Anatomy - Week 7 - Abdomen And Anterior Abdominal Wall/ lower GIT, posterior abdominal wall and arteries supplying the GIT Flashcards
What 3 pieces ?
Ilium, pubis, ischium
In order to carry out a thorough examination of a patients abdomen, what do you needa know?
9 regions and 4 quadrants of the abdomen
What are the 4 abdominopelvic quadrants?
Right upper quadrant (RUQ)
Left upper quadrant (LUQ)
Left lower quadrant (LLQ)
Right lower quadrant (RLQ)
What are the nine regions of the abdomen?
Right hypochondrium (right lobe of liver) Left hypochondrium (left lobe of liver & spleen) Epigastric region (liver and stomach) Right flank (lateral - ascending colon) Left flank (lateral - descending colon) Umbilical region (small intestine) Right groin (caecum, appendix) Left groin (sigmoid colon) Pubic region (lower part of small intestine, bladder, uterus)
What are the main planes of the 9 regions?
Midclavicular planes Subcostal plane (10th costal margin) Intertubercular plane (iliac tubercles)
What is the innervation of the anterior abdominal wall?
Intercostal nerves T7 - T11 and subcostal nerve T12 supply the skin and muscle of the anterior abdominal wall
What supplies the skin over the xiphoid process?
T6
What supplies the skin around the umbilicis?
T10
What does L1 supply?
Skin and muscle in the inguinal and suprapubic regions of the abdominal wall are supplied by L1
What are the anterolateral muscles of the abdominal wall?
5 muscles in this group (3 flat, 2 vertical) External oblique (most superficial, fibres pass toward the midline) Internal oblique (deep to external oblique, fibres passes away from midline) Transversus abdominis (deep to internal oblique, fibres transverse) 2 vertical muscles - rectus abdominis (long flat, extends along the anterior abdominal wall)
What is the direction of the external oblique muscle fibres?
Downward, forwards, medially
What is the aponeurosis of the external oblique?
It is a flattened tendon that arises from a muscle
What is the action of the abdominal muscleS?
Supports and protects abdominal contents, assist in forced expiration, micturition, defection, delivery by increasing intra-abdominal pressure
Describe the position rectus sheath
Between the costal margin and the level of the anterosuperior iliac spine, the aponeuroisis for the internal oblique splits to enclose the rectus muscle
The external oblique aponeurosis is directed in front of the muscle
Transversus aponeurosis is directed behind the muscle
What is the rectus sheath formed From?
Formed from the aponeurosis of the muscles of the anterior abdominal wall, the external and internal obliques and the transversus abdominis.
The anterior aspect of the sheath is formed from the aponeurosis of the external oblique muscle and anterior half of the internal oblique aponeurosis
The posterior aspect of the sheath is formed from posterior half of the internal oblique aponeurosis and the aponeurosis from transverse abdominis.
What forms the anterior wall?
Between the level of the anterosuperior iliac spine and the pubis , the aponeurosis of all three muscles form the anterior wall.
What forms the posterior wall?
Only the fascia transversalis ( the rectus muscle lies in contact with the fascia transversalis)
What is not attached to the posterior wall of the rectus sheath?
The rectus abdominis muscle
What is the anterior wall firmly attached by to the rectus sheath?
Muscles tendinous intersections
What the contents of the rectus sheath?
1- encloses the rectus abdominis and pyramidalis muscle (if present)
2- contains the anterior rami of lower six thoracic nerves and the superior and inferior epigastric vessels
What is the arterial supply of the antero-lateral abdominal wall?
Branches of the internal thoracic artery - the superior epigastric and musculophrenic arteries
Branches of the external iliac artery - inferior epigastric and deep circumflex arteries
Inferior phrenic artery - branch of the abdominal aorta
Lower posterior intercostal and subcostal arteries - from thoracic aorta
Lumbar arteries from the abdominal aorta
What is the nerve supply to the antero-lateral abdominal wall?
The oblique and transversus abdominis muscles are supplied by the lower six thoracic nerves and the iliohypogastric and ilioinguinal nerves (L1)
The rectus abdominis muscle is supplied by the lower six thoracic nerves
Where does the descending thoracic aorta pass through the diaphragm?
At the aortic hiatus at the level of the 12th thoracic vertebra