Unit 2 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
1Piriformis divides the greater sciatic foramen into the ( ).
Answer: A
Piriformis passes out of the pelvis through the greater sciatic foramen and fills its middle, splitting it into a suprapiriform foramen above and an infrapiriform foramen below. The greater and lesser sciatic foramina are created by the sacrospinous and sacrotuberous ligaments, not by piriformis.TMU Slide 8 · Gray's 4e p.566
2Which structures pass through the suprapiriform foramen?
Answer: B
Only one bundle uses the gap above piriformis — the superior gluteal nerve, artery and vein, running from lateral to medial. Every other option travels below piriformis.TMU Slide 10 · Gray's 4e p.571
3Which structure is the MOST LATERAL of those passing through the infrapiriform foramen?
Answer: C
Lateral to medial the order runs: sciatic nerve → posterior femoral cutaneous nerve → inferior gluteal nerve, artery and vein → internal pudendal artery and vein → pudendal nerve. The pudendal nerve is the most medial.TMU Slide 10
4Gluteus maximus is supplied by the ( ).
Answer: D
Gluteus maximus takes the inferior gluteal nerve, which reaches it through the infrapiriform foramen. The superior gluteal nerve supplies gluteus medius, gluteus minimus and tensor fasciae latae.TMU Slide 6 · Gray's 4e p.571
5A patient's pelvis drops on the left when standing on the right leg. Which nerve is damaged?
Answer: A
This is Trendelenburg's sign. Gluteus medius and minimus on the supporting side hold the pelvis level, so a drop on the left while standing on the right means the right superior gluteal nerve has failed. The sign always points to the side being stood on, not the side that drops.Gray's 4e p.568, Fig. 6.45B
6The safe site for an intramuscular gluteal injection is the ( ).
Answer: B
The anterior corner of the upper lateral quadrant is used. A needle there enters gluteus medius anterosuperior to the margin of gluteus maximus, well away from the sciatic nerve and the other gluteal nerves and vessels.Gray's 4e p.573, Fig. 6.49
7Piriformis originates from the ( ).
Answer: C
Piriformis arises from the anterior (pelvic) surface of the sacrum and must therefore leave the pelvis through the greater sciatic foramen to reach the greater trochanter. Gluteus maximus is the muscle arising from the gluteal surface of the ilium and the dorsal sacrum.TMU Slide 8
8How many structures pass through the infrapiriform foramen?
Answer: D
Eight: sciatic nerve, posterior femoral cutaneous nerve, inferior gluteal nerve, inferior gluteal artery, inferior gluteal vein, internal pudendal artery, internal pudendal vein and pudendal nerve. Three is the count for the suprapiriform foramen.TMU Slide 10
9The greater sciatic notch is converted into the greater sciatic foramen by the ( ).
Answer: A
The sacrospinous ligament closes the greater sciatic notch to form the greater sciatic foramen; the sacrotuberous ligament closes the lesser notch to form the lesser sciatic foramen.Gray's 4e p.566, Fig. 6.44
10The pudendal nerve reaches the perineum by passing through the ( ).
Answer: B
The pudendal nerve and internal pudendal vessels leave the pelvis through the infrapiriform foramen, hook around the sacrospinous ligament at the ischial spine, and immediately re-enter through the lesser sciatic foramen to reach the perineum. They barely enter the buttock at all.Gray's 4e p.566
11Which is NOT one of the deep lateral rotators of the hip?
Answer: C
Gluteus minimus belongs to the superficial abductor group with gluteus medius, and it medially rotates rather than laterally rotates the thigh. The deep lateral rotators are piriformis, obturator internus, the two gemelli and quadratus femoris.Gray's 4e p.568 · TMU Slide 13
12The sciatic nerve carries fibres from spinal segments ( ).
Answer: D
The sciatic nerve arises from the sacral plexus and carries L4 to S3. L2–L4 is the femoral/obturator range from the lumbar plexus; S2–S4 is the pudendal nerve.TMU Slide 6 (Lecture 3) · Gray's 4e p.597
13Gluteus maximus inserts into the ( ).
Answer: A
Most of the muscle inserts into the iliotibial tract, with the deeper part reaching the gluteal tuberosity of the femur. The greater trochanter is where piriformis, gluteus medius and minimus insert.TMU Slide 6
14Damage to the sciatic nerve from a misplaced gluteal injection produces ( ).
Answer: B
The sciatic nerve supplies the hamstrings and, through its tibial and common fibular divisions, everything below the knee. Injury therefore produces hamstring weakness plus foot drop. Loss of abduction would indicate the superior gluteal nerve; perineal numbness the pudendal nerve.Gray's 4e p.573
15Which nerve supplies tensor fasciae latae?
Answer: C
Tensor fasciae latae shares its nerve with gluteus medius and minimus — the superior gluteal nerve — because all three act together through the iliotibial tract to stabilise the hip and knee.Gray's 4e p.568
16The gluteal arteries are branches of the ( ).
Answer: D
Both the superior and inferior gluteal arteries arise from the internal iliac artery within the pelvis and leave through the suprapiriform and infrapiriform foramina respectively.Gray's 4e p.574, Fig. 6.50
17Which cutaneous nerves supply the skin of the buttock?
Answer: A
The cluneal nerves — superior, medial and inferior (clunis = buttock) — are the sensory supply. The superior and inferior gluteal nerves are purely motor.TMU Slide 4
18Piriformis syndrome is explained anatomically by ( ).
Answer: B
In most people the entire sciatic nerve passes below piriformis. In a minority the nerve divides within the pelvis and the common fibular part pierces or passes above the muscle, so muscular contraction compresses it — producing buttock pain radiating down the leg without any disc lesion.Gray's 4e p.573
19The action of gluteus maximus when the lower limb is fixed on the ground is to ( ).
Answer: C
With the foot planted the muscle works in reverse and raises the trunk — which is why it is recruited to stand from sitting and to climb stairs rather than in level walking.TMU Slide 6
20Which structure passes through BOTH the greater and the lesser sciatic foramina?
Answer: D
Obturator internus arises inside the pelvis, leaves through the lesser sciatic foramen, and turns sharply to reach the greater trochanter. The pudendal nerve and internal pudendal vessels also use both foramina — leaving through the greater (infrapiriform part) and re-entering through the lesser. The sciatic nerve and superior gluteal artery use the greater foramen only.Gray's 4e p.566
1 Suprapiriform foramen — 3′+
The opening between the upper border of piriformis and the upper margin of the greater sciatic foramen.
Contents (lateral → medial): superior gluteal nerve, superior gluteal artery, superior gluteal vein.TMU Slide 10 · Gray's 4e p.571
Contents (lateral → medial): superior gluteal nerve, superior gluteal artery, superior gluteal vein.TMU Slide 10 · Gray's 4e p.571
2 Infrapiriform foramen — 3′+
The opening between the lower border of piriformis and the sacrospinous ligament.
Contents (lateral → medial): sciatic nerve · posterior femoral cutaneous nerve · inferior gluteal nerve · inferior gluteal artery · inferior gluteal vein · internal pudendal artery · internal pudendal vein · pudendal nerve. Eight structures.TMU Slide 10
Contents (lateral → medial): sciatic nerve · posterior femoral cutaneous nerve · inferior gluteal nerve · inferior gluteal artery · inferior gluteal vein · internal pudendal artery · internal pudendal vein · pudendal nerve. Eight structures.TMU Slide 10
3 Greater sciatic foramen — 2′+
The opening formed when the sacrospinous ligament bridges the greater sciatic notch of the hip bone.
It is the main route between the pelvic cavity and the gluteal region, and it is subdivided by piriformis into the suprapiriform and infrapiriform foramina.Gray's 4e p.566
It is the main route between the pelvic cavity and the gluteal region, and it is subdivided by piriformis into the suprapiriform and infrapiriform foramina.Gray's 4e p.566
4 Lesser sciatic foramen — 2′+
The opening formed when the sacrotuberous ligament bridges the lesser sciatic notch.
Transmits: the tendon of obturator internus and its nerve, and the pudendal nerve with the internal pudendal vessels re-entering the pelvis to reach the perineum.Gray's 4e p.566
Transmits: the tendon of obturator internus and its nerve, and the pudendal nerve with the internal pudendal vessels re-entering the pelvis to reach the perineum.Gray's 4e p.566
5 Piriformis — 3′+
A muscle arising from the anterior surface of the sacrum and inserting on the greater trochanter of the femur, supplied by branches of the sacral plexus and acting as a lateral rotator of the thigh.
Key relationship: it passes through the greater sciatic foramen and divides it into the suprapiriform and infrapiriform foramina — making it the landmark for the whole gluteal region.TMU Slide 8
Key relationship: it passes through the greater sciatic foramen and divides it into the suprapiriform and infrapiriform foramina — making it the landmark for the whole gluteal region.TMU Slide 8
6 Trendelenburg's sign — 2′+
Drooping of the pelvis on the unsupported side when the patient stands on one leg, caused by weakness of gluteus medius and minimus on the supporting side following injury to the superior gluteal nerve.
A common iatrogenic cause is a misplaced intramuscular gluteal injection.Gray's 4e p.568
A common iatrogenic cause is a misplaced intramuscular gluteal injection.Gray's 4e p.568
1
Draw and describe the structures passing through the suprapiriform and infrapiriform foramina.
8′
Set as homework in TMU Lecture 2 — expect it as a drawing question.
The framework
The greater sciatic notch is converted into the greater sciatic foramen by the sacrospinous ligament. Piriformis, passing from the anterior surface of the sacrum to the greater trochanter, occupies the middle of this foramen and divides it into two openings.
Suprapiriform foramen — 3 structures (lateral → medial)
- Superior gluteal nerve
- Superior gluteal artery
- Superior gluteal vein
Infrapiriform foramen — 8 structures (lateral → medial)
- Sciatic nerve
- Posterior femoral cutaneous nerve
- Inferior gluteal nerve
- Inferior gluteal artery
- Inferior gluteal vein
- Internal pudendal artery
- Internal pudendal vein
- Pudendal nerve
Group them as: to the thigh (1–2), to the buttock (3–5), to the perineum (6–8).
Marking guide: naming piriformis as the divider 1 · suprapiriform contents 2 · infrapiriform contents 4 (½ each) · correct lateral-to-medial order 1.
2
Describe the muscles of the gluteal region, giving their nerve supply and main actions.
10′
Superficial group
- Gluteus maximus — inferior gluteal nerve — extends and laterally rotates the thigh; raises the trunk when the limb is fixed
- Gluteus medius — superior gluteal nerve — abducts the thigh; steadies the pelvis in gait
- Gluteus minimus — superior gluteal nerve — abducts and medially rotates the thigh
- Tensor fasciae latae — superior gluteal nerve — tenses the iliotibial tract, stabilising the knee in extension
Deep group — lateral rotators
- Piriformis — branches of sacral plexus
- Obturator internus and superior gemellus — nerve to obturator internus
- Inferior gemellus and quadratus femoris — nerve to quadratus femoris
All the deep group laterally rotate the thigh at the hip joint.
Structural point worth a mark
The nerves and vessels of the region lie in the plane between the superficial and deep muscle groups, which is why reflecting gluteus maximus exposes them all at once.
Marking guide: superficial group named 2 and nerves 2 · deep group named 2 and nerves 2 · actions 1 · the intermuscular plane 1.
3
Where is an intramuscular gluteal injection given, and why? What happens if it is given in the wrong place?
6′
Site
Divide the buttock into quadrants with a vertical line and a horizontal line. The injection is given in the anterior corner of the upper lateral quadrant. The needle enters gluteus medius, anterosuperior to the margin of gluteus maximus.
Why there
- The sciatic nerve emerges below piriformis and descends through the middle and lower part of the region
- The superior gluteal nerve and vessels run forwards above piriformis
- The upper lateral quadrant is furthest from both
Consequences of a misplaced injection
- Lower medial quadrant → sciatic nerve injury: burning pain down the limb, hamstring weakness, and foot drop from loss of the common fibular division. May be permanent.
- Too deep and superior → superior gluteal nerve injury: weakness of gluteus medius and minimus, giving a positive Trendelenburg's sign.
Marking guide: quadrant named 2 · muscle entered 1 · anatomical reasoning 1 · sciatic consequence 1 · superior gluteal consequence 1.
4
Trace the course of the sciatic nerve from its origin to its termination, and state its branches in the thigh.
7′
Origin
From the sacral plexus, root value L4–S3. It is the thickest nerve in the body.
Course
- Leaves the pelvis through the greater sciatic foramen, below piriformis (infrapiriform foramen), as the most lateral structure
- Descends midway between the ischial tuberosity and the greater trochanter
- Passes deep to gluteus maximus and then down the midline of the back of the thigh on adductor magnus
- Ends at the superior angle of the popliteal fossa by dividing into the tibial and common fibular nerves
Branches in the thigh
- Muscular branches to semitendinosus, semimembranosus and the long head of biceps femoris (tibial division)
- Muscular branch to the short head of biceps femoris (common fibular division)
- Branch to the hamstring part of adductor magnus (tibial division)
- Articular branches to the hip and knee joints
Marking guide: root value 1 · exit through infrapiriform foramen 1 · course in thigh 2 · termination and site 2 · branches 1.
5
What is piriformis syndrome? Explain its anatomical basis.
5′
Definition
Compression of the sciatic nerve by the piriformis muscle, producing buttock pain that radiates down the back of the thigh — clinically resembling sciatica from a lumbar disc lesion but arising outside the spine.
Anatomical basis
Normally the entire sciatic nerve passes through the infrapiriform foramen, below the muscle, where it is not compressed. In a minority of people the nerve divides within the pelvis and the common fibular division pierces piriformis, or passes above it through the suprapiriform foramen. In these people contraction or spasm of the muscle compresses the nerve directly.
Clinical features
- Buttock pain radiating down the limb, worse on sitting
- Worse on internal rotation of the hip, which stretches piriformis
- No lumbar spine signs and normal imaging of the spine
Marking guide: definition 1 · normal relationship 1 · the variant course 2 · one clinical feature 1.