Anatomy Lecture 20_Anterior Abdominal Wall

Question 1

Increasesd abdominal pressure can aid in what 4 bodily processes?

Answer 1

• Respiration • Defecation • Micturition • Parturition

Question 2

What causes hernias?

Answer 2

Increased intra-abdominal pressure in areas of weakness

Question 3

What are the nine subdivisions of the abdominal cavity

Answer 3

1. Right hypocondriac
2. Right Lumbar
3. Right iliac/ inguinal
4. Epigastric
5. Umbilico
6. Hypogastric
7. Left hypocondriac
8. left lumbar
9. Left iliac/inguinal

Question 4

What are the 8 layers of the anterior abdominal wall

Answer 4

1. Skin
   2.Superficial fatty (Camper’s) fascia
   3.Deep membranous (Scarpa’s) fascia
   4.Potential space
   5.Muscular layers (3) separated by superficial,
   intermediate, deep investing fasciae
   6.Endoabdominal fascia (Transversalis fascia)
2. Extraperitoneal fat (variable)
   8.Parietal peritoneum

Question 5

Where does the Superficial fatty (Camper’s) layer of
subcutaneous fascia extend and what ateries and blood vesseles does it contain?

Answer 5

• continuous with superficial fascia of
thorax & lower limb
• continues into labia majora (females)
• NOT scrotum (males)
• contains superficial epigastric arteries
and veins

Question 6

Where does the Deep membranous (Scarpa’s) layer of
subcutaneous fascia extend in the body. can it be sutured

Answer 6

• Scrotum (as Dartos fascia)
• Perineum (as Colles’ fascia)
• Does NOT continue into thighs

Yes sufficiently dense to hold sutures

Question 7

What is the clinical significance of the potential space between Scarpa’s fascia and underlying superficial investing fascia?

Answer 7

Extravasated fluids can pool there

Question 8

What are the three muscle layers in the abdominal wall (order from most superficial to deep)

Answer 8

External obliques

Internal obliques

Transverse Abdominales

Question 9

What is the Endoabdominal (transversalis) fascia

Answer 9

It is the deepest layer of facia in the abdominal cavity. It is continiouse with the endothoracic fascia. it is seperate from the deep investing facia that encases the transverse abdominales

Question 10

What is the serous lining of abdominal cavity

Answer 10

Parietal peritoneum

Question 11

What 2 nerves inervates the external obliques?

Answer 11

Thoraco-abdominal nn. (T7-T11) &
Subcostal n. (T12)

Question 12

How do the external obliques rotate the trunk

Answer 12

to the side opposite the one contracting

Question 13

What directions do the internal obliques rotate the trunk?

Answer 13

To the side that is contracting

Question 14

What 4 nerves inervate the internal obliques?

Answer 14

• Thoraco-abdominal n. (T6-T11)
• Subcostal n. (T12)
• Iliohypogastric n. (L1)
• Ilioinguinal n. (L1)

Question 15

What 4 nerves intervate the transvers abdominalis

Answer 15

• Thoraco-abdominal n. (T6-T11)
• Subcostal n. (T12)
• Iliohypogastric n. (L1)
• Ilioinguinal n. (L1)

Question 16

What motion do the transverse abdominales cause?

Answer 16

not really any. They compress the abdomen bilaterally

Question 17

What muscle forms the inguenal ligament and where does it attach? What does it do?

Answer 17

The external obliques form the inguinal ligament and it attaches at the ASIS and pubic tubercle. it acts as a retinaculum for neurovasculature to the thigh

Question 18

What is the conjoint tendon and where does it attach?

Answer 18

It is the union of the internal obliques and the transverse abdominous. It attaches at the pubis.

Question 19

How do the EO, IO ,and TA contribute to the sub ingunial region?

Answer 19

EO forms the Inguinal ligament, the IO have muscle fibers that extend down there, and the TA do not contribute.

Question 20

What nerves innervate the rectus abdominus

Answer 20

• Thoraco-abdominal n. (T6-T11)
• Subcostal n. (T12)

Question 21

What does the Pyramidalis muscle do?

Answer 21

It connects the linea alba to the pubis

Question 22

Where is the arcuate line?

Answer 22

It is below umbilicus

Question 23

Above the arcuate line, what forms the the anterior rectus sheath. What forms the posterior rectus sheath?

Answer 23

The Anterior rectus sheath is formed by the aponeurosis of the external oblique and half the aponeurosis of the the internal oblique.

The posterior rectus sheath is formed by half of the aponeurosis of the internal oblique and the aponeurosis of the transverse abdominales.

Question 24

What forms the anterior and posterior rectus sheath below the arcuate line?

Answer 24

The anterior rectus sheath is formed by the aponeruosis of EO, IO, and TA.

The posterior rectus sheath is formed by the endoabdominal facia and the parietal peritonium only. This leads the posterior rectus sheath to be some what weak and prone to herniation

Question 25

Where is the Falciform ligament?

Answer 25

it is between the right and left lobs of the liver and joins to the anterior wall. This inferior aspect of this ligament is called the round ligament.

Question 26

what is significant about Lateral umbilical fold

Answer 26

it is in the region of the Inferior epigastric artery

Question 27

what are the 4 land marks in the abdominal cavity

Answer 27

Falciform ligament Lateral umbilical fold Medial umbilical fold Median umbilical fold

Question 28

Define Epigastric Hernias

Answer 28

Congenital or acquired weakness in the linea alba. Often small (\<1cm) and rarely involve bowl (typically just fat globules)

Question 29

Umbilical & Para-umbilical Hernias

Answer 29

They can be congenital or aquired. Congenital umbilical hernias happen as a result of incomplete closure of the umbilical ring. aquired umbilical/paraumbilical typically happen secondary to a primary condition including obesity, cirrhosis of the liver, and pregnancey.

Question 30

What are the thoracoabdominal nerves

Answer 30

They are the anterior rami of T6-T11. They are a continuation of the intercostal nerves. they "become" thoracodominal nerves when they move inferior to the costal margin. They travel in the neurovascular space between IO and TA. They Supply all muscles of anterolateral wall & skin to about the level of umbilicus

Question 31

What is the subcostal nerve

Answer 31

It is the anterior rami of T12. It intervates all muscles of the antereolateral abdominal wall as well as the anteriolateral skin from about the the iliac crest to umbilico.