GI Flashcards
Describe the areas of the abdomen.
R hypochondrium - Epigastrium - L hypochondrium
R lumbar - Periumbilical - L lumbar
R iliac fossa - Hypogastrium - L iliac fossa
What lines create the 9 areas of the abdomen?
Midclavicualar lines vertically and Subcostal/transpyloric/addison’s and transtubercular line horizontally
How are the muscles of the abdomen arranged from external to internal.
External oblique and rectus sheath
Rectus abdominus with linea alba
Internal oblique
Transversus abdomenus
What direction do the external oblique fibres run?
Inferior - medial
What is the function of the rectus abdominus?
Flex lumbar spine
What is the function of the external oblique?
Flex torso and contralateral trunk rotation
What is the function of the transversus abdominus?
Compress abdo contents
At what level is the umbilicus located?
L3/4
How are the abdominal muscles arranged above the umbilicus?
Anterior AND posterior of rectus sheath
What innervates the anterior abdominal wall?
Ventral rami of T7-L1
What are the attachments of the inguinal ligament?
Anterior superior iliac spine and pubic tubercle
What fascia is below the transversus abdominus?
Transversalis fascia
In males and females what emerges through the inguinal ligament?
Males = spermatic cord Females = round ligament
What causes an inguinal hernia?
Direct (weak spot in posterior muscle, superficial ring) or indirect (weakness in deep ring)
What is most lateral, the superficial or deep inguinal rings?
Superficial
What are the main epigastric vessels?
Superior and inferior
Where does the superior epigastric vessel arise from?
Internal thoracic artery
Where does the inferior epigastric vessel arise from?
External iliac artery
Name the layers of the gut tube?
Mucosa
Submucosa
Muscularis propria
Serosa (or adventitia)
What are the layers of the mucosa of the gut tube?
Epithelium
Lamina propria
Muscularis mucosae
What is the structure of the muscularis propria/externa?
Circular and longitudinal layers
What are the 4 basic mucosal types?
Protective
Secretory
Absorptive
Protective/Absorptive
What epithelium is found in the oesophagus and anal canal?
Stratified squamous
What epithelium is found in the stomach?
Simple columnar with tubular glands
What epithelium is found in the small intestine?
Villi with short crypts (Brunner’s glands)
What epithelium is found in the large intestine?
Closely packed straight glands with goblet cells
What layer of peritoneum is more sensitive to pain?
Parietal peritoneum
What layer of peritoneum results in autonomic referred pain?
Visceral
What nerves stimulate the parietal peritoneum?
Lower 6 thoracic and L1 somatic
Name 4 intraperitoneal organs.
Stomach
Transverse Colon
Sigmoid colon
Ileum
Name 4 retroperitoneal organs.
Kidneys
Ascending colon
Descending colon
Pancreas
What are the 2 sacs formed from the peritoneum?
Greater and lesser
What links the greater and lesser sacs of the peritoneum?
Epiploic foramen
What is connected by the greater omentum?
Greater curvature of stomach to transverse colon
What is connected by the lesser omentum?
Lesser curvature of stomach to the liver
What is the function of the greater omentum?
“Abdominal policeman” - adheres to infection and wraps round infected organs/protects against serious/diffuse peritonitis
Describe the blood supply to the gut tube (off the abdominal aorta).
Celiac trunk
Superior mesenteric
Inferior mesenteric
What is the level of the celiac trunk?
T12
What is the level of the superior mesenteric?
L1
What is the level of the inferior mesenteric?
L3
What artery supplies the foregut?
Celiac trunk
What artery supplies the hindgut?
Inferior mesenteric artery
What artery supplies the midgut?
Superior mesenteric artery
Where does blood from the abdominopelvic gastrointestinal tract drain?
Via portal system to liver
superior mesenteric + inferior mesenteric + splenic vein –> hepatic portal vein
Name 4 sites of portocaval anastomoses.
Distal oesophagus
Oesophageal junction
Around umbilicus
Anorectal junction
In portal hypertension the portocaval anastomoses become congestion and cause dilatations resulting in?
Oesophageal varices
Haemorrhoids
Caput medusae
What is the SNS supply to abdominal viscera?
Greater, lesser and least abdominopelvic splanchnic nerves (prevertebral ganglia and abdominal aortic plexus)
What is the PNS supply to abdominal viscera?
Pelvic splanchnic nerves (S2, 3 and 4) (anterior and posterior vagal trunks)
What action does the SNS have on the abdominal viscera?
Decrease secretion
Decrease motility
Vasoconstriction
What action does the PNS have on the abdominal viscera?
Increase secretion
Increase motility
Vasodilatation
What else is located in the oesophageal opening of the diaphragm?
Vagus
Left inferior phrenic vessels
Oesophageal arteries
What is the artery supply of the abdominal aorta?
Branches of the left gastric artery
What are the nodes associated with the abdominal oesophagus?
Left gastric and celiac nodes
What veins drain the oesophagus?
Left gastric vein –> portal
Azygous vein –> systemic
How is the pyloric sphincter formed?
Thickening of the muscularis externa
What forms the rugal folds?
Mucosa and submucosa
Where is the regal folds most apparent?
Greater curvature and pyloric antrum
What arteries supply the stomach?
Celiac trunk -> left gastric artery, right gastric artery, left gastro-omental, right gastro-omental
What lymph nodes does the stomach drain into?
Superior gastric
Supra-pyloric
Inferior gastric sub-pyloric
Pancreaticosplenic
What is the nerve supply of the stomach?
Vagus
What does the vagus nerve do to the stomach?
Constriction of pyloric
Increase gastric secretions
What are the parts of the small intestine?
Duodenum - Jejunum - Ileum
How is the duodenum peritonised?
Part 1 = intraperitoneal
Part 2-4 = retroperitoneal
Where is the foregut/midgut boundary?
Between 1st and 2nd parts of the duodenum
What part of the small intestine has greater vascularity?
Jejunum
What part of the small intestine has more fat in the mesentery?
Ileum
What part of the small intestine has low and sparse circular folds?
Ileum
What causes reduced secretion and motility of the small intestine?
Sympathetic splanchnic nerves
What are the characteristic features of the large intestine?
Omental appendices
Haustra
Teniae coli
Name three organs that are retroperitoneal.
Ascending colon
Descending colon
Pancreas
Name three organs that are intraperitoneal.
Caecum
Transverse colon
Sigmoid colon
What does the superior mesenteric supply up to?
Up to 2/3 transverse colon
Where does the inferior mesenteric artery supply from?
Last 1/3 of the transverse colon
What opens into the cecum?
Ileum and appendix
What is McBurney’s point?
Site of max tenderness in acute appendicitis
What is the blood supply to and from the rectum?
Superior, Middle and inferior
How is the rectum peritonised?
Super = anterolateral Middle = retroperitoneal Inferior = no peritoneum
What can structurally be seen in the rectum?
Columns of morgagni, pectinate line
What is the visceral innervation of the rectum?
Inferior hypogastric plexus
What is the somatic innervation of the rectum?
Inferior anal nerves
What is the falciform ligament a remnant of?
Umbilical vein
What does the falciform ligament contain?
Round ligament
Where are the paracolic gutters located?
Between colon and abdominal wall
Lateral to ascending and descending colons
What is the clinical significance of the parabolic gutters?
Pus and fluid can collect here
Surgeons can store abdominal contents here
What epithelium is found in the oesophagus?
Stratified squamous non-keratinised epithelium
What is found in the muscularis mucosae in the oesophagus?
Smooth muscle
What cells are found in the stomach?
Goblet cells
Parietal cells
Chief cells
What type of epithelium is found in the small intestine?
Simple columnar non-keratinised
When do glands extend past the muscularis mucosae?
Duodenum
How do you locate the trans-pyloric plane?
Hands breadth below the xiphoid process
What is found on the transpyloric plane?
Pyloris of stomach, origin of portal vein, neck of pancreas, duodenojejunal flexure
What radiological tests exist for looking at the gut tube?
Barium meal –> Stomach
Barium follow-through –> SI
Barium enema –> LI
What is the function of the spleen?
Lymphoid organ
Immune response
Blood filter
Stores RBCs
What connects the pancreas to the duodenum?
Ampulla of Vater
What is significant about the bare area of the liver?
No peritoneal covering
What lobe of the liver is located beside the gall bladder?
Quadrate lobe
What is present in the porta hepatis?
Portal vein, hepatic artery, hepatic duct (wrapped with visceral peritoneum)
Where is bile produced?
In liver
Where is bile stored?
Gall bladder
What forms the common bile duct?
Common hepatic duct and cystic duct
What forms Calot’s cystohepatic triangle?
Inferior surface of liver, common hepatic duct and cystic duct
What type of mucosa is found in the oesophagus?
Protective
What type of mucosa is found in the stomach?
Secretory
What type of mucosa is found in the SI?
Absorptive
What type of mucosa is found in the LI?
Absorptive/secretory
What is the difference between adventitia and serosa?
Serosa = peritonised
Adventitia = non-peritonised
What is the function of the internal oblique muscles?
Compress abdomen and ipsilateral trunk rotation
What muscle is responsible for contralateral trunk rotation?
Contralateral trunk rotation
What direction do the transversus abdominal muscles travel?
Horizontally
What thoracic spinal segments innervate the anterior abdominal wall?
T7-L1
What type of hernia is women most likely to get?
Indirect femoral > inguinal
Name three contents of the inguinal canal in men.
Ileolingual nerve, femoral artery and spermatic cord
Name three contents of the inguinal canal in women.
Ileolingual nerve, femoral artery and round ligament of uterus
Name the posterior abdominal wall muscles.
Psoas major
Psoas minor
Quadratus lumborum
Iliacus
What is the affect of vagotomy on gastric secretion?
Decreases
What is vagotomy used to treat?
Peptic ulcers
What is the anterior to posterior arrangement of structures entering the hilum of the kidney?
Renal vein -> Renal artery -> Ureter
Name the 4 groups of lymph nodes that drain the stomach.
Superior gastric
Inferior gastric
Pancreatocolineal
Supra-pyloric
What group of lymph nodes do the 4 groups of lymph nodes eventually drain into?
Celiac trunk
In the anal canal, what are somatic nerves sensitive to?
Pain, temp, touch and pressure
In the anal canal, what are visceral nerves sensitive to?
Stretch
What drains the first part of the duodenum?
Portal system
What are the hepatoduodenal and hepatogastric ligaments a part of?
Lesser omentum
How is the spleen peritonised?
Intraperitoneal
What is present in Calot’s cystohepatic triangle?
Cystic artery
What is found in red and white pulp in the spleen?
Red = blood cells, platelets, granulocytes, RBCs White = lymphatic tissue
At what vertebral level is the recto-sigmoid junction?
Anterior to S3
What are the 3 muscular layers of the stomach?
Inner oblique
Middle circular
External longitudinal
What is the rule for obstruction when looking at scans?
Should be SI < 3cm, LI < 6cm, Caecum <9cm
What are plaice circulars?
Folds of the SI seen in imaging
On imaging, if there is air in the rectum, what is this a sign of?
No obstruction