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