Introduction to the Abdomen

Question 1

What are the superior and inferior boundaries of the abdominal cavity?

Answer 1

The respiratory diaphragm and the pelvic inlet.

Question 2

The abdomen can be divided into 4 quadrants using which 2 planes?

Answer 2

The median sagittal plane and the umbilical plane.

Question 3

List the names for planes L1-L5.

Answer 3

L1 - Transpyloric plane
L2 - Subcostal plane
L4 -Supracristal plane
L5 - Transtubercular plane

Question 4

Which 2 horizontal planes divide the abdomen into 9 regions?

Answer 4

The Subcostal plane (L2) and Transtubercular plane (L5).

Question 5

List the regions in the 9 region model.

Answer 5

1. Epigastric
2. Umbilical
3. Pubic
4. Left Hypochondrium
5. Left Lateral
6. Left Iliac Fossa
7. Right Hypochondrium
8. Right Lateral
9. Right Iliac Fossa

Question 6

What is a dermatome?

Answer 6

An area of skin which is given sensation to and innervated by a single spinal nerve.

Question 7

Which dermatome sits over the umbilicus?

Answer 7

T10.

Question 8

What is the name of the strap muscle on the front of the abdomen?

Answer 8

Rectus Abdominis

Question 9

What are the layers of the abdominal wall going from superficial to deep?

Answer 9

Skin
Camper's fascia 
Scarpa's fascia 
Muscles and aponeuroses 
Transversalis fascia 
Parietal peritoneum

Question 10

What is the inguinal ligament formed by?

Answer 10

The free lower border of the aponeurosis of the external oblique muscle.

Question 11

Where does the Inguinal ligament run from and to?

Answer 11

Runs from the anterior superior iliac spine (ASIS) to the pubic tubercle.

Question 12

Going from superior to deep, what are the side muscles of the abdominal wall?

Answer 12

1. External oblique
2. Internal oblique
3. Transversus abdominis

Question 13

What are the attachment points of the linea alba?

Answer 13

The xiphoid process of the sternum and the pubic symphysis.

Question 14

What is the rectus sheath?

Answer 14

A fibrous jacket formed by the aponeuroses of the external and internal obliques, and the transversus abdominis.

Question 15

How does the rectus sheath differ in the top 3/4 of the abdominal wall compared to the bottom 1/4 (below the umbilicus)?

Answer 15

The top 3/4 has the rectus sheath enclosing the rectus abdominis (it is in front and behind it), whereas below the umbilicus the rectus sheath sits entirely anterior to the rectus abdominis - only the transversalis fascia sits posterior to the rectus abdominis below the umbilicus.

Question 16

What is a hernia?

Answer 16

The protrusion of a tissue, organ or structure through the tissue(s) that normally retain(s) it.

Question 17

Which 2 arteries do the superior and inferior epigastric arteries unite?

Answer 17

The subclavian artery and the external iliac artery.

Question 18

What are somites?

Answer 18

Building blocks of mesoderm that migrate around the body pulling their nerve supply with them.

Question 19

Where does lymphatic fluid drain to in the upper and lower quadrants of the abdomen?

Answer 19

Upper - axillary nodes

Lower - superficial inguinal nodes

Question 20

What does intra-peritoneal and retro-peritoneal mean?

Answer 20

Intra-peritoneal means the structure is covered in peritoneum and retro-peritoneum means the structure is behind (outside) the peritoneum.

Question 21

What is a mesentery?

Answer 21

A fold of peritoneum suspending an organ from the abdominal wall.

Question 22

From which embryonic tissue does the peritoneum form?

Answer 22

Mesoderm

Question 23

What types of pain are viscera (organs) sensitive to?

Answer 23

1. Stretch
2. Inflammation
3. Hypoxia