Pain perception

Question 1

A delta

Answer 1

A delta
myelinated; fast responding; sharp, acute; thermal pain
C-type
slow responding; building pain;
mechanical; thermal; chemical

Question 2

The stages of pain pathway

Answer 2

• Transduction
• Conduction
• Modulation
• Perception

Question 3

1. Transduction

Answer 3

Starts with activation of nociceptors (specialized sensory receptors that detect harmful or potentially damaging stimuli) The harmful stimulus is converted into an electrical signal (action potential) by the nociceptors. involves the opening of ion channels in the nociceptor’s membrane, leading to depolarization and the generation of an action potential
Most of the nociceptors are subtypes of either chemoreceptors or
mechanoreceptors

Question 4

2. Conduction

Answer 4

An AP generated in nociceptor
terminals is conducted across the peripheral process to the central process were it depolarizes the presynaptic terminal. The presynaptic
terminal interfaces with a network of interneurons
and second order neurons
in the dorsal horn. Interneurons can facilitate or inhibit
transmission to second order neurons

Question 5

3. Modulation

Answer 5

Modulation means that the pain signal can be increased or decreased before it reaches the brain/ happens mainly in the spinal cord and brain.
Both excitatory and inhibitory mechanisms are involved. Chemicals (like neurotransmitters) can either amplify or dampen the pain signal. Adaptive process helps the body decide how important the pain is.

Question 6

4. Perception

Answer 6

• Action potentials ascending the spinothalamic tract are decoded by the thalamus, sensorimotor cortex, insular cortex and the anterior
  cingulate to be perceived as an unpleasant sensation that can be localized to a specific region of the body.
• Action potentials ascending the spinobulbar tract are decoded by the amygdala and hypothalamus to generate a sense of urgency and intensity. It is the integration of sensations, emotions and
  cognition that result in our perception of pain

Question 7

Gate Control Theory

Answer 7

Pain perception is not solely determined by the intensity of the stimulus but also by the balance of activity
between different types of nerve fibers and descending influences from the brain.- Non-painful stimuli can modulate pain perception by activating A-beta fibers and closing the gate.- Psychological factors can influence pain perception by modulating the descending pathways from the brain

Question 8

Endorphins

Answer 8

When your body detects pain, it releases endorphins that bind to receptors in the brain and spinal cord, effectively blocking the transmission of pain signals.
The pain-relieving effects are due to their ability to bind to opiate receptors in the brain and nervous system.