Anterior Abdominal Wall Flashcards
What are the 4 transverse planes of the anterior abdominal wall?
Transpyloric plane
Subcostal plane
Transtubercle plane
Interspinous plane
Which of the following is found at L1?
A. Subcostal plane
B. Transpyloric plane
C. Transtubercle plane
D. Interspinous plane
B. Transpyloric plane
The transpyloric plane at L1 is used as a reference point for the location of what organs?
Gallbladder fundus Pylorus Pancreatic neck SMA origin Hepatic portal vein Root of transverse mesocolon Hila of kidneys
Where is the subcostal plane located?
Passes inferior border of 10th costal cartilage
Level of L3
The subcostal plane is an important landmark for what organ?
Transverse colon
Where is the transtubercle plane located
Between iliac tubercles at the level of iliocecal junction
Level of L5
Where is the interspinous plane located
Between ASIS
Level of S2
The interspinous plane is an important landmark for what 2 organs?
Appendix
Sigmoid colon
The abdominopelvic cavities include the abdomen and pelvis, existing between thoracic diaphragm and pelvic diaphragm; it can extend as high as the ____ intercostal space. The abdomen is separated from the pelvis by the imaginary border of the pelvic ______, above which is the ____ pelvis
4th
Inlet
Greater
The abdominopelvic cavity walls are mostly bone, muscle, and CT, lined by _______
Peritoneum
The anteriolateral abdominal wall is mostly made up of what 2 components?
Muscle
Aponeurosis
What are the boundaries of the anteriorlateral abdominal wall?
Upper 7-10 costal cartilages
Lower inguinal ligament and pelvic bones
Components of outer layer of anteriolateral abdominal wall
Skin
Camper’s fascia
Scarpa’s fascia
Aponeurosis (rectus sheath)
Differentiate between Camper’s and Scarpa’s fascia
Both are integument
Camper’s = fatty layer of superficial fascia
Scarpa’s = membranous underlying CT layer of superficial fascia; continuous with Colle’s fascia of perineum but fused with fascia lata of lower limb
What is the significance of Scarpa’s fascia in terms of fluid flow?
Fluid cannot go from abdominal wall into leg but could flow into or out of superficial perineum
The serratus anterior m. interdigitates with what abdominal muscle?
External oblique m.
Origin of external oblique m.
Lower 6 ribs
Insertion of external oblique m.
Aponeurosis and linea alba, anterior iliac crest and pubic tubercle
The inguinal ligament is formed by what structures? What are its attachment points?
The lower portion of the external oblique m. rolls under to form the inguinal ligament attached to ASIS and pubic tubercle
The lower portion of the external oblique m. rolls under to form the inguinal ligament which forms the opening of the __________, as well as a reflection beneath that forms the _______ ligament
Superficial inguinal canal; lacunar
Innervation of external oblique m.
Ventral rami of T7-12 of intercostal nn.
Action of external oblique m.
Compresses abdomen and increases intra abdominal pressure; moves trunk and retains posture
Origin of internal oblique m.
Iliac crest and some of thoracolumbar fascia
Insertion of internal oblique m.
Lower 10-12 ribs, aponeurosis, linea alba, and pubic crest; lower part makes part of conjoint tendon (falx inguinalis)
Some fibers of the internal oblique m. follow the spermatic cord to make the ______ muscle
Cremasteric
The upper 3/4s of the internal oblique aponeurosis splits to encompass what muscle
Rectus abdominis m.
Innervation of internal oblique m.
T7-12 and L1
Action of internal oblique m.
Compresses and supports viscera, laterally flexes and rotates
The _____ ______ m. runs transversomedially except for some running toward the pubic crest to contribute to the _____ tendon
Transversus abdominis
Conjoint
Origin of transversus abdominis m.
Lower 7-12 costal cartilages, thoracolumbar fascia, iliac crest, outer third of upper inguinal ligament
Insertion of transversus abdominis m.
Linea alba
Pecten pubis
Pubic crest
T/F: the aponeurosis of the transversus abdominis m. contributes to the rectus sheath
True
Innervation of transversus abdominis m.
T7-L1
Action of transversus abdominis m.
Compresses and supports viscera
Origin of rectus abdominis m.
Pubic symphysis and pubic crest
Insertion of rectus abdominis m.
Xiphoid process and outer surface of 5-7th intercostal cartilages
Tendinous intersections of rectus abdominis muscle form part of rectus sheath at what 3 approximate locations?
Umbilical, xiphoid, and midway levels
Innervation of rectus abdominis m.
Ventral rami of T7-12
Action of rectus abdominis m.
Flexes abdomen and compresses it
What forms the lateral border of the rectus abdominis m.?
Linea semilunaris
What muscle, missing in 20% of the population, may be found at the inferior region of the rectus abdominis m., near the pubic crest?
Pyramidalis m.
How do the aponeuroses of EO, IO, and TA muscles contribute to the rectus sheath?
EO aponeurosis is always anterior
IO aponeurosis splits in upper 3/4 but is all anterior in lower 1/4
TA aponeurosis is posterior except in lower 1/4
______ = sharp transition where all EO, IO, and TA aponeuroses become anterior to rectus abdominis m.
Arcuate line
Below the arcuate line, the rectus abdominis is in contact with _______ ______
Transversalis fascia
Nerves of anterior abdominal wall
Thoracoabdominal n.
Subcostal n.
Iliohypogastric n.
Ilioinguinal n.
Thoracoabdominal n. (T7-T11) form as continuation of _____ nn.
Motor or sensory?
Intercostal
Both motor and sensory
The nerves of the anterior abdominal wall run between what 2 muscles?
Transversus abdominis m.
Internal oblique m.
Location of subcostal n.
Is it motor or sensory?
Subcostal n. = T12, runs along inferior 12th rib
Motor; sensory is superior to iliac crest
Location of iliohypogastric n.
Motor or sensory?
Iliohypogastric n. = L1, runs between 2nd and 3rd muscle layers
Motor to IO and TA; sensory to upper inguinal and hypogastric region
Location of ilioinguinal n.
Motor or sensory?
Ilioinguinal n. = L1
Motor to lower IO and TA; sensory to lower inguinal, anterior scrotum/labia, near medial thigh
Arteries of anterior abdominal wall exist as continuation of _____ arteries. Lumbar arteries branch from the _______ _______
Intercostal; abdominal aorta
Major arteries of anterior abdominal wall
Superficial epigastric a. Superficial circumflex iliac a. Deep circumflex iliac a. Inferior epigastric a. Superior epigastric a.
The superficial epigastric a. branches from what a.?
Femoral a.
Superficial circumflex iliac a. branches from what a.? What anatomical landmark does it run along?
Femoral a.
Runs along inguinal ligament
Deep circumflex iliac a. branches from what a.? What anatomical landmark does it run along?
External iliac a.
Runs deep along inguinal ligament
Inferior epigastric a. branches from what a.? What anatomical landmark does it run along and what does it anastomose with?
External iliac a.
Runs posterior to rectus abdominis m.
Anastomosis with superiro epigastric a.
The superior epigastric a. is a terminal branch of what a.?
Internal thoracic a.
What a. runs anterior to the posterior layer of the rectus sheath?
Inferior epigastric a.
What fold exists on the interior surface of the anterior abdominal wall due to obliterated urachus?
Median umbilical fold
What fold exists on the interior surface of the anterior abdominal wall due to obliterated umbilical aa.?
Medial umbilical fold
What fold exists on the interior surface of the anterior abdominal wall due to inferior epigastric a.?
Lateral umbilical fold
What fossa exists on the interior surface of the anterior abdominal wall as a gutter on either side of the upper bladder?
Supravesicular fossa
What fossa exists on the interior surface of the anterior abdominal wall as a gutter lateral to medial umbilical folds?
Medial inguinal fossa
What fossa exists on the interior surface of the anterior abdominal wall as a gutter lateral to lateral umbilical folds?
Lateral inguinal fossa
What important anatomical landmark delineates the path of lymph drainage in the abdomen?
Transumbilical plane
Superficial vessels superior to the umbilicus (transumbilical plane) drain into ______ nodes, with a few going to the ______ nodes
Superficial vessels below the umbilicus (transumbilical plane) drain to ________ nodes
Axillary; parasternal
Superficial inguinal
T/F: deep lymph vessels accompany the deep veins of the abdominal wall like the external and internal iliac veins
True
Where would you make a subcostal incision? What organs could you access here?
2.5 cm inferior from margin; access to gallbladder and biliary tract and spleen
What type of incision can be made rapidly d/t few blood vessels or nerves?
Midline incision
How would you make a paramedian incision?
Open anterior sheath, push rectus m. aside laterally and enter peritoneum
What type of incision is typical of appendectomy?
Gridline (McBurney’s point) - muscle splitting
What type of incision is used in most non-laparascopic gynecological/obstetrical surgeries?
Suprapubic
Origin; insertion; innervation; action of:
External oblique m.
Origin: lower 6 ribs
Insertion: aponeurosis and linea alba, anterior iliac crest and pubic tubercle
Innervation: ventral rami of T7-12 of intercostal n.
Action: compress abdomen and increase intraabdominal pressure; move trunk; retain posture
Origin; insertion; innervation; action of:
Internal oblique m.
Origin: iliac crest and some of thoracolumbar fascia
Insertion: lower 10-12 ribs, aponeurosis, linea alba, and pubic crest, lower part makes part of conjoint tendon (falx inguinalis)
Innervation: T7-L1
Action: compresses and supports viscera, laterally flexes and rotates
Origin; insertion; innervation; action of:
Transversus abdominis m.
Origin: lower 7-12 costal cartilages, thoracolumbar fascia, iliac crest, and outer third of inguinal ligament
Insertion: linea alba, pecten pubis, and pubic crest
Innervated by T7-L1
Action: compresses and supports viscera
Origin; insertion; innervation; action of:
Rectus abdominis m.
Origin: pubic symphysis and pubic crest
Insertion: xiphoid process and outer surface of 5-7th intercostal cartilages
Innervation: ventral rami of T7-12
Action: flexes abdomen and compresses it
Organs found in RUQ
Liver (R lobe) Gallbladder Stomach (pylorus) Duodenum (parts 1-3) Head of pancreas R suprarenal gland Right kidney Right colic flexure Ascending colon: superior part Transverse colon: right half
Organs found in LUQ
Liver (L lobe) Spleen Stomach Jejunum and proximal ilium Pancreas: body and tail L kidney L suprarenal gland L colic flexure Transverse colon: left half Descending colon: superior part
Organs found in RLQ
Cecum Appendix Most of ileum Ascending colon: inferior part R ovary R uterine tube R ureter: abdominal part R spermatic cord: abd part Uterus (if enlarged) Urinary bladder (if full)
Organs found in LLQ
Sigmoid colon Descending colon: inferior part L ovary L uterine tube L ureter: abdominal part L spermatic cord: abd part Uterus (if enlarged) Urinary bladder (if full)
How might muscles of the anterior abdominal wall contribute to respiration?
Anterior abdominal mm. that increase intraabdominal pressure act to oppose the diaphragm and thus facilitate expulsion of air from the lungs
[forced exhalation]
Actions of external, internal, and innermost intercostals for respiration
External = elevate ribs during forced inspiration
Internal = depression of ribs
Innermost = depression of ribs
When would erector spinae be used for respiration?
Forced inhalation
