Anterior Abdominal Wall Flashcards
What are the superior and inferior tissue boundaries of the abdomen?
Thoracic diaphragm (4th intercostal space) to pelvic inlet
The abdomen is skeletally bound by what structures?
Costal cartilages 7-10, ribs 11-12, xiphoid process, L1-5, and os coxae (ilium and pubis)
What are the boundaries of the greater pelvis or false pelvis?
Superior ilium border to pelvic inlet
What are the boundaries of the lesser pelvis or true pelvis?
Pelvic inlet to pelvic diaphragm
What happens to the diaphragm and abdominal muscles during inspiration?
Contraction of diaphragm and relaxation of abdominal muscles
What happens to the diaphragm and abdominal muscles during expiration?
Relaxation of diaphragm and contraction of abdominal muscles
The most superficial fascia of the abdomen is called…
camper fascia
Is camper fascia fatty or membranous?
Fatty
Which fascia is deep to camper fascia?
Scarpa fascia
Is scarpa fascia fatty or membranous?
Membranous
Where is scarpa fascia?
Inferior to umbilicus and deep to camper fascia
What is investing fascia and where is it found?
Mostly epimysium covering the external surface of muscles and aponeuroses
What type of fascia will cover the external surface of muscles?
Investing fascia
What muscle is immediately deep to scarpa fascia?
External oblique
What direction do the fibers of the external obliques run?
Direction of hands in pockets
What direction do the fibers of the internal obliques run?
Direction of prayer hands, opposite to external obliques
What muscle is immediately deep to internal obliques?
Transversus abdominus
What fascia is deep to the investing fascia around transversus abdominus?
Endoabdominal fascia (transversalis fascia)
Where is endoabdominal fascia found?
Lines anterolateral abdominal wall deep to muscles
What is immediately deep to endoabdominal fascia?
Extraperitoneal fat
What is found deep to extraperitoneal fat?
Peritoneum
abdominal wall muscles
Name the flat muscles
External oblique
Internal oblique
Transversus abdominis
abdominal wall muscles
Name the vertical muscles
Rectus abdominis
Pyramidalis
Origin and insertion of external oblique
O: external surfaces of ribs 5-12
I: Linea alba, pubic tubercle, and anterior half of iliac crest
Innervation of external oblique
Anterior rami of T7-12 and subcostal nerve
Action of external oblique
Compress and support abdominal contents; together flex trunk; contralaterally bends trunk
Origin and insertion of internal oblique
O: thoracolumbar fascia, anterior two thirds of iliac crest, and connective tissue deep to lateral third of inguinal ligament
I: Inferior borders of ribs 10-12, linea alba, and pecten pubis via conjoint tendon
Innervation of internal oblique
Anterior rami of T6-12 and first lumbar nerve
Action of internal oblique
Compress and support abdominal contents; together flex trunk; ipsilaterally bends trunk
Origin and insertion of transversus abdominis
O: Internal surfaces of 7-12 costal cartilages, thoracolumbar fascia, iliac crest, and connective tissue deep to lateral third of inguinal ligament
I: Linea alba with aponeurosis of internal oblique, pubic crest, and pecten pubis via conjoint tendon
Innervation of transversus abdominis
Anterior rami of T6-12 and first lumbar nerve
Action of transversus abdominis
Compresses and supports abdominal viscera
Origin and insertion of rectus abdominis
O: Pubic symphysis and pubic crest
I: Xiphoid process and costal cartilages 5-7
Innervation of rectus abdominis
Anterior rami of T6-12
Action of rectus abdominis
Flexus trunk (lumbar vertebrae) and compresses abdominal viscera; stabilizes and controls tilt of pelvis (antilordosis)
Origin and insertion of pyramidalis
O: Front of pubis and pubic symphysis
I: Linea alba
Innervation of pyramidalis
Anterior ramus of T12
Action of pyramidalis
Tenses or draws down the linea alba
Fibers of the flat muscles end near the midclavicular line forming… which blend to form…
… forming aponeuroses which blend to form the rectus sheath
The rectus sheath surrounds…
rectus abdominis (except inferior fourth of posterior portion)
What marks the end of the posterior rectus sheath?
Arcuate line
Inferior to the arcuate line is what fascia?
Transversalis fascia
What forms the linea alba?
Interweaving aponeuroses
What does the linea alba separate?
Rectus abdominis muscles
What is the lateral margin of rectus abdominis?
Linea semilunaris
What is the function of tendinous intersections?
Attach to anterior rectus sheath and subdivide rectus abdominis
Improve generation of force
The rectus sheath contains which vessels?
Superior and inferior epigastric arteries and veins, and lymphatic vessels
Innervation of rectus sheath
Ventral rami of thoracoabdominal nerves (T6/7-11) and subcostal nerve (T12)
Name five anterolateral abdominal wall nerves
- Thoracoabdominal nerves
- Lateral (thoracic) cutaneous branches
- Subcostal nerve
- Iliohypogastric
- Ilioinguinal
Which nerves’ motor branches supply all the muscles of the abdominal wall?
Thoracoabdominal nerves (ventral/anterior rami (T6) T7-11)
Which nerves’ cutaneous branches provide the dermatomes?
Thoracoabdominal nerves (ventral/anterior rami (T6) T7-11)
Spinal levels of thoracoabdominal nerves
Ventral/anterior rami of T6/7-11
Spinal levels of lateral (thoracic) cutaneous branches
T7-9/10
Spinal level of subcostal nerve
Ventral/anterior ramus of T12
Spinal level of iliohypogastric nerve
Terminal branch of ventral/anterior ramus of L1
Spinal level of ilioinguinal nerve?
Terminal branch of ventral/anterior ramus of L1
venous supply
Skin and subcutaneous tissues drain into…
superior vena caval system
venous supply
The internal thoracic vein drains into the superior vena caval system in which direction?
Medially
venous supply
The lateral thoracic vein drains into the superior vena caval system is which direction?
Laterally and inferiorly
venous supply
Cutaneous veins surrounding umbilicus anastomose with…
hepatic portal vein tributaries
arterial supply
What arrangement do the arteries of the abdominal wall follow?
Arrangement of muscles: oblique and circumferential laterally and vertical anteriorly
arterial supply
What are circumferential vessels?
Continuations of 7-11 posterior intercostal, subcostal, and deep circumflex iliac vessels
arterial supply
What are the vertical vessels?
Superior and inferior epigastric vessels, musculophrenic artery and branches
lymphatics
Describe lymphatic draining superior to transumbilical line
Superficial lymphatic vessels drain into axillary lymph nodes and parasternal lymph nodes
lymphatics
Describe lymphatic draining inferior to transumbilical line
Superficial lymphatic vessels drain into superficial inguinal lymph nodes
lymphatics
Deep lymphatic vessels are like…
deep veins
lymphatics
Describe draining in deep lymphatic vessels
Drain into external iliac, common iliac, right and left lumbar lymph nodes
Based on the regional divisions of the abdominopelvic cavity, which quadrant would you expect to find the liver?
Right upper quadrant or right hypochondrium
In the anterior abdominal wall, ___ fascia is only found inferior to the umbilicus superficial to extraperitoneal fat
transversalis (endoabdominal)
What is the linea alba?
The midline fusion of the aponeuroses of the anterolateral abdominal muscles
Which dermatome is associated with the umbilicus?
T10
