ANS Pain Flashcards
Which spinal cord level controls parasympathetic outflow?
craniosacral
Which spinal cord level controls sympathetic outflow?
thoracolumbar
Where are the preganglionic parasympathetic cell bodies found?
brainstem and sacral spinal cord (S2-S4)
Where are the preganglionic sympathetic cell bodies found?
lateral horn of grey matter (VII) in spinal cord; T1-L1/L2
Where are the postganglionic parasympathetic cell bodies found?
in autonomic ganglia close to their target organ/gland
Where are the postganglionic sympathetic cell bodies found?
paravertebral (sympathetic chain) or prevertebral autonomic ganglia (in abdomen); project to entire body (unlike para.)
Which nerves are innervated by the parasympathetic nervous system?
- CN III, oculomotor
- CN VII, facial
- CN IX, glossopharyngeal
- CN X, vagus
- pelvic splanchnic nerves (S2-S4)
Is vagus innervation of the stomach afferent or efferent?
both
Which organs does the parasympathetic system innervate?
all internal organs of the body, but NONE in body wall (e.g. skin)
How does parasympathetic innervation affect the GI tract?
dilate blood vessels leading to GI tract, increasing blood flow and peristalsis
How does parasympathetic innervation affect the lens of the eye?
accommodation
How does parasympathetic innervation affect the pupils?
constrict
How does parasympathetic innervation affect salivary glands?
stimulate secretion
How does sympathetic innervation affect the muscles?
dilate vessels for muscles
How does sympathetic innervation affect the lungs?
dilate bronchioles –> greater alveolar oxygen exchange
How does sympathetic innervation affect heart rate?
increases HR
How does sympathetic innervation affect the pupils and ciliary muscles?
dilate pupils and relax ciliary muscles –> more light enters the eye and far vision
How does sympathetic innervation affect the GI tract?
divert blood flow away from GI tract, inhibit peristalsis
How does sympathetic innervation affect the liver?
glucose secreted from liver
Which autonomic motor division causes us to sweat?
sympathetic
At which spinal cord levels and for which organs do sympathetic preganglionic neurons synapse in the sympathetic chain?
T1-T5: eye, salivary glands, heart, lung (head to diaphragm/lung
At which spinal cord levels and for which organs do sympathetic preganglionic neurons NOT synapse in the sympathetic chain?
T5 - L1/L2: liver, gallbladder, stomach, pancreas, spleen, large intestine, small intestine, adrenal medulla, kidney, urinary bladder, scrotum, penis, ovary, uterus
What is the path leading to visceral afferents in visceral referred pain?
celiac trunk (stomach, liver, etc.) –> prevertebral (celiac) ganglia in abdominal aorta –> white ramus communicans –> dorsal root –> spinal cord –> cerebral cortex
What is visceral referred pain? What are some examples?
- pain arises from a visceral organ, but the pain is perceived as arising from somatic structures supplied by those same spinal levels
- e.g. MI, appendicitis, cholecystitis, menstrual pain
Which spinal nerves does the brain identify pain coming from during a heart attack?
T1-T5 (chest body wall)
Which spinal nerves does the brain identify pain coming from during a stomach ulcer?
T7-T9 (epigastric region on body wall)
What is somatic referred pain? At what level of the dermatome is the pain detected? Describe how embryological displacement of the diaphragm can lead to somatic referred pain. Where on your body do you feel the pain?
- somatic referred pain is carried by spinal nerves
- pain is sharp and easily localized
- C3-C5
- inflamed liver/gallbladder can rub against misplaced diaphragm –> pain is referred to C3-C5 dermatome
- feel shoulder pain because C3-C5 innervates both diaphragm and shoulder
