The Anterolateral Wall of the Abdomen, Abdominal Cavity, Its Contents and Major Viscera Flashcards
Prominent visual features of the anterior abdominal wall
- Epigastric region
- Umbilicus
- Periumbilical region
- Hypogastric region
- Anterolateral wall tissues and muscles
- Anterior superior iliac spine
- Iliac crest
- Pubic tubercle
- Linea alba
- Semilunar line
Theoretical landmarks of the anterior abdominal wall
- Transpyloric plane
- Trans-tubercular plane
- Spino-umbilical line
- McBurney’s point
- Mid-clavicular line
- Mid-inguinal line
- Arcuate line
What does the transpyloric plane pass through?
Pylorus of the stomach
What vertebral level is the transpyloric plane at?
L1
What is the transpyloric plane midway between? (2 sets)
- Jugular notch of sternum and pubic symphysis
- Xiphoid process and umbilicus
What does the mid-inguinal point form the midpoint of?
Imaginary line joining anterior superior iliac spine and pubic symphysis
What does the mid-inguinal point mark?
Position where the external iliac artery leaves the abdomen to become femoral artery
What is McBurney’s point?
Point on right side of abdomen 1/3 of the distance from anterior superior iliac spine to umbilicus
Gross boundaries of abdominal cavity
- Diaphragm (superior)
- Pelvic brim (inferior)
- Anterolateral abdomino-pelvic wall (ant-lat)
- Posterior abdominal wall (posterior)
2 groups of the muscles of the anterolateral wall
- Lateral group
- Midline group
Muscles of the lateral group
- External oblique
- Internal oblique
- Transversus abdominis
Muscles of the midline group
- Rectus abdominis
- Pyramidalis
Where is the arcuate line found?
- Posterior to rectus abdominis
- Half distance from umbilicus to pubic crest
Tissue layers of rectus sheath superior to arcuate line
- Aponeurosis of external oblique (anterior to rectus abdominis
- Aponeurosis of internal oblique (surrounds RA)
- Aponeurosis of transversus abdominis (posterior to RA)
- Transversalis fascia (posterior to RA)
Tissue layers of rectus sheath inferior to arcuate line
- Aponeurosis of all 3 muscles anterior to rectus abdominis
- Transversalis fascia (posterior to RA)
How is the abdomen divided into quadrants?
Perpendicular lines from umbilicus
How is the abdomen divided into 9 compartments?
- 2 vertical lines joining mid-clavicular points to mid-inguinal points
- Sub-costal plane
- Trans-tubercular plane
Where is the sub-costal plane?
Across the lowermost bony point of ribcage (10th costal cartilage)
Where is the trans-tubercular plane?
Across the 2 tubercles of iliac crests
What are the 9 regions called?
- Left and right sides (top to bottom)
> L/R hypochondriac region
> L/R lumbar region
> L/R iliac region - Central (top to bottom)
> Epigastric region
> Umbilical region
> Hypogastric region
What does the peritoneum line?
- All interior surfaces of abdominal wall (except bare area of liver)
- Surfaces of all viscera of abdomen (except bare area of liver)
What is peritoneum classified as histologically?
Simple squamous epithelium
What is the parietal peritoneum innervated by?
Sensory division of somatic nervous system
What is the visceral peritoneum innervated by?
Sensory division of autonomic nervous system
3 compartments of abdominal cavity
- Peritoneal compartment
- Intraperitoneal compartment
- Extraperitoneal compartment
What is a mesentery?
- Double layer of peritoneum connecting organs to body wall
- Allow for passage of nerves and blood vessels to organs
What is a ligament?
- Double layer of peritoneum connecting organs to other organs or to the body wall
- Carry less vessels and nerves than mesenteries
What is the omentum?
Double layer/fold of peritoneum connecting stomach to other organs
Greater vs lesser omentum
- Greater drapes inferiorly over transverse colon and coils of jejunum and ileum
- Lesser attaches stomach, duodenum and liver
Layers of anterior abdominal wall
- Skin
- Camper’s fascia (fatty layer of superficial)
- Scarpa’s fascia (membranous layer of superficial
- External oblique
- Internal oblique
- Transversus abdominis
- Transversalis fascia
- Extraperitoneal fascia
- Parietal peritoneum
