Pelvis

Question 1

What bones form the pelvic girdle?

Answer 1

Two pelvic bones (ilium, ischium, pubis) and the sacrum.

Question 2

What are the three parts of a pelvic bone?

Answer 2

Ilium (superior), ischium (posteroinferior), pubis (anteroinferior).

Question 3

What does the pelvic inlet separate?

Answer 3

False pelvis (superior) and true pelvis (inferior).

Question 4

What organs are in the false vs true pelvis?

Answer 4

• False: abdominal organs (e.g., sigmoid colon)
• True: pelvic organs (e.g., bladder, uterus).

Question 5

What type of joint is the anterior sacroiliac joint (SIJ)?

Answer 5

Synovial joint.

Question 6

What type of joint is the posterior SIJ?

Answer 6

Fibrous joint.

Question 7

Why do pelvic ring fractures often occur in two places?

Answer 7

Because of the ring’s mechanical integrity—forces travel around and break it at weak points.

Question 8

In what plane can you view the full sacral canal?

Answer 8

Sagittal plane.

Question 9

Can S1–3 nerve roots be seen in one coronal slice?

Answer 9

No, due to angulation of the sacrum.

Question 10

What is the anterior-to-posterior organ arrangement in the male pelvis?

Answer 10

Bladder → rectum.

Question 11

What is the anterior-to-posterior organ arrangement in the female pelvis?

Answer 11

Bladder → uterus/vagina → rectum.

Question 12

What does the rectum usually contain that aids identification on imaging?

Answer 12

Gas.

Question 13

What bone lies anterior to the bladder?

Answer 13

Pubic bones/symphysis.

Question 14

What is the most dependent part of the abdomen when erect?

Answer 14

Rectouterine pouch (of Douglas).

Question 15

Why is the pouch of Douglas clinically important?

Answer 15

Fluid, pus, or metastases can collect there.

Question 16

Where are ovaries located in the pelvis?

Answer 16

Lateral pelvic walls.

Question 17

What lies inferior to the male bladder?

Answer 17

Prostate (more dense than bladder).

Question 18

What is found at the posterior aspect of the male bladder?

Answer 18

• Seminal vesicles
• Vas deferens
• Ureters.

Question 19

What large bowel parts sit in the iliac fossae?

Answer 19

• Right: caecum/appendix
• Left: sigmoid colon.

Question 20

At what vertebral level does the rectum begin?

Answer 20

S3.

Question 21

What bones form the hip joint?

Answer 21

Head of femur + acetabulum of pelvis.

Question 22

Can the femoral head and greater trochanter appear in the same axial slice?

Answer 22

Yes, especially in more inferior slices.

Question 23

Which muscles insert onto the greater trochanter?

Answer 23

• Gluteus medius
• Gluteus minimus.

Question 24

Where do gluteus medius and minimus originate?

Answer 24

Gluteal surface of ilium.

Question 25

Which muscles insert onto the lesser trochanter?

Answer 25

* Psoas major * Iliacus.

Question 26

How do psoas and iliacus appear on CT?

Answer 26

* Psoas: round * Iliacus: flat and thin.

Question 27

What does a foramen look like on cross-section?

Answer 27

A space between bony structures (often filled with muscles or vessels).

Question 28

Which muscle passes through the greater sciatic foramen?

Answer 28

Piriformis.

Question 29

What important structure lies anterior to piriformis?

Answer 29

Sacral plexus.

Question 30

Which muscle passes through the lesser sciatic foramen?

Answer 30

Obturator internus.

Question 31

At which vertebral levels do the aorta and IVC bifurcate?

Answer 31

* Aorta: L4 * IVC: L5.

Question 32

What is the relationship between iliac arteries and veins?

Answer 32

Veins run medial and beneath arteries (risk of compression).

Question 33

Which structure crosses anterior to the bifurcation of the common iliac artery?

Answer 33

Ureter.

Question 34

What muscle lies posterior to the external iliac vessels?

Answer 34

Psoas major.

Question 35

What is the lateral-to-medial order in the femoral triangle?

Answer 35

* Nerve * Artery * Vein.

Question 36

Where do sacral plexus roots exit the sacrum?

Answer 36

Anterior sacral foramina.

Question 37

Why can’t you see all sacral nerve roots in one coronal slice?

Answer 37

Sacrum is angled.

Question 38

The sacral plexus forms on the anterior surface of which muscle?

Answer 38

Piriformis.

Question 39

Through which foramen does the sciatic nerve exit the pelvis?

Answer 39

Greater sciatic foramen.

Question 40

What can compress the sciatic nerve at its exit point?

Answer 40

Tumor, piriformis syndrome, or pelvic fracture.