Lecture 10: Lumbar Plexus and Pain Flashcards
What is the excitatory hormone of the somatic NS, are there ganglia, and what are the axons like?
- Ach
- No ganglia in this pathway
- Axons are thick and myelinated
What is the NT used by pre-ganglionic cell bodies in the sympathetics; how about post-ganglionic?
Pre-ganglionic = Ach
Post-ganglionic = NE
What are the 2 components of the sympathetic trunk?
Paravertebral ganglion + Interganglionic connections
What are the 3 cervical ganglion?
- Superior
- Middle
- inferior
What ganglion is formed by the fusion of the inferior cervical ganglion w/ the ganglion of T1?
- Stellate ganglion
What are the 4 options for pre-synaptic fibers entering the sympathetic trunk?
1) Ascend
2) Descend
3) Synapse at same level
4) Traverse the trunk w/o synapsing and become part of an abdominopelvic splanchnic nerve or for innervation of the suprarenals
What are gray rami communicans; how many spinal nerves?
- All 31 spinal nerves
- Arise as lateral branches
- Carry post-synaptic fibers to body wall and limbs for distribution via spinal nerves
What are the cephalic arterial rami?
- Go to periarterial plexuses of carotid arteries
- Arise from cervical ganglia
- Post-synaptic fibers to head for distribution via periarterial plexuses
What are the 3 primary effects of the parietal branches of sympathetic trunks?
1) Vasomotion
2) Sudomotion - sweating
3) Pilomotion - erector pilae m. = goosebumps
What is the primary contribution to the celiac ganglion?
Greater splanchnic n
What is the primary contribution to the aorticorenal ganglion?
Predominantly lesser splanchnic
What is the primary contribution to the SMG?
Contributions from all
What is the primary contribution to the IMG?
Primarily lumbar
How do abdominopelvic splanchnic nerves enter the diaphragm?
They pierce the muscle
Which fiber type do the cardiopulmonary splanchnic nerves convey and what kind of ganglia do they synapse in?
- Convey POST-synaptic fibers to thoracic viscera
- Synapse in PARA-vertebral ganglia
Which fiber type do the abdominopelvic splanchnic nerves convey and what kind of ganglia do they synapse in?
- Convey PRE-synaptic fibers
- Synapse in PRE-vertebral ganglia
Do the paravertebral ganglia of sympathetic trunks distribute fibers to the abdominopelvic viscera?
NO, everywhere else
*Pre-vertebral ganglia of para-aortic plexus distribute to abdominopelvic viscera
Why is innervation of the suprarenal glands an exception?
Pre-synaptic fibers to the suprarenals will pass through the pre-vertebral ganglia WITHOUT synapsing. The synapse occurs directly on the secretory cells of the medulla which act as postsynaptic neurons.
How are the pre-synaptic neurons of the sympathetics and parasympathetics different?
Sympathetics = short
Parasympathetics = long
What is the dominant outflow of the parasympathetic presynaptic neurons; where does it extend to?
Cranial outflow is dominant (extends to left colic flexure)
Where are the parasympathetic postsynaptic neurons located in the trunk?
- Widely spread and irregularly spaced
- Located in or on effector (intrinsic/enteric ganglia)
- Found in the Musculosa Externa
What are the parasympathetic postsynaptic neurons in the head?
1) Ciliary
2) Otic
3) Pterygopalantine
4) Submandibular
Do the parasympathetics go to body walls or limbs; are they components of spinal nerves?
- Do NOT go to body walls or limbs, except erectile tissue of external genitalia
- Never components of spinal nerves of their peripheral branches, except for initial parts of S2-S4
What is the left colic (splenic) flexure a landmark for?
Where cranial outflow (i.e., Vagus n.) stops and the Sacral outflow (S2-S4) starts
What is the effect of the sympathetic NS on the BV’s of the GI, sphincters, peristalsis, and suprarenal glands?
- Constricts BV’s of skin and GI tract
- Decreases peristalsis of gut, constricts sphincters
- Stimulates suprarenal glands to release adrenaline
Where does the sympathetic NS not produce vasoconstriction?
The heart and muscles
What is the effect of the parasympathetic NS on gut peristalsis, sphincters, the rectum, and bladder?
- Increases peristalsis
- Inhibits sphincters
- Stimulates contraction of bladder and rectum
Which part of the autonomics is the primary stimulator of the GI tract?
Parasympathetic
*Is active in elimination (defecation and urination)
Where are the cell bodies for visceral afferent fibers?
Dorsal root ganglion
Normal homeostatic reflexes (physiologic receptors) travel w/ which part of the autonomics?
The parasympathetics
Pain travels with which part of the autonomics and what is the transition point?
The sympathetics until the pelvic pain line, then switches to parasympathetics
Where is the pelvic pain line?
Middle of the sigmoid colon
Differentiate acute, chronic, and subacute abdominal pain?
Acute = <3 days
Chronic = >3 weeks
Subacute = 3 days - 3 weeks
Which type of pain is well localized, which type of pain is not?
Visceral = not well localized
Parietal (somatic) = well localized
Parietal pain is caused by?
Irritation of fibers that innervate the parietal peitoneum (i.e somatic nerves - thoracoabdominals)
How can parietal pain be localized?
To the dermatome superficial to the site of the pain stimulus
How can visceral pain be localized?
By the sensory cortex to an approximate spinal cord level determined by the embryologic origin of the organ involved
Where is pain produced from: foregut, midgut, and hindgut organs?
Foregut = Epigastrium Midgut = Periumbilical Hindgut = Suprapubic/Hypogastric region
What pathologies will cause pain in the umbilical region?
- Appendicitis (early)
- Mesenteric adenitis
- Meckel’s diverticulitis
- Lymphomas
What pathologies will cause pain in the right inguinal region?
- Appendicitis (late)
- Chron’s Disease
- Cecum obstruction
- Ovarian Cyst
- Ectopic pregnancy
Which pathologies can lead to pain in the shoulder; how?
- Liver
- Gallbladder
- Duodenum
*Irritation of the diaphragm
Retroperitoneal pain is commonly felt where; which structures cause this pain?
- Felt in the back
- Pancreas, kidneys, aorta
What is Colicky pain; causes?
- Intermittent cramp-like pain
- Bowel obstructions/adhesions, stone in ureter, stone in neck of gallbladder
If the patient has epigastric pain that is worse after eating what is the underlying pathology; how about 2-5 hours after eating?
- Immediate = stomach
- Delayed (2-5 hrs) = Duodenum
Anytime something ruptures or is extremely inflamed what kind of pain is likely to follow?
Generalized or localized peritonitis
If patient has midgut visceral colicky pain, vomiting, NO flatus or bowel action, and increased bowel sounds, what is the likely pathology?
Adhesive small bowel obstruction
Pt has a sudden onset of very severe colicky pain in the flank region, severe back pain, tender renal angle, possible hematuria, what is likely pathology?
Passage of a kidney stone
Pt is older w/ sudden weight loss, hindgut visceral colicky pain, no flatus/feces, increased bowel sounds, a mass in LLQ, what is the pathology?
Obstructing cancer of descending colon
Women of childbearing age, missed her last menstrual period, sudden onset of severe hypogastrium pain radiating to sacral area, localized suprapubic peritonitis; what is likely pathology?
Ruptured ectopic pregnancy
Pt is an elderly male w/ hx of atherosclerotic disease (HTN or cardiac) w/ a sudden onset of severe back pale, appears pale and shocked, is HYPOtensive and has a palpable impulse in epigastrium; what is the likely dx?
Leaking aortic aneurysm
Pain from which organs will be traveling with greater splanchnic afferent nerve fibers?
- Liver
- Stomach
- Spleen
- Supra-adrenals
Pain at the ileocecal junction, cecum, appendix, ascending or transverse colon will travel with which afferent nerve fibers?
Lesser splanchnics
Pain in the duodenum, ileum, and jejunum will be carried w/ which afferent nerve fibers?
Greater and Lesser splanchnic
Pain in the descending colon will be carried w/ which afferent nerve fibers?
Least and lumbar splanchnic
Pain in the kidneys will be carried with which afferent nerve fibers?
Lesser, least, and lumbar splanchnics
Which nerve fibers will transmit pain from the sigmoid colon and rectum?
Pelvic splanchnic
Which areas will cause pain initially in the suprapubic/hypogastric area?
- Hindgut organs (most of colon, including 1/2 sigmoid)
- Intraperitoneal portions of the genitourinary tract
Potential causes of epigastric pain
- esophagitis
- peptic ulcer
- perforated ulcer
- pancreatitis
Potential causes of Right hypochondriac (RUQ) pain
- gallstones
- cholangitis
- hepatitis
- liver abscess
Potential causes of left hypochondriac (LUQ) pain
- spleen abscess
- acute splenomegaly
- spleen rupture
Potential causes of flank/lumbar pain
- ureteric colic
- pyelonephritis
Potential causes of Hypogastric/pubic pain
- testicular torsion
- urinary retention
- cystitis
- placental abruption
Potential causes of left inguinal pain
- diverticulitis
- ulcerative colitis
- constipation
- ovarian cyst
- hernias
What would you expect for a pain presentation for a gastric ulcer?
- worse on eating
- foregut visceral pain = midline, colicky pain
What would you expect for a pain presentation for a perforated gastric ulcer
- sudden severe pain spreading diffusely
- generalized peritonitis signs
- foregut chronic visceral pain
- epigastric pain when localized
What would you expect for a pain presentation for acute cholecystitis
- foregut visceral pain
- somatic pain in RUQ w/ referred to right shoulder
- N/V, fever, tender RUQ
- Murphy’s sign
What would you expect for a pain presentation for acute appendicitis?
- midgut visceral pain
- somatic pain in RLQ
- N/V, fever
- tender RLQ
- if ruptured, localized peritonitis in RLQ
What would you expect for a pain presentation for adhesive small bowel obstruction
- hx of previous abd surgery
- midgut visceral colicky pain
- V, no flatus or bowel action
- possible dehydration
- distended, soft, non tender abdomen
- increased bowel sounds
What would you expect for a pain presentation for kidney stones?
- sudden very severe colicky pain from loin-> groin and severe back pain
- writhing and pacing in pain
- possible hematuria
- afebrile
- soft abdomen w/ tender renal angle
What would you expect for a pain presentation for an obstructing cancer of descending colon?
- older pt w/ weight loss
- hindgut visceral colicky pain
- no flatus, feces w/ distended abdomen
- possible mass in LLQ
- increased bowel sounds
What would you expect for a pain presentation for a ruptured ectopic pregnancy?
- missed LMP
- sudden onset severe hypogastrium pain radiating to sacrum
- afebrile
- localized peritonitis in suprapubic (hypogastric) area
- tender in rectouterine pouch on rectal/vag exam
What would you expect for a pain presentation for a leaking aortic aneurysm?
- hx of cardiac disease (ex: htn)
- sudden severe back pain
- pale, shocked, hypotensive
- tender epigastrium
- palpable impulse from aneurysm in epigastrium