What is a retroperitoneal structure?
Organs are retroperitoneal if they have peritoneum on their anterior side only. Structures that are not suspended by mesentery in the abdominal cavity and that lie between the parietal peritoneum and abdominal wall are classified as retroperitoneal
What are the retroperitoneal structures of the abdomen?
Suprarenal (adrenal) glands
Aorta and IVC
Duodenum (2nd through 4th parts only)
Pancreas (except tail)
Colon (descending and ascending)
Esophagus (thoracic portion)
What does the falciform ligament do?
it connects the liver to the anterior abdominal wall
What structures are found within the falciform ligament?
ligamentum teres hepatis
Where does the ligamentum teres derive from?
the umbilical vein
T or F. The ligamentum teres is a derivative of the ventral mesentery
What does the hepatoduodenal ligament do?
connects the liver to the duodenum
What structures are contained within the hepatoduodenal ligament?
portal triad: proper hepatic a., portal vein, and common bile duct
What is a pringle maneuver?
pinching the heaptoduodenal ligament in between the thumb and index finger while placed in the omental foramen to control bleeding
What does the gastrohepatic ligament do?
connect the liver to the lesser curvative of the stomach
What does rhe splenorenal ligament do? What structures are contained within it?
it connects the spleen to the posterior abdominal wall and contains the splenic a. and v., and the tail of the pancreas
What are the layers of the gut wall from luminal to internal?
Mucosa (includes the epithelium, lamina propria, and the muscularis mucosa)
Submucosa (including the Meissner plexus)
Muscularis externa (including the Auerbach nerve plexis)
What is the epithelium of the esophagus?
nonkeratinized stratified squamous
What are the branches of the aorta at T12?
Celiac trunk anteriorally and two inferior phrenic aa. laterally
What are the branches of the aorta at L1?
the SMA anteriorally and the left middle suprarenal a. and
slightly below these two branch the left and right renal aa.
What branches anteriorally off the aorta just below the left and right renal aa. at about L2?
the left and right testicular/ovarian aa.
What branches from the aorta at L3?
the inferiror mesenteric. a
Where does the aorta bifurcate?
Describe the arterial supply, parasympathetic innervation, and vertebral levels of the foregut
Describe the arterial supply, parasympathetic innervation, and vertebral levels of the midgut
Describe the arterial supply, parasympathetic innervation, and vertebral levels of the hindgut
What structures are supplied by the embryonic foregut?
pharynx (vagus n. only)
low esophagus to proximal duodenum
liver, gallbladder, pancreas, spleen
What structures are supplied by the embryonic midgut?
distal duodenum to proximal 2/3 of the transverse colon
What structures are supplied by the embryonic hindgut?
Distal 1/3 of transverse colon to upper portion of rectum above the pectinate line
What are the branches of the celiac trunk?
common hepatic a.
left gastric a.
What is the pectinate line?
this forms in the rectum where the endoderm (hindgut) meets ectoderm
What are some associations above the pectinate line?
internal hemorrhoids, adenocarcinoma
What is the arterial supply above the pectinate line?
superior rectal a. from the IMA
What is the venous drainage above the pectinate line?
superior rectal vein to the inferior mesenteric vein to the portal system
Are internal hemorrhoids painful? Why or why not?
No, because they receive visceral innervation
What is the lymphatic drainage above the pectinate line?
internal iliac nodes
What are some associations below the pectinate line?
external hemorrhoids, anal fissures, and squamous cell carcinomas
What is the arterial supply below the pectinate line?
the inferior rectal a., a branch of the internal pudendal a.
What is the venous drainage below the pectinate line?
inferior rectal vein to the internal pudendal vein to the internal iliac vein to the common iliac vein to the IVC
Why are external hemorrhoids painful?
they receive somatic innervation from the inferior rectal branch of pudendal n. and are thus painful if thrombosed
What is the lymph drainage below the pectinate line?
What hepatic zone is affected first by viral hepatitis?
Zone 1 aka periportal zone (also the site for ingested toxins like cocaine)
What zone is affected by yellow fever?
Zone II (intermediate zone)
Describe the pericentral vein (centrilobular) zone
-affected 1st be ischemia
-contains CYP P450s
-most sensitive to metabolic toxins
-site of alcoholic hepatitis
Describe the flow of bile
the right and left hepatic ducts combine to form the common hepatic duct which combines with the cystic duct from the gallbladder to form the common bile duct which combines with the main pancreatic duct to empty into the 2nd part of the duodenum at the ampulla of vater
Describe the organization of the femoral region
Lateral to medial: NAVEL
Nerve-Artery-Vein-Empty Space- Lymphatics (contained in the femoral ring-site of femoral hernias)
What structures are contained within the femoral sheath?
femoral vein, artery, and canal but not femoral nerve
What are the main types of hernias?
What is a diaphragmatic hernia?
herniation of abdominal structures upward through the diaphragm
What are the most common causes of diaphragmatic hernias?
typically congenital due to defect in the pleuroperitonel membrane, or as a result of trauma.
NOTE: These msot commonly occur on the LEFT side due to relative protection of right hemidiaphragm by the liver
What is the most common type of diaphragmatic hernia?
A hiatal hernia, in which the stomach herniates through the esophageal hiatus at T10 and more specifically, a sliding hiatal hernia (center below) in which the gastroesophageal junction is displaced upward ("hourglass" stomach)
What is a paraesophageal hernia?
a diaphragmatic hernia in which the gastroesophageal junction is not displaced but the stomach fundus protrudes into the thorax
What is an indirect inguinal hernia?
this is herniation of abdominal contents via the following route:
through the deep ingunal ring LATERAL to the INFERIOR EPIGASTRIC A., out of the external (superficial) inguinal ring and into the scrotum (i.e. the path of the testes when they descend to the scrotum)
T or F. Indirect inguinal hernias are covered by all 3 layers of spermatic fascia (i.e. the internal spermatic fascia, cremasteric fascia and muscle, and external spermatic fascia)
Why would an indirect hernia occur in infants?
due to failure of the processus vaginalis to close properly
What is a direct inguinal hernia?
herniation through Hesselbach's triangle, located between the rectus abdominis muscle medially, the inguinal ligament inferiorly, and the inferior epigastric vessels laterally (thus this occurs MEDIAL to the inferior epigastric vessels)
A direct inguinal hernia goes through the _____ inguinal ring only
superficial (so it is covered by the external spermatic fascia only). These usually occur in older men than indirect
Describe femoral hernias
these are protrusions below the inguinal ligament through the femoral canal more commonly in FEMALES