Abdomen Anatomy Flashcards
Superficial fatty layer of abdominal wall?
Campers fascia
Deep membranous layer of abdominal wall?
Scarpa fascia
Transversalis fascia
membranous sheet lining internal surface of the abdominal wall
Parietal peritoneum
Separated from transversalis fascia by extraperitoneal fat
What covers the three muscle layers of the abdominal wall?
Investing fascia (superficial, intermediate, and deep)
Nerves of the anterior abdominal wall?
Thoraco-abdominal nerves (T7-T11)
Subcostal (T12)
Iliohypogastric (L1)
Ilioinguinal (L1)
Muscles of abdominal wall (lateral group)?
External abdominal oblique, internal abdominal oblique, transversus abdominus
Anterior muscles of the abdominal wall?
Rectus abdominus and pyramidalis
Rectus sheath
Formed by aponeurosis of the 3 lateral muscles and encloses the rectus abdominus
Contains the superior epigastric artery (branch of internal thoracic artery) and the inferior epigastric artery (branch of the external iliac artery)
Linea alba
Midline raphe extending from the xiphoid process to the pubic symphysis. Formed by aponeuroses
Linea semilunaris
Represents the lateral border of the rectus sheath
Tendinous intersections
Divide the rectus abdominus into segments
Arcuate line
A feature of the posterior rectus sheath found below the umbilicus that indicates a change in the composition of both the anterior and posterior rectus sheath
Composition of the rectus sheath above the arcuate line?
Anterior: Aponeurosis of external abdominal oblique & 1/2 aponeurosis of internal abdominal oblique
Posterior: 1/2 aponeurosis of internal abdominal oblique & Aponeurosis of transversus abdominus & transversalis fascia
Composition of the rectus sheath below the arcuate line?
Anterior: aponeuoses of external & internal abdominal obliques & aponeurosis of transversus abdominus
Posterior: transversalis fascia
Inguinal ligament
The rolled inferior edge of the external abdominal oblique aponeurosis
Extends from the anterior superior iliac spine to the pubic tubercle
Inguinal canal
4 cm long passage that lies parallel and just superior to the medial half of the inguinal ligament. Superior opening is the deep inguinal ring, inferior is the superficial inguinal ring
Contains the spermatic cord in males and the round ligament of the uterus in females
Is the deep inguinal ring lateral or medial to the inferior epigastric vessels?
Lateral
Indirect hernia
Passes through the deep inguinal ring lateral to the inferior epigastric vessels; usually congenital & more common in males
Direct inguinal hernia
Passes directly through the abdominal wall (medial to the inferior epigastric vessels)
Femoral hernia
Passes through the femoral canal inferior to the inguinal ligament; more common in women
Peritoneum formations: mesenteries
Double layer of peritoneum which connects an organ to the posterior abdominal wall; contains blood and lymphatic vessels
Peritoneum formations: ligaments
Double layer of peritoneum that connects an organ to another organ
Peritoneum formations: greater omentum
4 layers of peritoneum associated with the greater curvature of the stomach
Peritoneum formations: lesser omentum
2 layers of peritoneum associated with the lesser curvature of the stomach
Three ligaments of the greater omentum
- Gastrophrenic - greater curvature + diaphragm
- Gastrosplenic - between greater curvature and spleen
- Gastrocolic - between greater curvature and transverse colon (extends past the transverse colon and folds back to make the 4 layer “omental apron”)
Three ligaments of the lesser omentum
- Hepatoduodenal - contains the portal triad
- Hepatogastric
- Hepatoesophageal
Portal triad contains?
Portal vein, proper hepatic artery & the common bile duct
What connects the greater & lesser peritoneal sacs?
Epiploic foramen (or foramen of Winslow)
Located posterior to the hepatoduodenal ligament/portal triad
Intraperitoneal organs
Almost completely covered with visceral peritoneum
Spleen, stomach, and transverse colon
Retroperitoneal organs
Only partially covered by peritoneum
Kidneys and most of the pancreas
Abdominal aorta boundaries
T12 (aortic hiatus in the diaphragm) to L4 (bifurcation just below umbilicus)
Unpaired branches of abdominal aorta
Celiac trunk (T12), Superior Mesenteric Artery (L1), Inferior mesenteric artery (L3)
Paired branches of the abdominal aorta
Suprarenal arteries (L1), renal arteries (L1), and gonadal arteries (L2)
Blood supply to gastrointestinal tract?
- Celiac trunk - foregut. Inferior esophagus to proximal half of duodenum (plus liver, gallbladder, spleen & pancreas)
- Superior mesenteric artery - midgut. From distal portion of the duodenum to proximal 2/3 of transverse colon
- Inferior mesenteric artery - hindgut. From distal 1/3 of transverse colon to superior portion of the rectum
Branches of the celiac trunk?
- Left gastric artery (most superior)
- Splenic artery (most inferior)
- Common hepatic artery (only branch to the right!!)
Inferior vena cava
Begins by the union of the common iliac veins at L5. Passes through the diaphragm at the caval opening (T8)
Tributaries of the inferior vena cava?
Hepatic veins, renal veins, right suprarenal vein, and right gonadal vein
Tributaries of the left renal vein?
Left gonadal vein + left suprarenal vein
Note: the left renal vein is longer than the right renal vein because it has to cross the midline to the IVC, which sits more toward the right
Tributaries of the portal vein?
- splenic vein
- superior mesenteric vein
- Inferior mesenteric vein
Borders of the inguinal canal?
Anterior: Aponeurosis of external abdominal oblique
Posterior: transversalis fascia + conjoint tendon
Roof: Muscle fibers of internal abdominal oblique + transversus abdominus
Floor: Inguinal ligament
Borders of the epiploic foramen?
Anterior: Hepatoduodenal ligmanet
Posterior: Peritoneum over IVC
Superior: Caudate lobe of liver
Inferior: 1st part of duodenum
Autonomic supply to abdominal organs?
Via autonomic plexuses that follow arteries to organs. Each plexus contains sympathetic and parasympathetic fibers
Sympathetic fibers originate from sympathetic chains & parasympathetic fibers original from the vagus up until the splenic flexure and then the pelvic splanchnic (S2, 3, 4)
Foregut: organs, blood supply, innervation
Esophagus, stomach, duodenum until major duodenal papilla
Arterial Supply: Celiac Trunk
Venous drainage: hepatic portal vein
Innervation: Celiac Plexus
Parasympathetic - Vagus CN X
Midgut: organs, blood supply, innervation
Duodenum after the major duodenal papilla, jejunum, ileum, cecum, ascending colon, transverse colon until left colic flexure
Artery supply: Superior mesenteric artery
Venous drainage: hepatic portal vein
Innervation: Superior mesenteric plexus
Parasympathetic: Vagus CN X
Hindgut: organs, blood supply, innervation
Descending colon, sigmoid colon, rectum
Artery supply: Inferior mesenteric artery
Venous drainage: hepatic portal vein
Innervation: Inferior mesenteric plexus
Parasympathetic: pelvic splanchnics (S2,3,4)
Stomach: retroperitoneal or intraperitoneal?
Intraperitoneal
Duodenum: retroperitoneal or intraperitoneal?
Retroperitoneal except for the first part (superior portion)
Where is the major duodenal papilla located?
The descending duodenum
Note: where the foregut becomes the midgut
Jejunum and ileum: retroperitoneal or intraperitoneal?
Intraperitoneal
Components of the large intestines?
Cecum w/ vermiform appendix, ascending colon, transverse colon, descending colon, and sigmoid colon
What portions or the large intestines are intraperitoneal?
Transverse and sigmoid
External features of large intestines
Teniae coli - tree thickened bands of longitudinal smooth muscle; converge at the veriform appendix
Haustra - sacculations or pouches of colon between teniae
Epiploic appendages - small fatty outpouchings
Blood supply and innervation of the liver?
Artery: Common hepatic artery (25%), Hepatic portal vein (75%)
Venous drainage: hepatic veins to IVC
Innervation: celiac plexus
Two surfaces of the liver
Diaphragmatic and visceral
Falciform ligament
From liver to anterior abdominal wall; separates anatomic larger right lobe from smaller left lobe
Round ligament of liver
Free thickened edge of falciform ligament; obliterated umbilical vein
Bare area of liver
In direct contact with diaphragm and not covered by peritoneum
Porta hepatis
Transmits the portal triad: proper hepatic artery, portal vein, and common bile duct
Three parts of the galbladder
Fundus, body, neck
Blood supply and innervation of the gall bladder
Blood supply: cystic artery
Which part of the pancreas isn’t retroperitoneal?
The tail
Parts of the pancreas
Head, uncinate process, neck, body, tail
Blood supply and innervation of the pancreas
Bloody supply: celiac trunk + superior mesenteric artery
Venous drainage: Hepatic Portal Vein
Innervation: Celiac + Superior mesenteric plexuses
Spleen surfaces
Diaphragmatic and visceral surfaces
Blood supply and innervation of the spleen
Blood supply: Splenic artery from celiac trunk
Venous drainage: splenic vein to hepatic portal vein
Innervation: celiac plexus
Kidney blood supply and innervation
Blood supply: renal arteries
Venous drainage: Renal veins to IVC
Innervation: renal plexus
Where do the suprarenal arteries arise from?
Superior suprarenal arteries (inferior phrenic arteries), middle suprarenal arteries (aorta), inferior suprarenal arteries (renal arteries)
Order of structures in the kidney hilum?
Vein is anterior, artery is in the middle, pelvis is posterior
Caval hiatus
T8
IVC, Right phrenic nerve
Esophageal hiatus
T10
Esophagus, anterior and posterior vagal trunks
Aortic hiatus
T12
Aorta, azygos vein, thoracic duct
Muscles of the posterior abdominal wall
Psoas major, quadratus lumborum, iliacus
What narrows to form the thoracic duct at the aortic hiatus?
Cisterna chyli
Retroperitoneal organs?
2nd - 4th sections of duodenum, ascending colon, descending colon, rectum (middle 1/3), pancreas (except tail), kidneys, suprarenal glands
Intraperitoneal organs?
Stomach, first part of the duodenum (bulb), jejunum, ileum, cecum, appendix, transverse colon, sigmoid colon, liver, spleen, tail of pancreas
What supplies the superior epigastric artery?
Internal thoracic artery
Supplies blood to the superior portion of the rectus abdominus!
What supplies the inferior epigastric artery?
The external iliac artery
Supplies blood to the inferior portion of the rectus abdominus!