Physiology of Nociception

Play an AI-generated podcast conversation about this lesson

Which type of nociceptor is responsible for conducting slow, poorly-localized pain and itching sensations?

A-delta fibers

C fibers (correct)

Polymodal nociceptors

Silent nociceptors

What type of stimuli can activate polymodal nociceptors?

High intensity mechanical, chemical, or thermal stimuli (correct)

Prolonged exposure to cold temperatures

Lack of inflammatory response

Low intensity mechanical stimuli

Which type of nociceptor is responsible for conducting sharp, well-localized pain?

C fibers

A-delta fibers (correct)

Fast pain fibers

Silent nociceptors

In which setting would silent nociceptors be 'awakened' to transmit pain information?

In the setting of continuous damage or inflammation Signup and view all the answers

What is the conduction velocity range of C fibers?

0.5 – 2 m/sec Signup and view all the answers

Which type of fiber is primarily responsible for transmitting thermoception (temperature) sensations?

C fibers Signup and view all the answers

Which type of pain is carried by A-delta fibers?

Fast pain Signup and view all the answers

Where do the fibers of the paleospinothalamic pathway synapse?

Thalamic nuclei Signup and view all the answers

What is the likely reason for the projection neurons to be inhibited in the spinal cord?

Release of enkephalins Signup and view all the answers

Which type of pain sensation likely ascends along the anterior spinothalamic tract?

Visceral pain Signup and view all the answers

What is responsible for bringing the most relief when activated due to its higher concentration on C-fibers?

Mu opioid receptors Signup and view all the answers

Which type of pain perception does not exhibit adaptation like touch, taste, and smell?

Fast pain Signup and view all the answers

What is a characteristic of dermal pain?

Often described as sharp or burning Signup and view all the answers

Which type of nociceptors are activated by intense pressure applied to a structure?

Mechanical nociceptors Signup and view all the answers

Which part of the body is often associated with dull, pressure-like pain?

Skeletal muscle Signup and view all the answers

Which type of pain can be described as dull, cramping, but can also be sharp?

Visceral pain Signup and view all the answers

What is a characteristic of mesothelial linings pain?

Usually described as sharp Signup and view all the answers

Which areas in the CNS share similar geographic areas for pain perception and mood disorders?

Amygdala, cingulate gyrus, insular cortex Signup and view all the answers

What monoamine areas in the midbrain are linked to both descending modulation of pain and the pathophysiology of depression?

Serotonin and norepinephrine Signup and view all the answers

What distinguishes referred pain from superficial skin nociception?

Referred pain is often confused with visceral pain Signup and view all the answers

Why is referred pain sometimes described as 'mixed message' pain?

Because it is confused with visceral pain Signup and view all the answers

Which type of fibers extend from the heart to areas like T1 – T2, causing referred pain to the inner side of the arm?

C fibers Signup and view all the answers

Which of the following statements about substance P is correct?

It is released by C fibers and causes long-lasting depolarization of projection neurons. Signup and view all the answers

What is the main reason why nerve injury can sometimes cause neuropathic pain instead of analgesia?

Nerve injury reduces the stimulation of inhibitory interneurons, leading to excessive activation of excitatory interneurons and nociceptive projection neurons. Signup and view all the answers

Which of the following statements accurately describes the role of A-beta fibers in the pain gate theory?

A-beta fibers stimulate inhibitory interneurons, reducing the transmission of pain from projection interneurons. Signup and view all the answers

What is the difference between the transmission of pain signals by A-delta fibers and C fibers?

A-delta fibers transmit fast, sharp pain, while C fibers transmit slow, dull pain. Signup and view all the answers

Which of the following pathways is associated with the transmission of fast, sharp pain?

Neospinothalamic pathway Signup and view all the answers

Which of the following statements accurately describes the concept of referred pain?

Referred pain occurs when pain is perceived in an area different from the site of injury or inflammation. Signup and view all the answers