Anterior Abdominal Wall & Inguinal Region Flashcards
What are the 9 regions of the body and the body parts?
Right hypogastric: liver, gallbladder
Epigastric: pancreas, stomach, celiac, trunk
Left hypochondriac: spleen, left colic flexure, splenic vessels
Right lumbar: cecum
Umbilical: small intestine, SMA, renal arteries.
Left lumbar: descending colon
Right iliac: appendix, right ovary bladder (when full), MA
Left iliac: left ovary, sigmoid colon
What are the planes of the body?
2 vertical planes: midlingual (left & right)
2 horizontal planes:
Subcostal/trabspyloric(below costal margin, L1)
Transtubercular(L5, iliac tubercles)
What are the layers of the superficial abdominal fascia?
The superficial fascia of the thorax, abdomen and perineum, are all continuous
Lower abdomen-2 layers
Camper’s fascia
-external, fatty
-males: losses most of its fat, fuses with Scarpa’s layer to form Dartos fascia
-females: retains the fat, forms part of labia majora
Scarpa’s fascia
-deeperlocated aand membranous
Describe Scarpa’s fascia
Continues into the thigh and fuses with the fascia pata(deep fascia of thigh)
Attached firmly to Linea alba and public symphysis on the midline
-It continues into the anterior part of the perineum —> attached to the ischiopubic rami+ perineal membrane /(posteriorly). It is now called the superficial perineal (Colle’s) fascia
What is the action of the external oblique?
Bilateral- anterior flexure of trunk
Unilateral- lateral flexion, rotation
Describe structures of external oblique
Fibers travel downward-medially
The aponeurosis forms part of the anterior layer of the rectus sheath
The inferior free edge forms the inguinal ligament
What is the innervation of the external oblique?
Innervated by segmental nerves
What is the inguinal ligament?
From anterior superior iliac spine(ASIS) to pubic tubercle
Medial part reflected laterally = lacunar ligament
What are the actions of the internal oblique?
Action:
Bilateral- anterior flexion of trunk
Unilateral- lateral flexion, rotation
How are internal oblique muscle organized?
Fibers travel upward-medially, at right angles to the external oblique muscle
-The aponeurosis forms a different portion of the rectus sheath above and below the arcuate line
The inferior portion joins with the aponeurosis of transversus abdominis to form the conjoint tendon
What is the innervation of the of the internal oblique?
Innervated by segmental nerve
What is the action of the transverse Abdominis?
Compress and support abdominal viscera
How are transverse Abdominis muscles organized?
Fibers travel transversely
The aponeurosis forms a different portion of the rectus sheath above and below the arcuate line
The inferior portion joins with the internal oblique to form the conjoint tendon
Deep surface lined by transversalis fascia
How are transverse Abdominis innervated?
Segmental nerves
What are the anterior abdominal wall muscles?
Rectus Abdominis.
Pyramidilis
What is the action and innervation of the rectus Abdominis?
Action: flexion, tenses wall
Innnervated: segmental nerves (T7-12)
What is the innervation and action of the Pyramidalis?
Action: tenses the linea alba
Innervation: T12
What is the function of the rectus sheath?
The aponeurosis of the lateral abdominal muscles forms a thick sheath that encloses the rect7s Abdominis
All aponeurosis fuse in the midline(linea alba) to separate the left and right muscles
The lateral border of the rectus sheath is another region of fusion demarcating the linea semiluaris
The anterior and posterior rectus sheath is comprised of different combinations of the aponeuroses depending on the level
What is the function of the abdominal wall muscles?
Contraction of the wall abdominal muscles increases intra abdominal pressure, especially when the diaphragm is fixed and allows for:
- defecation
- mictruition
- parturition
When the abdominal muscles contract and diaphragm relaxes simultaneously it allows for forced expiration
Describe the superficial muscle of the abdominal wall blood supply
Superficially-
- Superior part of the wall- musculophrenic (terminal branch of internal thoracic)
- Inferior part of the wall- superficial epigastric artery+ superficial circumflex iliac artery (both branches of the femoral artery)
What is the blood supply of the deep muscles of the abdominal wall?
- Superior part of the wall-superior epigastric artery (terminal branch of the internal thoracic artery)
- Lateral part of the wall- intercostal arteries + subcostal artery
- Inferior part of the wall- inferior epigastric artery + deep circumflex iliac artery (both branches of the iliac artery). The superior + inferior epigastric arteries both enter the rectus sheath. They anastomose with each other.
Summarize veinous drainage in he abdominal muscles
Follows arterial supply.
Veins clinically important in Porto-caval anastomosis.
And
Cavo-caval anastomosis (with azygos vein)
What are the cutaneous lymphatic drainage?
Lymphatic drainage follows veinous drainage
Different above and below the umbilicus
-Area above the umbilicus drain to the axilla or parasternal nodes
-Areas below the umbilicus drain into the superficial inguinal nodes
Summarize the innervation of the abdominal wall and inguinal region
Innervation is segmental
- Motor supply to muscles
- Cutaneous supply to skin (think dermatomes)
Nerves travel between internal oblique and transversus Abdominis (compare with intercostal nerves)
Give off lateral and anterior cutaneous branches
What is an abdominal incision determined by?
- organs of interest
- surrounding structures
- location of blood vessels and nerves
- strength of tissue for suture placement
- clinical information
What are the considerations of abdominal incisions ?
Access, ability to enlarge site when necessary
What are laparoscopic incisions?
- Ports are placed through small incisions
- Umbilicus is used for 1 degree port= camera
- Additional ports are placed at 60 degree angles and atleast 5 cm from each other
- Depends highly on area of exploration or procedure
What are the types of abdominal incisions?
- median
- para-median
- pfannenstiel
- Mc Burney’s point
- Linea semilunaris
- Kocher
Where is the purpose for a median abdominal incisions being made?
At the linea alba good for exploratory laparotomy; advantage is that no blood vessels cross the area, good suture repair
Where is para-median abdominal incisions made?
Laterally to the linea alba
Where is the Pfannenstiel found? What is the main purpose ?
Above the pubic symphysis (bikini line through external abdominal oblique and rectus Abdominis muscles)
Caesarean section
Where is McBurney’s point made? What is it used for?
2/3 between the umbilicus and ASIS
-appendectomy
What is the linea semilunaris used for? Where is it found?
Incision made in the linea semilunaris
What is the kocher abdominal incision? What is it used for?
Subcostal
-for access to the gall bladder
Explain in detail: the workings of McBurney’s point
2/3 distance from the umbilicus to the anterior superior iliac spine
- locate the base of the cecum
- origin of the appendix
- Incision is made through subcutaneous tissue
- The transversalis fascia, extraperitoneal fascia, and parietal peritoneum is also cut
- Avoids ilioinguinal nerve (#12) and iliohypogastric nerve
What are the boundaries of the inguinal canal?
Anterior wall- external abdominal oblique aponeurosis
Floor- inguinal ligament, lacunar ligament
Posterior wall- transversalis fascia
Roof- inferior edge of anterior abdominal oblique, transverse abdominal and conjoint tendon
