Lower Abdomen Flashcards
Lower abdomen
Stomach
Large intestine
Small intestine
Stomach
Cardiac orifice Pyloric sphincter Body Fundus Lined with rugae= expansion and movement
Small intestine
Duodenum -‘fixed and immobile because part retroperitoneal
Jejunum and ileum
-tethered by Mesentery proper
-intraperitoneal
-combined length 20 ft
- plicae circularis will have permanent folds to increase surface area
-becomes more diffuse distally, absorption decreases
Ileocecal junction
Where the ilium meets the cecum of the large intestine
Duodenum
Superior- intraperitoneal, L1 level
Descending- retroperitoneal L2-L3 level, c shaped
Inferior- posterior to SMA but anterior to the aorta, L3
Ascending- goes to duodenal jejunal junction held by ligament of triats– region where it becomes intraperitoneal
Jejunum
Wall are thicker Plicae circularis more prominent Vasa recta longer Arterial arcades shorter 2/5 Supplied by SMA
Ileum
Thinner walls Less plicae circularis Short vasa recta Long arterial arcades 3/5 Supplied by SMA
Meckels diverticulum
Remnants of embryonic yolk stalk Appears as finger like pouch 1 m proximal to ileocecal valve May become inflamed Fistula is the example
Large intestine
5 segments and 2 flexures Cecum ascending transverse descending sigmoid Terminates into rectum R colic or hepatic flexure L colic or splenic flexure
Veriform appendix
Opens into cecum inferior to ileocecal orifice
Triangular Mesentery = mesoappendix
Commonly retro Cecil but varies considerably
Inflammation possible when food gets stuck
Appendicitis
Vague pain in the peri umbilical
From T10 level
R lower quadrant hurts next with point irritation of peritoneum
Pain most severe in ASIS and umbilicus
Colon
Teniae coli-3 smooth muscle bands paralleling the length of the colon
Haustra coli- outpouching produced by teniae coli
Epiploic appendages- fat tags found along colon
Superior mesenteric artery
Midgut 2nd major branch of aorta 15-18 intestinal branches Ileocolic branch Right colic branch Middle colic branch Inferior pancreaticoduodenal
Inferior mesenteric
3 red major branch Hind gut Supplies colon from distal 1/3 of transverse colon Left colic Sigmoid -4 Superior rectal
Marginal artery of Drummond
Cross the transverse colon which anastomoses with the SMA to IMA
Pancreatic anastomoses
Superior pancreaticoduodenal from gastroduodenal
Inferior pancreaticoduodenal from SMA
Anastomoses to supple pancreas and duodenum
Splenic arteries supply rest of pancreas
Renal arteries
About same level as SMA
Enter hi lim of each kidney
Have branches to adrenal gland
Gonadal Arteries
Lateral branches of abdominal aorta Inferior to renal arteries Males pass thru inguinal canal and descend into scrotum Females travels to ovaries Ovarian or testicular arteries
Portal vein
Splenic vein– inferior mesenteric
Superior mesenteric
Then through the liver and into IVC
Drains: spleen pancreas gallbladder abdominal gastrointestinal tract
Portal caval anastomoses
Gastric veins portal and esophageal veins caval
Paraumbilical veins portal and epigastric veins caval
Superior rectal vein portal and inferior rectal vein caval
Colic vein portal and retroperitoneal vein caval
Sympathetic abdomen
Preganglionic splanchnic n synapse in collateral ganglia
Postganlionic fibers leave ganglia to reach effectors
T5-L2
1. Ascending synapse
2. Synapse at level of exit
3. Descend the synapse
4. Pass without synapsing, find a collateral ganglia
Sympathetic plexus
Greater splanchnic nerve- celiac ganglion, T5-T9
Lesser splanchnic nerve- SMA ganglion, T10-T11
Least splanchnic nerve- aorticorenal ganglion, T12
Lumbar splanchnic nerve- IMA ganglion, L1-L2
Parasympathetic abdomen
Preganlionic from CNX travel on upper arterial branches, vagus nerve
-celiac, SMA,renal,
Preganglionic from S2-S4 travel on lower arterial branches
-IMA
SYNAPSES ON THE EFFECTOR ORGAN
Parasympathetic plexus
Vagus nerve or CNX contributes to Celiac ganglion Superior mesenteric ganglion Aorticorenal ganglion Sacral nerves contribute to Inferior mesenteric ganglion
