Anatomy Flashcards
How is the Abdomen divided?
4 quadrants and the 9 regions
What are the names of the 9 regions?
Right hypochondrium, epigastrium, left hypochondrium,
right flank, umbilical region, left flank,
right groin, suprapubic region and left groin.
Where does the foregut end?
Halfway along the duodenum
Where does the midgut end?
2/3 along the transverse colon
Where does the hindgut end?
The upper anal canal
What 3 main arteries branch off the abdominal artery to supply the foregut, midgut and hindgut?
Celiac trunk, superior mesenteric artery and the inferior mesenteric artery
Peritoneum
Serous lining. Parietal peritoneum lines the inner aspect of the abdominal wall. Visceral peritoneum covers organs within.
Thin cavity between the 2 layers called the peritoneal cavity, contains peritoneal fluid.
Innervation of Peritoneum
Parietal peritoneum is innervated by somatic nerves. (well localised, sharp and severe)
Visceral peritoneum is innervated by the same visceral sensory nerves that innervate the organs it covers. (poorly localised, vague, dull)
The abdominal aorta
Left of midline on posterior abdominal wall.
Bifurcates at L4/5 into right and left common iliac arteries. Abdominal aorta gives rise to paired and unpaired branches.
Right and left common iliac arteries supply…
the pelvis and lower limbs
Abdominal aortic aneurysm can present as
Sudden onset severe abdominal or back pain, rapid bleeding, circulatory shock. Has high mortality.
3 unpaired branches which leave the anterior aspect of the abdominal aorta and supply the gut…
Coeliac trunk at T12 (foregut)
Superior mesenteric artery at L1 (midgut)
Inferior mesenteric artery at L3 (hindgut)
These arteries further divide which anastomose with each other.
Branches of the coeliac trunk
Left gastric artery (stomach)
Splenic artery (spleen, stomach and pancreas. Also has left gastro-omental branching off.)
Common hepatic artery (supplies liver, gallbladder, stomach, duodenum. Divides into gastro-duodenal which bifurcates into right gastro-omental, hepatic artery proper which bifurcates into right and left hepatic arteries)
Superior Mesenteric artery (SMA) branches
Jejunal and ileal branches (supply jejunum and ileum)
Ileocolic artery (supplies ileum, caecum, appendix, ascending colon)
Right colic artery (supplies ascending colon)
Middle colic artery (supplies transverse colon)
Inferior Mesenteric Artery (IMA) branches
Left colic artery (supplies descending colon)
Sigmoid branches (supplies sigmoid colon)
Superior rectal artery (supplies upper rectum)
Veins of abdomen
Systemic veins, carry blood to IVC. Renal veins hepatic veins
Portal system, carries nutrient-rich venous blood from the gut to the liver. From liver, blood enters hepatic veins and returns to IVC.
Splenic, superior mesenteric and inferior mesenteric veins.
Liver
Has 2 lobes
2 smaller accessory lobes (caudate next to IVC and quadrate next to the gallbladder)
Mostly covered by peritoneum
Falciform ligament
Separates left and right lobes.
Remains of embryological mesenteries.
Connects the liver to the anterior abdominal wall.
Continuous with the coronary ligaments (anterior and posterior merge together to from left triangular ligament. Anchor the liver to the diaphragm)
Areas of liver with no peritoneum
Porta hepatis (where blood vessels come in), the bare area and under gallbladder
Porta hepatis
region on the liver where the vessels and ducts enter and exit the liver. Run in free edge of the lesser omentum.
Portal triad
Bile duct, hepatic artery proper and the hepatic portal vein.
Gallbladder
small hollow organ,
stores and concentrates bile.
Gallstones
Usually composed of cholesterol, usually asymptomatic. Don’t show up on x-ray. Use ultrasound.
Gallstone in bile duct
Blockage bile drainage (jaundice)
Bile backed up into liver and spills into blood –> jaundice
water retention
distention
