Abdominal Wall & Peritoneum Flashcards
What are the bony landmarks of the abdominal region?
- xiphoid process
- Costal margins
- ilium
- pubis
What is the pelvic inlet?
-a line (linea terminalis) that separates the true pelvis from the false pelvis
+superior to linea terminalis is the abdomen or false pelvis
+inferior to linea terminalis is the pelvis or true pelvis
What is the pelvic inlet formed by?
- pectin pubis (pubic bone)
- arcuate line (ilium)
- sacral promontory (sacrum)
What are the fatty layer and membranous layer of the skin of the abdomen/superficial abdominal layer?
Camper’s layer (fatty layer):
- superficial
- continuous with the fatty layers in the thorax, thigh and peritoneum
- superficial blood vessels run in the fatty layer of the superficial fascia
Scarpa’s layer (membranous):
- deep
- continuous with fascia lata in the thigh and the deep layer of superficial perineal fascia
- continuous with penis and scrotum in males
Where are sutures held in the abdomen?
- deep fascia
- investing fascia of the muscles
Where is the potential space?
- located between the membranous layer of the superficial fascia and the deep fascia of the external abdominal oblique muscle
- fluid can leak into the potential space
What are the 4 surface anatomical structures talked about in class? Be able to locate them on a picture.
- Linea semilunaris (semilunar line): lateral border of rectus abdominal muscle
- Linea alba: abdominal midline
- Umbilicus (belly button)
- Superficial inguinal canal
What are the 5 planes of the abdomen?
- Transpyloric planceta
- Subcostal plane
- Supracrestal plane
- Transtubular plane
- Interspinous plane
What are the 9 regions of the abdomen?
- Epigastric
- Umbilical
- Pubic
- L hypochondriac
- L lateral (lumbar) region
- L inguinal
- R hypochondriac
- R lateral (lumbar)
- R inguinal
What organs are found in which quadrants?
RUQ:
- liver
- gall bladder
- stomach
- transverse and ascending colon
- small intestine
- kidney and suprarenal gland
- pancreas
- duodenum
LUQ:
- stomach
- transverse and descending colon
- small intestine
- spleen
- pancreas
- kidney and suprarenal glands
RLQ:
- small intestine
- ascending colon
- ureter
- bladder
LLQ:
- small intestine
- descending colon
- bladder
- ureter
Which muscles hold the abdominal organs in place?
-anterior and lateral
- external and internal obliques
- transversus abdominis
- rectus abdominis
Which muscles located posteriorly to flex the spine and lower limb?
- iliacus
- psoas Major and minor
- quadratus lumborum
What is the rectus sheath?
- an aponeurosis that the three flat anterior/lateral abdominal muscles end in
- encloses rectus abdominis
- midline of the rectus sheath is the linea alba
- -layers of fascia and aponeuroses of the muscles forming the rectus sheath are arranged differently in the upper abdominal wall than they are in the lower wall
What is the arcuate line?
- the line where the arrangement between the aponeuroses where the arrangement changes. (Rectus abdominis)
- located about 1/2 way between umbilicus and pubic symphysis
- below the arcuate -> anterior
Where do the deep system of arteries originate?
- superiorly from the subclavian
- branches in the mid-abdomen from the abdominal aorta
- inferiorly from the external iliac
Where do the superficial system of arteries originate?
- superiorly from perforating branches
- inferiorly from branches of the femoral artery
What are the deep arteries of the abdomen?
- musculophrenic
- sup. epigastric
- inf. epigastric
- intercostal
- subcostal
- lumbar
- deep circumflex iliac
What are the superficial arteries in the abdomen?
- run in superficial fascial layer
- superficial circumflex iliac a
- superficial epigastric a
- external pudental a (deep and superficial)
What drains deep in the abdomen?
-drains to subclavian v -> external iliac v -> lumbar and intercostal v
What does superficial drainage?
- within Campers fascia
- thoracoepigastric v
- lateral thoracic v
- superficial epigastric v
What are the nerves in the anterior abdominal wall?
- cutaneous branches of ventral rami, intercostal nerve
- lie between internal abdominal oblique and transversus abdominis
- pierce the rectus sheath to innervate the rectus abdominis muscles
- supply skin, muscles, and parietal peritoneum
-L1 and L2
-iliohypogastric nerve
+L1/T12
+supplies suprapubic region
-ilioinguinal nerve
\+L1
\+enters inguinal canal and emerges through through superficial inguinal ring
\+supplies groin and scrotum and
scrotum/labium majora
-genitofemoral nerve
+L1 and L2
+genital branch (innervates cremaster muscle of labia majora)
+femoral branch (to femoral triangle area)
Where does the superficial and deep lymphatics drain?
Superficial:
- superiorly from umbilical to ant. Axillary and sternal nodes
- inferiorly from umbilical region to superficial inguinal nodes
Deep:
- along post. Intercostal and lumbar vessels to deep abdominal nodes
- from testes to deep abdominal nodes
What is a hernia?
- a portion of the viscera protrudes through a weakened point of the muscular wall of and abdominopelvic cavity
- significant problem when the intestines swells -> can causes the intestine to die (stangulated intestinal hernia)
What are the two types of hernias? Which one is more common?
- inguinal hernia (more common)
- femoral hernia
Which sex is more likely to develop an inguinal hernia?
Males
How does an inguinal hernia develop?
-rising pressure in the abdominal cavity provides the force to push a segment of the SI into the canal
What are the two types of inguinal hernia?
- direct: the loop of the SI protrudes directly through the inguinal ring, but not the entire length of the inguinal canal. Creates a bulge in the lower anterior abdomen.
- indirect: herniation travels down the entire inguinal canal and may even extend all the way into the scrotum -> follows path of spermatic cord
What is a femoral hernia?
- occurs in the upper thigh, just inferior to the inguinal ligament originating in the femoral triangle
- medial part of femoral triangle is relatively weak and prone to stress injury
Which sex more commonly develops femoral hernias?
-females due to greater width of femoral triangle
What is an umbilical hernia?
- occurs when a portion of the intestine pushes through abdominal wall musculature in the periumbilical or umbilical region
- most common in infants, but can occur in adults as well
What are the content of the abdominal region?
- peritoneal cavity
- GI tract and associated glands and digestive organs
- nerves, lymphatics, and blood vessels
- renal system
What are the derivatives of the foregut?
- esophagus
- stomach
- duodenum
- liver
- gallbladder
- spleen
- pancreas
What are the derivatives of the midgut?
- duodenum
- jejunum
- ileum
- cecum
- appendix
- ascending colon
- 2/3 of transverse colon
What are the derivatives of the hindgut?
- 1/3 transverse
- descending and sigmoid colon
- rectum
- anal canal
What are subdivisions of the of the serous membrane?
-parietal
+lines the body wall
+has abundant pain fibers via nerves from the body wall
-visceral
+covers viscera
+lacks pain fibers
What is the difference between intraperitoneal and retroperitoneal organs?
-intra:
+covered on most sides by visceral peritoneum
+suspended by mesentery from the body wall
Retro:
+lie deep to the parietal peritoneum
+covered by parietal peritoneum on one side only
Nerves from the adjacent body wall supply _________ peritoneum.
Parietal
+supply pain and vasomotor fibers
Which organs are considered primarily retroperitoneal?
- kidneys
- ureters
- adrenals
- gonads
- aorta and inferior vena cava
What organs are considered secondarily retroperitoneal?
-retroperitoneal during development
- duodenum
- pancreas
- ascending and descending colon
What is the mesentery?
-2 layered fold of the peritoneum
- attaches the free small intestine to the posterior body wall
- jejunum
- ileum
What is the transverse mesocolon?
- mesentery of the transverse colon
- holds the transverse colon to the posterior body wall
- fuses with the posterior layer of the greater omentum
What is the sigmoid mesocolon?
- mesentery of the sigmoid colon
- holds sigmoid to posterior body wall
What is the mesoappendix?
-mesentery of the vermiform appendix
Which organs lose their mesentery and are considered secondarily retroperitoneal?
- duodenum
- ascending and descending colon
- cecum
What are peritoneal ligaments?
- subdivisions of a larger structure
- usually transmit nerves and vessels
- usually lack CT and are not the same as ligaments that join bones
- gastrosplenic ligament
- splenorenal ligament
What is the omentum/epiploon?
-broad, 2-4 layered sheet of peritoneum that attaches the stomach to other viscera
What does the lesser omentum develop from and what are the subdivisions?
-develops from the ventral mesogastrium
-subdivided into:
+hepatogastric ligament
+hepatoduodenal ligament
What ligaments are associated with the liver?
- coronary ligament
- right and left triangular ligament
- falciparum ligament
- ligamentum teres hepatis
What are folds in the mesentery?
-a ridge or elevation in the peritoneum produced by underlying vessels
What are fossa/recesses in mesentery?
-depressions between folds
What are peritoneal/umbilical folds?
- structures cursing through the extraperitoneal tissue form elevations in the interior abdominal wall
- median umbilical fold: urachus and midline from bladder
What are involved in the medial and lateral umbilical folds?
Medial:
- medial umbilical ligaments
- obliterated umbilical aa
Lateral:
- inferior epigastric vessels
- functional aa and vv
What is the supravesical fossa?
- between the median and medial umbilical folds
- site for supravesical hernias (rare)
What is the medial inguinal fossa?
- between the medial and lateral umbilical folds
- site for direct inguinal hernias
- also called inguinal triangle
What is the lateral inguinal fossa?
- lateral to the lateral umbilical folds
- site for indirect inguinal hernias
What is the greater sac in the peritoneal cavity?
- most potential space within the abdomen
- subdivided into supracolic and infracolic by the colon and transverse mesocolon
Where is the supracolic region?
- superior and anterior to the liver and stomach
- includes hepatorenal and subphrenic spaces and fossa of the anterior wall
Where is the peritoneal space located?
-closed space between parietal and visceral layers of peritoneum
- subphrenic recess
- subhepatic/hepatorenal recess
- rectovesical/rectouterine recess
Why is the greater sac clinically important?
-abscesses may develop and excess fluid pools here
What is in the inframesocolic region?
- inferior and posterior part of the greater sac
- subdivided by mesenteries and ligaments
- right and left paracolic gutters are lateral to the ascending and descending colon
- upper and lower parts are divided by the mesentery into right and left infracolic spaces
Why is the inframesocolic clinically important?
- where intraperitoneal infections spread
- phrenicolic ligament limits the spread of fluid superiorly
Where is the lesser sac/omental bursa?
- lesser sac is posterior and inferior to the stomach
- greater and lesser peritoneal sacs communicate through the epiploic foramen
What are the recesses in the lesser sac? Why is it clinically important?
- superior recess: posterior to liver
- inferior recess: potential space between the 2 layers of the gastrocolic ligament
- splenic recess: posterior to and left of the stomach
- important in relationship to the liver, pancreas, stomach, and spleen
What is the epiploic foramen?
-opening between the greater and lesser sac
- anterior: heptoduodenal ligament with portal vein, hepatic artery and bile duct
- posterior: IVC, diaphragm
- superior: liver, caudate lobe
- inferior: duodenum
