lecture 4 visceral pain

Question 1

what does the enteric nervous system consist of

Answer 1

400-600 million intrinsic neurones that extend most of length of GIT

Question 2

what is the ENS arranged in

Answer 2

glanglionated plexuses with interconnecting bundles of unmyelinated nerve fibres

Question 3

what is the function of the ENS

Answer 3

enable GIT to preform basic reflex functions of secretion, absorption, mixing and gut movement without influence of CNS or ANS

Question 4

how does the CNS communicate with ENS intrinsic neurones to modulate GIT functions

Answer 4

via sympathetic and parasympathetic nerves

Question 5

where do axons of intrinsic neurones of ENS also project to

Answer 5

sympathetic ganglia, pancreas, gall bladder, trachea, spinal cord, brain stem

Question 6

structure of GIT (lumen to exterior)

Answer 6

lumen - mucosa (lamina propria and muscularis mucosae; glands) - MALT - submucosa (glands; submucosal plexus of Meissner) - muscularis (for peristalsis; circular then myenteric plexus of Auerbach, then longitudinal) - serosa (epithelium) - mesentery (nerve and artery)

Question 7

where is intrinsic network of neurones of ENS situated

Answer 7

2 plexuses in tissues of gut wall from oesophagus to anus (submucosal and muscularis)

Question 8

structure and divisions of ANS

Answer 8

different to somatic NS (ganglia, myelination, neurotransmitters); 2 divisions (sympathetic and parasympathetic) which innervate organs of abdomen and pelvis

Question 9

where does ANS arise from

Answer 9

different anatomical regions of CNS; sympathetic from spinal cord segments T1-L2, parasympathetic from cranial nerves III, VII, IX, X in brain stem, and spinal cord segments S2-S4

Question 10

slide 8

Answer 10

sympathetic chain; ganglia form separate spinal cord segments; parasympathetic: vagus to abdomen, sacral parasympathetic outflow to pelvis

Question 11

functions of efferent ANS nerves to abdomen

Answer 11

motor to smooth muscle; secretomotor to glands

Question 12

functions of afferent ANS nerves to abdomen

Answer 12

sympathetic: pain; parasympathetic: specific functional sensation e.g. stretch

Question 13

sympathetic nerves to abdomen (visceral)

Answer 13

from T1-L2; sympathetic trunks, diaphragm, splanchnic (visceral) nerves, coeliac ganglion

Question 14

vagus nerves to abdomen (visceral)

Answer 14

left and right vagus nerves splitting into anterior and posterior vagul trunks

Question 15

sympathetic chain to abdomen: greater splanchnic nerve level

Answer 15

T5-T9

Question 16

sympathetic chain to abdomen: lesser splanchnic nerve level

Answer 16

T10-T11

Question 17

sympathetic chain to abdomen: least splanchnic nerve level

Answer 17

T12

Question 18

nerves from lumbar sympathetic chain

Answer 18

go to different parts; all splanchnic nerves and autonomic plexus won’t be retained in dissection

Question 19

parasympathetic supply

Answer 19

vagus (cranial nerve X) and S2-S4

Question 20

what ANS division goes to peripheral vessels and skin

Answer 20

sympathetic

Question 21

what do sympathetic nerves run with to same region of peripheral vessels and skin

Answer 21

somatic nerves (no parasympathetic supply to somatic nerves; don’t run with spinal nerves)

Question 22

what do autonomic nerves run with to same organs which lack somatic innervation

Answer 22

arteries, but a few run separately

Question 23

peripheral distribution of ascending sympathetics

Answer 23

C1/C2-C8 (posterior and anterior ramus)

Question 24

peripheral distribution of descending sympathetics

Answer 24

L3-coccyx (posterior and anterior primary rami)

Question 25

T1 to L2

Answer 25

lateral horn of spinal cord to sympathetic chain to body wall

Question 26

sympathetic nerves to viscera

Answer 26

greater, lesser and least splanchnic nerves, lumbar splanchnic nerves (L1-L2), sacral splanchnic nerves from paravertebral sympathetic trunk

Question 27

where are ANS nerves to abdomen routed via and where is this

Answer 27

preverterbal plexus at midline of body surrounding abdominal aorta and its branches, synapse at ganglia associated with plexuses

Question 28

what are plexuses and ganglia named according to

Answer 28

associated blood vessels

Question 29

autonomic plexuses and ganglia

Answer 29

anterior (left) vagal trunk, superior mesenteric ganglion, inferior mesenteric ganglion, sympathetic trunk and ganglion, coeliac trunk and ganglion, renal plexus and ganglion, superior hypogastric plexus (at bifurcation of abdominal aorta), inferior hypogastric plexus

Question 30

what are the 3 nerve plexuses and ganglia around aorta and branches

Answer 30

parasympathetic nerves from vagus, sympathetic nerves from sympathetic chain T5-L2, parasympathetic nerves from S2-S4

Question 31

organs supplied by nerve plexuses and ganglia around aorta and branches; sympathetic ganglion chain continue to coccyx to form plexus

Answer 31

coeliac artery (T5-9, vagus), superior mesenteric artery (T10-11, vagus), renal arteries (T10-12, vagus), testicular/ovarian arteries (T10-11, vagus), inferior mesenteric artery (T12-L2, S2-4), superior and inferior hypogastric plexuses (T12-L2, S2-4)

Question 32

what is referred pain

Answer 32

pain referred from visceral organs and diaphragm (contains somatic nerves but no "sensory map") to dermatomes supplied by nerves with same segmental supply (autonomic nerve supply in abdomen)

Question 33

define dermatome

Answer 33

area of skin supplied by single spinal nerve

Question 34

significance of overlapping dermatomes

Answer 34

at least 3 spinal nerves would have to be blocked to produce region of complete anaesthesia

Question 35

what cervical level is there no dermatome

Answer 35

C1

Question 36

dermatomes in limbs

Answer 36

larger (more drawn out)

Question 37

sensory map of cerebral cortex

Answer 37

lips, hand and face more sensitive

Question 38

motor map of cerebral cortex

Answer 38

hand and face more innovated

Question 39

abdominal regions

Answer 39

9 abdominal regions so referred pain to these

Question 40

what level is the epigastric region

Answer 40

T7/T8 (sympathetic and somatic)

Question 41

visceral source of epigastric pain

Answer 41

referred pain from foregut structures, as far as duodenal papilla

Question 42

structures involved in epigastric referred pain

Answer 42

stomach, proximal duodenum, pancreas, liver, gall bladder

Question 43

visceral source of umbilical pain

Answer 43

T10; referred pain from midgut structures, from duodenal papilla to splenic flexure

Question 44

what can be referred to periumbilical region

Answer 44

inflamed appendix pain

Question 45

feature of periumbilical region

Answer 45

colicky (intermittent with bowel contractions)

Question 46

where do afferent pain fibres from midgut structures enter spinal cord

Answer 46

T10 (same as umbilical dermatome region)

Question 47

what level is inguinal region

Answer 47

T12/L1

Question 48

progression of pain in appendicitis (type of pain and region)

Answer 48

when inflammation spreads to surrounding peritoneum; at right inguinal region pain becomes localised and constant

Question 49

what elicits pain in appendicitus

Answer 49

movement of hip joint, coughing

Question 50

visceral source of subrapubic (hypogastric) pain

Answer 50

referred pain from hindgut structures, descending colon to anal canal

Question 51

what level is suprapubic region

Answer 51

T12, L1-L2

Question 52

visceral referred pain

Answer 52

stomach (T7-8), spleen (T10), kidney and ureter (T11-L2)