Understanding the Peritoneal Cavity Flashcards
Boundaries of the Abdominal Wall:
- superiorly?
- inferiorly?
- posteriorly?
- anterolaterally?
- Superior - Costal margin, Xiphoid process
- Inferior - Pelvic bones, iliac crest
- Posterior - Lumbar vertebrae
- Anterolateral - Abdominal muscles
Boundaries of the Abdominal Cavity:
- superiorly?
- inferiorly?
- posteriorly?
- anterolaterally?
- Superior - Diaphragm
- Inferior – Pelvic inlet
- Posterior – Abdominal wall muscles
- Anterolateral - Abdominal wall muscles
Boundaries/Contents of the pelvic cavity:
- superiorly?
- posteriorly?
- anteriorly?
- inferiorly?
- laterally?
- Superiorly – pelvic brim
- Posteriorly - sacrum and coccyx
- Anterior – pubic symphysis
- Floor – pelvic floor muscles
- Lateral – Obturator internus
Five main layers of the anterolateral abdominal wall:
- Skin
- Superficial fascia: Camper’s (fatty) and Scarpa’s (membranous)
- Muscles: Obliques (lateral), Rectus Abdominis (anterior)
- Deep Fascia: Transversalis Fascia
- Peritoneum: Parietal, Visceral
Abbrieviation to remember the five main layers of the anterolateral abdominal wall:
- SSMDP
- skin, superficial fascia, muscles, deep fascia, peritoneum
Abbrieviation to remember the five main layers of the anterolateral abdominal wall:
- SSMDP
- skin, superficial fascia, muscles, deep fascia, peritoneum
Abdominal Cavity
Abdominal Cavity
Pelvic Cavity
Layers of the anterolateral abdominal wall
Muscle of the Anterolateral Abdominal Wall: What is the function of the external oblique muscle?
Works with the internal oblique muscle for torisional movement of the trunk
Muscle of the Anterolateral Abdominal Wall: What is the function of the internal oblique muscle?
flex and rotate trunk; compress viscera
Muscle of the Anterolateral Abdominal Wall: What is the function of the transversus abdominis?
compress and support viscera
Muscle of the Anterolateral Abdominal Wall: What is the function of the rectus abdominis?
flexes trunk; compress viscera
Muscles of the Anterolateral Abdominal Wall:
- external oblique
- works with the internal oblique for torsional movement of the trunk
Muscles of the Anterolateral Abdominal Wall:
- internal oblique
- flex and rotate trunk; compress viscera
Muscles of the Anterolateral Abdominal Wall:
- transversus abdominis
- compress and support viscera
Muscles of the Anterolateral Abdominal Wall:
- rectus abdominis
- flexes trunk; compress viscera
Formation of Rectus Sheath
Abdominal Wall Blood Supply: Centrally:
- Superior epigastric artery, arises
from the internal thoracic artery - Inferior Epigastric artery, arises
from external iliac artery, enters
rectus sheath at Arcuate line
Abdominal Wall Blood Supply: Laterally:
Musculophrenic artery, Deep Circumflex Iliac artery, Subcostal artery
Abdominal Wall Blood Supply: Venous Drainage:
- corresponds to the named arteries
- superior epigastric veins and
superficial iliac veins drain into
Great Saphenous Vein
Foregut:
- upto duodenum proximal to major
papilla - oesophagus
- stomach
- proximal half duodenum
- liver pancreas
Midgut:
- distal to major papilla
- distal half duodenum, Jejunum,
Ileum, Cecum, Ascending & 3/4
transverse colon
The primitive gut is held in position by
mesenteries (a structure of mesodermal origin), which is formed by a double layer of peritoneum
The primitive gut
What is the exception the ventral mesentery degeneration?
foregut
Peritoneum and Mesentery
Dorsal Mesentery attaches
gut organs to the posterior anterior abdominal wall
Dorsal Mesentery gives rise to (4)(3):
- Greater Omentum
- Gastrosplenic ligament
- Gastrophrenic ligament
- Gastrocolic ligament
- Splenorenal ligament
- Mesentery of the small and large
bowel
Ventral Mesentery gives rise to (3)(2):
- ligaments around the liver
- Falciform ligament
- Lesser Omentum:
- hepatogastric ligament
- hepatoduodenal ligament
The gut developed from what embryological structure?
endoderm
Ventral Mesentery attaches
Peritoneum
layer of serous membrane comprising of connective tissue and squamous epithelium, which lines the abdominal cavity
Two components of the peritoneum:
- parietal peritoneum
- visceral peritoneum
Parietal Peritoneum adheres to (3):
- anterior and posterior abdominal
walls - undersurface of the diaphragm
- cavity of the pelvis
Outside parietal peritoneum is
extraperitoneal connective tissue, which adheres to:
- loose areola tissue - dense, fibrous tissue - fat - closely related to the deep layer of abdominal muscles
The parietal peritoneum anchors ——— structures such as (3):
- retroperitoneal structures
- pancreas
- duodenum
- ascending and descending colon
Innervation of the parietal peritoneum
- segmental spinal nerves -
intercostal, diaphragm, lumbar
Visceral Peritoneum
- extension of the parietal peritoneum
- invests the viscera:
- passes over the front of organs
(duodenum, right and left colon)
- 2 leaves lying together which
splits around an organ, forming
a mesentery - spaces and recesses: pelvic organs
project into the pelvis (rectum,
uterus, bladder)
Innervation of the Visceral Peritoneum
visceral nerves
Peritoneal Cavity
- potential speace between serous
coated organs - small volume of fluid to lubricate
- two spaces: greater sac (Coelom),
Lesser Sac, outpouch of greater sac
behind stomach)
Peritoneal Cavity
Greater Sac: Supra Colic Compartment:
- above transverse mesocolon
- Upper abdominal Organs:
- stomach
- liver and biliary tree
- pancreas
- spleen - lives under the costal margin,
below the diaphragm
Supra Colic Compartment: Greater Sac: Location:
Greater Sac: Supra Colic Compartment: Investing peritoneum of upper abdominal organs:
- Includes stomach from oesophagus
to 1st part of duodenum - Support ligaments – gastrophrenic,
gastrosplenic, spleno-renal
Greater Sac: Supra Colic Compartment: Greater Omentum:
- two layers which are fused and
extend from the stomach and
proximal duodenum to lay over the
infracolic compartment contents - contains fat, blood vessels and
lymphatics
Greater Sac: Supra Colic Compartment: Lesser Omentum:
- Investing peritoneum of stomach
joins to form a fold:
- Right border of oesophagus
- Lesser curve of stomach to 1st
part of duodenum- Extends upwards to
undersurface of left lobe of liver
upper abdominal organs
- Extends upwards to
Omentum Diagram:
Greater Sac: Supra Colic Compartment: Lesser Sac: Outpouching of Greater Sac:
- outpouching of Greater Sac: behind the
stomach, anterior to pancreas and great
vessels in the retroperitoneum
Greater Sac: Supra Colic Compartment: Lesser Sac: Communication with Greater Sac:
- Epiploic Foramen:
- anterior: hepatoduodenal ligament,
hepatogastric ligament - posterior: IVC, right crus of diaphragm
- superior: caudate lobe of liver
- inferior: superior part of the abdomen
- anterior: hepatoduodenal ligament,
Greater Sac: Infra-Colic Compartment:
- below transverse mesocolon
- para-colic gutters: right and left
- infracolic compartment: right and left
Greater Sac: Infra-colic Compartment: Para-colic Gutters: Right Para-Colic Gutter:
- upper pole right kidney
- undersurface right lobe of liver (hepato-renal
pouch) - lateral to ascending colon and caecum to
pelvic cavity
Greater Sac: Infra-colic Compartment: Para-colic Gutters: Left Para-Colic Compartment:
- wholly infracolic
- bound superiorly by the phrenicocolic
ligament - left side of transverse mesocolon
- pelvic cavity
Greater Sac: Infra-Colic Compartment:
Greater Sac: Infra-Colic Compartment:
- divided by root of small bowel mesentery
attachment to the posterior abdominal wall - 15cm, Duodeno-jujunal flexure obliquely to
right illiac fossa - fans out to up to 6m small bowel: jejunum and
ileum - contains small intestine, ascending and
descending colon)
Greater Sac: Right Infra-Colic Compartment:
- laterally (right of) caecum and ascending
colon - medially small bowel mesentery
- upper limit: right half of transverse colon
- Upper aspect overlies 3rd/4th part of the
duodeum and lower pole of right kidney
Greater Sac: Left Infra-Colic Compartment:
- laterally (left of) descending colon
- medially small bowel mesentery
- upper limit left half of transverse mesocolon
- sweeps down into the pelvis
Peritoneal Reflections and Folds (3):
- Vesico-uterine pouch
- Recto-uterine pouch
- Recto-vesicle pouch
Pelvic Pouches
Peritoneum Function:
- parietal
- visceral
-
-
- Parietal: innervated by somatic nerves, pain
sensitive - Visceral: innervated by autonomic nerves, pain
insensitive - Fluid Exchange: peritoneal dialysis
- Infection:
- contains phagocytes to protect viscera
- mesothelial cells transform to fibroblasts
for healing
- greater omentum physically protects
Peritonitis:
- inflammation of the peritoneum
- appendicitis
- appendix mass - abscess
- perforation
