Anterior Abdominal Wall Flashcards
What are the bony landmarks of the abdomen and pelvis? (13)
ribs costal cartilages transverse processes ilium iliac crest pubic symphysis pubic rami pubic tubercles pecten pubis ASIS AIIS greater pelvis lesser pelvis
What are the 9 divisions of the abdominal wall?
Right and left hypochondrium epigastric region right and left flank (lateral) umbilical region (center) right and left inguinal region pubic region
What are the 4 quadrants of the abdomen?
RUQ
RLQ
LUQ
LLQ
What internal organs are found within the RUQ?
Right lobe of the liver gallbladder pylorus duodenum (parts 1-3) superior part of ascending colon right 1/2 of transverse colon head of pancreas right kidney suprarenal gland (right)
What internal organs are found within the LUQ?
spleen body and tail of pancreas left lobe of the liver stomach jejunum proximal ileum left kidney left suprarenal gland superior part of descending colon left half of transverse colon left colic (splenic) flexure)
What organs are found within the RLQ?
cecum appendix most of the ileum inferior part of ascending colon right ovary right uterine tube right ureter (abdominal part) right spermatic cord (abdominal part) uterus (if enlarged) urinary bladder (if super full)
What organs are found within the LLQ?
sigmoid colon inferior part of descending colon left ovary left uterine tube left ureter (abdominal part) left spermatic cord (abdominal part) uterus (if enlarged) urinary bladder (if super full)
Identify the boundaries of the abdominal cavity: (5)
superior - diaphragm
inferior - pelvic inlet
posterior - lumbar vertebrae
anterior - abdominal wall w/fascia (campers and scarpa’s)
anterolateral - upper 7-10 costal cartilages
What are the abdominal planes? What level are they at?
transpyloric plane - level of L1
subcostal plane - inferior to border of 10th costal cartilage
transtubercle plane - around L5, between iliac tubercles
interspinous plane - between ASIS (~L2)
What organs are at the level of the transpyloric plane?
gallbladder fundus, pylorus, pancreatic neck, SMA origin, hepatic portal vein, root of the transverse megacolon, hila of kidneys
(This one has by far the most)
What organs are at the level of the subcostal plane?
transverse colon
What organs are at the level of the transtubercle plane?
iliocecal junction
What organs are at the level of the interspinous plane?
appendix
sigmoid colon
What are the layers of the fascia and muscles of the anterior abdominal wall?
From superficial to deep:
skin Campers fascia (fatty) Scarpa's fascia (membranous) aponeurosis External oblique m. Internal oblique m. transversus abcominis m. rectus abdominis m.
What is the function, innervation, origin, and insertion of the external oblique muscle? What structures does its fascia make?
Function - compresses abdomen, increases intra-abdominal pressure
Innervation - ventral rami T7-T12
Origin - ribs 5-12
Insertion - aponeurosis and linea alba, anterior iliac crests, pubic tubercle
It makes: the inguinal ligament and opening of the superficial inguinal ring
What is the function, innervation, origin, and insertion of the internal oblique muscle? What other structures does it make?
Function - compresses viscera, laterally flexes and rotates
Innervation - T7-12, L1
Origin - inguinal ligament, iliac crest, lumbodorsal fascia
Insertion - linea alba, pectin pubis, lower 10-12 ribs, pubic crest
Other structures: inguinal falx, cremasteric muscle
What is the function, innervation, origin, and insertion of the transversus abdominis muscle? What other structures does it make?
Function - compresses and supports viscera
Innervation - T7-L1
Origin - iliac crest, inguinal ligament, thoracolumbar fascia, costal cartilages 7-12
Insertion - xiphoid process, linea alba, pubic crest, pecten pubis
Other structures: contributes to rectus sheath
What is the function, innervation, origin, and insertion of the rectus abdominis?
Function - flexes abdomen and compresses
Innervation - ventral rami T7-T12
Origin - crest of pubis
Insertion - costal cartilages of ribs 5-7, xiphoid process
What muscles are involved in inspiration?
external intercostal muscles
serratus anterior muscle
diaphragm (contracts to move down)
What muscles are involved in expiration?
internal intercostal muscles
innermost intercostal muscles
diaphragm (relaxes)
What is the function of the overall function of the anterior abdominal muscles?
To compress the viscera, flex the core, laterally flex, and rotate
What is the function of the erector spinae muscles?
To stabilize the spine
What is the function of the intercostal muscles and diaphragm?
External intercostals - assist with forceful inspiration (lift ribs)
Internal intercostals - assist with forceful expiration (compress ribs)
Innermost intercostals - assist with forceful expiration (compress ribs)
Diaphragm - change the pressure of the thorax to assist with breathing
What is the arcuate line?
The sharp transition where all external oblique, internal oblique, and transversus abdominis aponeuroses become anterior to the rectus abdominis muscle.
What is below the arcuate line? (fascia-wise)
The rectus abdominis is in contact with transversalis fascia
What is above the arcuate line? (fascia-wise)
The external oblique fascia and internal oblique fascia overly the rectus abdominis muscle, the oblique fascia splits so that it and the transversalis fascia run below the rectus abdominis muscle
What are the main nerves of the anterior abdominal wall? (4)
Thoracoabdominal nerves
subcostal n.
iliohypogastric n.
ilioinguinal n.
What are the spinal level, locations and function of the thoracoabdominal nerves?
T7-T12
Function - is a continuation of the intercostal nerves, does motor and sensory at this level. Runs between TA and IO
What is the location, spinal level and function of the subcostal n.?
T12
Location - runs along inferior 12th rib
Function - does sensory superior to iliac crest
What is the location, spinal level and function of the iliohypogastric n.?
L1
Location - runs between 2nd and 3rd muscle layers
Function - is motor to IO and TA, sensory to upper inguinal and hypogastric region
What is the location, spinal level and function of the ilioinguinal n.?
L1
Location - runs between 2nd and 3rd muscle layers
Function - is motor to lower IO and TA, sensory to lower inguinal, anterior scrotum/labia
What arteries supply the anterior abdominal wall? (6)
lumbar a. superficial epigastric a. Superficial circumflex iliac a. deep circumflex iliac a. inferior epigastric a. - off external iliac a. (runs posterior to rectus abdominis m, anastomoses w/superior epigastric a.) superior epigastric a.
Where does the lumbar a. branch from?
comes off abdominal aorta
Where does the superficial epigastric a. branch from?
off femoral a.
Where does the superficial circumflex iliac a. branch from, and where does it run?
off femoral a.
runs along inguinal ligament
Where does the deep circumflex iliac a. branch from, and where does it run?
off external iliac a.
runs deep along inguinal ligament
Where does the inferior epigastric a. branch from, and where does it run?
off external iliac a.
runs posterior to rectus abdominis m., anastomoses w/superior epigastric a.
Where does the superior epigastric a. come from?
it is a terminal branch of the internal thoracic a.
Where would you make a subcostal incision, and for what purpose?
along the inferior margin of the rib, about 2.5 cm inferior to it
This location gives access to the gallbladder and spleen, depending on what side you cut from, It cuts about parallel to the fibers of the muscle in the location (lower tension) and near the intercostal nerves.
Where would you make a midline incision, and for what purpose?
Right at abdominal midline, along linea alba
There are no nerves in this area, and the incision can be made rapidly to give access to the abdominal vicera
Where would you make a paramedian incision and for what purpose?
On either side of the linea alba
Similarily, to give access to the abdominal viscera. May make this incision if for some reason need to avoid central incision. Is muscle-splitting, can damage muscle’s lateral blood and nerve supply, resulting in muscle atrophy
Where would you make a gridiron incision and for what purpose?
Is made over McBurney’s point for appendectomies
Is muscle-splitting. If it follows Langer’s lines, the wound tension is decreased.
Where would you make a suprapubic incision and for what purpose?
In lower abdomen above pubic bone
Is muscle splitting, generally used in OBGYN surgeries.
Where do you predict cancer of the anterior abdominal wall would spread? (2 locations)
If superficial and ABOVE umbilicus, would travel to axillary, parasternal LN’s
If superficial and BELOW umbilicus, would travel to superficial inguinal LN’s
