Abdomen Flashcards
Describe the borders of external oblique.
What is its innervation?
- lower 8th ribs lateral to anterior extremities (lowest 4 interdigitate with lat dorsi, upper 4 with serratus anterior)
- insert into anterior iliac crest (muscular)
- aponeurosis at ASIS
- aponeurosis at pubic tubercle
- free posterior border
- free edge from 5th rib to xiphoid sternum
INNERVATION
T7-12 anterior rami (lateral cutaneous branches)
L1 iliohypogastric
What is the lumbar triangle (of Petit)?
What is its clinical relevance?
Anterior boundary: posterior border of external oblique
Floor: internal oblique
Medial border: anterior border of latissimus dorsi
Inferior border: iliac crest.
Can be site of lumbar hernia
What are the boundaries of the inguinal canal?
What are the contents?
Where is the superficial inguinal ring and deep inguinal ring?
BOUNDARIES
- Ant: aponeurosis of external oblique
- Post: transversalis fascia
- Roof: inferior edges of internal oblique and transversus abdominis
- Floor: inguinal ligament and lacunar ligament at most medial portion
Contents:
- genital branch of genitofemoral nerve
- ilioinguinal nerve
- spermatic cord in males, round ligament in females
SUPERFICIAL: above the pubic tubercle, lateral to lacunar ligament, medial to intercrural fibres of inguinal ligament
DEEP: just above the midpoint of the inguinal ligament and lateral to the epigastric vessels.
What are the boundaries of internal oblique?
What is its innervation?
- fleshy fibres from lumbar fascia
- up across costal margin
- anterior 1/3 of iliac crest
- lateral 2/3 of inguinal ligament
- become aponeurotic at tip of 9th costal cartilage
INNERVATION Intercostal nerves (T7-T11), subcostal nerve (T12), iliohypogastric nerve (L1), ilioinguinal nerve (L1)
Where is the arcuate line? What does it delineate?
2.5cm below umbilicus
Below this, aponeurosis of internal oblique passes wholly in front of rectus muscle
What are some landmarks of the umbilicus?
at level between 3rd and 4th lumbar vertebrae
midway between xiphoid and pubis
What is the conjoint tendon?
medial fibres of Internal oblique and transversus abdominis
Medial internal oblique tendon fuses along pectineal line of pelvic ramus
What are the boundaries of transversus abdominis?
What is its innervation?
- fleshy slip from INSIDE costal margin interdigitating with diaphragm
- lumbar fascia lateral to quadratus lumborum
- lliac crest (anterior 2/3)
- inguinal ligament (lateral half)
Intercostal nerves (T7-T11), subcostal nerve (T12), iliohypogastric nerve (L1), ilioinguinal nerve (L1)
What are the boundaries of rectus abdominis?
Where are its tendinous intersections?
What is its innervation?
Origin - MEDIAL Pubic symphysis, LATERAL Pubic crest
Insertion - Xiphoid process, Costal cartilages of ribs 5-7
Umbilicus, xiphisternum, one midway between the two
Innervation - Intercostal nerves (T6-T11), Subcostal nerve (T12)
What do i have to know about pyramidalis?
between rectus abdominis and its sheath. fuses with linea alba 4cm above origin
p381 “the unimportant pyramidalis is supplied by the subcostal nerve T12”
What are the contents of the rectus sheath?
Intercostal nerves 7-12 Rectus abdominis Pyramidalis Anterior intercostal vessels Superior and inferior epigastric arteries
What is a Kocher’s Subcostal incision? What is the relevance of this?
3cm parallel to and below right costal margin from midline to beyond lateral border of rectus sheath
- may injure 8th and 9th intercostal nerves
- must ligate superior epigastric vessels
- gives good access to biliary structures
Distinguish between the median and medial umbilical ligaments. Where are they?
What do they represent?
MEDIAN: Extending from the apex of the bladder to the umbilical ring on the anterior abdominal wall
- contains remnant of urachus
MEDIAL:
Paired structures from the internal iliacs to umbilicus
- contain remnants of the umbilical arteries which give rise to middle and superior vesical arteries
What is a McBurney’s incision?
What is it used for?
What are the structures that can be injured iatrogenically?
Through junctin of upper/middle third of line drawn from ASIS to umbilicus
Used for appendicectomy.
Iliohypogastric and ilioinguinal nerves can be seen
If extended laterally, may cut deep circumflex iliac artery ascending branch
Where do parasympathetic vs sympathetic neurons synapse in the abdomen?
Sympathetics: synapse in the coeliac, SM and IM ganglia.
Parasympathetics: synapse right at their end organs after the plexi
What is the arrangement of lumbar vessels to the lumbar part of the sympathetic trunk?
Arteries and veins expected to pass posterior, but occasionally veins pass anterior.
WATCH OUT IN LUMBAR SYMPATHECTOMY
At what vertebral level does the IVC arise?
5th lumbar vertebra
Last’s p 459 IVC
At what vertebral level does the aorta bifurcate?
The bifurcation of the aorta is below and to the left of the umbilicus, at approximately the level of the disc between the fourth and fifth lumbar vertebrae.
Truncal Vagotomies. What are the different types? What are the complications
Truncal: cutting vagal trunks at the level of abdominal oesophagus
Selective vagotomy: cuts the branches on lesser curvature.
Highly selective vagotomy: cuts only branches to fundus and body, leaving antral nerves intact
Vagotomies diminish gastric secretion. Truncal and selective often have gastric stasis. Highly selective vagotomy avoids this.
What is the vomiting reflex?
AFFERENT: vagal fibres to vomit centre and chemoreceptor trigger zone of area postrema
EFFERENT: reticulospinal fibres run to anterior horn to activate diaphragm and abdominal muscles
Lumbar sympathetcomy. What is it?
Removal of 3rd and 4th lumbar ganglia via transverse muscle cutting incision in anterior abdominal wall.
Threatened structures: take care to avoid gonadal vessels, ureter and genitofemoral nerve overlying psoas major.
Which veins drain into the IVC and not the hepatic portal system?
- hepatic veins
- R) inferior phrenic
- R) adrenal
- R) renal
- R) gonadal
- 4 x paired lumbar veins
- L) renal (drains L) adrenal, L) gonadal) and L) inf phrenic)
- common iliacs
How many lumbar arteries do we have? What are their tributaries and supply?
What is the great radicular artery (of Adamkiewicz)?
4 x paired
pass posterior to lumbar ganglia
medial branch: supplies spinal cord
middle branch: deep muscles of spine, joints of spine and skin of back/anastomotic
lateral branch: run over quad lumborum and pierce transversus abdominus, supply abdominal muscles
anastomosing with the ipsilateral subcostal, posterior intercostal, iliolumbar, deep circumflex iliac and inferior epigastric arteries
GREAT RADICULAR ARTERY: major artery from 1st left lumbar branch, anastomoses with the anterior spinal artery and is the main source of arterial blood to the lower two-thirds of the spinal cord
What are the key markings of the ureters on a radiograph?
Medial to lumbar transverse processes
Cross pelvic brim at the SI joints
Over the ischial spines
Towards pubic tubercles
What is the order of structures in the renal hilum from posterior to anterior?
Renal pelvis/ureters
Renal artery
Vein
ADRENALS
- embryological origin (what type of tissue
- nerve supply
- where are they?
- blood supply
- drainage
- medulla of neuroectodermal, cortex from mesoderm
- presynaptic sympathetics directly from greater splanchnic/lesser splanchnic to the medulla
- R: pyramidal on upper pole
- L): crescentic over medial border
- inferior phrenic, renal arteries, suprarenal arteries
- single vein
What are the layers of the adrenal gland from outer to inner? What do these layers produce?
CORTEX - glomerulosa: aldosterone - fasciculata: glucocorticoids/cortisol - reticularis: sex hormones/androgens MEDULLA - adrenaline 80% - noradrenaline 20%
MNEMONIC GFR: deeper you go, sweeter it gets ;)
How long is the ureter?
25cm
What are the branches of the renal artery?
Ant and posterior renal
Suprarenal
Ureteric
What is the level of the transpyloric plane?
Midway between the xiphisternum and the umbilicus/ a hand’s breadth below the xiphisternal joint cutting each costal margin at tip of the 9th costal cartilage.
Posteriorly, at the level of the 1st lumbar vertebra
Supracolic compartment above, infracolic compartment below
What relevant structures are at the level of the transpyloric plane?
- pylorus (mobile)
- head, neck and body of pancreas
- fundus of gall bladder
- SMA leaves aorta
- splenic vein joints IMV to make portal
- right kidney hilum below, left kidney hilum above
Lobes of liver
Left, caudate, quadrate, right
Anatomical division of right and left lobe of the liver
Porta hepatis
Which lobe does the caudate and quadrate lobe belong to?
Functionally to the left lobe because their blood supply is from LEFT branches of hepatic artery and portal vein
Deliver bile to LEFT hepatic duct
What are the 4 anatomical segments of the liver?
Left lateral, left medial, right anterior, right posterior
Borders of the caudate lobe
Posteriorly between IVC (lateral) ligamentum venosum (medially)
Borders of the quadrate lobe
Anteriorly
Fossa of gall bladder (lateral)
groove of ligamentum (medially)
What is the caudate process?
Isthmus of liver connecting the caudate lobe to right lobe
Which structures are on the POSTERIOR SURFACE of the liver?
- bare area and bounding ligaments
- R) suprareanl impression
- SVC groove
- the caudate lobe and caudate process
- fissure for ligamentum venosum
- oesophagus and upper stomach
- tuber omentale of pancreas
What structures lie on the INFERIOR SURFACE of the liver
- porta hepatis
- lesser omentum -> ligamentum venosum
- R) kidney and suprarenal gland
- second part of duodenum
- R) colic flexure
- Gall bladder
- ligamentum teres fissure
- gastric impression
What are the borders of the bare area?
BASE: IVC
SIDES: upper and lower layers of coronary ligament
What structures are not covered by peritoneum in the bare area?
IVC and R) suprarenal gland
What is the blood supply in and out of the liver?
IN
- hepatic artery
- portal vein
OUT
- hepatic veins x 3 to IVC
What is the difference in branching between hepatic artery and portal vein?
Hepatic artery divides into Y
Portal vein divides into T
What is the anatomical difference between the branching of R) and L) hepatic arteries?
R) : behind hepatic duct to form anterior and posterior branches
L): divides into medial and lateral branches
Where does the middle hepatic vein drain?
in 60% of people, middle hepatic joins left hepatic before draining into IVC
Where does collateral blood flow come from in the liver?
Anastomoses with phrenic vessels eg. on bare area
What are the branches of the coeliac trunk?
Common hepatic, left gastric, splenic
What are the anatomical relations of the common hepatic artery?
RETROPERITONEAL
- over pancreas
- inferiorly to the right
- in the lesser sac
When does the common hepatic artery become the hepatic artery?
When it curves upward into space between two layers of lesser omentum
What are the branches of the common hepatic artery?
- hepatic artery
- right gastric
- gastroduodenal
What is the relationship of the common hepatic duct to
- portal vein
- hepatic artery
At what level does it join with the cystic duct?
- anterior to the right edge of portain vein
- to the right of the hepatic artery
Joins the cystic duct 1 cm above the duodenum
p 445 Lasts
What are the contents of the lesser omentum?
- Bile duct
- Hepatic artery proper
- Left and right gastric arteries
- anterior vagal trunk
What is the origin of the appendicular artery?
The appendicular artery normally arises from the posterior caecal artery which in its turn arises from the descending terminal branch of the ileocolic artery
What are the organs that form the stomach bed?
- spleen
- L) kidney and suprarenal
- pancreas
- transverse mesocolon
What are the boundaries of the epiploic foramen (of Winslow)?
ANTERIOR: free edge of lesser omentum POSTERIOR: IVC SUPERIOR: caudate lobe INFERIOR: duodenum (1st part) https://www.instantanatomy.net/diagrams/AB019.png
What are the key distinguishing features between the jejunum and ileum?
- thickness of wall
- peyers patches
- blood supply (loops and arcades)
- mesenteric fat
JEJUNUM
- thicker (feels doubled walled)
- no peyer’s patches
- long arcades
- less mesenteric fat
ILEUM
- thinner
- peyers patches in the antimesenteric border
- layered series of arcades, shorter
- more mesenteric fat
What is the orientation of the 3 taeniae coli?
What is the exception to this orientation?
- anterior
- posteromedial
- posterolateral
Exception is in the transverse colon, where the anterior rotates to lie posteriorly, while the other two lie anteriorly
What are the structures that pass behind the median, medial and lateral arcuate ligaments?
MEDIAN
- aorta and vagi
MEDIAL
- sympathetic trunk
LATERAL
- subcostal nerve and vessels
p 318 Last’s “openings in the diaphragm”
