GI anatomy Flashcards
what planes are used to divide the abdomen into quadrants?
median + transumbilical
which planes are used to divide the abdomen into 9 regions?
left and right midclavicular planes, subcostal plane, transtubercular plane
what are 9 regions of the abdomen?
right hypochondriac, epigastric, left hypochondriac, right lumbar, umbilical, left lumbar, right inguinal, pubic, left inguinal
which organs are found in the right hypochondriac region?
right lobe of liver, hepatic flexure, right kidney, duodenum, pyloric stomach
which organs are found in the left hypochondriac region?
stomach, spleen, splenic flexure, left kidney, pancreas
which organs are found in the epigastric region?
oesophagus, stomach, left lobe of liver, pancreas, transverse colon
which organs are found in the right lumbar region?
ascending colon, right kidney, duodenum, jejunum
which organs are found in the left hypochondriac region?
descending colon, left kidney, jejunum, ileum
which organs are found in the umbilical region?
duodenum, jejunum, ileum,
which organs are found in the right inguinal region?
caecum, appendix, ileum, right ureter, right ovary/spermatic cord
which organs are found in the pubic region?
ileum, bladder, (uterus)
which organs are found in the left inguinal region?
sigmoid colon, left ureter, left ovary/spermatic cord
what is the linea alba?
midline of rectus abdominis
what is the linea semilunaris?
the line around the outside of the rectus abdominis
where does the RA attach to?
pubic crest and xiphoid process and costal cartilages of ribs 5 to 7
what type of muscle is RA?
paired strap muscle
what covers the RA?
rectus sheath?
what makes up the rectus sheath from deep to superficial?
the aperneurosis of transversus abdominis, internal oblique and external oblique muscles
where does TA originate from?
Iliac crest, inguinal ligament, thoracolumbar fascia, and costal cartilages 7-12
which direction do the fibres of TA run?
mostly horizontally unless forms part of inguinal canal
Where does IO originate from?
Inguinal ligament, Iliac crest, thoracolumbar fascia
which direction do the fibres of IO run?
down and backwards unless forms part of inguinal canal
where does EO originate from?
eight fleshy digitations from the external surfaces and inferior borders of ribs 5 to 12
what does the free edge of External oblique form?
inguinal ligament
what is the defect in the fibres of EO?
superficial inguinal ring
what does the internal thoracic artery bifurcate into?
musculophrenic and superior epigastric arteries
what does the musculophernic artery supply?
diaphragm and anterior abdominal wall
what does the superior epigastric artery supply?
Rectus abdominis - pierces the rectus sheath
where does the inferior epigastric artery come from?
external iliac artery
where does the external iliac artery run and what does it give rise to?
runs into the pelvis deep to the inguinal ligament and gives rise to the femoral artery
which abdominal artery does the femoral artery give rise to?
superficial epigastric
which thoracic nerves supply the abdomen?
continuations of nerves T8-T12
which nerves arise from L1 and where do they supply?
ileohypogastric - supplies inguinal region
lieoinguinal - travels through inguinal canal to innervate parts of the genitalia
between which layers do the nerves and arteries of the abdomen run?
transversus abdominis and internal oblique
above the umbilicus, list the layers of the PAW from superficial to deep
skin, subcutaneous tissue, external oblique, internal oblique, rectus abdominis, internal ablique, transversus abdominis, transversalis fascia, parietal peritoneum
below the umbilicus, list the layers of the PAW from superficial to deep
skin, subcutaneous tissue, external oblique, internal oblique, transversus abdominis, rectus abdominis, transversalis fascia, parietal peritoneum
what and where is the arcuate line?
cresent shaped line where the rectus sheath pierces RA. lies 1/3 way between umbilicus and pubic crest. it is also where the inferior epigastric perforates the RA muscle
list the bony features of the pelvis that we need to know.
ASIS, pubic tubercle, pubic crest, pubic symphisis, inferior and superior pubic rami, oburator foramen
where does the inguinal ligament run from and to?
ASIS to pubic tubercle
what does the inguinal ligament form?
floor of inguinal ligament
what is the lacunar ligament formed from?
lateral reflection of inguinal ligament from pubic tubercle to pectineal line
Where is the superficial ring located?
Supralateral to pubic tubercle
What thickens the lateral edges of the SIR?
Medial and lateral crura
Where is the deep inguinal ring?
Halfway down the inguinal ligament
What makes up the 4 walls of the inguinal ring?
Anterior – External oblique, Inferior – inguinal ligament, posterior – Transversalis fascia, superior – Internal oblique and Transversus abdominis.
What makes up the conjoint tendon and where is it found?
Made up of fused fibres of IO and TA. Lies directly posterior to the superficial inguinal ring
What is the epiploic foramen and what forms its 4 walls?
Gap between the greater and lesser sacs. Superior – liver, inferior – duodenum, anterior – lesser omentum, posterior – inferior vena cava
How many layers of peritoneum does the greater omentum have above the Transverse colon?
6
How many layers of peritoneum does the greater omentum have below the Transverse colon?
4
Which two ligaments form the lesser omentum?
Hepatoduodenal and hepatogastric
What does the free edge of the lesser omentum carry?
The portal triad – portal vein, hepatic artery, bile duct
What are the 9 retroperitoneal organs?
Suprarenal gland, aorta, duodenum, pancreas, ureter, colon (ascending and descending), kidneys, Oesophagus, rectum
Which hepatic ligament does the lesser sac form?
Posterior coronary ligament
Which hepatic ligament does the greater sac form?
Anterior coronary ligament
What lies between the Posterior and anterior coronary ligaments?
Bare area of the liver
At what spinal level does the oesophagus pierce the diaphragm?
T10
List the parts of the stomach.
Cardia, fundus, body, pylorus (pyloric antrum, pyloric canal, pyloric sphincter)
What attaches to the greater curvature of the stomach?
Greater omentum
What attaches to the lesser curvature of the stomach?
Lesser omentum
What are the 4 parts of the duodenum?
Superior, descending, horizontal, ascending
Which landmark splits the foregut from the midgut?
Major papilla
What is the function of the papillae in the duodenum?
Allow bile and pancreatic juice to pass into the intestine
What are the jejunum and ileum suspended by?
The mesentery
Where does the jejunum start?
At the duodenojejunal flexure
In which direction does the small intestine run?
UL quadrant to LR quadrant
What is the demarcation between ileum and jejunum?
There isn’t one
What are the differences between ileum and jejunum?
Jejunum redder, greater calibre, thicker walls