Anterior Abdominal Wall and Inguinal Region

Question 1

What is an aponeurosis?

Answer 1

Flattened tendinous structure that connects anterolateral abdominal wall muscles to linea alba

Question 2

What are the functions of the anterior abdominal wall muscles?

Answer 2

Movement (flexion and rotation of trunk, control of pelvic tilt)

Increasing intra abdominal pressure

Question 3

Whatg is the nerve supply to the skin and muscle of the anterior abdominal wall?

Answer 3

T7-T11 (Intercostal nerves)

T12 (Subcostal nerve)

L1 (Iliohypogastric and ilioinguinal)

Question 4

Which dermatome lies at the level of the xiphisternum?

Answer 4

T6

Question 5

Which dermatome lies at the level of the umbilicus?

Answer 5

T10

Question 6

Which dermatome lies at the level of the pubic tubercle?

Answer 6

T12/L1

Question 7

What is Scarpa’s fascia?

Answer 7

Membranous layer of superficial fascia on the anterior abdominal wall

Question 8

Scarpa’s fascia is continuous inferiorly with the membranous layer of superficial fascia of the perineum.

What name is given to this fascia in the perineum?

Answer 8

Colle’s fascia

Question 9

In which direction do the fibres of external oblique run?

Answer 9

Downwards and forwards (like external intercostal)

Question 10

The free inferior border of external oblique forms what structure?

Answer 10

Inguinal ligament

Question 11

What structure is found superior to the pubic tubercle, as a ‘gap’ in the aponeurosis of external oblique?

Answer 11

Superficial inguinal ring

Question 12

As it passes through the superficial inguinal ring, the aponeurosis of external oblique forms which component the spermatic cord?

Answer 12

External spermatic fascia

Question 13

What forms the anterior wall of the inguinal canal?

Answer 13

Aponeurosis of external oblique

also has lateral reinforcement by muscle fibres of internal oblique

Question 14

What forms the posterior wall of the inguinal canal?

Answer 14

Transversalis fascia, with medial reinforcement by conjoint tendon

Question 15

What forms the roof of the inguinal canal?

Answer 15

Laterally: transversalis fascia

Centrally: musculoaponeurotic arches of internal oblique and transversus abdominis

Medially: Medial crus

Question 16

What forms the floor of the inguinal canal?

Answer 16

Laterally: iliopubic tract

Centrally: inguinal ligament

Medially: Lacunar ligament

Question 17

What is the origin(s) of external oblique?

Answer 17

External surfaces of ribs 5-12

Question 18

What are the insertions of external oblique?

Answer 18

Linea alba

Pubic tubercle

Anterior half of iliac crest

Question 19

What is the origin(s) of internal oblique?

Answer 19

Thoracolumbar fascia

Anterior two-thirds of iliac crest

Connective tissue deep to lateral third of inguinal ligament

Question 20

What are the insertions of internal oblique?

Answer 20

Inferior borders of ribs 10-12

Linea alba

Pecten pubis (via conjoint tendon)

Question 21

What is the origin(s) of transversus abdominis?

Answer 21

Internal surface of 7th-12th costal cartilages

Thoracolumbar fascia

Iliac crest

Connective tissue deep to lateral third of inguinal ligament

Question 22

What are the insertions of transversus abdominis?

Answer 22

Linea alba

Pubic crest

Pecten pubis (via conjoint tendon)

Question 23

Where does the neurovascular plane of the anterior abdominal wall lie?

Answer 23

Between transversus abdominis and internal oblique

Question 24

What is the origin(s) of rectus abdominis?

Answer 24

Pubic symphysis and pubic crest

Question 25

What are the insertions of rectus abdominis?

Answer 25

Xiphoid process 5th-7th costal cartilages

Question 26

In which direction do the fibres of internal oblique run?

Answer 26

Upwards and forwards

Question 27

How to the fibres of transversus abdominis relate to the inguinal canal?

Answer 27

Superior to deep inguinal ring Roof, then posterior wall as conjoint tendon

Question 28

What and where is the conjoint tendon?

Answer 28

Union of internal oblique and transversus abdominis Located posterior to the superficial inguinal ring

Question 29

What and where is the transversalis fascia?

Answer 29

This connective tissue layer, between transversus abdominis and parietal peritoneum. Thickest at level of inguinal canal

Question 30

Which vessels run through the rectus sheath, deep to rectus abdominis?

Answer 30

Inferior and superior epigastric

Question 31

The deep inguinal ring is a defect in which layer of the abdominal wall?

Answer 31

Transversalis fascia

Question 32

What is the tunica vaginalis, from where is it derived?

Answer 32

Serous covering of the testes, derived from the processus vaginalis (embryonic outpouching of the parietal peritoneum)

Question 33

What is the cremasteric reflex?

Answer 33

Reflex observed when the superomedial portion of the thigh is stroked. This tightens the cremaster muscles, elevating the testes on the ipsilateral side

Question 34

What structures are found in the spermatic cord?

Answer 34

Mnemonic: Papers Don't Contribute To A Good Specialist Level 3 arteries, 3 nerves, 3 other things ``` P: pampiniform plexus D: ductus deferens C: cremasteric artery T: testicular artery A: artery of the ductus deferens (deferential artery) G: genital branch of the genitofemoral nerve S: sympathetic nerve fibers L: lymphatic vessels ```

Question 35

Where is the deep inguinal ring located?

Answer 35

2cms above the midpoint of the inguinal ligament

Question 36

What are the medial and lateral borders of the deep inguinal ring?

Answer 36

Medial: Inferior epigastric artery Lateral: Transversalis fascia

Question 37

What are the medial and lateral borders of the superficial inguinal ring?

Answer 37

Medial and lateral crura of external oblique muscle

Question 38

What is the approximate length of the inguinal canal?

Answer 38

4cm

Question 39

Which nerve enters the inguinal canal through the deep inguinal ring and what does it supply?

Answer 39

Genital branch of genitofemoral artery Females: Labia majora and mons pubis Males: Cremaster and skin of scrotum

Question 40

How does the ilioinguinal nerve enter the inguinal canal and what does it supply?

Answer 40

Enters anterior abdominal wall between transversus abdominis and internal oblique Supplies skin of the upper and medial part of the thigh, and:: Males ("anterior scrotal nerve"): to the skin over the root of the penis and upper part of the scrotum. Females ("anterior labial nerve"): to the skin covering the mons pubis and labia majora.

Question 41

What is a hernia?

Answer 41

Protrusion of a structure through the body cavity in which it is normally contained

Question 42

What is the difference between an indirect and a direct hernia?

Answer 42

Direct: Protrudes through anterior abdominal wall via Hesselbach's triangle Indirect: Protrusion through deep inguinal ring