Week 4: Abdominal Wall

Question 1

What is the order of the structures at the hilum of the kidney?

Answer 1

Renal vein, renal artery and most posterior is the renal pelvis (that goes onto forming the ureter).

Question 2

External Oblique

Answer 2

Outer layer, inferomedial direction of fibres.

Attachments:

Superior: ribs 5-12
Inferior: pelvic bone (iliac crest, ASIS)
Medial: linea alba via the external oblique aponeurosis.

Pubic symphysis attachment via aponeurosis.

Question 3

The free edge of the external oblique is called

Answer 3

the inguinal ligament

Question 4

Internal Oblique

Answer 4

Superomedial fibres direction. Middle muscle layer of the anterior abdominal wall.

Attaches medially to via an aponeurosis to linea alba and pubic crest via conjoint tendon.
Attach to the iliac crest and inguinal ligament.
Also attaches superiorly to the costal margin.

Question 5

Transverse Abdominis

Answer 5

Deepest muscular layer. Fibre direction is transverse.

Attached superiorly to the costal margin on the internal surface of it, inferiorly to the iliac crest and inguinal ligament. Attaches medially to the linea alba (via aponeurosis) and pubic crest via conjoint tendon.

Question 6

Rectus Abdominis

Answer 6

The muscle located in the midline with vertical fibres.

Question 7

Why are the “6-pack/8-pack” divisions of the rectus abdominis m. relevant for function?

Answer 7

Rectus abdominis m. is really long. It attaches to pubic symphysis and crest “proximally” and its distal attachment are xyphoid process, 5th and 7th costal cartilages.
The small breaks in between allows the muscle contraction to create greater force.

Question 8

Major Arteries of the Anterior Abdominal Wall

Answer 8

Internal thoracic splits into

→ Musculophrenic

→ Superior Epigastric which later merges with the Inferior Epigastric.

Question 9

Posterior abdominal wall muscles anchor to

Answer 9

Vertebraes, ribs, thoracolumbar fascia (TFL)

Question 10

Name the arcuate ligaments and how many of them can we find.

Answer 10

Lateral (2), Medial (2) and Median (1)

Question 11

Which abdominal muscles are attached to the thoracolumbar fascia (TFL)?

Answer 11

Internal oblique and transverse abdominal muscles. The external oblique does not attach to the TFL.

Question 12

What is the main function of the kidney?

Answer 12

To filter blood and produce urine.

Question 13

Where is the kidney located?

Answer 13

The kidney is considered a retroperitoneal organ, located on the posterior abdominal wall. It is closely related with the psoas major and quadratus lomborum muscles. Superior and anterior to the right kidney is the liver, which pushes the right liver down and it makes it sit slightly lower than the left kidney.

Question 14

What are the 2 solid tissues from the kidney?

Answer 14

Cortex and medulla

Question 15

Renal Artery branching

Answer 15

1. Renal a.
2. Segmental arteries
3. Interlobar arteries
4. Arcuate arteries
5. Cortical arteries

Question 16

Where can we find perinephric fat? What about paranephric fat?

Answer 16

Perinephric fat is surrounding the kidney within the fascia, whilst paranephric fat is the fat close to it but outside the fascia. The perinephric fat helps the kidneys maintain their relative position in the abdominal wall.

Question 17

What structures compose the tubular system of the kidney?

Answer 17

Minor Calyx, Major Calyx, Renal Pelvis, Ureter.

Question 18

Which kidney sits more inferiorly and why?

Answer 18

The right one, as the kidney is pressing down on it.

Question 19

Which ribs are protecting each kidney?

Answer 19

Right: Rib 12
Left: Ribs 11 and 12

Question 20

Rectus Sheath is formed by the

Answer 20

aponeuroses of the lateral component muscles of the anterior abdominal wall. It houses the rectus abdominis m.

Question 21

The vertically oriented fibres of Rectus Abdominis are divided by tendinous intersections known as

Answer 21

Linea Semilunaris

Question 22

What happens to the Rectus Sheath after the arcuate line?

Answer 22

All of the aponeurosis coming from the lateral muscles will blend anteriorly, therefore, the posterior aspect of the sheath disappears.

Question 23

Boundaries of Inguinal Canal

Floor, Roof, Anterior wall and Posterior Wall

Answer 23

Floor: Inguinal Ligament
Roof: Arching fibres of Internal Oblique and TA
Anterior wall: IO aponeurosis and EO aponeurosis
Posterior wall: Conjoint tendon and Transversalis Fascia