Anterolateral abdominal wall Flashcards
What is the superior border of the anterolateral abdominal wall?
Xiphoid process of sternum
Costal cartilages of ribs 7-10
What is the inferior border of the anterolateral abdominal wall?
Iliac crest
Inguinal ligament
Pubic symphysis
What are the layers of the anterolateral abdominal wall, from superficial to deep?
Skin
Superficial fascia
Muscles and associated fascia layers
Extraperitoneal fat
Parietal perioneum
What is the superficial fascia made up of above the umbilicus?
Connective tissue
What happens to the superficial fascia below the umbilicus?
It splits into two layers
What are the two layers of superficial fascia below the umbilicus?
Superficial fatty layer
Deep membranous layer
What is the difference between the compositions of the superficial fatty layer and the deep membranous layer?
Superficial fatty layer contains largely fat
Deep membranous layer contains more collagen and elastic fibres
What are the different groups of muscles in the anterolateral abdominal wall?
Flat muscles
Vertical muscles
Where are the flat muscles located in the anterolateral abdominal wall?
Laterally
What are the flat muscles of the anterolateral abdominal wall, from superficial to deep?
External oblique
Internal oblique
Transversus abdominis
What direction do the fibres of external oblique run in?
Infero-medial direction (hands in pockets)
What does the inferior part of the external oblique form?
Inguinal ligament
What direction do the fibres of internal oblique run in?
Supero-medial
perpendicular to external oblique fibres
What are the actions of the external and internal oblique muscles?
Compress abdomen
Flex trunk
Rotate trunk
What direction do the fibres of transversus abdominis run in?
Horizontal
What is the action of the transversus abdominis musce?
Compresses abdomen
Where are the neurovascular structures supplying the anterolateral abdominal wall located?
Between the internal oblique and transversus abdominis muscle
What happens to the flat muscles as they approach the anterior midline?
From aponeuroses - flattened tendons
Where exactly do the flat muscles form aponeuroses as they approach the anterior midline?
Medial to the mid-clavicular line
What happens to the aponeuroses of the flat muscles at the mid-clavicular line?
Fuse together
to form linea semilunaris
What is the name of the aponeuroses formed by the flat muscles medial to the mid-clavicular line?
Rectus sheath
What happens to the rectus sheath in the anterior midline?
Rectus sheath on each side fuses with the other side
forming the linea alba
What does the linea alba run between?
The xiphisternum
to the pubic symphysis
What is the vertical muscle of the anterolateral abdominal wall?
Rectus abdominis
Where is the rectus abdominis located in the anterolateral abdominal wall?
Anteriorly
What separates the right and left rectus abdominis muscles?
Linea alba
What is the rectus abdominis muscle contained in?
The rectus sheath
How does the rectus sheath attach to the rectus abdominis muscle?
Anterior part of rectus sheath attaches to the anterior surface of rectus abdominis
at three horizontal tendinous intersections
What are the actions of rectus abdominis?
Compresses abdomen
Flexes trunk
What are the different walls of the rectus sheath?
Anterior wall that is anterior to rectus abdominis
Posterior wall that is posterior to rectus abdominis
What is the anterior wall of the rectus sheath made up of?
Aponeurosis of external oblique
Half of aponeorosis of internal oblique
What is the posterior wall of the rectus sheath made up of?
Half of aponeurosis of internal oblique
Aponeurosis of transversus abdominis
Where does the arcuate line run?
Horizontal line midway between umbilicus and pubic symphysis
What happens to the rectus sheath at the arcuate line?
Anterior wall of rectus sheath is made up of aponeurosis of all three flat muscles
Posterior wall of rectus sheath is made up of transversalis fascia
What happens to the layers of the abdominal wall at the umbilicus?
They fuse together
What are the functions of the anterolateral abdominal wall?
Protect and support abdominal viscera
Compress abdomen, increase intra-abdominal pressure
Assist in excretion of substances from abdomen
Assists in forceful expiration
Can also stretch to accommodate increased volume of abdominal viscera
Moves the trunk
