Nerve Conduction and Pain Mechanics

These flashcards cover key concepts about nerve conduction, pain mechanics, pathways of pain modulation, and the role of various nerves involved in pain perception.

What is the threshold potential required to start nerve conduction?

-55mV

What is depolarization in the context of nerve conduction?

A change in charge or polarity from negative to positive, characterized by a rapid influx of Na+ ions.

What occurs at the peak of action potential?

The inside of the cell membrane becomes increasingly electropositive, reaching +40mV.

What is repolarization?

The phase when K+ channels open, allowing efflux of K+ ions, causing the membrane potential to become more negative.

What is hyperpolarization?

A state where the action potential is more negative than the resting potential.

What is the refractory period?

The duration after a nerve impulse during which the neuron cannot fire again.

What are the two pathways involved in pain modulation?

Ascending and Descending pathways.

What is the difference between pain threshold and pain tolerance?

Pain threshold is the minimum intensity of a stimulus to be perceived as pain, while pain tolerance is the maximum intensity an individual can endure.

How does fear relate to pain perception in patients?

Fear and anxiety can enhance the perception of pain, as fear can activate physiological changes that intensify the pain experience.

What is acute pain?

Pain that lasts for a few seconds to no more than 6 months.

What defines chronic pain?

Pain that persists for more than 6 months, with or without an identifiable cause.

What are nociceptive pain and neuropathic pain?

Nociceptive pain is caused by injury or disease in body tissues, while neuropathic pain is due to nerve injury or dysfunction.

What is pain catastrophizing?

An overwhelming level of anxiety and apprehension in anticipation of pain.

What is the role of the trigeminal nerve in pain perception?

It provides sensory innervation to the face and oral cavity, playing a crucial role in transmitting pain signals.

Why is the Substantia Gelatinosa important in pain modulation?

It acts as a 'Gate' in the Gate Control Theory, regulating the transmission of pain signals from the periphery to the brain.

What is the threshold potential required to start nerve conduction?

-55mV

What is depolarization in the context of nerve conduction?

A change in charge or polarity from negative to positive, characterized by a rapid influx of Na+ ions.

What occurs at the peak of action potential?

The inside of the cell membrane becomes increasingly electropositive, reaching +40mV.

What is repolarization?

The phase when K+ channels open, allowing efflux of K+ ions, causing the membrane potential to become more negative.

What is hyperpolarization?

A state where the action potential is more negative than the resting potential.

What is the refractory period?

The duration after a nerve impulse during which the neuron cannot fire again.

What are the two pathways involved in pain modulation?

Ascending and Descending pathways.

What is the difference between pain threshold and pain tolerance?

Pain threshold is the minimum intensity of a stimulus to be perceived as pain, while pain tolerance is the maximum intensity an individual can endure.

How does fear relate to pain perception in patients?

Fear and anxiety can enhance the perception of pain, as fear can activate physiological changes that intensify the pain experience.

What is acute pain?

Pain that lasts for a few seconds to no more than 6 months.

What defines chronic pain?

Pain that persists for more than 6 months, with or without an identifiable cause.

What are nociceptive pain and neuropathic pain?

Nociceptive pain is caused by injury or disease in body tissues, while neuropathic pain is due to nerve injury or dysfunction.

What is pain catastrophizing?

An overwhelming level of anxiety and apprehension in anticipation of pain.

What is the role of the trigeminal nerve in pain perception?

It provides sensory innervation to the face and oral cavity, playing a crucial role in transmitting pain signals.

Why is the Substantia Gelatinosa important in pain modulation?

It acts as a 'Gate' in the Gate Control Theory, regulating the transmission of pain signals from the periphery to the brain.

What is the typical resting membrane potential of a neuron?

About -70mV, maintained primarily by the Na+/K+ pump and K+ leak channels.

What is the main function of the Sodium-Potassium (Na+/K+) pump in nerve cells?

It actively transports 3 Na+ ions out of the cell and 2 K+ ions into the cell, maintaining the resting membrane potential and restoring ion gradients after an action potential.

How does myelination affect the speed of nerve impulse conduction?

Myelination significantly increases the speed of nerve impulse conduction through saltatory conduction, where the action potential 'jumps' between Nodes of Ranvier.

According to the Gate Control Theory of Pain, what mechanism can reduce pain perception?

Non-painful input can 'close the gate' to painful input, preventing pain sensations from reaching the central nervous system. This is achieved through the activation of A\beta fibers that inhibit the transmission cells in the spinal cord.

What is allodynia?

Pain caused by a stimulus that does not normally provoke pain, such as light touch or brushing of the skin.