Abdomen (SEM 2) Flashcards
2 layers of subcutaneous tissue of anterior abdominal wall
superficial = fatty (camper’s) fascia
membranous (scarpa’s) fascia
-continues as collet’ fascia over penis/scrotum/labia major
external oblique
internal oblique
transversus abdominis
EO -most superficial
- origin = outer 5-12th ribs
- lower costal nerves/subcostal nerve
- contralateral rotation
IO
- origin = inguinal lig/iliac crest
- inserts = lower margin of 10-12th ribs / lateral inguinal ligament
- ipsiolateral rotation
- lower costal nerves/subcostal/L1 spinal
TA
- inner surface of 7-12th cartilage ribs
- same nerve supply as IO
- compresses abdominal contents
L1 spinal nerve gives rise to
iliohypogastric
ilioinguinal nerves
supplies internal oblique and transverses abdominis
surgical importance of linea alba
no important nerves/vessels - common place for incision
rectus sheath
made up of external oblique, internal oblique and transversus abdominis
contains rectus abdominis muscle
rectus abdominis
linea alba down middle
semilunaris on lateral side
vertical muscle fibre orientation
origin: pubis/pubic symphysis
insertion: xiphoid/cartilage processes 5-7
arcuate line
what is present above but not below
line found L1 below umbilicus
posterior rectus sheath only above arcuate line (anterior still present below)
what arteries supply the anterior abdominal wall above/below umbilicus
above = superior epigastric (branch of internal thoracic)
below = superficial epigastric (branch of femoral artery after inguinal ligament)
what is the inferior epigastric artery a branch of
external iliac artery
transversus abdominis plane (TAP) blocks
Anesthetists are commonly insert TAP under ultrasound guidance to provide post-operative anesthesia to nerves of the anterior abdominal wall
inguinal ligament -where
what is it formed by
ASIS - pubic tubercle
formed by aponeurosis of external oblique
boundaries of inguinal canal
found in the half of the inguinal ligament closest to pubis
floor = inguinal ligament
anterior wall = external oblique aponeurosis (+ internal oblique, laterally)
posterior wall = conjoint tendon and transversalis fascia
roof = overarching fibres of internal oblique and transversus abdominis
when does inguinal canal close
contraction of internal oblique/ transversus abdominis (roof)
these are innervated by L1 fibres (iliohypogastric and ilioinguinal)
structures which enter the deep/internal inguinal ring of canal
spermatic cord
- vas deferens
- testicular artery
- lymphatics
- veins of pampiniform plexus
-genital branch of genitofemoral nerve
(ilioinguinal nerve does not enter via deep ring)
structures that exit out of the superficial/external inguinal ring of canal
ilioinguinal nerve
genital branch of genitofemoral nerve
spermatic cord/ round ligament
spermatic cord:
3 x CANT
3 coverings from muscle:
- external oblique
- cremasteric muscle
- internal oblique
3 arteries from internal iliac artery:
- testicular
- artery to vas deferens (from superior vesicle artery -internal iliac)
- cremasteric (branch of inferior epigastric- external iliac)
3 nerves:
- genital branch of genitofemoral (cremasteric)
- parasympathetic (point)
- sympathetic (shoot)
3 tubes:
- vas deferens
- pampiniform plexus of veins
- lymphatics
where does spermatic cord end
testis
direct and indirect inguinal hernia
inferior epigastric artery marks medial border of deep inguinal ring
if hernia is
- medial to the artery = direct
- lateral = indirect
direct (acquired)
- does not transverse the entire inguinal canal (usually only its medial part)
- almost never enters scrotum
- less likely to strangulate blood supply
indirect (congenital)
- transverse the entire inguinal canal
- exits through superficial inguinal canal–> scrotum = inguino-scrotal
- strangulation –> bowel ischaemia
difference between femoral and inguinal hernia
inguinal hernia sac is ABOVE pubic tubercle and through the inguinal canal
femoral hernia is BELOW pubic tubercle (not through inguinal canal)
inguinal hernias more common
women more likely to get femoral
men more likely to get inguinal (testis descend through inguinal canal)
conjoint tendon
Combined fibres from lower internal oblique and aponeurosis of transversus abdominis muscles to the pubic crest
nerve supply = ilioinguinal nerve (L1)
forms medial/roof part of posterior wall of inguinal canal
falciform ligament
double fold of peritoneum
Attaches anterior surface of liver to anterior abdominal wall
derived from ventral mesentery (foetal)
lower end wraps around the round ligament of liver (remnant of foetal umbilical vein)
difference between intraperitoneal and retroperitoneal
retroperitoneal = only parietal covering ANTERIOR surface
(primary and secondary)
intraperitoneal structures = enveloped posterior and anterior by visceral peritoneum
retroperitoneal structures
SADPUCKER
S- uprarenal (adrenal) glands A- orta/IVC D- uodenum (except proximal 2cm) P- ancreas (except tail) U- reters C- olon (only ascending and descending) K- idneys E- (o)esophagus R- ectum (only lateral 2/3rds)
omentum and mesentery
omentum = SHEETS of visceral peritoneum
greater(4): greater curvature–> transverse colon (policeman)
lesser(2): lesser curvature–> liver
mesentery = double layer of visceral connecting intraperitoneal organs to POSTERIOR abdominal wall
- transverse mesocolon
- mesentery of small intestine
- sigmoid mesocolon
divisions of peritoneal cavity
transverse mesocolon:
infra colic and supracolic
mesentery of small intestine subdivides infracolic into left/right
differences of mesentery of jejunum and ileum
jejunum
- less fat
- thicker diameter
- longer vasa recta
- fewer arcades
ileum
- more fat
- thinner diameter
- shorter vasa recta
- more arcades
Sigmoid volvulus
sigmoid colon twists on mesentery —> cant pass wind —> distended stomach
how is the position of duodenojejunal junction maintained
by a suspensory ligament (the suspensory ligament of Trietz)
peritoneal fold attached to underside of diaphragm
bleeding in GIT is divided into
- upper (proximal to ligament)
- lower (distal to ligament)
What is a gridiron (McBurney’s incision)
For appendectomy
Begins 2/5cm above ASIS —> lateral 1/3rd way to umbilicus
what is found on the free border of lesser omentum
Hepatodudenal ligament
3 structure found in this free edge
- common bile duct (cystic duct+common hepatic duct)
- portal vein
- hepatic artery
pringle’s manoeuvre = clamping this
what level is coeliac trunk
superior and inferior mesenteric arteries
coeliac - T12
SMA- L1
IMA - L3
venous drainage of stomach
mainly by splenic vein–> hepatic portal vein
Incisura angularis
angle on lesser curvature side of pyloric part of stomach
how many parts of duodenum and how many parts are derived from foregut
2 out of 4 total parts
1st part = intraperitoneum
what part of duodenum = peptic ulceration occur mostly in
what is Kocherisation
1st part
this can perforate into peritoneal cavity (because intraperitoneal)—> peritonitis
anterior ulcers tend to perforate
posterior ulcers tend to bleed
Mobilising duodenum before performing other procedures
sliding and para-oesophageal(rolling) hiatal hernia
sliding = cardia and fundus of stomach—> hiatus (T10)
-common regurgitation–>Barretts
rolling = cardia remains in place, pouch of peritoneum containing fundus extends through the hiatus anterior to oesophagus
-rare regurgitation
(More hazardous)
branches of SMA
Jejunal and ileal arteries
Ileocolic artery
Right colic artery
Middle colic artery
branches of IMA
marginal artery of drummound : Connects the IMA and SMA –> arc of Riolan
Left colic artery
Sigmoidal arteries
Superior rectal artery (continuation of IMA)
what ligaments do the peritoneal reflections that pass from the surface of the liver onto the underside of the diaphragm form
coronary ligament
left and right triangular ligaments
What causes the colonic wall to have a sacculated appearance
sacculated appearance = haustra
tone of Taeniae coli = Longitudinal muscle of colon is confined to 3 thin bands
Anorectal junction
derived from what above and below
pectinate line
Above: derived from embyronic hindgut
Below: from ectoderm of proctodeum
lined by non-keratinised stratifeid squamous epithelium (anal pecten) smooth
Anal lymphatic drainage
pararectal lymph nodes –> inferior mesenteric nodes
Lymph from lower aspect of rectum drains directly into internal iliac lymph nodes
where is a vertebral fracture common
between T12 and L1 because of the pressure on L1
trapezius
Origin = occipital + C7-T12 insert = spine of scapula
accessory nerve
latissimus dorsi
spinous processes T12-L5/iliac crest —> floor of inter tubercular groove of humerus
thoracodorsal nerve (C6-8)from posterior cord of brachial plexus
shoulder adduction/extension
internal rotation of arms
erector spinae
iliocostalis
longissimus
spinalis
Quadratus lumborum
origin: posterior iliac crest
insertion: inferior border of 12th rib + transverse process L1-4
stabilises 12th rib/lateral flexion/ depression of 12 the ib and diaphragm for expiration
lateral to psoas major
lateral arcuate ligament over it in diaphragm
lumbar arteries from aorta
psoas major
psoas minor
major
-origin: T12-L5
-insertion: lesser trochanter
(is one of the iliopsoas muscle with iliacus)
minor (anterior to major)
- origin:T12/L1 vertebrae
- insertion: iliopectineal arch on pelvis
what could be mistaken as AAA
abdominal aorta is posterior to stomach/pancreas
if there is a tumour on these organs it will transmit the pulse from the aorta and easily mistaken as abdominal aortic aneurysm (bulge caused by weakness of blood vessel)
pulsations of a large aneurysm would be felt left from midline and easily moved side to side
AAA rupture mortality rate = 90%
branches of coeliac trunk
splenic
left gastric
hepatic
For renal transplantation which artery is preferred for anastomosis with the renal artery of the donor’s kidney
external iliac artery because it is more superficial
at what lumbar vertebrae do the common iliac veins join –> IVC
L5
posterior to aorta, to the right
