Lecture 3 (A) - Retroperitoneum

Question 1

What organs come into contact with the posterior abdominal wall?

Answer 1

• Kidneys and ureters
• Suprarenal glands
• Aorta and inferior vena cava
• Nerves (lumbar plexus and sympathetic trunk)
• Oesophagus
• Rectum
• Duodenum (except for first part)
• Pancreas (apart from pancreas)
• Colon (ascending and descending only)

Question 2

Which kidney is more superior than the other?

Answer 2

Left is more superior (T11) than the right (12).

Question 3

Describe the location of the pancreas.

Answer 3

• Head, neck and uncinate process lies in the G of the duodenum and anterior to the IVC
• The body extends from the left side across the aorta to the left kidney
• The tail extends from the kidney to the spleen in the dorsal foregut mesentery

Question 4

Describe the anatomy of the kidney.

Answer 4

• Superior poles are more medial than the inferior poles
• 12th ribs run diagonally across the posterior surfaces of the kidneys
• Posteriorly lie on the diaphragm, psoas major, quadratus lumborum and transverses abdominis muscles

Question 5

Describe the pathway of the ureters.

Answer 5

The ureters descend vertically, anterior to the lumbar transverse processes, narrowing at three places:

• Ureteropelvic junction
• Pelvic brim (where the the common iliac vessels cross)
• Entrance to the urinary bladder

Question 6

What is the linea alba?

Answer 6

A linear, fibrous structure that is formed from the aponeurosis of the lateral abdominal muscles. It runs from the xiphoid process to the pubic symphysis.

Question 7

What are the linea semilunaris?

Answer 7

A curvilinear tendinous intersection found on either side of the rectus abdominis muscles.

Question 8

Describe the structure of Camper’s fascia in males and females.

Answer 8

Camper’s fascia is the fatty layer in the superficial fascia.

Males - continues over the penis then loses its fat and fuses with the deeper membranous layer to form part of the scrotum.
Females - it retains some fat and is a component of the labia majora

Question 9

Describe the structure of Scarpa’s fascia.

Answer 9

A deeper, membranous layer that contains little or no fat. It also forms a ligament in the penis called the fundiform ligament in which Camper’s fascia is not involved in the development.

Question 10

What is the innervation of the external obliques?

Answer 10

Anterior rami of the lower six thoracic spinal nerves (T7-12)

Question 11

What is the innervation of the internal obliques?

Answer 11

Anterior rami of the lower six thoracic spinal nerves (T7-12) and L1.

Question 12

What is the innervation of the transversus abdominis?

Answer 12

Anterior rami of the lower six thoracic spinal nerves (T7-12) and L1.

Question 13

What is the innervation of the rectus abdominis muscles?

Answer 13

Anterior rami of the lower six thoracic spinal nerves (T7-12)

Question 14

Which vertebra do the iliohypogastric and ilio-inguinal nerves come from?

Answer 14

L1

Question 15

What is the blood supply for the rectus abdominis muscles?

Answer 15

Superior and inferior epigastric arteries.

Question 16

What happens to the abdominal wall muscles during breathing?

Answer 16

• Relax during inspiration to accommodate the expansion of the thoracic cavity
• Diaphragm contracts and pushes abdominal viscera downwards
• Contracts during expiration to assist in elevating the diaphragm and reduce thoracic volume

Question 17

How can intra-abdominal pressure be increased?

Answer 17

• Contraction of abdominal muscles

- Closure of epiglottis in the larynx (stops air from exiting the lungs)

Question 18

When is intra-abdominal pressure increase?

Answer 18

• Defecation
• Voiding of the bladder
• Giving birth

Question 19

Where can the femoral pulse be palpated?

Answer 19

At the mid-inguinal point which is halfway between the pubic symphysis and the anterior superior iliac spine.

Question 20

Where is the midpoint of the inguinal ligament?

Answer 20

Halfway between the pubic tubercle and the anterior superior iliac spine - the deep inguinal ring is located just above this point (1.5cm).

Question 21

The deep inguinal ring forms whole in which tissue?

Answer 21

Transversalis fascia

Question 22

What is the superficial inguinal ring?

Answer 22

A triangular opening in the aponeurosis of the external oblique muscles that marks the end of the inguinal canal and is superior to the pubic tubercle.

Question 23

What are the two muscles that make up the roof of the inguinal canal?

Answer 23

• Internal oblique muscle

- Transverse abdominis muscle

Question 24

What makes up the anterior wall of the inguinal canal?

Answer 24

• External oblique aponeurosis (whole length)

- Internal oblique aponeurosis (reinforces the lateral 3rd)

Question 25

What makes up the inferior wall (floor) of the inguinal canal?

Answer 25

• Inguinal ligament

- Lacunar ligament

Question 26

What makes up the posterior wall of the inguinal canal?

Answer 26

• Transversalis fascia

- Conjoint tendon

Question 27

What is the conjoint tendon?

Answer 27

The lowest fibres of the internal oblique aponeurosis and similar fibres of the transversus abdominis aponeurosis join to form the conjoint tendon. It is attached medially to the linea alba.

Question 28

What are examples of secondary retroperitoneal organs?

Answer 28

• 2-4th parts of duodenum
• Pancreas (apart from tail)
• Ascending/descending colon

Question 29

What are examples of primary retroperitoneal organs?

Answer 29

• Kidney and ureters
• Suprarenal glands
• Aorta/IVC
• Nerves (lumbar plexus, sympathetic trunk)
• Oesophagus
• Rectum

SAD PUCKER

Question 30

What vertebral levels does the pancreas extend over?

Answer 30

L1-3