Ch 16 Pain Flashcards
What is the difference between a special sense and a general sense?
general senses have simple receptors and are located in the body; special senses have complex receptors and are located in the head
What are the general senses
touch, pressure, stretch, heat, cold, and pain
Special senses
vision, hearing, equilibrium, taste, and smell
What are the 3 neurons in a sensory pathway?
first order, second order, and third order
Where do first order neurons synapse?
- signals from the head: pons and medulla
- signals from below the head: posterior horn of the spinal cord
Where do second order neurons synapse?
- signals from the head: brainstem and then decussate to the contralateral thalamus
- signals from the lower body: ascend the spinal cord through pathways
Where do third order neurons synapse?
thalamus
First order neuron function
sends sensations to the central nervous system
Second order neuron function
soma located in brain or spinal cord cross to reach thalamus
Third order neuron function
soma in thalamus allow for perception
Two types of pain
nociceptive and neuropathic
What causes nociceptive pain?
tissue injury such as cuts, burns, chemical irritation etc.
Three types of nociceptive pain
visceral, deep somatic, and superficial somatic
Origin of visceral pain
internal organs
Origin of deep somatic pain
bones, joints, muscles
Origin of superficial somatic pain
skin
What causes neuropathic pain?
damage to the nerves, spinal cord, meninges, or brain
What is referred pain?
pain coming from one organ that is perceived to be coming from a different location
What causes referred pain?
the convergence of neural pathways in the central nervous system
What is a nociceptor?
pain receptor
Why are some nociceptors myelinated or unmyelinated?
for fast pain and slow pain; the myelination of the receptor allow for fast pain
What cranial nerves do pain come from?
V trigeminal, VII facial, IX glossopharyngeal, and X vagus
