Abdomen and Pelvis 1.5

Question 1

What are the two large muscles in the posterior abdominal wall?

Answer 1

1. Psoas major: flexor of the thigh or of the trunk
2. Posas minor: minor flexor of trunk (if present)
3. Quadratus lumborum: stabiliser of 12th rib, flexor and lateral flexor of the trunk
4. Iliacus: flexor of the thigh

Question 2

What are the two major arterial supplies to the abdominal wall?

Answer 2

1. Segmental arteries running in axial plane

2. Longitudinal arteries

Question 3

What are. the segmental arteries?

Answer 3

1. Intercostal 7-11
2. Subcostal arteries
3. In similar pattern the 5 lumbar arteries

Question 4

Describe the longitudinal supply anteriorly?

Answer 4

1. Superior epigastric: (from internal thoracic)
   - It’s anastomosis are in the region of the umbilicus with an ascending artery
2. Inferior epigastric: (from external iliac)

Question 5

What do the two longitudinal arteries do?

Answer 5

-Anastomose in region of umbilicus to form a possible anterior by pass to the aorta

Question 6

What are the segmental veins?

Answer 6

1. Subcostal veon
2. 1st and 2nd lumbar revise join to form the ascending lumbar vein on either side
   - Drain into the azygous system
3. 3rd and 4th lumbar veins drain directly into the inferior vena cava

Question 7

What are the anterior longitudinal veins?

Answer 7

1. Superior to the umbilicus the superior epigastric veins drain into the internal thoracic
2. Inferior to the umbilicus the inferior epigastric veins drain into the external iliac

Question 8

Where do the superior epigastric artery and the inferior epigastric artery

Answer 8

beneath the rectus muscle on the posterior part of the rectus sheath and inferiorly transversalis fascia

Question 9

What do the segmental nerves do?

Answer 9

Supply anterior wall

Question 10

What do the inferior epigastric vessels do?

Answer 10

1. These vessels, either arise from or drain into the external iliac.
2. So they have to pass immediately to enter and descend to enter the rectus sheath.
3. The rectus muscles are much narrower inferiorly than they are superiorly
4. This leaves an area of weakness between the inferior epigastric vessels and the rectus sheath at the lowest part of the aponeurosis of the anterior lateral abdominal wall.
5. This is of importance in our latest studies of the inguinal canal and inguinal hernia

Question 11

What is the nerve supply like tot the abdominal wall?

Answer 11

1. The abdominal supply starts below the rib cage in the mid-line at T7 and descends all the way down to L1,
2. just above the pubic bone
   - In reality, as we descend from T7-L1, the nerves, their course, becomes more and more oblique.
   - T7: epigastrium
   - T10: umbilicus
   - L1: inguinal liagemtn

Question 12

Which nerves have root values of L1?

Answer 12

The subcostal nerve which obviously is from T12, the Iliohypogastric and Ilioinguinal nerves going down to the inguinal region which have root values of L1

Question 13

What does the genital femoral nerve do?

Answer 13

-The genital femoral nerve which divides to give a genital branch and a short femoral branch is derived from L1 and L2 roots

Question 14

What does the lateral cutaneous nerve of the thigh do?

Answer 14

• The lateral cutaneous nerve of the thigh which passes just below the lateral part of the inguinal ligament to extend into the thigh and is derived from L2 and L3.
• The remaining nerves from this lumbosacral plexus are going to supply the lower limb

Question 15

What is the lymphatic draining of the abdominal wall do?

Answer 15

-These are superficial lymphatic vessels that drain the abdominal wall

Question 16

What is the basic pattern of lymphatic drainage of the abdominal wall?

Answer 16

1. above the umbilicus lymph drains to the axillary nodes
2. below the umbilicus, lymphatics drain to the superficial inguinal nodes in the groin just below the inguinal ligament.

Question 17

What is the inguinal canal?

Answer 17

-The inguinal canal is a canal through the inferior part of the abdominal wall.

Question 18

What does the inguinal canal do in the male?

Answer 18

-In the male, it transmits the spermatic cord

Question 19

What does the inguinal canal do in the female?

Answer 19

-In the female it transmits the round ligament of the uterus w

Question 20

What does the spermatic cord do?

Answer 20

-The spermatic cord passes into the scrotum in the male and towards the labia majora in the female.

Question 21

What is the passage of the canal?

Answer 21

-This canal passes obliquely and inferiorly from lateral to medial and it is formed by the muscles and the aponeurosis of the flank muscles.

Question 22

What is the anterior wall do the inguinal canal formed by?

Answer 22

• External oblique aponeurosis reinforced laterally by internal oblique
• This canal passes obliquely and inferiorly from lateral to medial and it is formed by the muscles and the aponeurosis of the flank muscles.

Question 23

What is the floor of the inguinal canal?

Answer 23

• This ligament is the most inferior part of the external oblique aponeurosis that bends posteriorly inferiorly to form a gutter and this is the floor of the inguinal canal.
• Gutter like upper surface of inguinal ligament and its medial pectineal part

Question 24

What is the roof of the inguinal canal?

Answer 24

• The roof is formed by arching fibers of internal oblique. (laterally to medial) becoming the conjoint tendon medially
• These fibers start laterally anterior to the canal, pass over it to form its roof and medially join with the aponeurosis of transversus abdominis to form the conjoint tendon.

Question 25

What is the posterior wall of the inguinal canal?

Answer 25

1. The posterior wall, throughout its length, is formed by transversalis fascia and this has a deficiency in it which is the abdominal entrance to the canal and this is known as the deep inguinal ring.
2. Medially, transversalis fascia is reinforced by the conjoint tendon and you will remember that the conjoint tendon is conjoint tendon of internal oblique and transversus abdominis.
   - Transerversalis fascia reinforced medially by conjoint tendon (of internal oblique and transverses abdominis)

Question 26

What is the bony landmark at C7?

Answer 26

Vertebra prominens

Question 27

What is the bony landmarks at T3?

Answer 27

Medial end of scapular spine

Question 28

What is the bony landmarks at T7?

Answer 28

Inferior angle of scapula

Question 29

What is the bony landmarks at L2?

Answer 29

Inferior extent of lowest rib

Question 30

What is the bony landmarks at L4?

Answer 30

Iliac crest

Question 31

What is the annulus fibrosus (invertebratal discs)?

Answer 31

An outer fibrous ring made of both type I and type II collagen (this collagen limits rotation)

Question 32

What is the nucleus pulposus (invertebratal discs)?

Answer 32

An inner gel like centre which helps to distribute pressure evenly across the disc - absorbs compression forces