Abdominal Wall Flashcards
What forms the costal margins (arch)?
Rib 7 and ribs 8-10 that attach to 7.
What is in the abdominal region?
Peritoneal cavity
Gastrointestinal tract and associated glands and digestive organs
Nerves (lots of autonomics, particularly parasympathetics), lymphatics, blood vessels
Renal system
What sits between the costal margins superiorly?
Xiphoid process
What bony landmarks for the anterior abdominal wall on are the ilium?
Crest
Anterior superior iliac spine
Tubercle of iliac crest
What bony landmarks for the anterior abdominal wall are found on the pubis?
Pubic tubercle
Pubic symphysis
Pubic crest
What is the linea terminalis
A line that separates the true pelvis from the false pelvis
What is superior to the linea terminalis?
Abdomen or false pelvis
What is inferior to the linea terminalis
Pelvis or true pelvis
What forms the linea terminalis
Pectin pubis
Arcuate line of the ilium
Sacral promontory of the sacrum
What are the three superficial fascia of the abdomen?
Skin
Fatty layer: (camper’s)(more superficial)
Membranous layer: (Scarpa’s) (deeper)
What is the fatty layer continuous with in the abdomen?
Continuous with the superficial fatty layers in the thorax, thigh and perineum
What is the membranous layer in the abdomen continuous with?
Continuous with the fascia lata in the thigh and with the deep layer of superficial perineal fascia
What layer do the superficial blood vessels run in, in the abdomen?
The fatty layer of superficial fascia
What superficial layer in the abdomen fuses with the fascia lata and is continuous over the penis and scrotum?
The membranous (deep) layer of superficial fascia (Scarpa’s)
What layer does not follow the same pattern as the membranous layer of superficial fascia and is clinically important for holding sutures?
Deep fascia of the abdominal wall (investing fascia of the muscles)
Where is there a potential space in the layers of the abdomen? Clinically: this space could have an infection start in the abdomen from an incision and the fluids could travel to the penis and scrotum.
Between the membranous layer of the superficial fascia and the deep fascia of the external abdominal oblique muscle
What is the linea alba?
The abdominal midline where muscles from each side meet
What is the linea semilunaris?
Semilunar line= lateral border of the rectus abdominus muscle
What is the umbilicus?
Belly button
What is the superficial inguinal ring?
A triagnular opening that forms the exit of the inguinal canal. Spermatic cord in men or the round ligament in women are housed in the inguinal canal
Define aponeurotic
Layers of flat broad tendons. When dissected, they are papery and peel off by sections
Define transpyloric plane
Transverse plane midway between the superior borders of the pubic symphysis and the manubrium
Define subcostal plane
Plane at the lowest level of the costal margin (the inferior margin of the tenth costal cartilage)
Define supracrestal plane
Plane passing through the summits of the iliac crests
Define transtubercular plane
Plane at the level of the iliac tubercles (the iliac tubercle lies -5cm posterolateral to the anterior superior iliac spine)
Define interspinous plane
Plane at the level of the anterior superior iliac spine
What can the transpyloric plane locate?
The pylorus-the opening from the stomach into the small intestine
What planes divide the abdominal wall into regions?
Subcostal plane, Supracrestal plane, and midclavicular lines
From right to left name the superior regions of the abdominal wall
R hypochondriac region
Epigastric region
L hypochondria region
From right to left, name the mid-abdomen regions
R lateral (lumbar) region Umbilical region L Lateral (lumbar) region
From right to left, name the lower abdomen regions
R inguinal regions
Pubic regions
L inguinal region
What are the four quadrants?
Right upper quadrant (RUQ)
Left upper quadrant (LUQ)
Right lower quadrant (RLQ)
Left lower quadrant (LLQ)
What is in the center of the four quadrants?
periumbilical region
What quadrant is the liver, gallbladder, part of the duodenum and kidney located?
RUQ
What four pairs of muscles are located anteriorly and laterally collectively and compress and hold the abdominal organs in place?
External obliques
Internal obliques
Transversus abdominis
Rectus abdominis
The external obliques, internal obliques, transversus abdominis and rectus abdominis work together to do what?
Flex and stabilize the vertebral column
When the external and internal obliques, transversus abdominis and rectus abdominis unilaterally contract, what do they do?
Laterally flex the vertebral column
What four pairs of muscles are located posteriorly and flex the spine and lower limb?
Iliacus
psoas major
psoas minor
quadratus lumborum
What is the rectus sheath?
Three “flat” muscles of the anterior/lateral abdominal wall end anteriorly in a strong sheet of aponeurosis called the rectus sheath
What does the rectus sheath enclose?
The rectus abdominis
What is the midline of the rectus sheath?
Linea alba
How are the layers of fascia and aponeuroses of the muscles forming the rectus sheath arranged in the upper and lower abdominal wall?
They are arranged differently in the upper than they are in the lower. And the arcuate line is where the arrangment changes
Where is the arcuate line located?
About 1/2 way between umbilicus and pubic symphysis
What are the layers (anterior to posterior) of the rectus sheath above the arcuate line?
Skin
Fatty layer of superficial fascia
Membranous layer
Aponeurosis of external abdominal oblique fascia (2 layers)
Aponeurosis of internal abdominal oblique fascia (1 layer)
Rectus abdominis muscle
Aponeurosis of internal abdominal oblique fascia (1layer)
Aponeurosis of transversus abdominis (2 layers)
Transversalis fascia
Extraperitoneal tissue
Parietal peritoneum
What are the layers of the rectus sheath (anterior to posterior) below the arcuate line?
Skin
Fatty layer of superficial fascia
Membranous layer
Aponeurosis of external abdominal oblique fascia (2 layers)
Aponeurosis of internal abdominal oblique fascia (2 layers)
Aponeurosis of transversus abdominis (2 layers)
Rectus abdominis muscle
Transversalis fascia
Extraperitoneal tissue
Parietal peritoneum
Above the arcuate line, where does the rectus abdominis sit?
Sits between the two internal oblique aponeurosis layers
Below the arcuate line, where does the rectus abdominis muscle lie?
Directly on transversalis fascia
What forms the inguinal ligament?
The external obliques. The inguinal ligament is the lower edge of the external obliques
What makes the rectus abdominis stronger and not weak like a rubber band?
The tendinous intersections
Describe the deep system of arteries
- Originate superiorly from the subclavian artery
- Branches in the mid-abdomen are from the abdominal aorta
- Originate inferiorly from the external iliac artery
Describe the superficial system of arteries
- originate superiorly from perforating branches
2. Originate inferiorly from branches of the femoral artery
What are the arteries of the deep system?
Musculophrenic aa. Superior epigastric Inferior epigastric Intercostal aa Subcostal aa Lumbar aa Deep circumflex iliac aa
What are the arteries of the superficial system?
Arteries that run in the superficial fascial layer are the: Superficial circumflex iliac artery Superficial epigastric artery External pudendal artery -Superficial branch -deep branch
Where does deep drainage within abdominal wall muscles along with arteries go to?
To subclavian vv
to external iliac vv
to lumbar and intercostal vv
What are superficial drainage veins?
Within camper’s facia there are:
thoracoepigastric vv
lateral thoracic vv
superficial epigastric vv
What do thoracoabdominal intercostal nn become?
Lateral cutaneous branches that emerge at anterior axillary region, bifurcate into anterior and posterior branches
Anterior cutaneous branches end with medial and lateral branches
What are the sensory dermatome nerves in the anterior abdominal wall?
T7-L1
T7: xiphoid region (tip)
T10: umbilical region
L1: inguinal fold region
What nerves innervate the anterior abdominal muscles?
Intercostal nn T7-T11
subcostal nerve T12
Lumbar nn L1-L4
What are the anterior abdominal wall nerves?
Cutaneous branches of ventral rami, and intercostal nn
Lie between internal abdominal oblique and transversus abdominis
Pierce the rectus sheath to innervate the rectus abdominis muscles
Angle inferiomedially
What do the anterior abdominal wall nerves supply?
Skin, muscles, and parietal peritoneum
What nerves are part of the lumbar plexus?
L1 and L2
What is the iliohypogastric n?
L1 (sometimes +T12)
Lateral cutaneous branch
Anterior cutaneous branch
Supplies (supra) pubic region
What is the ilioinguinal n?
L1
Enters the inguinal canal and emerges through the superficial inguinal ring
Supplies groin and scrotum/labium majus
What nerves make up the genitofemoral nerve?
L1 and L2
What are the branches of genitofemoral nerve?
Genital branch: exits the inguinal canal through the superficial inguinal ring; innervates the cremaster muscle or is cutaneous to the labium majus
Femoral branch(es) Cutaneous to the femoral triangle area
Where does the superficial lymphatic drainage drain?
Drains superiorly from umbilical region to anterior axillary and sternal nodes
Drains inferiorly from umbilical region to superficial inguinal nodes
Where does the deep lymphatic drainage travel?
Along posterior intercostal and lumbar vessels to deep abdominal nodes
From testes to deep abdominal nodes
What is a hernia?
Portion of the viscera protrudes through a weakened point of the muscular wall of the abdominopelvic cavity
When does a significant medical problem develop with a hernia?
If the herniated portion of the intestine swells, becoming trapped
What happens if the herniated portion of the intestine swells and becomes trapped? What type of hernia is this?
Blood flow to the trapped segment may diminish, causing that portion of the intestine to die
Called a strangulated intestinal hernia - very painful and can be life threatening
What are the two types of hernia?
Inguinal hernias and femoral hernias
What is the most common type of hernia to require treatment?
Inguinal hernia
What is one of the weakest areas of the abdominal wall?
Inguinal region
Which sex is more likely to develop inguinal hernias?
Males
What causes inguinal hernia?
Rising pressure in the abdominal cavity provides the force to push a segment of the small intestine into the canal
What are the two types of inguinal hernia?
Direct inguinal hernia
Indirect inguinal hernia
What is direct inguinal hernia?
The loop of small intestine protrudes directly through the superficial inguinal ring, but not down the entire length of the inguinal canal, and creates a bulge in the lower anterior abdominal wall
What is indirect inguinal hernia?
Herniation travels down the entire inguinal canal and may even extend all the way into the scrotum
Which inguinal hernia will you see in an adult vs a child?
Direct in an adult and indirect in young males
What occurs more often with younger males and can be congenital,
Passes lateral to inferior epigastric vessels to enter deep inguinal ring and follows path of spermatic cord?
Indirect inguinal hernias
What is usually acquired because of a weak spot and can happen in females too, passes medial to inferior epigastric vessels punching through peritoneum and transversalis fascia?
Direct inguinal hernias
What is femoral hernia?
Occurs in the upper thigh, just inferior to the inguinal ligament, originating in the femoral triangle
Why can femoral hernia occur?
Medial part of the femoral triangle is relatively weak and prone to stress injury, allowing a loop of small intestine to protrude
What sex more commonly develops femoral hernias?
Women because of the greater width of their femoral triangle
What is umbilical hernia?
A portion of intestine pushes through abdominal wall musculature in the periumbilical or umbilical region
Umbilical hernias are most common in what stage of human development?
Infants, but can occur in adults as well
What organs are part of the foregut and are supplied by what artery?
Esophagus, stomach, duodenum, liver, gallbladder, spleen, and pancreas
Celiac trunk
What organs are part of the midgut? what supplies the midgut?
Duodenum, jejunum, ileum, cecum and appendix, ascending colon, 2/3 of transverse colon.
Superior mesenteric artery
What organs are part of the hindgut and are supplied by what artery?
1/3 transverse, descending and sigmoid colon, rectum and anal canal
Inferior mesenteric artery
