Unit 15 Question Bank
Sourcing: items tagged TMU 2021–22 come from the real final paper. Items tagged
Slide come from the TMU lecture. Items tagged Gray's are built from the textbook to cover
examinable content. Nothing here is invented; answers are verifiable against the cited page — check against
the official marking scheme where one exists.
0 / 20 answered
1The borders of the inguinal triangle are the inferior epigastric artery, the inguinal ligament and the ( ).
Answer: D
Laterally the inferior epigastric artery, medially the lateral border of rectus abdominis, inferiorly the inguinal ligament.TMU 2021–22 definition 1 · Gray's 4e p.287
2A DIRECT inguinal hernia passes ( ) the inferior epigastric vessels.
Answer: A
Medial — through the inguinal triangle. An indirect hernia enters the deep ring lateral to those vessels. This single relationship separates the two.Gray's 4e p.287
3The anterior wall of the inguinal canal is formed by the ( ).
Answer: B
The external oblique aponeurosis, with internal oblique muscle fibres reinforcing it laterally — where the deep ring lies.TMU Lecture 18 Slide 20
4The posterior wall of the inguinal canal is reinforced medially by the ( ).
Answer: C
The conjoint tendon, formed from the lowest fibres of internal oblique and transversus abdominis, reinforces the transversalis fascia medially — where the superficial ring lies.TMU Lecture 18 Slide 20
5The membranous layer of the superficial fascia of the abdomen is called ( ).
Answer: D
Scarpa's fascia is the membranous layer; Camper's is the fatty layer. Scarpa's continues into the perineum as Colles' fascia.TMU Lecture 18 Slide 4
6Extravasated urine from a ruptured urethra does NOT spread into the thigh because ( ).
Answer: A
Scarpa's fascia fuses with the fascia lata just below the inguinal ligament, so urine tracks up the abdominal wall and into the scrotum and penis but never down the thigh.Snell's 10e Ch.6 (clinical)
7Below the arcuate line, the posterior wall of the rectus sheath is formed by ( ).
Answer: B
Below the arcuate line all three aponeuroses pass in front of rectus abdominis, leaving only transversalis fascia behind it.Gray's 4e p.273
8The contents of the inguinal canal in the female are the ( ).
Answer: C
The round ligament of the uterus plus the ilioinguinal nerve (the male equivalent being the spermatic cord and the same nerve).TMU Lecture 18 Slide 28 · past paper fill-in-blank
9Which layer is NOT one of the nine layers of the lateral abdominal wall?
Answer: D
The fascia lata is the deep fascia of the thigh. The nine layers are skin, Camper's, Scarpa's, external oblique, internal oblique, transversus abdominis, transversalis fascia, extraperitoneal tissue and peritoneum.TMU past paper · Gray's 4e p.266
10The linea alba is formed by ( ).
Answer: A
The interlacing aponeuroses of external oblique, internal oblique and transversus abdominis of both sides, separating the two rectus muscles. Relatively avascular — hence its use for midline laparotomy.TMU past paper definition
11An INDIRECT inguinal hernia is caused by ( ).
Answer: B
It is congenital, from failure of the processus vaginalis to obliterate, so the sac follows the path of testicular descent through the whole canal. A direct hernia is acquired.Gray's 4e p.286
12The roof of the inguinal canal is formed by the ( ).
Answer: C
The arching fibres of internal oblique and transversus abdominis. On coughing they descend toward the floor, closing the canal — the shutter mechanism.TMU Lecture 18 Slide 21
13The inguinal ligament is formed by the ( ).
Answer: D
The rolled-under lower border of the external oblique aponeurosis, spanning from the anterior superior iliac spine to the pubic tubercle.TMU Lecture 18 Slide 6
14Rectus sheath haematoma is distinguished from an intra-abdominal mass because it ( ).
Answer: A
Fothergill's sign: a mass within the sheath remains palpable and does not move when the muscle is contracted, whereas an intra-abdominal mass becomes impalpable.Snell's 10e Ch.6 (clinical)
15A femoral hernia appears ( ) the pubic tubercle.
Answer: B
Below and lateral; both inguinal hernias appear above and medial. The pubic tubercle is the single bony landmark separating the two families.Gray's 4e p.565
16Which nerve lies in the inguinal canal in both sexes?
Answer: C
The ilioinguinal nerve traverses the canal and exits through the superficial ring, supplying skin of the upper medial thigh and the anterior scrotum or labium.TMU Lecture 18 Slide 28
17The neurovascular plane of the abdominal wall lies between ( ).
Answer: D
Between internal oblique and transversus abdominis — the same arrangement as the intercostal space, because the abdominal wall is developmentally continuous with it. This is the plane of a TAP block.Gray's 4e p.275
18The deep inguinal ring is an opening in the ( ).
Answer: A
The deep ring is a defect in the transversalis fascia, lateral to the inferior epigastric vessels. The superficial ring is in the external oblique aponeurosis.TMU Lecture 18 Slides 16, 24
19Which artery lies immediately lateral to the inguinal triangle?
Answer: B
The inferior epigastric artery, a branch of the external iliac artery, forms the lateral boundary — and is the landmark distinguishing direct from indirect hernia.Gray's 4e p.287
20Tendinous intersections are found in the ( ).
Answer: C
Three or more fibrous bands crossing rectus abdominis, adherent to the anterior wall of the sheath — they produce the 'six-pack' segmentation and prevent the muscle bunching up.TMU Lecture 18 Slide 29
1 Inguinal triangle (Hesselbach's triangle) — TMU 2021–22 · 3′+
A triangular area of potential weakness in the lower anterior abdominal wall.
Laterally: inferior epigastric artery.
Medially: lateral border of rectus abdominis.
Inferiorly: inguinal ligament.
Nothing passes through it. A direct inguinal hernia bulges forward through it, medial to the inferior epigastric vessels.TMU 2021–22 definition 1 · Gray's 4e p.287
Laterally: inferior epigastric artery.
Medially: lateral border of rectus abdominis.
Inferiorly: inguinal ligament.
Nothing passes through it. A direct inguinal hernia bulges forward through it, medial to the inferior epigastric vessels.TMU 2021–22 definition 1 · Gray's 4e p.287
2 Inguinal canal — 4′+
An oblique passage about 4 cm long above and parallel to the medial half of the inguinal ligament, running from the deep inguinal ring to the superficial inguinal ring.
Anterior wall: external oblique aponeurosis, reinforced laterally by internal oblique.
Posterior wall: transversalis fascia, reinforced medially by the conjoint tendon.
Roof: arching fibres of internal oblique and transversus abdominis.
Floor: inguinal ligament.
Contents: spermatic cord (male) / round ligament of the uterus (female) · ilioinguinal nerve.TMU Lecture 18 Slides 20–21, 28
Anterior wall: external oblique aponeurosis, reinforced laterally by internal oblique.
Posterior wall: transversalis fascia, reinforced medially by the conjoint tendon.
Roof: arching fibres of internal oblique and transversus abdominis.
Floor: inguinal ligament.
Contents: spermatic cord (male) / round ligament of the uterus (female) · ilioinguinal nerve.TMU Lecture 18 Slides 20–21, 28
3 Linea alba — 3′+
A fibrous median raphe of the anterior abdominal wall extending from the xiphoid process to the pubic symphysis, formed by the interlacing aponeuroses of the external oblique, internal oblique and transversus abdominis of both sides, and separating the two rectus abdominis muscles.
Clinical: relatively avascular and crossed by no nerves — the standard site for a midline laparotomy incision.TMU past paper definition · Snell's 10e Ch.6
Clinical: relatively avascular and crossed by no nerves — the standard site for a midline laparotomy incision.TMU past paper definition · Snell's 10e Ch.6
4 Layers of the lateral abdominal wall — past paper · 8′+
Superficial → deep:
1. Skin
2. Superficial fascia — fatty layer (Camper's)
3. Superficial fascia — membranous layer (Scarpa's)
4. External oblique abdominis
5. Internal oblique abdominis
6. Transversus abdominis
7. Transversalis fascia
8. Extraperitoneal tissue
9. Parietal peritoneumTMU past paper · Gray's 4e p.266
1. Skin
2. Superficial fascia — fatty layer (Camper's)
3. Superficial fascia — membranous layer (Scarpa's)
4. External oblique abdominis
5. Internal oblique abdominis
6. Transversus abdominis
7. Transversalis fascia
8. Extraperitoneal tissue
9. Parietal peritoneumTMU past paper · Gray's 4e p.266
5 Conjoint tendon — 2′+
The common tendon formed where the lowest fibres of the internal oblique and transversus abdominis aponeuroses fuse and attach to the pubic crest and pectineal line.
It reinforces the posterior wall of the inguinal canal medially, exactly where the superficial ring lies — a structural counterbalance to the weakness there.TMU Lecture 18 Slide 13 · Snell's 10e Ch.6
It reinforces the posterior wall of the inguinal canal medially, exactly where the superficial ring lies — a structural counterbalance to the weakness there.TMU Lecture 18 Slide 13 · Snell's 10e Ch.6
6 Arcuate line — 2′+
A crescentic line about a third of the way from the umbilicus to the pubic symphysis, marking the lower limit of the posterior wall of the rectus sheath.
Above it the internal oblique aponeurosis splits to pass both in front of and behind rectus abdominis. Below it all three aponeuroses pass in front, so the muscle rests directly on transversalis fascia.Gray's 4e p.273 · TMU Lecture 18 Slide 31
Above it the internal oblique aponeurosis splits to pass both in front of and behind rectus abdominis. Below it all three aponeuroses pass in front, so the muscle rests directly on transversalis fascia.Gray's 4e p.273 · TMU Lecture 18 Slide 31
1
Write down the layers of the lateral abdominal wall from superficial to deep.
8′
A recurring TMU past-paper question.
- Skin
- Superficial fascia — fatty layer (Camper's fascia)
- Superficial fascia — membranous layer (Scarpa's fascia)
- External oblique abdominis — fibres downward and forward
- Internal oblique abdominis — fibres at right angles to the external
- Transversus abdominis — fibres horizontal
- Transversalis fascia
- Extraperitoneal tissue (fat)
- Parietal peritoneum
Points that earn extra marks
- The three flat muscles run their fibres in three different directions, giving the wall plywood-like strength
- The neurovascular plane lies between internal oblique and transversus abdominis — the same arrangement as the intercostal space
- Scarpa's fascia continues into the perineum as Colles' fascia but fuses with the fascia lata below the inguinal ligament, which is why extravasated urine spreads into the scrotum and up the abdomen but never into the thigh
Marking guide: nine layers in correct order 6 (⅔ each) · muscle fibre directions 1 · one functional or clinical point 1.
2
Describe the inguinal canal — its walls, rings and contents.
8′
Definition and extent
An oblique passage about 4 cm long in the lower anterior abdominal wall, lying above and parallel to the medial half of the inguinal ligament, running from the deep inguinal ring to the superficial inguinal ring. It exists as the path of testicular descent.
The two rings
- Deep inguinal ring — an opening in the transversalis fascia, lateral to the inferior epigastric vessels
- Superficial inguinal ring — a triangular defect in the external oblique aponeurosis, above the pubic tubercle
The four walls
- Anterior: aponeurosis of the external oblique, reinforced laterally by internal oblique muscle fibres
- Posterior: transversalis fascia, reinforced medially by the conjoint tendon
- Roof: arching fibres of internal oblique and transversus abdominis
- Floor: the inguinal ligament
Contents
The spermatic cord in the male or the round ligament of the uterus in the female, together with the ilioinguinal nerve in both.
The shutter mechanism
The wall is reinforced anteriorly where the deep ring lies and posteriorly where the superficial ring lies, so there is always muscle behind a potential hernia. On coughing, the arching roof descends toward the floor and closes the canal.
Marking guide: extent and rings 2 · four walls 4 · contents 1 · shutter mechanism 1.
3
Compare direct and indirect inguinal hernias, and distinguish both from a femoral hernia.
7′
| Indirect | Direct | |
|---|---|---|
| Inferior epigastric artery | Lateral to it | Medial to it |
| Route | Through the deep ring, along the whole canal | Forward through the inguinal triangle |
| Cause | Congenital — persistent processus vaginalis | Acquired — muscular weakness |
| Age | Any age; commonest hernia overall | Older men |
| Descends into scrotum | Commonly | Rarely |
| Coverings | All three spermatic fascial layers | Usually external spermatic fascia only |
Femoral hernia — the third possibility
- Descends through the femoral canal, the medial compartment of the femoral sheath
- Appears below and lateral to the pubic tubercle; both inguinal hernias appear above and medial
- Commoner in women because of the wider female pelvis
- Strangulates far more readily, because the femoral ring is small and rigid — so it is more often a surgical emergency
The single most useful examination point: locate the pubic tubercle first, then decide whether the lump is above and medial, or below and lateral.
Marking guide: relation to inferior epigastric vessels 2 · route and cause 2 · femoral hernia position 2 · strangulation risk 1.
4
Describe the rectus sheath.
6′
Formation
The aponeuroses of the three flat abdominal muscles split and interlace around rectus abdominis, meeting their fellows in the midline to form the linea alba.
Above the arcuate line
- Anterior wall: external oblique aponeurosis + anterior lamina of internal oblique
- Posterior wall: posterior lamina of internal oblique + transversus abdominis aponeurosis
Below the arcuate line
- All three aponeuroses pass in front of the muscle
- The posterior surface rests directly on transversalis fascia — there is no aponeurotic posterior wall
Contents
- Rectus abdominis, with its tendinous intersections adherent to the anterior wall
- Pyramidalis
- Superior epigastric vessels (from the internal thoracic artery) and inferior epigastric vessels (from the external iliac artery), which anastomose within the sheath
- Terminal parts of the lower intercostal and subcostal nerves
Clinical
Rectus sheath haematoma from tearing of the inferior epigastric artery produces a tender mass that persists when the muscle is tensed (Fothergill's sign) — distinguishing it from an intra-abdominal mass.
Marking guide: formation and linea alba 1 · above the arcuate line 1.5 · below it 1.5 · contents 1.5 · clinical 0.5.
5
Explain the anatomical basis of the inguinal region's vulnerability to hernia.
6′
Why a weakness exists at all
The testis develops on the posterior abdominal wall and migrates to the scrotum, dragging its vessels, nerves and duct through the abdominal wall. The inguinal canal is the tunnel left behind — a deliberate defect in an otherwise continuous wall. This is why inguinal hernias are far commoner in males.
The two weak points
- Deep inguinal ring — in transversalis fascia, lateral to the inferior epigastric vessels. A persistent processus vaginalis allows an indirect hernia to follow the original path of descent.
- Inguinal (Hesselbach's) triangle — bounded by the inferior epigastric artery, rectus abdominis and the inguinal ligament, with no muscle behind it. A direct hernia bulges forward here when the musculature weakens.
The natural defences
- The canal is oblique, so raised intra-abdominal pressure presses its walls together
- The anterior wall is reinforced laterally where the deep ring lies; the posterior wall is reinforced medially by the conjoint tendon where the superficial ring lies — so muscle always lies behind a potential hernia
- The shutter mechanism: on coughing, the arching fibres of internal oblique and transversus descend toward the inguinal ligament, closing the canal
Hernia occurs when these defences fail — congenitally at the deep ring, or through acquired muscular weakness at the triangle.
Marking guide: embryological reason 1.5 · deep ring/indirect 1.5 · triangle/direct 1.5 · two defence mechanisms 1.5.