Anatomical Variations and Anomalies — MCQs

Anatomical Variations and Anomalies Indian Medical PG Practice Questions and MCQs

Question 71: Pectus excavatum is

A. Protrusion of sternum
B. Sternal cleft
C. Lateral displacement of sternum
D. Sternal depression (Correct Answer)

Explanation: ***Sternal depression*** - **Pectus excavatum** is a congenital chest wall deformity characterized by an **inward depression** of the sternum and costal cartilages, creating a caved-in appearance of the chest. - This condition is also known as "funnel chest" due to the characteristic depressed shape. *Protrusion of sternum* - This describes **pectus carinatum**, a condition where the sternum and costal cartilages **protrude outward**, giving a "pigeon chest" appearance. - Unlike pectus excavatum, pectus carinatum involves an outward convex deformity. *Sternal cleft* - A **sternal cleft** is a rare congenital malformation where the **sternum is incompletely fused**, resulting in a gap or split in the breastbone. - This condition leads to the heart being very close to the skin, or even exposed, and can be associated with other midline defects. *Lateral displacement of sternum* - Lateral displacement of the sternum typically refers to a rare deformity where the **sternum shifts to one side** of the chest, often associated with other chest wall anomalies or scoliosis. - This is distinct from the symmetrical inward depression seen in pectus excavatum.

Question 72: Commonest site of hypospadias is:

A. Glanular/Coronal (Correct Answer)
B. Scrotum
C. Perineum
D. Mid-penile

Explanation: ***Glanular/Coronal*** - The most common location for the ectopic urethral opening in hypospadias is **glanular** or **coronal** (distal type). - This accounts for approximately **65-70%** of all hypospadias cases. - The urethral meatus opens on or just proximal to the glans penis. *Scrotum* - This represents a more **severe form** of hypospadias, where the urethral opening is located on the scrotum. - While it occurs, it is far **less common** than the distal forms. - Classified as **proximal hypospadias**. *Perineum* - **Perineal hypospadias** is the **most severe** form, with the urethral opening located in the perineum (between the scrotum and anus). - This is a **rare occurrence** and often associated with other urogenital anomalies. - Also classified as **proximal hypospadias**. *Mid-penile* - **Mid-shaft hypospadias** involves the urethral opening being located along the mid-portion of the penile shaft. - While more common than scrotal or perineal, it is **less frequent** than the distal (glanular/coronal) types. - Classified as **middle hypospadias**.

Question 73: Darwin tubercle is seen in ?

A. Tragus
B. Helix (Correct Answer)
C. Antihelix
D. Lobule

Explanation: Correct: Helix - Darwin tubercle (tuberculum auriculae) is a congenital ear condition manifesting as small thickening of cartilage on the posterosuperior part of the helix - Located at the junction of upper and middle thirds of the helix - Represents a vestigial feature from evolutionary ancestors where the ear formed a point - Named after Charles Darwin who described it as evidence of evolution - Present in approximately 10% of the population and is usually bilateral *Incorrect: Tragus* - The tragus is the small pointed eminence of cartilage anterior to the external acoustic meatus - Not associated with Darwin tubercle *Incorrect: Antihelix* - The antihelix is the curved prominence parallel and anterior to the helix - Separates the concha from the scapha - Darwin tubercle is not located here *Incorrect: Lobule* - The lobule (earlobe) is the soft, fleshy lower part of the auricle without cartilage - Darwin tubercle is a cartilaginous thickening on the helix, not the lobule

Question 74: Haller cells are seen in?

A. Roof of nose
B. Lateral nasal wall
C. Maxillary sinus
D. Orbital floor (Correct Answer)

Explanation: ***Orbital floor*** - **Haller cells** (also called **infraorbital ethmoid cells**) are **ethmoid air cells** that pneumatize **laterally and inferiorly along the medial orbital floor**. - They are specifically located at the **inferomedial aspect of the orbit**, projecting into the **roof of the maxillary sinus**. - Their presence can **narrow the infundibulum** and ostium of the maxillary sinus, predisposing to **recurrent sinusitis** and are important landmarks in **endoscopic sinus surgery**. - This is the **most anatomically accurate location** to describe where Haller cells are "seen." *Maxillary sinus* - While Haller cells project **into** the superior-medial aspect of the maxillary sinus and can affect its drainage, they are not primarily "seen in" the maxillary sinus itself. - They originate from the **ethmoid complex** at the orbital floor level, not from within the maxillary sinus. - The relationship is that Haller cells **encroach upon** the maxillary sinus space rather than being located within it. *Roof of nose* - The roof of the nose is formed by the **cribriform plate** of the ethmoid bone and is associated with the **olfactory region**. - This area contains **fila olfactoria** and is not the location of Haller cells. *Lateral nasal wall* - The lateral nasal wall contains the **turbinates** (superior, middle, and inferior conchae) and the **ostia** of paranasal sinuses. - While ethmoid air cells open into this region, Haller cells specifically refer to those located at the **orbital floor**, not the lateral nasal wall proper.

Question 75: Where are Onodi cells located?

A. Sphenoethmoidal air cells
B. Maxillary sinus
C. Anterior ethmoidal sinus
D. Posterior ethmoidal sinus (Correct Answer)

Explanation: Explore the anatomical details of the ethmoid sinus. ***Posterior ethmoidal sinus*** - **Onodi cells** are a variation of the **posterior ethmoidal air cells** that pneumatize laterally and superiorly to the sphenoid sinus. - Their location is clinically significant due to their close proximity to the **optic nerve**, making them a risk factor during sinus surgery. *Sphenoethmoidal air cells* - This term refers to the region where ethmoid cells and the sphenoid sinus meet, but it is not the specific location of Onodi cells. - Onodi cells are defined as a specific type of **posterior ethmoidal cell** that extends into this region, rather than the region itself being an Onodi cell. *Maxillary sinus* - The **maxillary sinus** is the largest paranasal sinus, located in the cheekbones and draining into the middle meatus. - It is anatomically distinct from the ethmoid sinuses where Onodi cells are found. *Anterior ethmoidal sinus* - **Anterior ethmoidal cells** are located anteriorly in the ethmoid labyrinth and drain into the middle meatus. - Onodi cells are a variant of the **posterior ethmoidal cells**, which drain into the superior meatus.

Question 76: Most common location of accessory spleen?

A. Lesser omentum
B. Hilum of spleen (Correct Answer)
C. Greater omentum
D. None of the options

Explanation: ***Hilum of spleen*** - The **splenic hilum** and adjacent structures (gastrosplenic ligament and splenorenal ligament) are the **most common locations** for accessory spleens, accounting for **50-80% of cases** - Accessory spleens, also known as **splenunculi**, are congenital abnormalities consisting of small nodules of splenic tissue found in approximately 10-30% of the population - Their proximity to the main spleen is explained by embryological development from the dorsal mesogastrium - They have clinical significance as they can undergo torsion, be mistaken for tumors, or cause recurrence of hematological conditions after splenectomy due to hypertrophy [1] *Greater omentum* - The **greater omentum** is a recognized but **less common site** for accessory spleens, accounting for approximately 20-30% of cases - While they can occur here, the majority are found closer to the splenic hilum and its associated ligaments - They are often discovered incidentally during imaging studies or surgical procedures *Lesser omentum* - The **lesser omentum** is a rare location for accessory spleens - This is much less common compared to locations in the greater omentum or near the splenic hilum - The embryological origin of the spleen from the dorsal (not ventral) mesogastrium makes this an uncommon site *None of the options* - This option is incorrect because the **hilum of spleen** is the well-established most common location for accessory spleens - Other documented locations include tail of pancreas, left ovary/testis, and bowel mesentery, but these are all less common than the splenic hilum

Question 77: Which of the following statements is true regarding circumcaval ureter?

A. Mostly involves right ureter (Correct Answer)
B. It is a developmental anomaly of the ureter.
C. The ureter passes posterior to the inferior vena cava.
D. Type 1 is more common than type 2.

Explanation: ***Mostly involves right ureter*** - **Circumcaval ureter** typically affects the **right ureter** because of the embryological development anomaly involving the inferior vena cava and its relationship with the ureteric bud. - This anatomical variation leads to the ureter passing *behind* and *around* the IVC. *It is a developmental anomaly of the ureter.* - While it is a **developmental anomaly**, it is specifically an anomaly of the **inferior vena cava (IVC)** development, not primarily the ureter itself. - The ureter is merely *caught* in an abnormal position due to the persistence of an embryonic right subcardinal vein that forms the IVC. *The ureter passes posterior to the inferior vena cava.* - The ureter passes **medial** and **posterior** to the **inferior vena cava** before circling **anteriorly** to resume its normal course, rather than simply posterior. - This unusual course can cause **compression** of the ureter and lead to **hydronephrosis**. *Type 1 is more common than type 2.* - **Type 2 circumcaval ureter** is actually the more common type, characterized by the ureter following a **tighter, 'reverse J'** or **'S' curve** behind the IVC. - **Type 1** involves a **wider, 'fish-hook' configuration** of the ureter as it passes behind the IVC and is less frequently observed.

Question 78: Most common location of ectopic salivary gland is -

A. Posterior triangle
B. Parathyroid gland
C. Cervical lymph nodes (Correct Answer)
D. Anterior mediastinum

Explanation: Cervical lymph nodes - **Ectopic salivary gland tissue** is most frequently found within or adjacent to **cervical periparotid lymph nodes**. - This is thought to be due to inclusion of salivary gland anlage within lymph nodes during embryological development. *Anterior mediastinum* - While ectopic tissues can occur in the mediastinum, **salivary gland tissue** is not a common finding there. - The **mediastinum** is more commonly associated with ectopic **thymic** or **thyroid** tissue. *Posterior triangle* - The **posterior triangle of the neck** is a common site for various neck masses , but **ectopic salivary gland tissue** is rare in this location. - Masses here are more typically **lymphadenopathy**, **brachial cleft cysts**, or **fibromas**. *Parathyroid gland* - The **parathyroid glands** are endocrine glands located near or within the thyroid, and are not typically associated with containing **ectopic salivary gland tissue**. - Their embryological development is distinct from that of salivary glands.

Question 79: What is the significance of the term 'Corona mortis' in human anatomy?

A. Anastomosis between superior and inferior gluteal arteries
B. A ligament connecting the pubic symphysis
C. A nerve crossing the pelvic brim
D. Anastomosis between obturator and inferior epigastric vessels (Correct Answer)

Explanation: ***Anastomosis between obturator and inferior epigastric vessels*** - **Corona mortis**, meaning "crown of death" in Latin, refers to a clinically significant vascular anastomosis that passes over the superior pubic ramus. - This anastomosis usually occurs between the **obturator artery** (a branch of the internal iliac artery) and the **inferior epigastric artery** (a branch of the external iliac artery), posing a risk of severe hemorrhage during surgical procedures in the retropubic space [1]. *Anastomosis between superior and inferior gluteal arteries* - While gluteal arteries do anastomose, they form a crucial part of the **cruciate anastomosis of the thigh**, not the corona mortis. - This anastomosis is important for blood supply to the hip joint and thigh musculature, far removed from the retropubic space. *A ligament connecting the pubic symphysis* - The pubic symphysis is connected by ligaments such as the **superior and arcuate pubic ligaments**, which provide stability to the joint. - These are fibrous structures and do not represent a vascular anastomosis. *A nerve crossing the pelvic brim* - Several nerves cross the pelvic brim, such as the **obturator nerve** or the **femoral nerve**, but these are neural structures. - The term corona mortis specifically refers to a **vascular connection**, not a nerve.

Question 80: Spleniculi are most commonly found in which of the following locations?

A. Colon
B. Liver
C. Lungs
D. Hilum of the spleen (Correct Answer)

Explanation: No relevant citations could be added to the explanation as the provided text passages did not contain information regarding spleniculi (accessory spleens), their location, or their embryology. ***Hilum of the spleen*** - **Spleniculi** (accessory spleens) are most commonly found at the **hilum of the spleen**, accounting for approximately **75% of cases**. - During **embryonic development**, the spleen forms from mesenchymal tissue in the dorsal mesogastrium, and small fragments of splenic tissue can separate and persist as accessory spleens. - The **splenic hilum** is the most frequent location due to the close proximity during development, followed by the gastrosplenic ligament, tail of pancreas, and greater omentum. - Accessory spleens are found in **10-30% of the population** and are clinically significant in conditions requiring complete splenectomy (e.g., ITP, hereditary spherocytosis). *Colon* - The colon is part of the **gastrointestinal tract** with a completely different embryological origin (endodermal). - Splenic tissue development occurs in the **dorsal mesogastrium** (mesodermal origin), making the colon an anatomically and embryologically implausible location for spleniculi. *Liver* - The liver develops from the **ventral foregut endoderm** and is anatomically distant from the spleen's developmental region. - **Splenosis** (traumatic implantation) could theoretically occur, but congenital spleniculi in the liver are exceptionally rare and not a recognized common location. *Lungs* - The lungs are part of the **respiratory system**, developing from the foregut endoderm in the thoracic cavity. - There is no embryological connection between lung and splenic tissue development, making this an impossible location for congenital accessory spleens.

Practice by Chapter

Principles of Anatomical Variations

Practice Questions

Variations in Vascular Anatomy

Practice Questions

Variations in Musculoskeletal System

Practice Questions

Variations in Nervous System

Practice Questions

Variations in Visceral Anatomy

Practice Questions

Clinically Significant Anatomical Variations

Practice Questions

Congenital Malformations

Practice Questions

Genetic Basis of Anatomical Variations

Practice Questions

Surgical Implications of Variations

Practice Questions

Imaging Aspects of Anatomical Variations

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free