Describe the basic features of the abdominal wall
Lateral walls (left and right)
Lateral and anterior wall boundary is indefinite therefore the term 'anterolateral abdominal wall' is used to describe them together
Describe the boundaries of the anterolateral abdominal wall
Cartilages of the 7th - 10th ribs
Superior margin of the pelvic girdle (iliac crests, pubic crests and pubic symphisis)
What are the layers of the abdominal gut wall?
Subcutaneous tissue (superficial fascia and fat)
Muscles and their apneurosis
Label the black boxes
Top to bottom, right column first:
Superficial fatty layer of subcutaneous tissue
Deep membranous layer of subcutaneous tissue
Investing (Deep) fascia - superficial, intermediate and deep
What is the umbilicus?
Center of anterolateral abdominal wall
What is the Epigastric Fossa?
Slight depression in epigastrum
Just inferior to xiphoid process
Heartburn commonly felt at this site
What is the linea alba?
What is a common abnormality?
Apneuroses of abdominal muscles
Separates the left and right rectus abdominis
Visible in lean individual
Apneuroses of right and left, Intermediate and deep layers of the gut wall interweave here
If lax then rectus abdominis spread apart on contraction (Divercation of recti)
What is the inguinal groove?
Skin crease parallel and just inferior to inguinal ligament
Marks the division between abdominal wall and thigh
What are the Semilunar lines?
Slightly curved, tendinous lines on either side of the rectus abdominis
What are the tendinous intersections of the rectus abdominis?
Clearly visible (in lean individuals) horizontal lines through the rectus abdominis
What are the Arcuate lines?
Where the inferior limit of the posterior rectus sheath ends
1/3 of the way between the umbilicus and the pubic crest
Label the Boxes
Top to bottom:
Right costal margin
There are two types of muscle in the abdominal wall, what are they and what are the muscles in each category?
What directions do the fibres of the flat muscles of the abdominal wall run?
What is the order of the flat muscles in the abdominal wall?
Posterior to anterior
Anterior to posterior
What is the rectus sheath?
3 flat muscles are continued antero-medially as the the rectus sheath (apneuroses) that enclose the rectus abdominis and Pyrimidalis
Label the boxes
Apneuroses of TA
Apneuroses of Ext. Oblique
Lamina of apneuroses of Int. Oblique
Membranous and Fatty layers of Subcutaneous tissue
What are the major considerations when designing a surgical abdominal insicion
Capable of closing
Strong and long lasting
Minimise incidence of insicional herniae
Not directly through muscle (Sutures will 'cut out')
List the major abdominal incisions
Breifly describe a midline surgical incision
Insicion through linea alba
Briefly describe a transverse surgical incision
Cut through the external oblique apneuroses
Describe an appendicectomy incison
Incision at McBurney's point
2/3 the distance between umbilicus and ASIS
Through a Gidiron muscle splitting incision
What is a Gidiron incision?
Separation of the muscle fibres of the flat muscles with scissors to get through to the peritoneum
What is a 'patent urachus' and what is a common consequence?
What are the common causes?
Urachus connects the bladder and umbilicus, when patent allows urine to leak from the umbilicus
Benign prostatic hypertrophy in older men
What is the vitelline duct?
What are the abnormalities that can be caused by it's persistence?
A duct that connects the midgut to the yolk sac in the embryo
Describe a Meckel's Diverticulum?
Most common GI abnormality
Cul-de-sac in the ileum
Rule of 2's:
- 2% of pop. affected
- 2ft from ileocecal valve
- 2 inches long
- Usually detected in <2's
- 2:1 Male:Female
Can be asymptomatic
Can contain ectopic gastric/pancreatic tissue that secretes enzymes and acid causing ulceration
What is a vitelline cyst?
The vitelline duct forms a cyst connected to the lieum and abdominal wall via thin fibrous strands
What is a vitelline fistula?
Direct communication between umbilicus and intestinal tract
This can result in faecal matter coming out of the umbilicus
What is an Omphalocoele?
Persistence of physiological herniation
Part of the gut tube fails to return to the abdominal cavity following its normal herniation into the umbilical cord
Epithelial layer around the umbilical cord (Amnion) covers the defect
What is Gastroschisis?
Failure of closure of the abdominal wall during embryo folding
Leaves the gut tube and its derivatives outside the body
There is no covering of the gut tube as they herniate directly through the abdominal wall into the amniotic cavity
Label these 3 abnormal structures