Anterior Abdominal Wall & Surface Anatomy Flashcards
What is the role of the abdominal wall?
- Firm flexible wall which keeps abdominal viscera in abdominal cavity.
- Protection from injury.
- Assists in forceful expiration by pushing the abdominal viscera upwards.
- Assists with actions (coughing, vomiting) that increases intra-abdominal pressure
What are the 4 quadrants?
- RUQ, LUQ, RLQ, LLQ
What are the planes that form the nine regions?
- 2 vertical
1. The midclavicular lines. - 2 horizontal planes:
1. Transpyloric plane: Horizontal line halfway
between the xiphoid process and the umbilicus
2. Inter-tubercular plane: Horizontal line that joins the iliac crests
What are the nine regions formed?
- Right and left hypochondria
- Epigastric region
- Umbilical region
- Right and left flank
- Pubic region
- Right and left groin/ iliac fossa.
What are the positions of the horizontal planes with respect to the Lumbar vertebrae?
- Transpyloric Plane – L1
- Umbilicus –L3/4 intervertebral disc
- Transtubercular – L4-5
Discuss surgical incisions.
What are the layers of the abdominal wall?
- Skin
- Superficial fascia (or subcutaneous tissue)
- Muscles and associated fascia
- Transversalis fascia
- Parietal peritoneum
What makes up the superficial fascia?
- Made of fatty connective tissue.
- Two layers:
1. Camper’s fascia (fatty superficial layer)
2. Scarpa’s fascia (membranous deep layer)
*Superficial vessels and nerves run between these two layers of fascia.
What are the 5 muscles of the abdominal wall?
- Flat muscles: Situated laterally
1. External oblique
2. Internal oblique
3. Transverse abdominis - Vertical muscles – Situated near the
mid-line
1. Rectus abdominis
2. Pyrimdalis
What are the features of the External oblique?
-Most superficial. Runs inferomedially and form aponeurosis at midline.
Discuss the origins, insertions, innervation, blood supply and action of the External oblique.
- Origin: Ribs 5-12
- Insertion: Iliac crest and linea alba
- Innervation: Thoraco-abdominal T7-11 and
subcostal nerve T12 - Blood Supply: Lower intercostal arteries and
branches of either the deep circumflex iliac artery or the ilio-lumbar artery - Action: Compresses abdomen contents, contralateral rotation of torso
What is made from the aponeurosis of the abdomen?
- Linea alba.
- It extends from the xiphoid process to the pubic symphysis.
What is the inguinal ligament?
- A rolled in free lower border of the external oblique aponeurosis.
- Origins: ASIS
- Insertions: Pubic tubercle.
What is the inguinal canal?
- Canal between peritoneal cavity and abdominal wall.
- The medial half of inguinal ligament forms floor of inguinal canal.
What are the ligaments of the external oblique?
- Lacunar ligament: Crescent shaped extension of medial fibres
- Pectineal Ligament: Extended fibres along pelvic brim.