Anatomy Lecture 20_Anterior Abdominal Wall Flashcards
Increasesd abdominal pressure can aid in what 4 bodily processes?
• Respiration • Defecation • Micturition • Parturition
What causes hernias?
Increased intra-abdominal pressure in areas of weakness
What are the nine subdivisions of the abdominal cavity
- Right hypocondriac
- Right Lumbar
- Right iliac/ inguinal
- Epigastric
- Umbilico
- Hypogastric
- Left hypocondriac
- left lumbar
- Left iliac/inguinal
What are the 8 layers of the anterior abdominal wall
- Skin
2.Superficial fatty (Camper’s) fascia
3.Deep membranous (Scarpa’s) fascia
4.Potential space
5.Muscular layers (3) separated by superficial,
intermediate, deep investing fasciae
6.Endoabdominal fascia (Transversalis fascia) - Extraperitoneal fat (variable)
8.Parietal peritoneum
Where does the Superficial fatty (Camper’s) layer of
subcutaneous fascia extend and what ateries and blood vesseles does it contain?
• continuous with superficial fascia of
thorax & lower limb
• continues into labia majora (females)
• NOT scrotum (males)
• contains superficial epigastric arteries
and veins
Where does the Deep membranous (Scarpa’s) layer of
subcutaneous fascia extend in the body. can it be sutured
- Scrotum (as Dartos fascia)
- Perineum (as Colles’ fascia)
- Does NOT continue into thighs
Yes sufficiently dense to hold sutures
What is the clinical significance of the potential space between Scarpa’s fascia and underlying superficial investing fascia?
Extravasated fluids can pool there
What are the three muscle layers in the abdominal wall (order from most superficial to deep)
External obliques
Internal obliques
Transverse Abdominales
What is the Endoabdominal (transversalis) fascia
It is the deepest layer of facia in the abdominal cavity. It is continiouse with the endothoracic fascia. it is seperate from the deep investing facia that encases the transverse abdominales
What is the serous lining of abdominal cavity
Parietal peritoneum
What 2 nerves inervates the external obliques?
Thoraco-abdominal nn. (T7-T11) &
Subcostal n. (T12)
How do the external obliques rotate the trunk
to the side opposite the one contracting
What directions do the internal obliques rotate the trunk?
To the side that is contracting
What 4 nerves inervate the internal obliques?
- Thoraco-abdominal n. (T6-T11)
- Subcostal n. (T12)
- Iliohypogastric n. (L1)
- Ilioinguinal n. (L1)
What 4 nerves intervate the transvers abdominalis
- Thoraco-abdominal n. (T6-T11)
- Subcostal n. (T12)
- Iliohypogastric n. (L1)
- Ilioinguinal n. (L1)
What motion do the transverse abdominales cause?
not really any. They compress the abdomen bilaterally
What muscle forms the inguenal ligament and where does it attach? What does it do?
The external obliques form the inguinal ligament and it attaches at the ASIS and pubic tubercle. it acts as a retinaculum for neurovasculature to the thigh
What is the conjoint tendon and where does it attach?
It is the union of the internal obliques and the transverse abdominous. It attaches at the pubis.
How do the EO, IO ,and TA contribute to the sub ingunial region?
EO forms the Inguinal ligament, the IO have muscle fibers that extend down there, and the TA do not contribute.
What nerves innervate the rectus abdominus
- Thoraco-abdominal n. (T6-T11)
- Subcostal n. (T12)
What does the Pyramidalis muscle do?
It connects the linea alba to the pubis
Where is the arcuate line?
It is below umbilicus
Above the arcuate line, what forms the the anterior rectus sheath. What forms the posterior rectus sheath?
The Anterior rectus sheath is formed by the aponeurosis of the external oblique and half the aponeurosis of the the internal oblique.
The posterior rectus sheath is formed by half of the aponeurosis of the internal oblique and the aponeurosis of the transverse abdominales.
What forms the anterior and posterior rectus sheath below the arcuate line?
The anterior rectus sheath is formed by the aponeruosis of EO, IO, and TA.
The posterior rectus sheath is formed by the endoabdominal facia and the parietal peritonium only. This leads the posterior rectus sheath to be some what weak and prone to herniation
Where is the Falciform ligament?
it is between the right and left lobs of the liver and joins to the anterior wall. This inferior aspect of this ligament is called the round ligament.
what is significant about Lateral umbilical fold
it is in the region of the Inferior epigastric artery
what are the 4 land marks in the abdominal cavity
Falciform ligament
Lateral umbilical fold
Medial umbilical fold
Median umbilical fold
Define Epigastric Hernias
Congenital or acquired weakness in the linea alba. Often small (<1cm)
and rarely involve bowl (typically just fat globules)
Umbilical & Para-umbilical Hernias
They can be congenital or aquired. Congenital umbilical hernias happen as a result of incomplete closure of the umbilical ring. aquired umbilical/paraumbilical typically happen secondary to a primary condition including obesity, cirrhosis of the liver, and pregnancey.
What are the thoracoabdominal nerves
They are the anterior rami of T6-T11. They are a continuation of the intercostal nerves. they “become” thoracodominal nerves when they move inferior to the costal margin. They travel in the neurovascular space between IO and TA. They Supply all muscles of anterolateral wall
& skin to about the level of umbilicus
What is the subcostal nerve
It is the anterior rami of T12. It intervates all muscles of the antereolateral abdominal wall as well as the anteriolateral skin from about the the iliac crest to umbilico.
