Functions of the abdominal wall?
Firm flexible wall to keep abdominal viscera in the abdominal cavity Protect abdominal viscera from injury Maintain anatomical position of viscera against gravity Assist in forceful expiration by pushing viscera upwards Involved in any action (eg vomiting, coughing) that increases intra-abdominal pressure
What are the layers of the abdominal wall?
Skin Superficial fascia/subcutaneous fascia Muscles and associated fascia Parietal peritoneum Visceral peritoneum
Composition of subcutaneous tissue above the umbilicus?
Single sheet of connective tissue continuous with superficial fascia in other regions of the body
Composition of subcutaneous tissue below the umbilicus?
Two layers -fatty superficial layer -membranous deep layer
Epithelium of the peritoneum?
What separates the parietal peritoneum from muscular layers of the abdominal wall?
Extra peritoneal connective tissue Can contain lots of fat
Which layer of the peritoneum is sensitive to pain?
Which layer of the peritoneum is only sensitive to stretching and chemical irritation?
What is in the peritoneal cavity?
Just a small amount of lubricating liquid
At what vertebral level is the umbilicus?
What and where is the epigastric fossa?
A slight depression in the epigastric region Inferior to xiphoid process Heartburn is commonly felt here
What and where is the linea alba?
Aponeuroses of the abdominal muscles Separates left and right rectus abdominis
Clinical relevance of linea alba?
If linea albas is lax, when rectus abdominis contracts, muscles spread apart and get divarication of the recti Often seen in pregnancies as it gets weakened
Where is the inguinal groove? What does it mark?
Skin crease just inferior to the inguinal ligament Marks division of abdominal wall and thigh
What are the semilunar lines?
Slight curved, tendinous line on either side of the rectus abdominis
What is the proper term for what you see in a six pack?
Tendinous intersections of rectus abdominis
What is the arcuate/Douglas's line?
Where the posterior layer of the rectus sheath stops and just have the anterior layer.
Boundaries of the abdominal wall?
Costal cartilages of ribs 7-10 and xiphoid process of sternum, to the superior margins of anterolateral pelvic girdle
What type of incision is this?
Can be continued to curve around the umbilicus
Why is a median incision good?
Cut into linea alba - limited blood loss because it is poorly vascularised
Major nerves avoided
Can be used in any procedure that requires access to abdominal cavity
What type of incision is shown here? Why is it useful?
Provides access to more lateral structures such as kidneys, spleen, adrenals
Disadvantage of paramedian incision?
Ligates blood supply to muscles median to incision - atrophy
What type of incision is shown here? Advantages?
Causes least damage to nerve supply and abdominal muscles
Name this incision. Advantages?
Used when access to pelvic organs is needed
Disadvantage of a suprapubic incision?
Can perforate the badder because the fascia thins around the bladder area
Name this incision. Advantages?
Gridiron incision - done at McBurney's point
Can split the muscle fibres without cutting them and allows for excellent healing
How is a gridiron incision done and where?
Two perpendicular lines which split the muscle fibres
Performed at McBurney's point which is 1/3 of the distance between ASIS and umbilicus
What are primarily retroperitoneal organs?
Organs which have developed and remained outside of the parietal peritoneum
Examples of primarily retroperitoneal organs?
What are secondarily retroperitoneal organs?
Organs which were initially peritoneal, suspended by mesentery. During embryogensis, they became retroperitoneal. Their mesentery fuses with the posterior abdominal wall.