Anterior Abdominal Wall and Surface Anatomy Flashcards
What is the function of the abdominal wall?
- Keep abdominal viscera in the abdominal cavity
- Protect abdominal viscera from injury
- Maintain anatomical position of abdominal viscera against gravity
- Assist in forceful expiration
- Involved in any action that increases intra-abdominal pressure
What are the borders of the Anterior Abdominal Wall?
- Xiphoid Process
- Costal Margins
- Pelvic bones
How is the anterior abdominal Wall divided into 4 Quadrants?
2 lines:
- Xiphoid process to pubic symphysis
- Transumbilical line
What are the 4 quadrants of the anterior abdominal wall?
- Right Upper Quadrant
- Right Lower Quadrant
- Left Upper Quadrant
- Left Lower Quadrant
What lines divide the Anterior Abdomen into 9 regions?
- Right Midclavicular Line
- Left Midclavicular Line
- Transpyloric Plane
- Intertubercular PLane
Where is the Transpyloric Plane?
Horizontal line halfway between the xiphoid process and the umbilicus–> at level L1
Where is the Intertubercular Plane?
Horizontal line that joins the iliac tubercles
What are the 9 regions of the anterior abdomen?
- Epigastric
- Right Hypochondium
- Left Hypochondrium
- Umbilical
- Right flank
- Left flank
- Pubic
- Right Iliac/Groin
- Left Iliac/Groin
Where is Murphy’s Point?
At the intersection between the Right Midclavicular line and the transpyloric plane–> Also at the edge of the 9th costal cartilage
Where is McBurney’s Point?
1/3rd of the distance between anterior superior iliac spine and umbilicus
What is significant about McBurney’s Point?
It is where incisions are made to remove the appendix
What surgical incisions can be made on the anterior abdominal wall?
- Subcostal
- Medial
- Paramedian
- Transverse
- Pubic
- McBurney’s
What are the layers of the Abdominal Wall from Superficial to deep?
- Skin
- Camper’s Fascia
- Scarpa’s Fascia
- External Oblique Muscle
- Internal Oblique Muscle
- Transverse Abdominis Muscle
- Transversalis Fascia
- Parietal Peritoneum
- Visceral Peritoneum
Which of the Superficial Fascia layers is fatty?1
Camper’s Fascia
Which of the Superficial Fascia Layers is membranous?
Scarpa’s Fascia
What goes between the 2 layers of Superficial Fascia?
Superficial Vessels and Nerves (T7-L1)
What are the muscles of the abdominal wall?
- External Oblique
- Internal Oblique
- Transverse Abdominis
- Rectus Abdominis
- Pyrimdalis
What are the functions of the flat muscles of the abdomen?
- Flex the trunk
- Laterally flex the trunk
- Rotate the trunk
Describe the External Oblique muscle
Largest flat abdominal muscle, with its fibres running inferomedially and form an aponeurosis in the midline forming the line alba
What are the origins of External Oblique?
Ribs 5-12
Where does External Oblique insert?
- Iliac Crest
- Pubic Tubercle
- Linea Alba
What is the blood supply to External Oblique?
- Lower intercostal Arteries
2. Branches of either the deep circumflex iliac artery or the iliolumbar artery
What is the nerve supply to External Oblique?
- Thoracoabdominal nerves from T7-T11
2. Subcostal nerve from T12
What are the actions of External Oblique?
Controlateral Rotation of the Torso
Describe the Internal Oblique Muscle
Lying deep to External Oblique, its fibres run superomedially and near the midline, it forms aponeurotic fibres which contribute to line alba
What are the origins of Internal Oblique?
- Inguinal Ligament
- Iliac Crest
- Lumbodorsal Fascia
Where does Internal Oblique insert?
- Linea Alba
2. Pecten Pubis
What is the nerve supply to Internal Oblique?
- Thoracoabdominal Nerve (T6-11)
- Subcostal Nerve (T12)
- Iliohypogastric (L1)
- Ilioinguinal (L1)
What is the blood supply to the Internal Oblique?
Subcostal Arteries
What are the actions of Internal Oblique?
- Compresses the abdomen
2. Ipsilateral Trunk Rotation
Describe Transverse Abdominis
Deepest of the flat muscles with its fibres running transversely. It contributes aponeurotic fibres to line alba
What are the origins of Transverse Abdominis?
- Iliac Crest
- Inguinal Ligament
- Thoracolumbar Fascia
- Coastal Cartilages 7-12
Where does Transverse Abdominis insert?
- Xiphoid Process
- Linea Alba
- Pubic Crest
- Pecten Pubis
What is the nerve supply to Transverse Abdominis?
- Thoracoabdominal Nerve (T6-11)
- Subcostal Nerve (T12)
- Iliohypogastric (L1)
- Ilioinguinal (L1)
What is the blood supply to Transverse Abdominis?
Subcostal Arteries
What are the actions of Transverse Abdominis?
Compresses Abdomen
Describe Rectus Abdominis
Long, Paired muscle found either side of the midline in the abdominal wall–> Split into 2 by the line alba
Where are the origins of Rectus Abdominis?
Crest of Pubis
Where does Rectus Abdominis insert?
- Costal Cartilages 5-7
2. Xiphoid Process
What is the nerve supply to Rectus Abdominis?
Thoracoabdominal Nerve T7-T11
What is the blood supply to Rectus Abdominis?
Inferior Epigastric Artery
What are the actions of Rectus Abdominis?
Flexion of the lumbar spine
Describe Pyramidalis
Small Triangle-shaped muscle, found superficially to Recuts Abdominis
What are the origins of Pyramidalis?
Pubic Symphysis and Pubic Crest
Where does Pyramidalis insert?
Linea Alba
What is the nerve supply to Pyramidalis?
Subcostal Nerve
What is the blood supply to Pyramidalis?
Inferior and Superior Epigastric Arteries
What are the actions of Pyramidalis?
Tensing of Linea Alba
What is the Rectus Sheath formed by?
Aponeurosis of External Oblique, Internal Oblique and Transverse Abdominis
What is the anterior wall of the Rectus Sheath formed by?
Aponeuroses of the External Oblique and Half of Internal Oblique
What is the posterior wall of the Rectus Sheath formed by?
Aponeuroses of Half of Internal Oblique and Transverse Abdominis
Where does the Posterior Wall of the Rectus Sheath end?
Midway between the ubmbilicus and the pubic symphysis–> Arcuate Line
What are the borders of the Inguinal Canal?
Anterior Wall: Aponeurosis of External Oblique
Posterior Wall: Transversalis Fascia
Roof: Transversalis Fascia, Internal Oblique, and Transversus Abdominis
Floor: Inguinal Ligament
What are the openings of the Inguinal Canal?
- Superficial Inguinal Ring
2. Deep Inguinal Ring
Where is the Deep Inguinal Ring?
Above the Midinguinal Point
What makes the Deep Inguinal Ring?
Transversalis Fascia
What makes the Superficial Inguinal Ring?
Aponeurosis of the External Oblique
Where is the Superficial Inguinal Ring?
Superior to the Pubic Tubercle
What are the contents of the Inguinal Canal in Females?
- Ilioinguinal Nerve
2. Round Ligament of the Uterus
What are the contents of the Inguinal Canal in Males?
- Ilioinguinal Nerve
2. Spermatic Cord
What is in the Spermatic Cord?
3 Arteries: Testicular, Cremesteric, Vas
3 Nerves: Cremaster, Sympathetics, Ilioinguinal
3 Other Things: Vas Deferens, Pampiniform plexus of veins, Lymphatics
Where does the Cremesteric Artery come from?
Inferior Epigastric Artery
Where does the Artery of Vas come from?
Superior Vesical Nerve
Where does the Nerve to Cremaster come from?
Genitofemoral Nerve
Where would you find a Femoral Hernia?
Inferior and Lateral to the pubic tubercle
Where would you find an Inguinal Hernia?
Superior and Medial to the Pubic Tubercle
Describe an Indirect Inguinal Hernia
Congenital, with the Hernia going through the deep ring, along the inguinal canal, through the superficial ring to the scrotum
Describe a Direct Inguinal Hernia?
Acquired, with the Hernia going through the Superficial Ring
Describe the descent of the Testes into the Scrotum?
From the 8th month of Gestation, the Gubernaculum will drag the Testes down through the Inguinal Canal to the scrotum