I. Anatomy and Physiology
Lecture - Anatomy of the Abdominal Cavity
Diaphgram
- Mesoderm:
- Diaphragm develops cranial from the heart -> finds its place with embryo folding
- Pericardial and pleural cavities: phrenic nerve is pulled inwards leading to its
location on the pericardium
- Phrenic nerve: afferent signal of the pericardium
- Can explain referred pain
- Anatomy:
- Section of the diaphragm (above): central tendon, muscle, pericardium, aorta,
vena cava, esophagus, (hemi)azygos, thoracic duct (lymphatic system)
- Section (below): central tendon, muscle, sympathetic trunk (nerves),
(hemi)azygos
- median arcuate ligament: can cause median arcuate syndrome ; aorta
passes through this muscle (posterior)
- Vena cava: in the central tendon part
- esophageal hiatus: formed by the crura ; protects from GERD
- lumbocostal triangle: remnant of canals closed at the 20 week ; weakest
part of the diaphragm ; risk of hernia
- Hiatal Hernia
- Cauda of the stomach enters through the crura
- Short term: acid production of the cauda causes GERD-like symptoms
- Long term: sclerosis
- Complications: adenocarcinoma
Peritoneum
- Embryology
- Rotation: clockwise -> liver rotates to the right from the dorsal side
- Foregut: till half the duodenum ; possesses ventral and dorsal mesentery
- Midgut: till half of the transverse colon
- Hindgut: the rest of the colon ; dorsal mesentery (horseshoe shape of the cavity)
- Layers
- Skin
- Subcutaneous fat with connective tissue
- Lower abdomen: Camper’s fascia and Scarpa's fascia
- Abdominal fascia
- Muscles with tendon sheaths/aponeuroses
- Aponeuroses of external canal covers inguinal canal
- Rectus abdominis only attaches to anterior lamina
- Posterior lamina finishes at semicircular line (5-8cm after
umbilicus)
, - Finishes before anterior lamina -> weaker abdomen ->
Spigelian hernia
- Fascia transversalis: wraps muscles
- Parietal peritoneum
- Peritoneum (micro) = mesothelium (histo)
- Peritoneum: serous membrane lining the abdominal cavity
- Mesothelium: simple squamous layer, visceral peritoneum ; protective non
adhesive surface
- Visceral: lines the organs
- Parietal: lines the entire cavity
- Pathology: air presence
- Mesentery
- Definition: extension of the peritoneum ; only for intraperitoneal organs
- Function:
- suspends the organs within the cavity
- provides perfusion for the organs
- prevents herniations
- Division
- Ventral: divides the cavity
- Falciform ligament: ventral body wall towards the liver
- Contained: umbilical vein
- Contains the round ligament: used to be the veins
- Lesser Omentum: net between the liver, stomach and part of the
stomach
- Can be considered a ligament: hepatogastric ligament,
hepatoduodenal ligament
- Hepatoduodenal lig: portal triad (portal vein, proper
hepatic artery, common bile duct)
- Dorsal mesentery = large omentum: suspended from the colon ;
lymphatic structure
- Omental Bursa (part of the mesentery)
- Embryonic rotation forms the abdominal cavity recess behind the stomach =
omental bursa (lesser sac)
- Function: prevents friction
- Boundaries: stomach and lesser omentum (ventral)
- Lesser omentum: provides access to the pancreas
- Winslow or Omental or Epiploic foramen: communication between
omental bursa and abdominal cavity
- Peritoneal Cavity (greater sac)
- Intraperitoneal: have mesenteries
- Tunica serosa = mesothelium = visceral peritoneum
- Spleen: splenorenal ligament (= mesentery)
- Small intestines: mesentery (of the small intestine)
- Transverse colon: transverse mesocolon (=mesentery)
Lecture - Anatomy of the Abdominal Cavity
Diaphgram
- Mesoderm:
- Diaphragm develops cranial from the heart -> finds its place with embryo folding
- Pericardial and pleural cavities: phrenic nerve is pulled inwards leading to its
location on the pericardium
- Phrenic nerve: afferent signal of the pericardium
- Can explain referred pain
- Anatomy:
- Section of the diaphragm (above): central tendon, muscle, pericardium, aorta,
vena cava, esophagus, (hemi)azygos, thoracic duct (lymphatic system)
- Section (below): central tendon, muscle, sympathetic trunk (nerves),
(hemi)azygos
- median arcuate ligament: can cause median arcuate syndrome ; aorta
passes through this muscle (posterior)
- Vena cava: in the central tendon part
- esophageal hiatus: formed by the crura ; protects from GERD
- lumbocostal triangle: remnant of canals closed at the 20 week ; weakest
part of the diaphragm ; risk of hernia
- Hiatal Hernia
- Cauda of the stomach enters through the crura
- Short term: acid production of the cauda causes GERD-like symptoms
- Long term: sclerosis
- Complications: adenocarcinoma
Peritoneum
- Embryology
- Rotation: clockwise -> liver rotates to the right from the dorsal side
- Foregut: till half the duodenum ; possesses ventral and dorsal mesentery
- Midgut: till half of the transverse colon
- Hindgut: the rest of the colon ; dorsal mesentery (horseshoe shape of the cavity)
- Layers
- Skin
- Subcutaneous fat with connective tissue
- Lower abdomen: Camper’s fascia and Scarpa's fascia
- Abdominal fascia
- Muscles with tendon sheaths/aponeuroses
- Aponeuroses of external canal covers inguinal canal
- Rectus abdominis only attaches to anterior lamina
- Posterior lamina finishes at semicircular line (5-8cm after
umbilicus)
, - Finishes before anterior lamina -> weaker abdomen ->
Spigelian hernia
- Fascia transversalis: wraps muscles
- Parietal peritoneum
- Peritoneum (micro) = mesothelium (histo)
- Peritoneum: serous membrane lining the abdominal cavity
- Mesothelium: simple squamous layer, visceral peritoneum ; protective non
adhesive surface
- Visceral: lines the organs
- Parietal: lines the entire cavity
- Pathology: air presence
- Mesentery
- Definition: extension of the peritoneum ; only for intraperitoneal organs
- Function:
- suspends the organs within the cavity
- provides perfusion for the organs
- prevents herniations
- Division
- Ventral: divides the cavity
- Falciform ligament: ventral body wall towards the liver
- Contained: umbilical vein
- Contains the round ligament: used to be the veins
- Lesser Omentum: net between the liver, stomach and part of the
stomach
- Can be considered a ligament: hepatogastric ligament,
hepatoduodenal ligament
- Hepatoduodenal lig: portal triad (portal vein, proper
hepatic artery, common bile duct)
- Dorsal mesentery = large omentum: suspended from the colon ;
lymphatic structure
- Omental Bursa (part of the mesentery)
- Embryonic rotation forms the abdominal cavity recess behind the stomach =
omental bursa (lesser sac)
- Function: prevents friction
- Boundaries: stomach and lesser omentum (ventral)
- Lesser omentum: provides access to the pancreas
- Winslow or Omental or Epiploic foramen: communication between
omental bursa and abdominal cavity
- Peritoneal Cavity (greater sac)
- Intraperitoneal: have mesenteries
- Tunica serosa = mesothelium = visceral peritoneum
- Spleen: splenorenal ligament (= mesentery)
- Small intestines: mesentery (of the small intestine)
- Transverse colon: transverse mesocolon (=mesentery)
