAIDs must monitor for potential side effects, especially gastrointestinal bleeding, renal impairment, and cardiovascular risks, as prostaglandins also have protective functions in these systems.
What if? If a patient has a condition where NSAIDs are contraindicated (e.g., active peptic ulcer, severe kidney disease), a nurse would anticipate the use of alternative analgesics like acetaminophen or opioids, which work through different pain-relief mechanisms.

How to Approach the Question

First, identify the key terms in the question: 'increases the sensitivity,' 'pain receptors,' and 'enhancing the... effect of bradykinin.' This points to a process of pain modulation, specifically sensitization.
Next, evaluate each option based on its known role in pain physiology.
Recognize that a 'Nociceptor' is a receptor, not a chemical substance, which makes it an unlikely answer for a 'substance'.
Recall that 'Endorphins' and 'Encephalin' (a type of endorphin) are the body's natural painkillers (opioids) that reduce pain sensitivity, which is the opposite of what the question asks.
This leaves 'Prostaglandins.' Recall or deduce that prostaglandins are key mediators of inflammation known to sensitize nociceptors to other painful stimuli, perfectly matching the question's description.

Concept Tested & Keywords

QsZ2trz_WE806q1qdkflci