Chapter 31: Abdominal Wall

The abdomen is the portion of the ______ between the ____________ and the _________

The abdomen is the portion of the trunk between the thorax and the pelvis

What is the abdominal wall subdivided into:

1. Anterolateral abdominal wall

2. Posterior Abdominal Wall

What does the abdomen consist of?

It consists of an outer wall and an inner cavity termed the abdominal cavity

What should you do when examining and describing the abdomen?

relate pain, swelling, or position of an organ to one of its regions

What are the methods used to subdivide the regions of the abdominal wall?

One method has four regions and one method has nine regions

The system that subdivides the abdomen into 9 regions uses what planes of reference?

Two horizontal and two vertical

The transpyloric plane is a ____________ plane _________ between the __________ ________ of the __________ and the ______ _________. It lies at the level of ____.

The transpyloric plane is a horizontal plane halfway between the jugular notch of the sternum and the pubic symphysis. It lies at the level of LV1.

The transtubercular plane is a ____________ plane through the _____________ of the _______ _______. It lies at the level of _____.

The transtubercular plane is a horizontal plane through the tubercles of the iliac crests. It lies at the level of LV5.

The Right and Left Mid clavicular (lateral) Planes are located in the ___________ of the _______

The Right and Left Midclavicular (lateral) Planes are located in the midpoint of the clavicle

Name the 9 abdominal regions

1. Umbilical Area

2. Epigastric area

3. Pubic (Hypogastric) area

4 and 5. Right and Left hypochondriac areas

6. and 7. Right and Left lateral (lumbar) area

8. and 9. Right and Left inguinal area

The Umbilical Area is the

Midgut referred pain

The Epigastric Area of epigastric fossa is what

Just inferior to infrasternal angle

-Foregut referred pain

Pubic (Hypogastric) Area

Above the pubic symphysis

-Hindgut referred pain

Right and left hypocondriac Areas

Related to costal cartilages

What does the system that subdivides the abdomen into four regions use for both the horizontal and vertical planes?

The umbilicus

Upper Right Quadrant Contents:

1. Liver

2. Gallbladder

3. Superior Part of ascending colon

4. Right colic or hepatic flexure of the colon

5. Right half of the transverse colon

Upper Left Quadrant Contents:

1. Stomach

2. Spleen

3. Pancreas

4. Left half of the transverse colon

5. Left colic or splenic flexure of the colon

6. Superior part of the descending colon

Lower Right Quadrant Contents:

1. Inferior part of the ascending colon

2. Cecum

3. Vermiform appendix

Lower Left Quadrant Contents:

1. Inferior part of the descending colon

2. Sigmoid Colon

What is the anterolateral abdominal wall composed of?

1. Skin

2. Subcutaneous tissue

3. Muscles

4. Peritoneum

Compare the skin of the abdomen in terms of thickness to the other parts of the body

it is of average thickness as compared with other parts of the body

What is sometimes seen in the skin of the abdomen during pregnancy?

Reddish lines known as striae gravidarum

After parturition, what do the striae gravidarum changed into?

Thin, white, scarlike lines: The lineae albicante

What are the layers of the subcutaneous tissue of the abdominal wall?

1. Superficial Fatty Layer (Camper's Fascia)

2. Deep membranous Layer (Scarpa's Fascia)

What are the muscles of the anterolateral abdominal wall?

1. External Oblique

2. Internal Oblique

3. Transversus Abdominus

4. Rectus Abdominus

External Oblique origin

Lower 8 ribs (Interdigitates with the serratus anterior and latissimus dorsi)

External Oblique insertion

Iliac crest, rectus sheath via aponeurosis

External Oblique action

-Tenses the abdominal wall

-Aids in rotation of the trunk

-Aids in lateral flexion of the trunk

-Important in forced expiration

What does aponeurosis of the external oblique form?

Inguinal ligament

External Oblique innervation

-Thoracoabdominal Nerves

-Subcostal nerve

How do the external oblique fibers course?

Medially and inferiorly

Internal Oblique origin

Iliac Crest

Internal Oblique insertion

-Costal margin (superiorly)

-Rectus sheath via aponeurosis (anteriorly)

-Pubic crest (inferiorly)

Internal Oblique action

-Tenses the abdominal wall

-Aids in rotation of the trunk

-Aids in lateral flexion of the trunk

-Important in forced expiration

Internal Oblique innervation

-Thoracoabdominal Nerves

-Subcostal nerve

-L1

How do the fibers of the internal oblique course?

Its fibers fan out coursing anteriorly and superiorly in the upper half and transversely and inferiorly in the lower half of the muscle

What is the transversus abdominis orgin

-Iliac crest

-Fascia of the back

-Lower 6 costal cartilages

What is the transversus abdominis insertion?

-Rectus sheath via aponeurosis

What is the transversus abdominis action?

-Tenses the abdominal wall

-Aids in rotation of the trunk

-Aids in lateral flexion of the trunk

-Important in forced expiration

What is the transversus abdominis innervation?

-Thoracoabdominal Nerves

-Subcostal nerve

-L1

What is the fiber direction of the transverses abdominis?

Transverse, as its name indicates

Rectus Abdominis origin

-Pubic crest

-Pubic Symphysis

Rectus Abdominis insertion

-Xiphoid process

-Costal cartilages of ribs 5 to 7

Rectus Abdominis action

Flexion of the trunk

Rectus Abdominis innervation

-Thoracoabdominal Nerves

-Subcostal nerve

What is the fiber direction of the rectus abdominis?

Vertical

Tendinous Intersections of the Rectus abdominis are what?

3 or 4 fibrous bands that pass transversely across the muscle and adhere to the rectus sheath

The rectus sheath is formed by the aponeurosis of what?

1. External Oblique

2. Internal Oblique

3. Transversus Abdominis

Name the anatomical lines formed by the rectus sheath:

1. Linea alba

2. Linea semilunaris

3. Arcuate line

The linea alba is a median _________ from the __________ ________ to the ________. It consists of a tough, ___________ ________ of ___________ fibers of the _____________ of each side

The linea alba is a median furrow from the xiphoid process to the pubis. It consists of a tough, tendinous raphe of interlacing fibers of the aponeuroses of each side

The linea semilunaris is a ________ line at the _________ border of the ________ __________. It is formed where the __________ of the __________ oblique splits to form the layers of the ________ ________

The linea semilunaris is a curved line at the lateral border of the rectus abdominis. It is formed where the aponeurosis of the internal oblique splits to form the layers of the rectus sheath

What is the Arcuate line

The arcuate line is a horizontal landmark change in the rectus sheath

What is the Parietal Peritoneum

Lining the inner wall of the abdomen

What are the Chief arteries of the abdominal wall:

1. Two branches of the internal thoracic artery or internal mammary artery (superiorly)

2. Two branches of the external iliac artery (inferiorly)

What are the two branches of the internal thoracic artery or internal mammary artery (superiorly)

1. Superior epigastric

2. Musculophrenic

What are the two branches of the external iliac artery (inferiorly)?

1. Inferior epigastric

2. Deep circumflex iliac

Two Longitudinal channel are formed by 1. The anastomoses of the ______ and ______ epigastric represent an anastomosis between the _______ and the ________

The anastomoses of the superior and inferior epigastric represent an anastomosis between the subclavian artery (via the internal mammary artery) and the external iliac artery

Two longitudinal channels are formed by 2. The anastomoses of ______ and _______ also represent an anastomosis between the ______ and the ______

2. The anastomoses of musculophrenic and deep circumflex iliac also represent an anastomosis between the subclavian artery and the external iliac artery

What are the muscles of the anterior abdominal wall segmentally innervated by?

The thoracoabdominal nerves and the subcostal nerve

In addition to innervating the abdominal wall muscles, the thoracoabdominal nerves and the subcostal nerve do what?

Give off anterior cutaneous branches and lateral cutaneous branches to the skin of the abdomen

What muscles make up the posterior abdominal wall?

1. Quadratus Lumborum

2. Psoas major