Abdomen I: Abdominal Wall & Cavity Flashcards
What are the 4 boundaries of the Abdomen?
- Superior
- Posterior
- Anterolateral
- Inferior
Where is the Superior boundary?
The diaphragm
(fifth intercostal space)
Where is the Posterior boundary?
Lumbar vertebrae and quadratus lumborum muscles
Where is the Anterolateral boundary?
The muscles of abdominal wall
Where is the Inferior boundary?
The pelvic brim
What is the abdominal wall function?
- RETAIN (help hold everything in) and PROTECT Abdominal Organs
- Produce ANTERIOR & LATERAL FLEXION and help maintain POSTURE
- INCREASE intra-abdominal PRESSURE:
- forced expiration
- defecation
- urination
- vomiting
- childbirth
What are the 4 Quadrants of the Abdominal?
- Right upper quadrant (RUQ)
- Left upper quadrant (LUQ)
- Right lower quadrant (RLQ)
- Left lower quadrant (LLQ)
What are in all of the 4 quadrants?
intestines
- can travel through all if there’s a problem
What are the 9 abdominal regions?
- Right hypochondria region
- Epigastric region
- Left hypochondria region
- Right lumbar region
- Umbilical region
- Left lumbar region
- Right Iliac (inguinal) region
- Hypogastric (public) region
- Left iliac (inguinal) region
What are the 9 layers of the abdominal wall?
- Skin
- Superficial fascia - fatty layer (Camper’s fascia)
- Superficial fascia - membranous layer (Scarpa’s fascia)
- External oblique muscle
- Internal oblique muscle
- Transversus abdominis muscle
- Transversalis fascia
- Extraperitoneal fascia
- Parietal peritoneum
What are the functions of the Anterolateral Abdominal Wall?
- Retain & PROTECT abdominal
viscera - Maintain POSTURE via anterior & lateral flexion and rota)on of trunk
- Maintain & INCREASE INTRA- ABDOMINAL PRESSURE during respira)on, defeca)on, urina)on, vomi)ng, and child birth
What is the innervation of the Anterolateral Abdominal Wall muscles?
Thoracoabdominal nerves (T7-T11), subcostal (T12), and L1 nerves
Where is the External Oblique? & what is its actions?
- Outermost layer of abdominal muscles
- Fibres run DOWN AND TOWARDS THE MIDLINE “Hands in your pockets”
Actions: flexion and rota)on of the trunk, compression of viscera
Includes the External oblique aponeurosis - CT that extends from muscles (makes midline stronger - gives extra strength)
What is the Internal Oblique? & what is its actions?
- Middle layer of abdominal muscles
- Fibres run DOWN AND AWAY FROM THE MIDLINE – Int. perpendicular to externaloblique obliques
- Actions: flexion and rotation of the trunk, compression of viscera
Includes the Internal oblique aponeurosis
What is the Transversus Abdominis? What is its action?
- Deepest and thinnest layer of abdominal muscles
- Fibres run HORIZONTALLY
therefore - Actions: compression of viscera only! No trunk movement! “Suck it in”
Includes Transverse abdominis aponeurosis & Transversalis fascia (helps give structure to wall)
What is the Rectus Abdominis? What is its actions?
- Pair of long, straplike muscles that extend vertically from the pelvis to the ribs
- Separated by the LINEA ALBA (midline)
- Enclosed within the rectus sheath (aponeuroses of obliques)
- Muscle is separated into segments by TENDINOUS INTERSECTIONS (allow for: 8 pack)
- bands of CT
- Actions: Flexion of the trunk, compression of viscera
Includes: Linea Alba
What is an Abdominal Wall Hernia?
when abdominal wall is weak
What are the 4 types of hernias?
- Linea Alba Hernia
- Umbilical Hernia
- Spigelian Hernia
- Incisional Hernia (after surgery)
Which organs can pop out of a hernia?
intestines
What are the 4 muscles of the Anterolateral Abdominal Wall?
- External Oblique
- Internal Oblique
- Transversus Abdominis
- Rectus Abdominis
What are the 2 muscles of the Posterior Abdominal Wall?
- Quadratus Lumborum
- Psoas major
What is the Quadratus Lumborum?
- Square-shaped muscle originating on the pelvis
- Powers lateral flexion of the lumbar spine
- Stabilizes the 12TH RIB against the action of the diaphragm during inspiration