Normal Abdominal Wall

UT 302 - Abdomen 1

what is the white arrow pointing to? describe its echogenicity

• diaphragm

• hyperechoic

what type of artifact happens on the opposite side (in the lungs)?

mirror image artifact

what are inferior and superior to the diaphragm?

• inferior: liver and abdominal organs

• superior: lungs and heart

which arrow is pointing to the crus?

2

label the structures

1. IVC

2. crus of diaphragm

3. aorta

4. vertebra

indications for ultrasound of abdominal wall

• palpable lump

• pain

• pain with an associated intermittent mass

• inflammation

• post surgical complication

• trauma

which probe should be used to scan the abdominal wall?

• use the highest frequency TDR possible

• might be necessary to use the curvilinear TDR on some patients

what are the two major body cavities?

• dorsal cavity (posterior)

• ventral cavity (anterior)

the dorsal cavity is divided into the …

cranial and spinal cavity

the ___ separates the thoracic cavity from the abdominopelvic cavity

diaphragm

the abdominopelvic can be separated into the

• abdomen (superior)

• pelvis (inferior)

abdominopelvic cavity

nine regions of the abdomen

1. R hypochondriac region

2. epigastric region

3. L hypochondriac region

4. R lumbar region

5. umbilical region

6. L lumbar region

7. R iliac region

8. hypogastric region

9. L iliac region

R hypochondriac region organs

• liver

• gallbladder

• R kidney

• small intestine

epigastric region organs

• stomach

• liver

• pancreas

• duodenum

• spleen

• adrenal glands

L hypochondriac region organs

• spleen

• colon

• L kidney

• pancreas

R lumbar region organs

• gallbladder

• liver

• R colon

umbilical region organs

• umbilicus

• part of the small intestine

• duodenum

L lumbar region organs

• descending colon

• L kidney

R iliac region organs

• cecum

• appendix

hypogastric region organs

• bladder

• sigmoid colon

• female reproductive organs

L iliac region organs

• descending colon

• sigmoid colon

four abdominal quadrants

• right upper quadrant (RUQ)

• left upper quadrant (LUQ)

• right lower quadrant (RLQ)

• left lower quadrant (LLQ)

fascia

a fibrous tissue network located between the skin and the underlying structures

aponeuroses

• large, sheet-like layers of connective tissue with a similar composition to tendons

• can also attach to bone, as in the scalp, and to the fascia of other muscles or tissues

• their large form and shape provides structure and distributes tension across a wider area or large number of muscle groups

aponeurosis vs. tendon

• tendons connect muscle to bone

• aponeuroses connect muscle to muscle, muscle to bone, muscle to fascia, or muscle to skin

abdominal fascia can be divided into

• superficial: attached to skin

• deep: covers muscles and partitions them into groups

anterolateral abdominal wall layers

1

investing (deep) fascia divided into

• superficial (external oblique muscle fascia)

• intermediate (internal oblique muscle fascia)

• deep (transverse abdominis muscle fascia)

2

deep membranous layer of subcutaneous tissue (Scarpa fascia)

3

superficial fatty layer of subcutaneous tissue (Camper fascia)

4

skin

5

parietal peritoneum

6

endoabdominal (transversalis) fascia

7

extraperitoneal fat

8

transverse abdominis muscle

9

internal oblique muscle

10

external oblique muscle

anterior abdominal wall has 5 bilaterally paired muscles

• rectus abdominis

• external oblique

• internal oblique

• transverse abdominis

• pyramidalis

rectus abdominus muscle

• bilaterally-paired, long, broad, vertical, strap-like muscle that is mostly enclosed in the rectus sheath

• medial and anterior

the 3 flat, bilaterally paired muscles of the anterolateral group are the …

1. external oblique muscle (most superficial)

2. internal oblique muscle (middle)

3. transverse abdominis muscle (deepest)

pyramidalis muscle

small triangular muscle, missing in 20% of the population

rectus sheath

strong, fibrous compartment for the rectus abdominis and pyramidalis muscles as well as for some arteries, veins, lymphatic vessels and nerves

the ___ ___ separates the rectus muscles from the peritoneum

transversalis fascia

linea alba

• oriented vertically and courses the length of the anterior abdominal wall

• it separates the bilateral rectus sheaths

• "white line"

umbilicus

the area where all layers of the anterolateral abdominal wall fuse

umbilical ring

a defect in the linea alba and is located under the umbilicus This is the area where the umbilical vessels passed to and from the umbilical cord and placenta

1

rectus abdominis

2

linea alba

3

anterior rectus sheath

4

posterior rectus sheath

1

subcutaneous tissue

2

linea alba

3

rectus abdominis muscle

4

anterior and posterior rectus sheaths

5

parietal peritoneum

1

adipose layer (subcutaneous fat)

2

external oblique muscle

3

internal oblique muscle

4

transverse abdominis muscle

5

abdominal cavity

6

small bowel

7

fascia transversalis

8

internal oblique muscle-transverse abdominis muscle fascia

9

external oblique muscle-internal oblique muscle fascia

10

external oblique muscle fascia

11

skin

label the image

• A - transverse abdominis

• B - internal oblique muscle

• C - external oblique muscle

• D - rectus abdominis muscle

diaphragm

• double domed, musculotendinous partition separating the thoracic cavity from the abdominal cavity

• “parachute”-shaped

pleural effusion

• fluid collection between the lungs and the chest wall

• superior to the diaphragm

ascites

• fluid collection in the peritoneal cavity

• inferior to the diaphragm

movement of the diaphragm during respiration

• can be imaged with m-mode

• during inspiration, the diaphragm contracts and moves downward (creating negative pressure in the thoracic cavity)

• during expiration, the diaphragm relaxes and moves upward (creating positive pressure in the thoracic cavity)

crus of the diaphragm

• musculotendinous bands that arise from anterior surface of the first 3 lumbar vertebrae

• right and left crura

  • right is longer and passes anteriorly to the aorta and posterior to IVC

1

skin

2

subcutaneous fat

3

linea alba

4

rectus abdominis muscle

5

extraperitoneal fat

6

parietal peritoneum