Abdomen Flashcards
What forms the roof of the inguinal canal?
Lateral half- internal oblique and transversus abdominis
Medial half- external oblique aponeurosis
What forms the anterior wall of the inguinal canal?
External oblique aponeurosis with some reinforcement laterally from internal oblique fibres
What forms the floor of the inguinal canal?
The inguinal ligament
What forms the posterior wall and deep inguinal ring of the inguinal canal?
Medially the conjoint tendon, laterally transversalis fascia
What stops bowel from herniating into the inguinal canal during increased abdominal pressure?
Contraction of internal oblique and transversalis fascia (supplied by L1 ilioinguinal and iliohypogastric nerves) this pulls the roof down and effectively shuts the canal
What is the interfoveolar ligament?
Fibres from transversus abdominis that arch down and strengthen the posterior wall of the inguinal canal and make up the medial portion of the deep inguinal ring
What is the course of the ilioinguinal nerve in the inguinal canal?
Comes in from the side and not through the deep ring. Runs in front of the spermatic cord, leaves through the superficial ring
What is an indirect inguinal hernia?
One that passes through the deep inguinal ring and into the inguinal canal?
What is a direct inguinal hernia?
One that passes medial to the inguinal triangle and enters the canal i.e. passes through a weak spot in the wall rather than through the deep inguinal ring
What passes deep to the posterior wall of the inguinal canal?
The inferior epigastric artery from the external iliac which lies just proximal to the inguinal ligament. The medial umbilical artery passes medially to the IEA obliquely across the posterior wall
What are the three coverings of the spermatic cord?
Internal spermatic fascia from the transversalis fascia
Cremasteric fascia and cremasteric muscle, from the internal oblique and transversus abdominis
External spermatic fascia from the external oblique aponeurosis (superficial ring)
What are the 6 contents of the spermatic cord?
- Ductus deferens (usually posterior)
- Arteries- testicular, artery to ductus, cremasteric
- Veins- pampiniform plexus
- Lymphatics
- Nerves- genital branch of genitofemoral nerve
- Processus vaginalis
What is the processus vaginalis
The obliterated remains of the peritoneal connection with the tunica vaginalis of the testis. When patent it forms the sac of an indirect inguinal hernia
What separates right and left sides of the scrotum?
The median scrotal septum
What is the gastrocolic ligament?
A sheet of peritoneum that connects the stomach to the transverse mesocolon
What lies over the stomach in the abdomen?
The left lobe of the liver
Where does the greater omentum attach to the stomach?
Along the whole of the greater curve of the stomach
Where does the lesser omentum attach to the stomach?
Along the lesser curve, the attachment is quite wide at the gastro-oesophageal junction.
It then attaches to the liver and the diaphragm.
Where else does the greater omentum attach?
The transverse mesocolon
What is the transpyloric plane?
Bisects the body between the jugular notch and pubic symphisis
Where is the transpyloric plane?
A point midway between the xiphisternum and umbilicus or about a handsbreadth below the xiphisternal joint
What does the transpyloric plane cut?
The ninth costal cartilage which is at the lateral border of the rectus abdominis (semilunar line)
What lies beneath the transpyloric plane?
On the right, the fundus of the gallbladder, on the left the body of the stomach
At which vertebral level is the transpyloric plane?
Between the lower body of L1 and upper border of L2
What structure does the transpyloric plane pass through?
It passes throught the pylorus, but note that this is free on a mesentery and therefore mobile.
The SMA leaves the aorta at this level and the splenic vein runs transversely behind the pancreas, the hilum of each kidney lies in this plane (left just above, right just below)
What does the peritoneum consist of?
A single layer of mesothelium
What is the mesentery supporting the transverse colon?
The transverse mesocolon
What is the mesentery supporting the appendix?
The mesoappendix
What is the mesentery supporting the sigmoid colon?
The sigmoid mesoappendix
what is the ligamentum teres?
obliterated remains of the umbilical vein
Where is the ligamentum teres?
In the falciform ligament
What is the course of the falciform ligament?
Goes upwards from the umbilicus behind the linea alba towards the xiphisternum, delivers ligamentum teres to liver and then continues up and to the right of midline
What does the median umbilical fold contain?
The median umbilical ligament
What is the median umbilical ligament?
The obliterated remains of the urachus
What does the medial umbilical fold contain?
The medial umbilical ligament
What is the medial umbilical ligament?
The obliterated remains of the umbilical artery
What does the lateral umbilical fold contain?
The inferior epigastric vessels that enter the rectus sheath by passing beneath the arcuate line
What is the purpose of the lesser sac?
Provides a slippery surface for the necessary mobility of the posterior surface of the stomach
What is the anterior wall of the lesser sac?
The lesser omentum and stomach
What is the left of the lesser sac?
The hilum of the spleen where the peritoneum forms the lienorenal and gastrosplenic ligaments
What is to the right of the lesser sac?
The epiploic foramen
What is the roof of the lesser sac?
Peritoneum covering the caudate lobe of the liver
What is the posterior wall of the lesser sac?
Peritoneum which overlies part of the diaphragm, pancreas and left kidney and suprarenal gland
What is the lowest part of the posterior wall of the lesser sac?
Transvers mesocolon attached to the lowest part of the pancreas
What can be palpated when placing fingers into the lesser sac through the epiploic foramen?
Aorta- giving off coeliac trunk Common hepatic artery Pancreaticoduodenal fold Left gastric artery Pancreaticogastric fold
Which part of the greater omentum forms the investment for the spleen?
The anterior (outer) layer
What forms the gastrosplenic ligament?
2 layers of peritoneum one from the lesser and one from the greater sac. These fuse and connect the stomach and spleen
What forms the lienorenal ligament?
2 layers of peritoneum one from the lesser and one from the greater sac. These fuse and connect the left kidney and the spleen
What forms the gastrophrenic ligament?
The greater omentum- passes from the stomach to diaphragm above the kidney
What are the gastrosplenic, lienorenal and gastrophrenic ligaments derived from?
They are derivatives of the dorsal mesogastrium
What is the attachment of the greater omentum?
Continuous attachment from the abdominal oesophagus to duodenum, along the left and lower border of the stomach (greater curvature)
What is the attachment of the lesser omentum to the stomach?
From the right side of the abdominal oesophagus and along the lesser curvature to the first inch of the duodenum