Pain Pathways Flashcards
What are the three types of pain?
- Superficial somatic pain
- Visceral pain
- Deep somatic pain
Superficial somatic pain involves skin receptors, visceral pain involves organs like uterus, and deep somatic pain involves muscles, joints, and tendons.
What is superficial somatic pain?
Stimulation of receptors in skin (cuts and burns)
This type of pain is typically sharp and localized.
What is visceral pain?
Stimulates receptors in visceral organs (contractions)
An example is pain during the first stage of labor, transmitted via T10-L1.
What is deep somatic pain?
Stimulation of receptors in muscles, joints, tendons
This type of pain is experienced in the second stage of labor, transmitted by S2-S4.
What identifies pain in the body?
Nociceptors (pain receptors that are free nerve endings found in every tissue of the body)
Nociceptors are crucial for the perception of pain.
What are mechanical nociceptors?
Respond to damage like cutting or crushing
They are one type of nociceptor that detects physical injury.
What do thermal nociceptors respond to?
Temperature
They detect extreme temperatures that can cause harm.
What do polymodal nociceptors respond to?
Pain receptor that responds to Damaging chemical irritants
How does a C neuron transmit pain?
Travels to spinal cord, then to brain stem reticular formation, thalamus, and cerebral cortex
This pathway helps in identifying and localizing pain.
How does an A neuron transmit pain?
nociceptor identifies pain, travels signal to spinal cord nociceptor. Misses brain stem reticular formation, straight to thalamus to identify there is pain, and combined with glutamate to go cerebral cortex to identy where pain is.
What are some physiological effects of pain?
- Increased HR
- Increased cardiac output
- Increased BP
- Increased RR
- Vasoconstriction
- Decreased uterine blood flow
- Nausea and vomiting
These effects are part of the body’s stress response to pain.
What are opioids?
Drugs that bind to opioid receptors within nociceptive afferent pathways
They alter pain perception and can cause various actions and effects.
What is the role of naloxone (Narcan)?
Blocks opioid receptors in overdose situations
It is an opioid antagonist that can reverse the effects of opioids.
Why can’t opioids be given close to birth?
They cross the placenta
This can affect the fetus and newborn.
What do local anesthetics like lidocaine do?
Block Na+ channels in neurons to stop pain messages
They are used to provide localized pain relief.
What is the gate control theory?
Stimulating larger sensory nerves can block smaller neurons transmitting pain
This theory explains how non-painful stimuli can inhibit the perception of pain.
What are common types of analgesia?
- Opioids
- Local anesthetics
- NSAIDs
- Non-pharmacological methods
Each type has different mechanisms and applications for pain management.
What are the 3 main types of nociceptors?
Mechanical
Thermal
Polymodal
Which nociceptor misses the brain stem reticular formation - A or C
A
