Pelvis and Perineum Practice Questions

Q: The Prostatic urethra is characterized by all of the following features, except:

It presents a concavity posteriorly.. ### Explanation The prostatic urethra is approximately 3 cm long and is the most complex portion of the male urethra. **Why Option B is the Correct Answer (The Exception):** The prostatic urethra descends through the prostate gland with a **slight anterior convexity**. Therefore, its **concavity is directed anteriorly**, not posteriorly. This curvature is an important anatomical landmark during the passage of urethral catheters or cystoscopes. **Analysis of Other Options:** * **Option A:** The prostatic urethra is indeed the **widest and most dilatable** part of the entire male urethra. This makes it a significant landmark during surgical procedures like TURP (Transurethral Resection of the Prostate). * **Option C:** It does not run through the center of the gland; rather, it traverses the prostate closer to its **anterior surface**. * **Option D:** The posterior wall of the prostatic urethra features the **urethral crest**. On either side of this crest lies the **prostatic sinus**, which receives the openings of approximately 15–20 prostatic ductules. **High-Yield Clinical Pearls for NEET-PG:** * **Verumontanum (Seminal Colliculus):** An elevation on the urethral crest where the prostatic utricle opens and the two ejaculatory ducts enter. * **Prostatic Utricle:** A blind pouch representing the male homologue of the uterus and vagina (Müllerian duct remnant). * **Narrowest Part:** The **membranous urethra** is the least dilatable part, while the **external urethral meatus** is the narrowest point of the entire urethra [1]. * **Length:** Prostatic (3 cm) > Membranous (1.5 cm) > Penile/Spongy (15 cm).

Q: What is the length of the adult female cervical canal?

2.5 cm. **Explanation:** The **cervix** is the lower, cylindrical portion of the uterus [1]. In a non-pregnant adult female, the total length of the uterus is approximately 7.5 cm [1], which is divided into the corpus (body) and the cervix. The cervix itself measures about **2.5 cm (1 inch)** in length [1]. The **cervical canal** is the interior passage of the cervix, extending from the **internal os** (opening into the uterine cavity) to the **external os** (opening into the vagina). It is spindle-shaped, being widest at its mid-point. **Analysis of Options:** * **Option B (2.5 cm):** This is the standard anatomical length of the adult cervical canal [1]. It represents roughly one-third of the total uterine length in a reproductive-age woman. * **Option A (2 cm):** This is slightly shorter than the average and may be seen in prepubertal girls or cases of cervical atrophy, but it is not the standard adult measurement. * **Option C (6 cm):** This is closer to the length of the entire **uterine cavity** (which is approximately 6–7 cm from the fundus to the external os) [2]. * **Option D (10 cm):** This is an incorrect dimension for the cervix; however, 10 cm is the average length of the **fallopian tubes** and the **vagina** (posterior wall). **High-Yield Facts for NEET-PG:** 1. **Uterine Proportions:** In adults, the ratio of the body of the uterus to the cervix is **2:1**. In infants, this ratio is reversed (**1:2**). 2. **Histology:** The cervical canal is lined by **simple columnar epithelium**, while the ectocervix (vaginal portion) is lined by **stratified squamous non-keratinized epithelium**. The junction between these two is the **Squamocolumnar Junction (SCJ)**, the primary site for cervical cancer screening (Pap smear). 3. **Clinical Significance:** During labor, the cervical canal undergoes "effacement" (thinning and shortening) and "dilatation" to allow the passage of the fetus [3].

Q: All are parts of the vulva except:

Perineal body. The **vulva** (pudendum) refers to the collective external female genitalia [1]. Anatomically, it is bounded by the mons pubis anteriorly, the perineum posteriorly, and the labia majora laterally [1]. **Why the Perineal Body is the Correct Answer:** The **perineal body** (central tendon of the perineum) is a fibromuscular mass located in the midline between the anal canal and the vagina/bulb of the penis [3]. While it serves as a critical structural anchor for the pelvic floor and perineal muscles, it is an **internal structure** of the pelvic outlet and is not considered a component of the external vulva [3]. **Analysis of Incorrect Options:** * **Labia majora:** These are two prominent longitudinal cutaneous folds that form the lateral boundaries of the vulval cleft [1]. They are homologous to the scrotum in males. * **Labia minora:** These are smaller, hairless vascular folds located medial to the labia majora [2]. They enclose the vestibule. * **Clitoris:** This is an erectile organ located at the superior junction of the labia minora [2]. It is the female homologue of the penis. **High-Yield NEET-PG Pearls:** 1. **Components of Vulva:** Mons pubis, labia majora, labia minora, clitoris, vestibule (containing urethral and vaginal orifices), and vestibular glands (Bartholin’s) [1],[2]. 2. **Perineal Body Attachments:** It is the meeting point for **8 muscles**: External anal sphincter, Bulbospongiosus, Superficial and Deep transverse perinei, Levator ani (Puborectalis), and fibers of the longitudinal muscle of the rectum [3]. 3. **Clinical Significance:** Damage to the perineal body during childbirth can lead to pelvic organ prolapse. It is the structure incised during a **mediolateral episiotomy** [3].

Q: Which of the following is an unpaired muscle of the perineal body?

Longitudinal muscle of the anal canal. The **perineal body** (central tendon of the perineum) is a fibromuscular mass located in the midline between the anal canal and the urogenital apparatus [2]. It serves as a critical anchoring point for several pelvic floor muscles. ### **Explanation of the Correct Answer** The **longitudinal muscle of the anal canal** is the correct answer because it is a single, midline muscular layer (derived from the outer longitudinal coat of the rectum) that descends between the internal and external anal sphincters. As it reaches the perineal body, it decussates and inserts into it as a **single, unpaired structure**. ### **Analysis of Incorrect Options** * **A. Bulbospongiosus:** These are **paired** muscles. In males, they surround the bulb of the penis; in females, they surround the orifice of the vagina. They meet in the midline at the perineal body. * **C. Deep transverse perineal muscle:** These are **paired** muscles located within the deep perineal pouch [2]. they extend from the ischial tuberosities to meet at the perineal body. * **D. Levator Ani:** This is a **paired** muscle complex (comprising pubococcygeus, puborectalis, and iliococcygeus) [1]. The anterior fibers (levator prostatae/sphincter vaginae) insert into the perineal body from both sides. ### **High-Yield NEET-PG Pearls** * **Muscles attaching to the Perineal Body (Rule of 10):** There are 10 muscles in total—3 pairs of bilateral muscles (6) and 4 single/unpaired muscles. * **Paired:** Bulbospongiosus, Superficial transverse perineal, Deep transverse perineal. * **Unpaired:** External anal sphincter, Internal anal sphincter, Longitudinal muscle of anal canal, and fibers of Levator ani (Puborectalis). * **Clinical Significance:** Damage to the perineal body during childbirth (episiotomy or perineal tear) can lead to pelvic organ prolapse or fecal incontinence due to the loss of structural integrity of the pelvic floor [2].

Q: The sympathetic fibers supplying the uterus are derived from which segments of the vertebrae?

T12 - L2. ### Explanation **1. Why the Correct Answer is Right (T12 - L2):** The autonomic nerve supply to the uterus is primarily derived from the **inferior hypogastric (pelvic) plexus**. The sympathetic component of this supply originates from the **preganglionic neurons** located in the lateral gray horn of the spinal cord segments **T12 to L2** [1]. These fibers pass through the lumbar splanchnic nerves to reach the hypogastric plexuses. Functionally, these sympathetic fibers are primarily vasomotor (causing vasoconstriction) and are responsible for the contraction of the uterine musculature (myometrium) and the internal os, although their role in labor is complex and modulated by hormonal factors. **2. Analysis of Incorrect Options:** * **A. T12 - L1:** This range is too narrow. While it includes the starting point, it misses the crucial L2 contribution which is consistently documented in anatomical texts for pelvic viscera. * **B. T11 - L2:** T11 typically contributes to the nerve supply of the kidneys and upper ureters (via the least splanchnic nerve), but the specific uterine sympathetic outflow begins at T12. * **C. T1 - S2:** This is incorrect as T1 is involved in the nerve supply to the head, neck, and upper limbs. S2 is part of the **parasympathetic** outflow (S2-S4, pelvic splanchnic nerves), not the sympathetic outflow. **3. NEET-PG High-Yield Pearls:** * **Pain Pathway:** Pain from the **uterine body** (intraperitoneal) travels with sympathetic fibers to **T12-L2** dorsal root ganglia. However, pain from the **cervix** (subperitoneal) travels with parasympathetic fibers to **S2-S4** [1]. * **Frankenhauser's Plexus:** Another name for the uterovaginal plexus (a division of the inferior hypogastric plexus) located in the base of the broad ligament. * **Clinical Correlation:** During childbirth, a spinal block typically targets T10-L2 to abolish uterine contraction pain, while a pudendal block (S2-S4) targets perineal pain.

Q: A female pelvis differs from a male pelvis by all of the following except:

Prominent muscle markings. The human pelvis exhibits significant sexual dimorphism, primarily adapted to the requirements of childbirth in females versus locomotion and weight-bearing in males [1]. **Why "Prominent muscle markings" is the correct answer:** Prominent muscle markings are a characteristic of the **male pelvis**, not the female pelvis. Because males generally have greater muscle mass and higher physical stress on the skeletal system, the sites of muscle attachment (like the iliac crests and ischial tuberosities) are more rugged and pronounced. In contrast, the female pelvis is smoother and lighter. **Explanation of incorrect options (Female Pelvic Characteristics):** * **Obtuse subpubic angle:** In females, the subpubic angle is wide (usually >80–90° or obtuse) to increase the diameter of the pelvic outlet. In males, this angle is acute (approx. 60–70°). * **Broad greater sciatic foramen:** The female greater sciatic foramen is wider and shallower, which contributes to a roomier pelvic cavity. * **Broad lesser sciatic foramen:** Similar to the greater foramen, the lesser sciatic foramen is wider in females to accommodate the wider pelvic outlet. **High-Yield NEET-PG Clinical Pearls:** * **Gynaecoid Pelvis:** The most common female pelvic type (50%), characterized by a round inlet and blunt ischial spines [2]. * **Android Pelvis:** The typical male pattern; if present in females, it increases the risk of "deep transverse arrest" during labor [2]. * **Sacrum:** In females, the sacrum is shorter, wider, and more curved posteriorly to increase the capacity of the pelvic cavity [1]. * **Pelvic Inlet:** Typically transversely oval in females and heart-shaped in males [2].

Q: Where does urine collect in case of an extraperitoneal rupture of the bladder?

Above the urogenital diaphragm. ### Explanation **1. Why "Above the urogenital diaphragm" is correct:** The urinary bladder is located extraperitoneally in the **true pelvis**, resting superior to the urogenital diaphragm (triangular ligament). When an extraperitoneal rupture occurs—most commonly associated with **pelvic fractures** [1]—the integrity of the bladder wall is breached below the peritoneal reflection. Consequently, urine extravasates into the **prevesical space (Space of Retzius)** and the surrounding pelvic extraperitoneal connective tissue. Since the urogenital diaphragm forms the floor of the pelvic cavity, the extravasated urine remains confined **above** this diaphragm within the pelvic fascia [3]. **2. Why the other options are incorrect:** * **Options A & B (Perineal space / Below the urogenital diaphragm):** These locations are involved in **extraperitoneal rupture of the urethra**, not the bladder [2]. Specifically, a rupture of the bulbous urethra (below the urogenital diaphragm) leads to urine collection in the superficial perineal pouch. This urine can then track into the scrotum and anterior abdominal wall (deep to Scarpa’s fascia) but is anatomically separated from the bladder's pelvic compartment by the urogenital diaphragm. **3. Clinical Pearls for NEET-PG:** * **Intraperitoneal Rupture:** Occurs at the **bladder dome** (the only part covered by peritoneum), usually due to blunt trauma to a full bladder. * **Extraperitoneal Rupture:** Most common type; usually associated with **pubic arch fractures** [1]. * **Classic Presentation:** Gross hematuria, suprapubic pain, and inability to void [1]. * **Investigation of Choice:** Retrograde Cystography (shows "flame-shaped" extravasation in extraperitoneal cases) [1].

Question 1

The Prostatic urethra is characterized by all of the following features, except:

Accepted Answer

It presents a concavity posteriorly.

Answer

It is the widest and most dilatable part.

Answer

It lies closer to the anterior surface of the prostate.

Answer

It receives prostatic ductules along its posterior wall.

Question 2

What is the length of the adult female cervical canal?

Accepted Answer

2.5 cm

Answer

2 cm

Answer

6 cm

Answer

10 cm

Question 3

All are parts of the vulva except:

Accepted Answer

Perineal body

Answer

Labia minora

Answer

Labia majora

Answer

Clitoris

Question 4

It can be stated that the superior hemorrhoidal veins:

Accepted Answer

Leave the anal canal at the pectinate line.

Answer

Drain into the inferior mesenteric vein.

Answer

Have no valves.

Answer

Cause external hemorrhoids.

Question 5

During direct injection of prostaglandin E1 into the corpus cavernosum for erectile dysfunction, through which layers would the needle pass in order?

Accepted Answer

Skin, superficial penile fascia, Buck's fascia, tunica albuginea

Answer

Skin, Buck's fascia, superficial penile fascia, deep fascia, tunica albuginea

Answer

Skin, perineal membrane, superficial penile fascia, deep perineal fascia

Answer

Skin, superficial penile fascia, tunica albuginea, perineal membrane

Question 6

The obliterated umbilical artery is a continuation of which of the following arteries?

Accepted Answer

Anterior division of the internal iliac artery

Answer

Posterior division of the internal iliac artery

Answer

Superior vesical artery

Answer

Inferior vesical artery

Question 7

Which of the following is an unpaired muscle of the perineal body?

Accepted Answer

Longitudinal muscle of the anal canal

Answer

Bulbospongiosus

Answer

Deep transverse perineal muscle

Answer

Levator Ani

Question 8

The sympathetic fibers supplying the uterus are derived from which segments of the vertebrae?

Accepted Answer

T12 - L2

Answer

T12 - L1

Answer

T11 - L2

Answer

T1 - S2

Question 9

A female pelvis differs from a male pelvis by all of the following except:

Accepted Answer

Prominent muscle markings

Answer

Obtuse subpubic angle

Answer

Broad greater sciatic foramen

Answer

Broad lesser sciatic foramen

Question 10

Where does urine collect in case of an extraperitoneal rupture of the bladder?

Accepted Answer

Above the urogenital diaphragm

Answer

Perineal space

Answer

Below the urogenital diaphragm

Answer

None of the above

Pelvis and Perineum — MCQs

Pelvis and Perineum — MCQs

On this page

Practice by Chapter

Want unlimited practice?