Abdominal Wall & Peritoneum

Question 1

Boundaries of the abdomen?

Answer 1

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

Question 2

What is the inferior thoracic aperture?

Answer 2

Bottom of the ribcage

Question 3

4 division?

Answer 3

RUQ, LUQ, RLQ, LUQ

Question 4

9 divisions

Answer 4

Right hypochondrium, epigastric region, left hypochondrium, right flank, umbilical region, left flank, right groin, pubic region, left groin

Question 5

the three planes of the abdomen?

Answer 5

midclavicular, subcostal and intertubecular plane

Question 6

From SF to deep, what are the layers of the abdominal wall?

Answer 6

skin
SF fascia (x2) -camper's
                       - Scarpa's
Muscle (x3)     - Ext oblique
                        - Int oblique
                        - Transversus Abdominis
Tranversalis Fascia
Extraperitoneal Fascia
Parietal Peritoneum

Question 7

When does the SF fascia divide?

Answer 7

at umbilicus

Question 8

What are the two layers of SF below umbilicus and how are they different?

Answer 8

Camper's = SF and fatty
Scarpa's = deep and membranous ( thinner with little fat)

Question 9

Where do the blood vessels lie?

Answer 9

In the SF fascia

Question 10

What is the Rectus Abdominis

Answer 10

A paired abdominal muscle separated in the midline by ‘linea alba’. Along its course, it’s intersected by 3-4 tendinous insertions.

Question 11

O/I and action of Rectus Abdominis?

Answer 11

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

Question 12

Nerve supply and fibre direction of rectus abdominis?

Answer 12

Nerve: Anterior rami of thoracic spinal nerves
Fibres: extend longitudinally upwards

Question 13

External Oblique O/I and actions?

Answer 13

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

Question 14

External Oblique Nerve supply and fibre direction

Answer 14

Nerve: Anterior rami of thoracic spinal nerves
fibres: inferomedial

Question 15

The ext obliques aponeurosis…

Answer 15

Extends from xiphoid process to pubic symphysis

Question 16

Internal Oblique O/I and actions?

Answer 16

O:  thoracolumbar fascia, inguinal lig, and iliac crest 
I: ribs 9-12
Action: flex trunk
             bends trunk (single)
             turns to same side

Question 17

Internal Oblique Nerve supply and fibre direction

Answer 17

Nerve: Anterior rami of thoracic spinal nerves (and some L1)
Fibres: superomedial

Question 18

How do the internal and external obliques work together

Answer 18

the internal work antagonistically with the opposites sides external oblique

Question 19

Transversus abdominis O/I and action

Answer 19

O: thoracolumbar fascia
     iliac crest
     inguinal ligament
     costal cartilage rib 7-12
I: linea alba, pubic crest pectineal line
Action: Supports the abdominal wall

Question 20

Transversus Abdominis nerve and fibre direction

Answer 20

Nerve Supply: anterior rami of thoracic spinal nerves (and L1)
Fibres: Transverse

Question 21

What is the rectus sheath?

Answer 21

an aponeurotic tendinous sheath formed by internal oblique, external oblique and tranversus abdominis that surrounds rectus abdominis.

Question 22

The upper 3/4 of the rectus sheath

Answer 22

all 3 muscles surround rectus abdominis

Question 23

The lower 1/4 of the rectus sheath

Answer 23

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)

Question 24

The Arcuate Line is?

Answer 24

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

Question 25

Whats the arterial supply of the abdomen? How does it travel?

Answer 25

``` 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 ```

Question 26

What other arteries apart from the two main also supply the abdomen

Answer 26

- deep circumflex - musculophrenic - intercostal - lumbar - iliolumbar

Question 27

Venous drainage of the abdomen?

Answer 27

Thoracoepigastric veins > drain to axillary Superficial epigastric veins > drain to femoral

Question 28

Nervous supply to the abdomen?

Answer 28

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

Question 29

What dermatome/ spinal nerve is umbilicus at?

Answer 29

T10

Question 30

The lymphatic drainage of the abdomen?

Answer 30

Anterior axillary Superficial Inguinal Posterior axillary

Question 31

Visceral peritoneum

Answer 31

Covers abdominal organs - sensitive to stretch - ANS - afferent nerve fibres eg) stretching/ distension (when you eat too much/ gas) BUT no somatic pain sensation

Question 32

Mesentery

Answer 32

visceral peritoneum can come back around on itself, forming a mesentery and anchoring viscera (organs) to the posterior body wall

Question 33

Parietal Peritoneum

Answer 33

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

Question 34

Midgut and hindgut mesentery?

Answer 34

Suspended by only one dorsal mesentery

Question 35

Foregut mesentery?

Answer 35

Suspended in both a dorsal and a ventral mesentery. This is due to veins and umbilical cord coming in higher up

Question 36

Intra-peritoneal?

Answer 36

Completely contained in visceral peritoneum and suspended in mesentery eg) stomach, liver, gall bladder, spleen, proximal duodenum, SI, appendix, transverse colon, sigmoid colon

Question 37

Retro-peritoneal?

Answer 37

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

Question 38

Greater Sac

Answer 38

peritoneal cavity proper

Question 39

lesser sac

Answer 39

behind lesser omentum and stomach. Created due to rotation of foregut structures where LO is dragged around to create a pocket)

Question 40

What is the opening to the lesser sac, the free end called?

Answer 40

``` Omental foramen (foramen of Winslow) Bound anteriorly by lesser omentum, posteriorly by IVC ```

Question 41

Paracolic Gutters

Answer 41

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