Pelvis and Perineum — MCQs
On this page
The increased incidence of infection in the ischiorectal fossa is due to which of the following factors?
In which type of pelvis is the anteroposterior (AP) diameter maximum?
A resident physician is performing a pelvic examination on a young woman. One hand's fingers are in the patient's vagina, palpating the cervix, while the other hand presses on the abdomen. With the palm of this abdominal hand, the physician feels a bony structure in the lower midline. What is this structure most likely?
Testicular lymphatics drain into which group of lymph nodes?
Which of the following statements regarding the fallopian tube is NOT true?
The ala of the sacrum is not crossed by which of the following structures?
Lymph from the glans penis drains into which of the following lymph nodes?
All of the following statements regarding the vas deferens are true except:
Smegma is secreted by which of the following glands?
A transverse vaginal septum corresponds to which anatomical structure?
Pelvis and Perineum Indian Medical PG Practice Questions and MCQs
Question 111: The increased incidence of infection in the ischiorectal fossa is due to which of the following factors?
- A. Absence of deep fascia
- B. Proximity to the anus
- C. Poor blood supply (Correct Answer)
- D. Presence of fibrofatty tissue
Explanation: ### Explanation The **ischiorectal (ischioanal) fossa** is a wedge-shaped space located on either side of the anal canal. It is filled with a large amount of loose, granular fat (the ischiorectal fat pad). **1. Why "Poor blood supply" is correct:** The primary reason for the high incidence of infection (ischiorectal abscess) and its subsequent rapid spread is the **poor vascularity** of the ischiorectal fat. Adipose tissue, in general, has a limited blood supply compared to muscle or skin. In the ischiorectal fossa, this lack of robust circulation means that immune cells and systemic antibiotics cannot reach the site of infection effectively [1]. Furthermore, the fat is arranged in small lobules separated by fibrous septa; once an infection starts, the low metabolic activity and poor perfusion allow bacteria (often from the anal glands) to multiply rapidly, leading to necrosis and abscess formation [1]. **2. Analysis of Incorrect Options:** * **Absence of deep fascia:** This is incorrect. The fossa is actually bounded by deep fascia (the obturator fascia laterally and the fascia of the pelvic diaphragm medially). * **Proximity to the anus:** While the proximity explains the *source* of the bacteria (E. coli, etc.), it does not explain the *increased incidence* or the body's inability to contain the infection. Many areas are proximal to the anus without having such high infection rates. * **Presence of fibrofatty tissue:** While the tissue is fibrofatty, it is specifically the **poor blood supply** within that fat that predisposes it to infection, rather than just the presence of the tissue itself. **3. High-Yield Clinical Pearls for NEET-PG:** * **Boundaries:** Lateral wall is formed by the **Obturator internus** muscle and its fascia. * **Pudendal Canal (Alcock’s Canal):** Located in the lateral wall; contains the pudendal nerve and internal pudendal vessels. * **Horseshoe Abscess:** The two ischiorectal fossae communicate behind the anal canal via the **deep postanal space**, allowing infections to spread from one side to the other. * **Nerve Supply:** The **inferior rectal nerve** and vessels traverse the fossa to reach the anal canal [1]. Damage during surgery can lead to fecal incontinence [2].
Question 112: In which type of pelvis is the anteroposterior (AP) diameter maximum?
- A. Platypelloid
- B. Android
- C. Anthropoid (Correct Answer)
- D. Gynaecoid
Explanation: **Explanation:** The classification of the female pelvis is based on the **Caldwell-Moloy system**, which categorizes pelvises into four types based on the shape of the pelvic inlet [1]. **1. Why Anthropoid is Correct:** The **Anthropoid pelvis** is characterized by an oval-shaped inlet where the **anteroposterior (AP) diameter is significantly greater than the transverse diameter**. It resembles the pelvis of great apes. Because of this elongated AP diameter, the fetal head often engages in the occipito-posterior position [3]. **2. Analysis of Incorrect Options:** * **Platypelloid:** This is a "flat" pelvis. It is the exact opposite of the anthropoid type; the **transverse diameter is much wider** than the AP diameter [2]. It has the shortest AP diameter among all types. * **Android:** Known as the "masculine" or heart-shaped pelvis. The inlet is heart-shaped with a narrow fore-pelvis. While the AP diameter is adequate, the widest transverse diameter is located posteriorly, making it unfavorable for labor. * **Gynaecoid:** This is the typical female pelvis (most common, ~50%). The inlet is **round**, and the AP and transverse diameters are roughly equal, providing the most ideal diameters for childbirth. **3. Clinical Pearls for NEET-PG:** * **Most Common Type:** Gynaecoid (Best prognosis for delivery). * **Least Common Type:** Platypelloid (Associated with transverse arrest of the fetal head). * **Anthropoid Association:** Often associated with **Non-rotation** of the fetal head (Persistent Occipito-Posterior position) [3]. * **Android Association:** Associated with **Deep Transverse Arrest** and "funneling" of the pelvis (convergent side walls and prominent ischial spines) [3].
Question 113: A resident physician is performing a pelvic examination on a young woman. One hand's fingers are in the patient's vagina, palpating the cervix, while the other hand presses on the abdomen. With the palm of this abdominal hand, the physician feels a bony structure in the lower midline. What is this structure most likely?
- A. Coccyx
- B. Ilium
- C. Ischium
- D. Pubis (Correct Answer)
Explanation: **Explanation:** The correct answer is **Pubis**. This question describes a **bimanual pelvic examination** [1], a fundamental clinical skill used to assess the size, shape, and position of the uterus and adnexa. **Why Pubis is correct:** In the lower midline of the abdomen, the most prominent bony landmark is the **pubic symphysis** (formed by the two pubic bones) [2]. When a physician presses on the lower abdominal wall (suprapubic region) while performing a vaginal examination, the palm of the external hand naturally rests over or just superior to the **pubis**. This bone forms the anterior boundary of the pelvic inlet and the anterior wall of the true pelvis [2]. **Why the other options are incorrect:** * **Coccyx:** This is the "tailbone" located at the most inferior and posterior part of the vertebral column. It is felt posteriorly during a digital rectal exam or deep vaginal palpation, not via the abdominal wall [2]. * **Ilium:** The iliac crests and anterior superior iliac spines (ASIS) are located laterally [2]. They do not occupy the lower midline position. * **Ischium:** The ischial tuberosities (the "sitting bones") and spines are located postero-inferiorly. They are deep within the perineum and are palpated laterally during a vaginal exam to assess pelvic outlet capacity, not through the abdomen. **High-Yield NEET-PG Pearls:** * **Pubic Symphysis:** A secondary cartilaginous joint (symphysis) that can widen slightly during pregnancy due to the hormone **relaxin**. * **Bimanual Exam:** Used to detect **anteversion** (angle between vagina and cervix) and **anteflexion** (angle between cervix and body of uterus) of the uterus. * **Clinical Landmark:** The superior border of the pubic symphysis is the landmark for measuring **Symphysio-Fundal Height (SFH)** in obstetrics to monitor fetal growth.
Question 114: Testicular lymphatics drain into which group of lymph nodes?
- A. Deep inguinal lymph nodes
- B. Internal iliac lymph nodes
- C. Paraaortic lymph nodes (Correct Answer)
- D. Superficial inguinal lymph nodes
Explanation: The lymphatic drainage of the testis is a classic high-yield topic in anatomy, governed by the embryological origin of the organ. **1. Why Paraaortic Lymph Nodes are Correct:** The testes develop in the posterior abdominal wall at the level of the **L2 vertebra** before descending into the scrotum through the inguinal canal. During this descent, they carry their original blood supply (testicular arteries from the abdominal aorta) and lymphatic vessels with them. Consequently, lymph from the testis follows the testicular veins back to the **paraaortic (pre-aortic and lateral aortic) lymph nodes** located near the origin of the renal arteries. **2. Why the Other Options are Incorrect:** * **Superficial Inguinal Lymph Nodes:** These drain the **scrotal skin** and the skin of the penis. A common exam trap is to confuse the drainage of the scrotum (superficial inguinal) with the drainage of the testis (paraaortic). * **Deep Inguinal Lymph Nodes:** These primarily drain the glans penis and the distal spongy urethra. * **Internal Iliac Lymph Nodes:** These drain most pelvic viscera (prostate, seminal vesicles, and bladder base) but not the testes. **3. Clinical Pearls for NEET-PG:** * **Testicular Cancer:** Because of this drainage pattern, testicular tumors metastasize first to the paraaortic nodes, not the groin. If a patient presents with enlarged inguinal nodes and a testicular mass, it suggests the tumor has invaded the **scrotal skin**. * **Ovarian Drainage:** Similar to the testes, the ovaries also drain into the **paraaortic lymph nodes** because they share a similar embryological site of origin. * **Key Landmark:** The specific nodes are often referred to as the **lumbar** or **lateral aortic** nodes at the level of L1–L3.
Question 115: Which of the following statements regarding the fallopian tube is NOT true?
- A. Fertilization commonly occurs in the ampullary portion of the fallopian tube.
- B. The interstitial portion of the fallopian tube lacks longitudinal muscle fibers.
- C. The fallopian tube receives blood supply from two distinct sources.
- D. The isthmus is the narrowest portion of the fallopian tube. (Correct Answer)
Explanation: ### Explanation The fallopian tube (salpinx) is a 10 cm long muscular tube essential for ovum transport and fertilization [1]. To identify the incorrect statement, we must analyze the anatomical segments and histology. **Why Option D is the Correct Answer (The "False" Statement):** While the isthmus is narrow, the **interstitial (intramural) portion** is the narrowest part of the fallopian tube, with a luminal diameter of approximately **0.5–1.0 mm**. It passes through the thick myometrium of the uterus. The isthmus is the narrowest *extra-uterine* part, but not the narrowest overall. **Analysis of Other Options:** * **Option A (True):** The **ampulla** is the widest and longest part of the tube. It is the most common site for both fertilization and ectopic pregnancies. * **Option B (True):** The histology of the fallopian tube typically consists of inner circular and outer longitudinal muscle layers. However, the **interstitial portion** is unique as it lacks a distinct longitudinal layer, being embedded within the uterine musculature. * **Option C (True):** The tube has a **dual blood supply**: the medial 2/3 is supplied by the **uterine artery** and the lateral 1/3 by the **ovarian artery** [2][3]. These two sources anastomose within the mesosalpinx. **High-Yield NEET-PG Pearls:** * **Epithelium:** Ciliated simple columnar epithelium (cilia beat toward the uterus) [3]. * **Peg Cells:** Non-ciliated secretory cells that provide nutrition to the ovum/zygote. * **Segments (Lateral to Medial):** Infundibulum (with fimbriae) → Ampulla → Isthmus → Interstitial part [4]. * **Lymphatic Drainage:** Primarily to the **Para-aortic nodes**.
Question 116: The ala of the sacrum is not crossed by which of the following structures?
- A. Sympathetic chain
- B. Iliolumbar artery
- C. Obturator nerve
- D. Ureter (Correct Answer)
Explanation: The **ala of the sacrum** is the large, wing-like lateral expansion of the base of the sacrum. It serves as a crucial anatomical landmark because several neurovascular structures pass anterior to it as they descend from the abdomen into the true pelvis. ### Why the Ureter is the Correct Answer The **ureter** does not cross the ala of the sacrum. Instead, it crosses the **bifurcation of the common iliac artery** (or the start of the external iliac artery) at the level of the sacroiliac joint to enter the pelvis. It lies more lateral and anterior compared to the structures that directly hug the bony surface of the ala. ### Explanation of Incorrect Options (Structures that DO cross the Ala) From medial to lateral, the structures crossing the ala of the sacrum are: 1. **Sympathetic Chain (Option A):** The pelvic continuation of the sympathetic trunk passes over the ala to lie medial to the pelvic foramina. 2. **Lumbosacral Trunk:** Formed by L4 and L5 nerve roots, it descends directly over the ala to join the sacral plexus. 3. **Iliolumbar Artery (Option B):** A branch of the internal iliac artery (posterior division) that ascends across the ala to reach the iliac fossa. 4. **Obturator Nerve (Option C):** Arising from the lumbar plexus (L2-L4), it runs over the lateral part of the ala to reach the obturator canal. ### High-Yield Facts for NEET-PG * **Mnemonic for structures crossing the Ala (Medial to Lateral):** "**S**illy **L**overs **I**n **O**hio" (**S**ympathetic chain, **L**umbosacral trunk, **I**liolumbar artery, **O**bturator nerve). * **Ureteric Constrictions:** The ureter is constricted at three points: (1) Pelviureteric junction, (2) Crossing the pelvic brim/iliac vessels, and (3) Vesicoureteric junction (narrowest part). * **Clinical Pearl:** During pelvic surgeries (like a radical hysterectomy), the ureter is most vulnerable at the point where it crosses the iliac vessels near the sacral promontory.
Question 117: Lymph from the glans penis drains into which of the following lymph nodes?
- A. Superficial inguinal nodes
- B. Deep inguinal lymph nodes (Correct Answer)
- C. Obturator nodes
- D. Internal iliac nodes
Explanation: The lymphatic drainage of the male external genitalia is a high-yield topic for NEET-PG, as it follows specific anatomical layers rather than a single uniform pathway. ### **Explanation of the Correct Answer** The **glans penis** (along with the distal spongy urethra) drains primarily into the **Deep Inguinal Lymph Nodes** (specifically the Node of Cloquet/Rosenmüller). From here, the lymph proceeds to the external iliac nodes. This is a critical distinction because the glans is a deeper structure compared to the overlying penile skin. ### **Analysis of Incorrect Options** * **A. Superficial Inguinal Nodes:** These nodes drain the **skin of the penis** and the **scrotum** (excluding the testes). A common examiner trap is to confuse the drainage of the penile skin (superficial) with the glans (deep). * **C. Obturator Nodes:** These primarily drain the pelvic viscera, such as the lower part of the bladder and the prostate, but are not the primary site for the glans penis. * **D. Internal Iliac Nodes:** These drain the **prostatic urethra**, seminal vesicles, and the base of the bladder. While some lymph from the glans may eventually reach the iliac chain, the immediate primary drainage is to the deep inguinal nodes. ### **NEET-PG High-Yield Pearls** * **Testis Drainage:** Drains to **Pre-aortic/Para-aortic nodes** (L2 level) because the testes descend from the posterior abdominal wall. * **Scrotum vs. Testis:** Scrotal cancer spreads to superficial inguinal nodes, while testicular cancer spreads to para-aortic nodes. * **Node of Cloquet:** Located in the femoral canal, it is the highest of the deep inguinal nodes and is a key site for metastasis from the glans penis and clitoris. * **Anal Canal:** Above the pectinate line drains to Internal Iliac nodes; below the pectinate line drains to Superficial Inguinal nodes.
Question 118: All of the following statements regarding the vas deferens are true except:
- A. The terminal part is dilated to form the ampulla.
- B. The terminal part is dilated to form the ampulla.
- C. The terminal part is dilated to form the ampulla.
- D. It is separated from the base of the bladder by the peritoneum. (Correct Answer)
Explanation: ### Explanation The **vas deferens (ductus deferens)** is a thick-walled muscular tube that transports spermatozoa from the epididymis to the ejaculatory duct. Understanding its pelvic course and relations is high-yield for NEET-PG. #### Why Option D is the Correct Answer (The False Statement) The vas deferens runs along the base of the bladder, medial to the seminal vesicles. Crucially, it lies **extraperitoneally** (subperitoneally) in this region. It is **not** separated from the bladder by the peritoneum; instead, it lies directly against the posterior wall of the bladder. The peritoneum actually reflects from the superior surface of the bladder onto the rectum, forming the rectovesical pouch, which lies posterior to the vas deferens. #### Analysis of Other Options * **The terminal part is dilated to form the ampulla:** This is a **true** statement [1]. Before joining the duct of the seminal vesicle, the vas deferens expands to form the **ampulla**, which serves as a reservoir for sperm. * *(Note: Options A, B, and C in the prompt were identical; in a standard exam, these would likely describe its length (~45cm), its origin from the tail of the epididymis, or its passage through the inguinal canal, all of which are true).* #### NEET-PG High-Yield Pearls * **Length:** 45 cm (similar to the thoracic duct, spinal cord, and femur). * **Course:** It crosses **superior** to the ureter ("Water under the bridge"—the ureter is the water, the vas is the bridge). * **Blood Supply:** Artery to the vas deferens (a branch of the **superior vesical artery** [1], which originates from the umbilical artery). * **Clinical Correlation:** In a **vasectomy**, the duct is ligated in the upper part of the scrotum to provide permanent contraception. It is easily palpable in the spermatic cord due to its "cord-like" or "wiry" consistency.
Question 119: Smegma is secreted by which of the following glands?
- A. Tyson gland (Correct Answer)
- B. Brenner gland
- C. Cowper's gland
- D. Bartholin's gland
Explanation: Smegma is a sebaceous secretion consisting of a mixture of exfoliated epithelial cells, skin oils, and moisture. It is primarily secreted by the Tyson glands (also known as preputial glands). These are modified sebaceous glands located on the internal surface of the prepuce (foreskin) and around the corona of the glans penis. In females, similar secretions occur around the clitoris and labia minora. Smegma serves as a lubricant but can lead to irritation or infection (balanitis) if hygiene is poor. **Analysis of Incorrect Options:** * **B. Brenner gland:** This refers to Brenner tumors, which are rare, usually benign ovarian tumors characterized by transitional epithelium (Walthard cell rests). There is no "Brenner gland" involved in secretion. * **C. Cowper’s gland:** Also known as Bulbourethral glands, these are located in the deep perineal pouch. They secrete a clear, alkaline pre-ejaculatory fluid into the penile urethra to neutralize acidity and provide lubrication. * **D. Bartholin’s gland:** Also known as Greater vestibular glands, these are the female homologs of Cowper’s glands. Located in the superficial perineal pouch, they secrete mucus to lubricate the vaginal orifice [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Homology:** Tyson glands (Male) ≈ Lesser vestibular glands (Female); Bartholin's glands are homologous to the bulb of the penis in males [1]. * **Pathology:** Accumulation of smegma is a known risk factor for Squamous Cell Carcinoma of the penis, as it may act as a chronic chemical irritant. * **Location:** Tyson glands are specifically found in the coronal sulcus.
Question 120: A transverse vaginal septum corresponds to which anatomical structure?
- A. External os (Correct Answer)
- B. Vesical neck
- C. Bladder base
- D. Hymen
Explanation: **Explanation:** The development of the vagina is a dual process involving the fusion of the **Müllerian ducts** (upper 4/5th) and the **urogenital sinus** (lower 1/5th) [1]. A **transverse vaginal septum** occurs due to a failure in the canalization of the vaginal plate at the junction where these two embryological origins meet [3]. 1. **Why External Os is Correct:** Anatomically, the junction between the Müllerian-derived upper vagina and the urogenital sinus-derived lower vagina corresponds to the level of the **external os** of the cervix. When canalization fails at this specific embryonic interface, a septum forms, most commonly in the upper or middle third of the vagina, aligning with the level of the external os. 2. **Why Incorrect Options are Wrong:** * **Vesical neck & Bladder base:** These are anterior relations of the vagina but do not represent the embryological junction points or the anatomical level where a transverse septum typically manifests [2]. * **Hymen:** The hymen represents the junction between the urogenital sinus and the exterior (sinovaginal bulbs) [1]. Failure of the hymen to perforate leads to an **imperforate hymen**, which is clinically distinct from a transverse vaginal septum [3]. **Clinical Pearls for NEET-PG:** * **Presentation:** Patients present with primary amenorrhea and cyclical pelvic pain due to **hematocolpos** (accumulation of blood). * **Differentiation:** Unlike an imperforate hymen, a transverse septum does **not** show a bulging, bluish membrane at the introitus on physical exam. * **Müllerian structures:** In transverse vaginal septum, the uterus and ovaries are typically normal (unlike Müllerian agenesis/MRKH syndrome) [3].
Practice by Chapter
Pelvic Walls and Floor
Practice Questions
Pelvic Viscera
Practice Questions
Urogenital Organs
Practice Questions
Pelvic Vasculature
Practice Questions
Pelvic Innervation
Practice Questions
Male Perineum
Practice Questions
Female Perineum
Practice Questions
Pelvic Lymphatics
Practice Questions
Applied Anatomy and Clinical Correlations
Practice Questions
Gender Differences in Pelvic Anatomy
Practice Questions
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free