Innervation of the GI TractInnervation of the GI Tract

•• Sympathetic innervation (T5-L2)Sympathetic innervation (T5-L2)

•• Paravertebral gangliaParavertebral ganglia

•• Prevertebral gangliaPrevertebral ganglia

Sympathetic AutonomicsSympathetic Autonomics

Unit II, p22Unit II, p22

ParavertebralParavertebral

PrevertebralPrevertebral

Innervation of the GI TractInnervation of the GI Tract

•• Sympathetic innervationSympathetic innervation

•• Paravertebral gangliaParavertebral ganglia

•• Prevertebral gangliaPrevertebral ganglia

•• Celiac gangliaCeliac ganglia

•• Superior mesenteric gangliaSuperior mesenteric ganglia

•• Aorticorenal gangliaAorticorenal ganglia

•• Inferior mesenteric gangliaInferior mesenteric ganglia

Innervation of the GI TractInnervation of the GI Tract

•• Parasympathetic innervationParasympathetic innervation

•• Vagus nerves (CN X)Vagus nerves (CN X)

•• Mouth to the sigmoid colonMouth to the sigmoid colon

•• Vagus means the wandererVagus means the wanderer

•• Sacral plexus (pelvic splanchnicSacral plexus (pelvic splanchnic

nerves, S2-S4)nerves, S2-S4)

•• Sigmoid colon to the rectumSigmoid colon to the rectum

Innervation of the GI TractInnervation of the GI Tract

Unit II, p23Unit II, p23

ComparisonComparison

Unit II, p24Unit II, p24

Enteric InnervationEnteric Innervation

Unit II, p25Unit II, p25

Referred Pain from AbdominalReferred Pain from Abdominal

VisceraViscera

•• Pain is perceived as originating inPain is perceived as originating in

areas supplied by the somaticareas supplied by the somatic

nerves because the autonomicnerves because the autonomic

afferent fibers enter the spinal cordafferent fibers enter the spinal cord

at the same spinal segment as theat the same spinal segment as the

sensory nerves from the bodysensory nerves from the body

wall/limbswall/limbs

Referred Pain from AbdominalReferred Pain from Abdominal

VisceraViscera

•• Visceral pain is dull and diffuseVisceral pain is dull and diffuse

•• Somatic pain is sharp and focusedSomatic pain is sharp and focused

Organ Spinal CordSegment

Referred Pain Site(s)

Stomach T6-T9 Epigastric and left hypochondriacregions

Duodenum T5-T9, T10 Epigastric region (right shoulder if ulcerperforates)

Pancreatic head T8-T9 Inferior part of epigastric region

Spleen T6-T8 Left hypochondriac region

Gallbladder and liver T6-T9 Epigastric region, right hypochondriacregion, posterior thoracic wall, rightshoulder

Jejunum and ileum T5-T9 Periumbilical region

Proximal colon T10-T12 Hypogastric region

Distal colon L1-L3 Left lower quadrant

Kidneys and ureters T11-T12 Lower back, flank, extending to groin

Pain Fields

(From Moore and Dalley, p 233, 1999)

DermatomesDermatomes

PelvisPelvis

PelvisPelvisTrueTrue

FalseFalse

Bony PelvisBony Pelvis

•• 3 fused bones (os coxae)3 fused bones (os coxae)

•• Ilium (NOT ileum)Ilium (NOT ileum)

•• Ischium (is-kIschium (is-k --um)um)

•• PubisPubis

Bony PelvisBony Pelvis

•• 3 fused bones (os coxae)3 fused bones (os coxae)

•• Ilium (NOT ileum)Ilium (NOT ileum)

•• Ischium (is-kIschium (is-k --um)um)

•• PubisPubis

•• Other partsOther parts•• AcetabulumAcetabulum•• RamiRami•• Pubic (Superior and inferior)Pubic (Superior and inferior)•• IschialIschial

Bony PelvisBony Pelvis

Ilium

Pubis

Ischium

Bony Pelvis

Ilium

Pubis

Ischium

Pelvic AnatomyPelvic AnatomyAnterior ViewAnterior View Superior ViewSuperior View

Anterior View

Ala of the ilium

Pubis

Ischium

Notches and ForaminaNotches and Foramina

•• Greater sciatic notch/foramenGreater sciatic notch/foramen

•• Lesser sciatic notch/foramenLesser sciatic notch/foramen

NotchesNotches

GreaterGreatersciaticsciatic

foramenforamen

LesserLessersciaticsciatic

foramenforamen

ForaminaForamina

GreaterGreatersciaticsciaticnotchnotch

LesserLessersciaticsciaticnotchnotch

Sciatic ForaminaSciatic Foramina

Sacro-Sacro-

spinousspinous

ligamentligament

Sacro-Sacro-

tuberoustuberous

ligamentligament

PosteriorView

Sacrospinousligament

PosteriorView

Sacrospinousligament

Sacrotuberous ligament

PosteriorView

Pelvic Inlet MeasurementsPelvic Inlet Measurements- OB/GYN -- OB/GYN -

Sex Differences in the PelvisSex Differences in the Pelvis

FemaleFemaleMaleMale

MaleMale FemaleFemale

Pelvic MusclesPelvic Muscles

•• Lateral (wall) musclesLateral (wall) muscles

•• PiriformisPiriformis

•• Obturator internusObturator internus

•• Floor muscles (Floor muscles (““pelvic diaphragmpelvic diaphragm””))

•• 2 muscles2 muscles

•• Levator ani (has 3 parts)Levator ani (has 3 parts)

•• ““CoccygeusCoccygeus”” (ischiococcygeus) (ischiococcygeus)

Levator Ani MuscleLevator Ani Muscle- 3 Parts -- 3 Parts -

•• Puborectalis (Puborectalis (““rectal slingrectal sling””))

•• PubococcygeusPubococcygeus

•• IliococcygeusIliococcygeus

Pelvic Muscles

Pelvic DiaphragmPelvic Diaphragm

Arteries in the Pelvis

Arteries in the PelvisArteries in the Pelvis

Anterior Division AA VVVessel Male Female

Umbilical

Superior vesical X X

Obturator X X

Inferior vesical X

Artery to the ductus deferens X

Prostatic X

Uterine X

Vaginal X

Internal pudendal X X

Middle rectal X X

Inferior gluteal X X

Syllabus G09B.69Syllabus G09B.69

Pelvic Vasculature

Syllabus G09B.67Syllabus G09B.67

Pelvic Vasculature

Nerves in the PelvisNerves in the Pelvis