Abdomen: Viscera Overview/Foregut Flashcards
Right costal margin
- Liver
- Gallbladder
Left costal margin
- Stomach
Ribs protect
- Spleen
- Part of the liver
- Kidneys
- Rib frx puts certain viscera at risk (liver, spleen, kidneys)
Foregut extends from
- Esophagus > 2nd part of duodenum
Foregut arterial supply
- Branches from the celiac trunk
Midgut extends from
- 2nd part of duodenum > distal 1/3 of transverse colon
Midgut blood supply
- Branches from superior mesenteric artery
Hindgut extends from
- Distal 1/3 transverse colon > upper anal canal
Hindgut blood supply
- Branches from the inferior mesenteric artery
The GI tract is largely drained by
- The hepatic portal venous system
Foregut innervation (sympathetic)
- Greater splanchnic nerve (T5-T9) > celiac ganglia
Midgut innervation (sympathetic)
- Lesser splanchnic nerve (T10-T11) > superior mesenteric ganglion, aorticorenal ganglia
Hindgut innervation (sympathetic)
- Lumbar splanchnic nerve (L1,L2) > inferior mesenteric ganglion
Least splanchnic nerve (T12) innervates
- Aorticorenal and renal plexus
Postsynaptic sympathetic fibers travel in _____ to destination
- Periarterial plexuses
Postsynaptic sympathetic fibers traveling in periarterial plexuses go to
- Renal plexus, hepatic plexus, etc.
Adrenal gland (medulla) receives
- Direct innervation from presynaptic fibers
- Exception of postsynaptic sympathetics destination pathway
Sympathetic primary functions in abdomen
- Altering vasomotor tone
- Slowing peristalsis
Presynaptics travel in (parasympathetic innervation of abdomina viscera)
- Vagus nerve (A/P vagal trunks)
- Pelvic splanchnic nerves
Vagus nerve innervation (presynaptic parasympathetic)
- Innervates lower esophagus to left colic flexure
- Foregut and midgut
Pelvic splanchnic nerves have nothing to do with
- Sympathetics
Pelvic splanchnic nerves are derived from
- Spinal segments S2-4
Pelvic splanchnic nerves travel through
- Inferior hypogastric plexus
Pelvic splanchnic nerves innervate (presynaptic parasympathetic)
- Descending colon to rectum (hindgut)
- Pelvic organs
Vagus and pelvic splanchnic (pre/para) synapse on
- Postsynaptic neuron on/in wall of viscera
Parasympathetic primary functions in abdomen
- Promote peristalsis and secretion
Visceral Afferents (Sensory)
- Unconscious reflexes
- Nociception
Visceral afferents (sensory) of foregut and midgut travel in
- Vagus nerve
Visceral afferents (sensory) of hindgut travel in
- Pelvic splanchnic nerves
Visceral afferent fibers conveying nociception follow
- Follow sympathetic fibers
- Travel in a reverse course to spinal cord
Visceral afferent fibers conveying nociception from foregut follow
- Foregut > greater splanchnic nerve
Visceral afferent fibers conveying nociception from midgut follow
- Midgut > lesser splanchnic nerve
Visceral afferent fibers conveying nociception from hindgut follow
- Hindgut > lumbar splanchnic nerves
- Descending colon
- Proximal ½ sigmoid colon
Exception to visceral pain afferents
- Midpoint of sigmoid colon to rectum
- Pain afferents follow parasympathetic fibers
- Pelvic splanchnic to cord levels S2-4
Abdominal esophagus
- Begins at T10 at the esophageal hiatus
- Joins stomach at cardiac region
Parts of the stomach
- Cardia
- Fundus
- Body
- Pylorus
Fundus of the stomach is positioned
- Against left dome of diaphragm
Parts of the pylorus
- Outflow region
- Pyloric antrum
- Pyloric canal
- Pyloric sphincter
- Pyloric orifice
Pyloric sphincter
- Thickened layer of smooth muscle
- Regulates release of chyme into duodenum
Interior of the stomach contains
- Gastric folds (rugae)
Stomach position and supine surface projection depends on
- Position
- Body type
- Fed-state
Intraperitoneal organ
- Covered by peritoneum (except at the “bare area”)
- Location of gastrophrenic ligament
Organs located anterior to the stomach
- Left lobe of liver
- Diaphragm
- Anterior abdominal wall
Organs located posterior (posterolateral) to the stomach
- Lesser sac
- Pancreas
- Left kidney
- Adrenal gland
- Spleen
Organs located superior to stomach
- Diaphragm
Organs located inferior to stomach
- Transverse colon
- Transverse mesocolon
Arterial bloody supply to stomach is from the
- Celiac trunk
Arteries supplying the stomach
- Rt. Gastric (RG)
- Lt. Gastric (LG)
- Rt. Gastroepiploic (Rt. GEP)
- Lt. Gastroepiploic (Lt. GEP)
- Short Gastric (SG)
Veins (same names as the arteries) drain into
- Portal venous system
Other branches supplying trunk
- Common hepatic artery (CHA)
- Hepatic artery proper (HAP)
- Gastroduodenal (GD)
- Splenic (Spl)
Spleen (lien) function
- Prenatal hmatopoiesis
- Storage and destruction of RBC and platelets
- Iron and globin recycling
- Immune function
Spleen (lien) location
- Left upper quadrant
- Lies on diaphragm (ribs 9-11)
- Recumbent position
- Long axis parallels rib 10