Anterior Abdominal Wall Flashcards
Names of anterior abdominal wall subdivisions
Four quadrants
Nine abdominopelvic region
What lines divide the anterior abdominal wall into four quadrants?
Horizontal transumbilical
Verticalmedian planes
What are the names of the four quadrants of the anterior abdominal wall?
Right upper
Right lower
Left upper
Left lower
Which planes form the nine abdominopelvic regions?
Superior subcostal plane - Passes under the costal margins of the 10th ribs
Inferior intertubercular plane - Connects the tubercules of the iliac crest
Midclavicular planes - Passes through the midpoint of each clavicle and halfway between the pubic symphysis and the anterior superior iliac spine
What are the names of the abdominopelvic regions?
What are striae distensae?
Stretch marks/elongated lines
Form in pregnant women, obese people and those with abdominal distention
Location of the superficial fascia
Just below the skin and consists of connective tissue
Superficial fascia superior to the umbilicus
Similar and continuous to the superficial fascia of the body and is made up mostly of one layer
Superficial fascia inferior to the umbilicus
Divided into two layers:
Superficial Camper’s Facia
Deep Scarpa’s Fascia
Composition of the superficial camper’s fascia?
Thick fatty layer
Has a variable degree of thickness
Composition of the deep scarpa’s fascia
Thinner and denser membranous layer overlying the muscle layer of the abdominal wall
Attachment points of the scarpa’s fascia
Attached to the Linea alba and pubic symphysis and fuses with the fascia lata (deep fascia of the thigh) right below the inguinal ligament
How is the fascia of the penis and the scrotum formed?
Camper’s fascia blends with the Scarpa’s fascia to form the superficial fascia of the penis
Scarpa’s fascia extends further on into the scrotum, where it contains smooth muscle fibers and becomes the dartos fascia
Formation and location of Colles’ fascia
Where the scarpa’s fascia continues into the perineum to form the superficial fascia of the perineum
In women it continues into the labia majora and anterior perineum
What are the muscle groups of the anterior abdominal wall?
Lateral flat group of muscles - Located on either side of the abdomen
Anterior vertical muscles - Located bilaterally to the linea alba
What are the muscles of the lateral flat group?
External oblique
Internal oblique
Transversus abdominis
What are the muscles of the anterior vertical group?
Rectus abdominis
Pyramidalis muscles
How can the external abdominal oblique muscle be identified?
Most superficial muscle layer
Fibers directed downwards and forwards
What happens to the external abdominal oblique muscles anteriorly?
Continues anteriorly as the external oblique aponeurosis, which courses anteriorly to the rectus abdominis muscle and inserts into the linea alba
Origin of the external abdominal oblique muscle?
External surface of ribs 5-12
Insertion of the external abdominal oblique muscle
Linea alba
Pubic tubercle
Anterior half of iliac crest
Actions of the external abdominal oblique muscle
Bilateral contraction - Trunk flexion, Compressesion of the abdominal viscera, Expiration
Unilateral contraction - Trunk lateral flexion (ipsilateral), Trunk rotation (contralateral)
How can the internal abdominal oblique muscle be differentiated?
Upward fibers
Origins of the internal abdominal oblique muscle
Thoracolumbar fascia
Anterior iliac crest
Iliopectineal arch
Nerve supply of the internal abdominal oblique muscle
Lower intercostal nerves (T7-T11)
Subcostal nerve (T12)
Iliohypogastric nerve (L1)
Ilioinguinal nerve (L1)
Actions of the internal abdominal oblique muscle
Bilateral contraction - Trunk flexion, Compressesion of abdominal viscera, Expiration
Unilateral contraction - Trunk lateral flexion (ipsilateral), Trunk rotation (ipsilateral)
Origin of the transversus abdominis muscle
Costal cartilages of ribs 7-12
Thoracolumbar fascia
Anterior iliac crest
Iliopectineal arch
Insertion of the transversus abdominis muscle
Continues anteriorly as the transverse abdominis aponeurosis and inserts into the pubic crest and pectineal line of pubis
Nerve supply of the tranversus abdominis muscle
Lower intercostal nerves (T7-T11)
Subcostal nerve (T12)
Iliohypogastric nerve (L1)
Ilioinguinal nerve (L1)
Action of the transversus abdominis muscle
Bilateral contraction - Compresses abdominal viscera, Expiration
Unilateral contraction - Trunk rotation (ipsilateral)
Origin of the rectus abdominis muscle
Pubic symphysis
Pubic crest
Origin of the rectus abdominis muscle
Pubic symphysis
Pubic crest
Insertion of the rectus abdominis muscle
Xiphoid process
Costal cartilages of ribs 5-7
Nerve supply of the rectus abdominis muscle
Intercostal nerves (T7-T11)
Subcostal nerve (T12)
Action of the rectus abdominis muscle
Trunk flexion
Compresses abdominal viscera
Expiration
Origin of the pyramidalis muscle
Pubic symphysis
Pubic crest
Insertion of the pyramidalis muscle
Linea alba
Nerve supply of the pyramidalis muscle
Subcostal nerve (T12)
Action of the pyramidalis muscle
Tenses linea alba
What are the deep fascial layers?
Transversalis fascia
Extraperitoneal fat
Parietal peritoneum
What is extraperitoneal fat?
A thin layer of connective tissue and fat lining the abdominal wall between the transversalis fascia and the parietal peritoneum
The extraperitoneal fat is more abundant in the posterior abdominal wall, especially around the kidneys and in the pelvic floor
What is parietal peritoneum?
Parietal peritoneum is a serous membrane lining the internal surface of the abdominal wall
The parietal peritoneum forms the mesentery that suspends the abdominal viscera and is continuous with the visceral peritoneum.
