Organization of the sympathetic NS and visceral sensory pathways Flashcards
How are 14 spinal cord levels (T1-L2) able to supply sweat glands for 31 dermatomes?
The sympathetic trunk is used as a pathway that lets levels T1-L2 share their preganglionic axons with somites at every level.
Where will sympathetics to the body wall synapse?
at the level where they are used
What are the 2 basic types of visceral sensation?
visceral pain
“visceral afferents”
The 2 basic types of visceral sensation are _____ different and use _____ pathways to reach the CNS.
qualitatively
different
How do you describe visceral pain?
dull
diffuse
poorly localized
(spread over a larger area)
What are the stimuli causing visceral pain:
ischemia
prolonged smooth muscle contraction (cramping)
distention (stretching)
Visceral pain axons for the thorax and abdomen follow which pathways?
sympathetic pathways backward (no matter how complicated)
Where are cell bodies of visceral pain axons for the thorax and abdomen found?
dorsal root ganglia
Visceral pain axons for the pelvis follow which pathways?
parasympathetic pathways backward via the pelvic splanchnic nerves
Where are cell bodies of visceral pain axons for the pelvis found?
dorsal root ganglia
T/F: most visceral afferent are perceived consciously.
F: NOT perceived consciously
What do visceral afferents (other than pain) help to regulate?
autonomic function
Some visceral afferents that reach the level of consciousness include ______ and ______.
hunger and nausea
Visceral afferents for the thorax and abdomen are carried by which nerve?
Vagus nerve (CN X)
Visceral afferents for the lower abdomen and pelvis are carried by which nerve?
pelvic splanchnic nerve
A stimulus affects an internal organ (usually causing visceral pain) and at the same time, somatic pain is felt in the dermatome(s) belonging to the same spinal cord level, although there is no real stimulus to cause pain the skin. This is known as:
referred pain
Most well known example of referred pain:
shoulder pain extending down the left upper limb during heart attack
Which type of pain is very valuable for diagnosis?
referred pain
