Abdominal Wall & Peritoneum Flashcards
Boundaries of the abdomen?
Superior: diaphragm, inferior thoracic aperture
Inferior: Iliac crest, inguinal lig. , pelvic inlet
Posterior: Lumbar vertebral column, psoas major, quadratus lumborum (abdominal wall muscles)
Anterior/lateral: Abdominal wall muscles
What is the inferior thoracic aperture?
Bottom of the ribcage
4 division?
RUQ, LUQ, RLQ, LUQ
9 divisions
Right hypochondrium, epigastric region, left hypochondrium, right flank, umbilical region, left flank, right groin, pubic region, left groin
the three planes of the abdomen?
midclavicular, subcostal and intertubecular plane
From SF to deep, what are the layers of the abdominal wall?
skin
SF fascia (x2) -camper's
- Scarpa's
Muscle (x3) - Ext oblique
- Int oblique
- Transversus Abdominis
Tranversalis Fascia
Extraperitoneal Fascia
Parietal PeritoneumWhen does the SF fascia divide?
at umbilicus
What are the two layers of SF below umbilicus and how are they different?
Camper's = SF and fatty Scarpa's = deep and membranous ( thinner with little fat)
Where do the blood vessels lie?
In the SF fascia
What is the Rectus Abdominis
A paired abdominal muscle separated in the midline by ‘linea alba’. Along its course, it’s intersected by 3-4 tendinous insertions.
O/I and action of Rectus Abdominis?
O: Pubic tubercle, crest & symphysis
I: Costal cartilages of ribs 5-7 and xiphoid procress
Action: Flex trunk, support/compress the abdominal wall
*also secondary resp muscle for forced expiration
Nerve supply and fibre direction of rectus abdominis?
Nerve: Anterior rami of thoracic spinal nerves
Fibres: extend longitudinally upwards
External Oblique O/I and actions?
O: ribs 5-12
I: iliac crest & linea alba via aponeurosis
action: flex trunk (both)
bends trunk to same side
turns trunk to opposite side
External Oblique Nerve supply and fibre direction
Nerve: Anterior rami of thoracic spinal nerves
fibres: inferomedial
The ext obliques aponeurosis…
Extends from xiphoid process to pubic symphysis
Internal Oblique O/I and actions?
O: thoracolumbar fascia, inguinal lig, and iliac crest
I: ribs 9-12
Action: flex trunk
bends trunk (single)
turns to same sideInternal Oblique Nerve supply and fibre direction
Nerve: Anterior rami of thoracic spinal nerves (and some L1)
Fibres: superomedial
How do the internal and external obliques work together
the internal work antagonistically with the opposites sides external oblique
Transversus abdominis O/I and action
O: thoracolumbar fascia
iliac crest
inguinal ligament
costal cartilage rib 7-12
I: linea alba, pubic crest pectineal line
Action: Supports the abdominal wallTransversus Abdominis nerve and fibre direction
Nerve Supply: anterior rami of thoracic spinal nerves (and L1)
Fibres: Transverse
What is the rectus sheath?
an aponeurotic tendinous sheath formed by internal oblique, external oblique and tranversus abdominis that surrounds rectus abdominis.
The upper 3/4 of the rectus sheath
all 3 muscles surround rectus abdominis
The lower 1/4 of the rectus sheath
Only supports and travels in front of rectus abdominis. At the back of rectus abdominis is transversalis fascia and parietal peritoneum (weak and allows BVs to pass through)
The Arcuate Line is?
The point where all of the aponeuroses are anterior to RA and there in no posterior wall of rectus sheath.
Happens approx halfway between umbilicus and pubic bones
Allows arterial supply (IE) to get through
Whats the arterial supply of the abdomen? How does it travel?
Superior Epigastric (from internal thoracic) and Inferior Epigastric (from external iliac) -These both run under RA (atop transversalis fascia and within the rectus sheath) and anastamose together
What other arteries apart from the two main also supply the abdomen
- deep circumflex
- musculophrenic
- intercostal
- lumbar
- iliolumbar
Venous drainage of the abdomen?
Thoracoepigastric veins > drain to axillary
Superficial epigastric veins > drain to femoral
Nervous supply to the abdomen?
Lateral cutaneous branches 7-12 intercostal nerves + iliohypogastric nerve (L1)
All anterior Rami
These travel in the neurovascular plane between int. oblique and transversus abdominus before piercing the muscular wall to reach the skin
What dermatome/ spinal nerve is umbilicus at?
T10
The lymphatic drainage of the abdomen?
Anterior axillary
Superficial Inguinal
Posterior axillary
Visceral peritoneum
Covers abdominal organs
- sensitive to stretch - ANS - afferent nerve fibres
eg) stretching/ distension (when you eat too much/ gas)
BUT no somatic pain sensation
Mesentery
visceral peritoneum can come back around on itself, forming a mesentery and anchoring viscera (organs) to the posterior body wall
Parietal Peritoneum
Lines body wall
-sensitive to pain, touch, temperature & pressure
Nervous supply:
- somatic nerves to body wall (thoracic and lumbar nerves)
- Phrenic Nerve (up by diaphragm)
- Obturator nerve (down in pelvis
Midgut and hindgut mesentery?
Suspended by only one dorsal mesentery
Foregut mesentery?
Suspended in both a dorsal and a ventral mesentery. This is due to veins and umbilical cord coming in higher up
Intra-peritoneal?
Completely contained in visceral peritoneum and suspended in mesentery
eg) stomach, liver, gall bladder, spleen, proximal duodenum, SI, appendix, transverse colon, sigmoid colon
Retro-peritoneal?
Lies between peritoneum and body wall. only has an anterior covering of peritoneum.
eg) kidneys, pancreas, distal duodenum, asc/desc colon, upper 2/3 rectum
Greater Sac
peritoneal cavity proper
lesser sac
behind lesser omentum and stomach. Created due to rotation of foregut structures where LO is dragged around to create a pocket)
What is the opening to the lesser sac, the free end called?
Omental foramen (foramen of Winslow) Bound anteriorly by lesser omentum, posteriorly by IVC
Paracolic Gutters
a peritoneal sulci (groove) lateral to the asc./desc. colons. They create a pathway for peritoneal fluid OR pus, bile, blood to migrate, and sometimes collect within the abdomen.
migration of fluids can cause pain to present in sites distant from affected (leaky organ)
sitting: fluid migrates down, presents as appendicitis
supine: fluid can migrate into lesser sac … abscess
