COMSAE PHASE 1 PELVIC & PERINEAL
ANATOMY PRACTICE EXAM WITH ACTUAL
QUESTIONS AND VERIFIED ANSWERS,
PLUS EXPLAINED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED 100% PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1. A 24-year-old woman sustains a penetrating injury to the lateral
pelvic wall. Imaging demonstrates damage to a nerve that courses along
the lateral pelvic wall, medial to the internal iliac vessels, before
entering the obturator canal. Which nerve has most likely been injured?
A. Pudendal nerve
B. Sciatic nerve
C. Obturator nerve
D. Inferior gluteal nerve
E. Femoral nerve
Answer: C. Obturator nerve
Rationale: The obturator nerve arises from the anterior divisions of
L2–L4 and descends along the lateral pelvic wall on the medial surface
of the obturator internus muscle. It exits the pelvis through the
obturator canal and supplies the muscles of the medial thigh. The
pudendal nerve exits the pelvis through the greater sciatic foramen
and reenters through the lesser sciatic foramen. The sciatic nerve exits
through the greater sciatic foramen, typically inferior to piriformis.
2. During pelvic surgery, a surgeon identifies a large nerve traveling
anterior to the internal iliac artery and descending along the lateral
1
,pelvic wall. The nerve is then observed passing through the greater
sciatic foramen inferior to the piriformis muscle. Which nerve is this?
A. Pudendal nerve
B. Sciatic nerve
C. Obturator nerve
D. Superior gluteal nerve
E. Inferior hypogastric plexus
Answer: B. Sciatic nerve
Rationale: The sciatic nerve is formed by L4–S3 ventral rami and is
the largest peripheral nerve in the body. It exits the pelvis through the
greater sciatic foramen, usually inferior to piriformis. The pudendal
nerve also exits through the greater sciatic foramen but then hooks
around the sacrospinous ligament and enters the perineum through
the lesser sciatic foramen.
3. A patient develops fecal incontinence following an obstetric injury
involving the nerve that supplies the external anal sphincter. Which
nerve is primarily responsible for motor innervation of this muscle?
A. Pelvic splanchnic nerve
B. Inferior hypogastric plexus
C. Pudendal nerve
D. Hypogastric nerve
E. Obturator nerve
Answer: C. Pudendal nerve
Rationale: The pudendal nerve arises from S2–S4 and provides
somatic motor innervation to the external anal sphincter as well as
other perineal muscles. It travels through the pudendal canal along
the lateral wall of the ischioanal fossa. Injury can cause impaired
voluntary control of the anal sphincter.
2
,4. A 31-year-old woman undergoes a pudendal nerve block for labor
analgesia. The anesthetic is injected near the ischial spine. Which
structure provides the key landmark around which the pudendal nerve
courses before entering the perineum?
A. Sacrotuberous ligament
B. Sacrospinous ligament
C. Iliolumbar ligament
D. Inguinal ligament
E. Pubofemoral ligament
Answer: B. Sacrospinous ligament
Rationale: The pudendal nerve exits the pelvis through the greater
sciatic foramen, passes around the ischial spine and sacrospinous
ligament, and then enters the perineum through the lesser sciatic
foramen. The ischial spine is therefore an important clinical landmark
for pudendal nerve anesthesia.
5. Which muscle forms the primary muscular component of the pelvic
diaphragm?
A. Piriformis and obturator internus
B. Coccygeus and piriformis
C. Levator ani and coccygeus
D. Obturator internus and levator ani
E. Gluteus maximus and coccygeus
Answer: C. Levator ani and coccygeus
Rationale: The pelvic diaphragm consists primarily of the levator ani
and coccygeus muscles, together with their associated fascia. Levator
ani includes puborectalis, pubococcygeus, and iliococcygeus. The
3
, pelvic diaphragm supports pelvic viscera and contributes to
continence.
6. A patient develops pelvic organ prolapse after repeated vaginal
deliveries. Weakness of which muscle component of levator ani would
most directly compromise the anorectal angle and fecal continence?
A. Iliococcygeus
B. Coccygeus
C. Puborectalis
D. Obturator internus
E. Piriformis
Answer: C. Puborectalis
Rationale: Puborectalis forms a muscular sling around the anorectal
junction. Its tonic contraction maintains the anorectal angle, which
contributes significantly to fecal continence. Relaxation of
puborectalis during defecation allows the anorectal angle to straighten
and facilitates passage of stool.
7. Which fascial structure provides the primary superior attachment of
the levator ani along the lateral pelvic wall?
A. Tendinous arch of levator ani
B. Arcuate line
C. Pectineal ligament
D. Sacrospinous ligament
E. Perineal membrane
Answer: A. Tendinous arch of levator ani
Rationale: The levator ani originates partly from the tendinous arch of
the obturator fascia, often termed the tendinous arch of levator ani,
4
ANATOMY PRACTICE EXAM WITH ACTUAL
QUESTIONS AND VERIFIED ANSWERS,
PLUS EXPLAINED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED 100% PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1. A 24-year-old woman sustains a penetrating injury to the lateral
pelvic wall. Imaging demonstrates damage to a nerve that courses along
the lateral pelvic wall, medial to the internal iliac vessels, before
entering the obturator canal. Which nerve has most likely been injured?
A. Pudendal nerve
B. Sciatic nerve
C. Obturator nerve
D. Inferior gluteal nerve
E. Femoral nerve
Answer: C. Obturator nerve
Rationale: The obturator nerve arises from the anterior divisions of
L2–L4 and descends along the lateral pelvic wall on the medial surface
of the obturator internus muscle. It exits the pelvis through the
obturator canal and supplies the muscles of the medial thigh. The
pudendal nerve exits the pelvis through the greater sciatic foramen
and reenters through the lesser sciatic foramen. The sciatic nerve exits
through the greater sciatic foramen, typically inferior to piriformis.
2. During pelvic surgery, a surgeon identifies a large nerve traveling
anterior to the internal iliac artery and descending along the lateral
1
,pelvic wall. The nerve is then observed passing through the greater
sciatic foramen inferior to the piriformis muscle. Which nerve is this?
A. Pudendal nerve
B. Sciatic nerve
C. Obturator nerve
D. Superior gluteal nerve
E. Inferior hypogastric plexus
Answer: B. Sciatic nerve
Rationale: The sciatic nerve is formed by L4–S3 ventral rami and is
the largest peripheral nerve in the body. It exits the pelvis through the
greater sciatic foramen, usually inferior to piriformis. The pudendal
nerve also exits through the greater sciatic foramen but then hooks
around the sacrospinous ligament and enters the perineum through
the lesser sciatic foramen.
3. A patient develops fecal incontinence following an obstetric injury
involving the nerve that supplies the external anal sphincter. Which
nerve is primarily responsible for motor innervation of this muscle?
A. Pelvic splanchnic nerve
B. Inferior hypogastric plexus
C. Pudendal nerve
D. Hypogastric nerve
E. Obturator nerve
Answer: C. Pudendal nerve
Rationale: The pudendal nerve arises from S2–S4 and provides
somatic motor innervation to the external anal sphincter as well as
other perineal muscles. It travels through the pudendal canal along
the lateral wall of the ischioanal fossa. Injury can cause impaired
voluntary control of the anal sphincter.
2
,4. A 31-year-old woman undergoes a pudendal nerve block for labor
analgesia. The anesthetic is injected near the ischial spine. Which
structure provides the key landmark around which the pudendal nerve
courses before entering the perineum?
A. Sacrotuberous ligament
B. Sacrospinous ligament
C. Iliolumbar ligament
D. Inguinal ligament
E. Pubofemoral ligament
Answer: B. Sacrospinous ligament
Rationale: The pudendal nerve exits the pelvis through the greater
sciatic foramen, passes around the ischial spine and sacrospinous
ligament, and then enters the perineum through the lesser sciatic
foramen. The ischial spine is therefore an important clinical landmark
for pudendal nerve anesthesia.
5. Which muscle forms the primary muscular component of the pelvic
diaphragm?
A. Piriformis and obturator internus
B. Coccygeus and piriformis
C. Levator ani and coccygeus
D. Obturator internus and levator ani
E. Gluteus maximus and coccygeus
Answer: C. Levator ani and coccygeus
Rationale: The pelvic diaphragm consists primarily of the levator ani
and coccygeus muscles, together with their associated fascia. Levator
ani includes puborectalis, pubococcygeus, and iliococcygeus. The
3
, pelvic diaphragm supports pelvic viscera and contributes to
continence.
6. A patient develops pelvic organ prolapse after repeated vaginal
deliveries. Weakness of which muscle component of levator ani would
most directly compromise the anorectal angle and fecal continence?
A. Iliococcygeus
B. Coccygeus
C. Puborectalis
D. Obturator internus
E. Piriformis
Answer: C. Puborectalis
Rationale: Puborectalis forms a muscular sling around the anorectal
junction. Its tonic contraction maintains the anorectal angle, which
contributes significantly to fecal continence. Relaxation of
puborectalis during defecation allows the anorectal angle to straighten
and facilitates passage of stool.
7. Which fascial structure provides the primary superior attachment of
the levator ani along the lateral pelvic wall?
A. Tendinous arch of levator ani
B. Arcuate line
C. Pectineal ligament
D. Sacrospinous ligament
E. Perineal membrane
Answer: A. Tendinous arch of levator ani
Rationale: The levator ani originates partly from the tendinous arch of
the obturator fascia, often termed the tendinous arch of levator ani,
4
