GI Flashcards
What are the 4 quadrants of the abdomen?
Right upper, right lower, left upper and left lower
What are the 9 regions of the abdomen? Where are they located?
Right and left hypochondium (right and left upper)
Epigastrium (upper middle)
Right and left lumbar (right and left middle)
Periumbilical (centre)
Right and left iliac fossa (right and left lower)
Hypogastrium (lower middle)
What are the lines used to divide the 9 regions?
Right and left midclavicular planes, transtubecular plane and subcostal plane
What organs are present in the right hypochondriac region?
liver, kidney and gallbladder
What organs are present in the epigastric region?
liver, stomach and oesophagus
What organs are present in the left hypochondriac region?
stomach and spleen
What organs are present in the right lumbar region?
ascending colon, gallbladder and liver
What organs are present in the periumbilical region?
small intestine, pancreas and stomach
What organs are present in the left lumbar region?
descending colon, left kidney and small intestine
What organs are present in the right iliac fossa?
appendix, caecum and small intestine
What organs are present in the hypogastrium?
prostate, rectum and ovaries
What organs are present in the left iliac fossa?
descending colon and sigmoid colon
What are the 4 muscles of the anterior abdominal wall?
external oblique, internal oblique, transversus abdominus and rectus abdominus
What is the external oblique innervated by?
T7-12
What is the internal oblique innervated by?
T-12 & lumbar nerve (L1)
What is the transversus abdominus innervated by?
T7-12 & L1
What is the rectus abdominus innervated by?
T7-12
What is the innermost of the anterior abdominal muscles?
transversus abdominus
What lies on top of the transversus abdominus?
internal oblique, then external oblique on top
What is the midline aponeurosis of the trunk called?
Linea alba
What is the rectus sheath? Which muscles does it involve?
Aponeurosis of the transversus abdominus, internal oblique and external oblique muscles
What vertebral level is the umbilicus?
L3/L4
What thoracic spinal segments innervate the anterior abdominal wall?
T7-11
What is the dermatome level of the sternal angle?
T2
What is the dermatome level of the nipple?
T4
What is the dermatome level of the umbilicus?
T10
How long is the inguinal canal?
approx. 4cm
The inguinal ligament is attached to which 2 bony points of the hip bone?
pubic tubercle and anterior superior iliac spine
What forms the anterior wall of the inguinal canal?
aponeurosis of external oblique and internal oblique
What forms the posterior wall of the inguinal canal?
transversalis fascia and conjoint tendon
What forms the roof of the inguinal canal?
internal oblique and transversus abdominus
What forms the floor of the inguinal canal?
inguinal ligament and lacunar ligament
What are the the names of the openings in the inguinal canal and where do they lie?
deep inguinal ring lies superiorly and superficial inguinal ring lies inferiorly
What does the superficial inguinal ring lie lateral to?
pubic tubercle
What do the epigastric vessels branch into inferiorly?
External iliac vessels
What do the epigastric vessels branch into superiorly?
internal thoracic vessels
What are the contents of the male inguinal canal?
spermatic cord, genital branch of genitofemoral nerve, ilioinguinal nerve and testicular artery
What are the contents of the female inguinal canal?
round ligament, genital branch of genitofemoral nerve, ilioinguinal nerve and uterine arteries
What are the most common type of hernias?
Inguinal hernias
What 4 histological layers are present throughout the entirety of the gut tube? (from inside to outside)
mucousa, submucosa, muscularis propria and serosa
What three layers are present in the mucosa of the gut tube?
epithelium, lamina propria and muscularis mucosa
What type of mucosa is protective? Where is it found?
stratified squamous
found in oral cavity, oesophagus and nasal canal
What type of mucosa is secretory? Where is it found?
simple columnar with tubular glands
found only in stomach
What type of mucosa is absorptive? Where is it found?
villi with short glands (crypts)
found in small intestine
What type of mucosa is absorptive/protective? Where is it found?
closely packed straight glands with goblet cells
found in large intestine
What are the 2 subdivisions of the peritoneum?
visceral (surrounding organs) and parietal (lining abdominal wall)
What is the peritoneal cavity?
continuous area between parietal peritoneum lining abdominal wall an visceral peritoneum surrounding abdominal organs
What are the two divisions of the peritoneal cavity?
greater and lesser sac
Through which foramen do the greater and lesser sacs communicate?
epiplioc foramen
Where is the epiploic foramen located?
just below the neck of the gallbladder
What organs are described as being retroperitoneal? (think SAD PUCKER)
suprarenal glands, aorta/IVC, duodenum (not first part), pancreas, ureters, colon (asc & desc), kidneys, esophagus and rectum
What organs are described as being intraperitoneal?
stomach, spleen, liver and transverse colon
What fluid is present in the peritoneal cavity?
peritoneal fluid
What is meant when an organ is retroperitoneal?
only covered by visceral peritoneum on it’s anterior surface
What is meant when an organ is intraperitoneal?
completely surrounded by visceral peritoneum
Which layer of the peritoneum is more sensitive to pain?
parietal
How many organs are within the peritoneal cavity?
NONE
What is the greater omentum? What are its attachments
large curtain-like fold of visceral peritoneum that hangs down from the stomach.
It’s attached from the greater curvature of the stomach to the transverse colon
What is the lesser omentum? What are its attachments?
A double layer of peritoneum
It’s attached from the lesser curvature of the stomach to the liver
What are the muscles of the posterior abdominal wall?
psoas major, psoas minor, iliacus and quadratus lumborum
What are the organs of the posterior abdominal wall?
kidneys, ascending and descending colon
What are the main vessels of the posterior abdominal wall?
Aorta and IVC
What are the nerves of the posterior abdominal wall?
subcostal and lumbar
What are the 3 major openings in the diaphragm?
caval, aortic and oesophageal
At what vertebral level is the caval opening?
T8
At what vertebral level is the oesophageal opening?
T10
At what vertebral level is the aortic hiatus?
T12
What are the 3 main branches of the aorta supplying the gut tube?
superior mesenteric, inferior mesenteric and celiac trunk
At what vertebral level does the aortia bifurcate to 2 common iliac arteries?
L4
At what level does the superior mesenteric artery occur?
L1
At what level does the inferior mesenteric artery occur?
L3
At what level does the celiac trunk occur?
T12
Name 2 foregut structures
Stomach and abdominal part of oesophagus
Name 2 midgut structures
Caecum and appendix
Name 2 hindgut structures
desc. colon and sigmoid colon
What is the artery supplying the foregut?
Celiac trunk
What is the artery supplying the midgut?
Superior mesenteric artery
What is the artery supplying the hindgut?
Inferior mesenteric artery
What additional organs derived from the midgut are not part of the gut tube?
spleen, liver, pancreas and gallbladder
What 2 veins join to form the hepatic portal vein?
superior mesenteric and splenic veins
What are the 4 sites of portocaval anastomosis?
Distal oesophagus, anal canal, paraumbilical region and retroperitoneal region
What does parasympethetic innervation do to GI secretion?
increases
What does parasympathetic innervation do to GI motility?
increases
What does parasympathetic innervation to do blood vessels?
vasoconstricts
What is the effect of a vagotomy on gastric secretion?
reduces secretion
At what vertebral levels do the kidneys lie?
T12-L3
Why does the right kidney lie slightly lower than the left?
it sits underneath the liver
What are the 3 structures entering/leaving the hilum of the kidney?
Renal vein, renal artery and pelvis of ureter
What is the anterior to posterior arrangement of the structures in the hilum of the kidney?
Vein -> artery -> pelvis
What are ureters?
muscular ducts carrying urine from kidneys to urinary bladder
What is the term used to describe the expanded upper part of the ureter?
renal pelvis
What are the 3 constrictions of the oesophagus called?
cervical, thoracic and diaphragmatic
What structures go through the oesophageal hiatus?
oesophagus, vagal trunk, branches of left gastric vessels and lymphatic vessels
What is the lymphatic drainage of the abdominal aorta?
left gastric nodes
What are the two curvatures of the stomach called?
lesser and greater curves
What are the 2 orifices of the stomach called?
cardiac and pyloric
What are the 2 surfaces of the stomach called?
anterior and posterior
What is the pyloric sphincter? What is its function?
a band of smooth muscle at junction between pylorus and duodenum, it controls the discharge of stomach contents into the duodenum.
The pyloric sphincter is formed by the thickening of which layer of the gut tube?
muscularis externa (circular)
What structures form the stomach bed?
left dome of diaphragm pancreas spleen left kidney colon adrenal gland
What 4 groups of lymph nodes drain the stomach?
superior gastric, suprapyloric, pancreaticolineal and inferior gastric
What do the lymph nodes draining the stomach eventually drain into?
celiac lymph nodes
What are the 3 parts of the small intestine?
Duodenum, jejunum and ileum
Which part of the small intestine receives the opening of the bile and pancreatic duct?
duodenum
What is the foregut/midgut boundary in the small intestine?
2nd part of duodenum
How is the small intestine peritonised?
1st part duodenum - intraperitoneal
2nd part duodenum - retroperitoneal
jejunum and ileum - intraperitoneal (mesentery)
What part of small intestine is shortest, widest and most fixed part?
duodenum
Give examples of some of the distinguishing characteristics of the jejunum and ileum
jejunum is deeper red (greater vascularity), wall is thicker and heavier and it contains less fat in its mesentery.
Ileum is paler pink, it is thin and light and it contains more fat in its mesentery.
Arterial arcades (arterial loops) are more common in the jejunum or ileum?
Ileum
What features of the large intestine distinguish it from the small intestine?
teniae coli (3 longitudinal bands of smooth muscle) haustra (sacculations of colon between teniae) omental appendices (small fatty projections)
How is the large intestine peritonised?
caecum - intra asc colon - retro transverse - intra (mesentery) desc - retro sigmoid - intra (mesentery)
What is the midgut/hingut boundary of the colon?
2/3rds along transverse colon
What 2 structures open onto the caecum?
ileum (terminal) and caecum
What is McBurney’s point? What is its clinical significance?
1/3rd of the distance from the anterior superior iliac spine to the umbilicus
Its the site of maximum tenderness in acute appendicitis
What is the arterial supply to the 3 parts of the rectum?
Superior 1/3 - superior rectal artery
Middle and inferior 1/3rds - middle rectal artery
What is the venous drainage of the 3 parts of the rectum?
superior 1/3 - superior rectal vein
middle 1/3 - middle rectal vein
inferior 1/3 - inferior rectal vein
What 3 structures are involved in maintaining faecal continence?
pelvic floor, anal sphincter and rectum
What is the arterial supply of the stomach?
branches of celiac artery - R and L gastric arteries
What is the arterial supply of the 1st part of duodenum?
branch of celiac artery - superior pancreaticoduodenal artery
What is the arterial supply of the 2nd part of duodenum?
branch of celiac artery - inferior pancreaticoduodenal artery
What is the arterial supply of the jejunum and ileum?
superior mesenteric artery
What is the arterial supply of he caecum and ascending colon?
superior mesenteric artery
What is the arterial supply of the right 2/3rds transverse colon?
superior mesenteric artery
What is the arterial supply of the left 1/3rd transverse colon?
inferior mesenteric artery
What is the arterial supply of the sigmoid colon?
inferior mesenteric artery
What is the falciform ligament? What does it separate?
a ligament attaching liver to anterior body wall
separates right and left lobes of liver
What structure in the falciform ligament is a remnant of an embryonic blood vessel?
round ligament is a remnant of the fetal umbilical vein of the liver
How many layers of peritoneum are present in the greater omentum?
4 (double layer folded onto itself)
Why is the greater omentum often called the ‘abdominal policeman’?
It fights inra-abdominal infection, contains macrophages
What are paracolic gutters? what are their clinical significance?
spaces between colon and abdominal wall
allow passage for infection fluids from different compartments of the abdomen
What type of muscle is found in the oesophagus?
Superior 1/3rd - skeletal
Middle 1/3rd - skeletal and smooth
Inferior 1/3rd - smooth
What type of epithelium is found in the oesophagus?
non-cornified stratified squamous
What is the function of the rugae (folds) in the stomach?
allows the stomach to expand as it fills
What are gastric pits? What secretory cells are found in them?
They are indentations in the stomach
Surface mucous cells are secreted
What are the large folds extending into the lumen of the small intestine called?
plicae
What are the finger like processes in the small intestine called?
villi
What kind of surface epithelium are found in the villi?
columnar
What kind of muscle is found in the small intestine?
smooth
What are the cells that looks like ‘spaces’ in the surface epithelium of the small intestine? What do they secrete?
goblet cells, they secrete mucous
What is the transpyloric plane?
horizontal line, halfway between the jugular notch and the pubic symphysis
What 5 structures lie in the transpyloric plane?
pylorus of stomach 2nd part duodenum neck of pancreas sphincter of oddi fundus of oddi
How is the spleen peritonised?
intraperitoneal, except its hilum
Does the spleen move with respiration?
yes, descends on inspiration
What are the 3 structures in the hilum of the spleen?
splenic artery, splenic vein and lymph vessels
What are the 4 main functions of the spleen?
storage of RBCs, storage of platelets, storage of WBCs and phagocytosis
What organ must a surgeon take care not to damage whilst removing a spleen?
pancreas
How is the duodenum related to the pancreas?
wrapped around its head
How is the pancreas peritonised?
retroperitoneal
What vein is formed posterior to the neck of the pancreas?
hepatic portal vein
Into which part of the duodenum does the pancreatic duct open?
2nd part
What are the 4 lobes of the liver?
right, left, caudate and quadrate
Is the caudate lobe superior or inferior to the quadrate lobe?
superior
What does the porta hepatis of the liver contain?
the portal triad - hepatic artery, portal vein and bile duct
What fold of peritoneum is folded around the portal triad?
lesser omentum
What does the extrahepatic biliary apparatus consist of?
right and left hepatic ducts, gallbladder, common hepatic duct, cystic duct and bile duct
Where is bile produced?
The liver
Where is bile stored?
the gallbladder
Where does bile enter the gut tube?
2nd part of duodenum
What two ducts join to form the common hepatic duct?
right and left hepatic ducts
What duct joins the common hepatic duct? What does this form?
Cystic duct joins common hepatic duct to form the bile duct
What duct does the common bile duct join?
main pancreatic duct
What is Calot’s triangle?
triangular space formed by the cystic duct, common hepatic duct and inferior surface of the liver
What does Calot’s triangle contain?
the cystic artery
What is the narrowing at the end of the common bile duct called?
Sphincter of Oddi
What are the 3 main histological features of the pancreas?
Islets of langerhans, pure serous acini and small lobules
What are the 2 main histological features of the liver?
cells arranged in sheets and converging towards centre
portal areas containing blood vessels and ducts
What are the 2 main histological features of the spleen? What do they contain?
White pulp - lymphoid aggregation
Red pulp - vascular anastomosing cords of cells
Which ribs are closely related to the spleen?
9, 10 and 11
