abdomen Flashcards
subcostal plane: location
inferior border of 10th costal cartilage
transtubercular plane: location
passes through iliac tubercles, body of L5
transumbilical plane: location
passes through umbilicus, IV discs between L3-L4
abdomen layers: superficial to deep
- skin
- camper fascia, scarpa fascia (subcutaneous)
- muscles: external oblique, internal oblique, transversus abdominis (with investing fascia in between)
- endoabdominal (transversalis) fascia
- extraperitoneal fat
- parietal peritoneum
linea alba: formation
aponeuroses interweave
arcuate line: distance
1/3 of the way from umbilicus to pubic crest
rectus sheath: formation
formed by aponeuroses of all 3 flat muscles
arcuate line: significance
- inferior to arcuate line, the aponeuroses of all 3 flat muscles pass anterior to rectus abdominis
- only transversalis fascia covers rectus abdominis posteriorly: potential site of weakness
median umbilical fold: location
- apex of bladder to umbilicus
- covers median umbilical ligament and remnant of urachus
medial umbilical folds: location
- cover medial umbilical ligaments, formed by occluded parts of umbilical arteries
lateral umbilical fold: location
- cover inferior epigastric vessels
lateral inguinal fossa: location, contents
- lateral to lateral umbilical folds
- contain deep inguinal rings (potential hernia site)
medial inguinal fossa: location, contents
- between medial and lateral folds
- forms inguinal triangle
supravesicular fossa: location, contents
- between median and medial folds, formed as peritoneum reflects from anterior abdominal wall onto bladder
inguinal ligament: formed by
free inferior border of external oblique aponeurosis
direct inguinal hernia: location
passes through/around inguinal canal, traversing medial third of canal. exits abdominal wall via superficial ring
indirect inguinal hernia: location
traverses inguinal canal (within processus vaginalis), entering deep inguinal ring and exiting superficial ring
inguinal region: location, function
- between anterior superior iliac spine, pubic tubercle
- where structures enter, exit abdominal cavity
inguinal canal: formation
formed in relation to relocation of gonads in fetal development
- fetal testes: pulled by gubernaculum, relocate from dorsal abdominal wall to deep inguinal rings
- fetal ovaries: relocate from dorsal abdominal wall to lesser pelvis, where gubernaculum attaches caudal pole of ovary
main structures of inguinal canal
spermatic cord: ductus deferens
vestigial round ligament of uterus
ilioinguinal nerve, blood vessels, lymphatics
inguinal canal: openings
deep ring: internal entrance, evagination of transversalis fascia
superficial ring: exit in external oblique aponeurosis
spermatic cord: fascia
- internal spermatic fascia: derived from transversalis fascia at deep inguinal ring
- cremasteric fascia: derived from internal oblique aponeurosis
- external spermatic fascia: derived from external oblique aponeurosis, its investing fascia
spermatic cord: blood supply to/from testes and epididymis
- testicular artery and veins: arise from aorta at L2
- pampiniform venous plexus: 12 veins that converge superiorly at testicular veins
spermatic cord: vas deferens
(same as ductus deferens) muscular tube that conveys sperm from epididymis to ejaculatory duct
cremaster and dartos: action, innervation
- cremaster: testicular elevation when cold, depression when warm, innervated by genital branch of genitofemoral nerve
- dartos: contracts skin of scrotum when cold, assists with testicular elevation, autonomic innervation
esophagus: venous drainage
- left gastric vein to hepatic portal vein
- proximal thoracic portion drains through esophageal veins entering azygos vein
abdominal aorta: 3 major branches
celiac trunk, superior and inferior mesenteric arteries
hepatic portal vein: formed by
union of superior mesenteric and splenic veins
celiac trunk: notable branches + supply
- left gastric artery: supplies esophagus, left lesser curvature
- splenic artery: supplies pancreas, spleen, greater curvature
- hepatic artery: supplies liver, gallbladder, duodenum, pancreas
stomach: venous drainage
left and right gastric veins drain into portal vein
hepatic artery: branches + supply
- right gastric artery: supplies right lesser curvature
- gastroduodenal artery: supplies first and second parts of duodenum
superior mesenteric artery: major branches + supply
- inferior pancreaticoduodenal supplies third and fourth parts of duodenum
- middle colic, right colic, ileocolic branches
- jejunal and ileal branches supply jejunum and ileum
inferior mesenteric artery: major branches + supply
- left colic, sigmoid, superior rectal
duodenum: venous drainage
superior mesenteric vein unites with splenic vein to form hepatic portal vein
jejunum and ileum: venous drainage
drain into superior mesenteric vein via jejunal and ileal veins
small intestines: sympathetic innervation
- presynaptic sympathetic fibers originate on T8-T10, pass through sympathetic trunk and abdominopelvic splanchnic nerves
- synapse on cell bodies of postsynaptic neurons in celiac and superior mesenteric ganglia
small intestines: parasymathetic innervation
- fibers derive from vagus nerve
- synapse with postsynaptic parasympathetic neurons in myenteric and submucosal plexuses
colon: arteries
- midgut (ascending, transverse) is supplied by branches of superior mesenteric (right, middle, and ileocolic arteries)
- hindgut (descending, sigmoid) is supplied by branches of inferior mesenteric (left colic and sigmoid arteries)
- marginal artery creates anastomosis for colon
colon: venous drainage
- right colic vein and ileocolic vein drain ascending colon
- inferior mesenteric vein drains descending and sigmoid colon, flows into splenic then hepatic portal vein
colon: sympathetic innervation
descending, sigmoid: lumbar splanchnic nerves, inferior mesenteric ganglia and periarterial plexuses on inferior mesenteric artery + branches
colon: parasympathetic innervation
splanchnic nerves via inferior hypogastric plexus
spleen: location
left upper quadrant
posteriorly associated w/ ribs 9-11
rests on L colic flexure
spleen: vasculature
splenic artery: runs along superior border of pancreas, posterior to omental bursa and anterior to L kidney
splenic vein: combines with superior mesenteric vein posterior to neck of pancreas to form hepatic portal
spleen: nerves
abdominopelvic splanchnic
vagus
pancreas: general location
retroperitoneal
posterior to stomach between duodenum on right
spleen on left
head of pancreas: location
surrounded by C-shaped curve of second part of duodenum
pancreas: uncinate process location
