A woman presents with a breast lump, associated with skin dimpling and nipple retraction. What is the most likely anatomical structure responsible for the skin dimpling?
What is the embryological basis for the uterine anomaly shown in the images?
Which of the following veins is involved in the formation of esophageal varices?
Injury to which part causes difficulty in dorsiflexion of the foot?
A 30-year-old man came with choking episodes after ingestion of fish bone while eating. The fishbone got impacted at the level of T4 in the esophagus. Which is the most likely site of obstruction?
A man fell on his shoulder with his head pushed in the opposite direction. He presented with the following deformity. Which nerve root values are most likely affected?
Which structure is formed by the structure indicated by the arrow?
Identify the nerve roots involved in the condition depicted in the image.
Which is the narrowest part of the adult laryngeal airway?
A man sustained trauma on the lateral side of his right knee. Two days later, he complains of difficulty in walking, as his toes keep dragging on the ground. He also notices numbness over the upper lateral aspect of the leg and dorsum of the foot. Which nerve is most likely injured?
FMGE 2025 - Anatomy FMGE Practice Questions and MCQs
Question 21: A woman presents with a breast lump, associated with skin dimpling and nipple retraction. What is the most likely anatomical structure responsible for the skin dimpling?
- A. Lactiferous ducts
- B. Suspensory (Cooper’s) ligaments (Correct Answer)
- C. Subcutaneous fat
- D. Pectoral fascia
Explanation: ***Suspensory (Cooper’s) ligaments*** - These are fibrous septa that run from the deep pectoral fascia to the dermis of the skin, providing structural support to the breast [1]. - Invasion and shortening of these ligaments by a growing tumor pull on the overlying skin, causing the characteristic **skin dimpling** or peau d'orange appearance [1]. *Lactiferous ducts* - These are the milk ducts that converge and open at the nipple [1]. - Malignant infiltration of the lactiferous ducts is more commonly associated with **nipple retraction** and pathologic nipple discharge, rather than skin dimpling [2]. *Pectoral fascia* - This is a deep layer of connective tissue that covers the pectoralis major muscle, on which the breast lies [1]. - Tumor invasion into the pectoral fascia can cause the breast to become **fixed** to the chest wall, a sign of advanced disease, but does not directly cause superficial skin dimpling. *Subcutaneous fat* - This tissue makes up the bulk of the breast volume and surrounds the glandular components. - Subcutaneous fat itself lacks the tensile strength to pull the skin inward; it is the **fibrous ligaments** passing through the fat that cause retraction [1].
Question 22: What is the embryological basis for the uterine anomaly shown in the images?
- A. Failure of fusion of metanephric duct
- B. Non-fusion of mesonephric duct
- C. Complete agenesis of Müllerian structures
- D. Non-fusion of paramesonephric ducts (Correct Answer)
Explanation: ***Non-fusion of paramesonephric ducts*** - The image shows a **uterus didelphys**, which is a complete duplication of the uterus and cervix. This anomaly occurs due to a complete failure of the two **paramesonephric (Müllerian) ducts** to fuse medially during embryogenesis. - The **paramesonephric ducts** are the embryological precursors to the fallopian tubes, uterus, cervix, and the upper one-third of the vagina. Their proper fusion is essential for forming a single uterine cavity. *Non-fusion of mesonephric duct* - The **mesonephric (Wolffian) ducts** are precursors to male internal genitalia (e.g., epididymis, ductus deferens, seminal vesicles) and largely regress in females. - Remnants of the mesonephric duct in females may form **Gartner's cysts**, but they do not contribute to the formation of the uterus. *Failure of fusion of metanephric duct* - The **metanephric duct**, or **ureteric bud**, is involved in the development of the urinary system, specifically the ureters, renal pelves, calyces, and collecting ducts of the kidneys. - This structure is entirely unrelated to the embryological development of the female reproductive tract. *Complete agenesis of Müllerian structures* - Complete agenesis of the **Müllerian structures** results in the congenital absence of the uterus, fallopian tubes, and upper vagina, a condition known as **Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome**. - The image clearly depicts the presence of uterine horns and a cervix, which contradicts a diagnosis of agenesis (complete absence).
Question 23: Which of the following veins is involved in the formation of esophageal varices?
- A. Left gastric vein (Correct Answer)
- B. Left gastroepiploic vein
- C. Right gastric vein
- D. Right gastroepiploic vein
Explanation: ***Left gastric vein*** - The **left gastric vein** (coronary vein) is the primary vessel involved in esophageal varices formation through **portosystemic anastomoses** at the **gastroesophageal junction** during portal hypertension [1]. - It connects the **portal circulation** to the **systemic circulation** via esophageal veins, creating the most clinically significant pathway for variceal development [1]. *Left gastroepiploic vein* - This vein drains the **greater curvature of the stomach** and flows into the splenic vein, not forming significant connections with esophageal circulation. - It does not participate in **portosystemic anastomoses** at the esophageal level where varices typically develop. *Right gastric vein* - Drains the **lesser curvature of the stomach** and flows directly into the portal vein [2], with minimal anatomical connection to esophageal vessels. - Does not form the critical **portosystemic anastomoses** necessary for esophageal varices formation during portal hypertension. *Right gastroepiploic vein* - Drains the **greater curvature of the stomach** and connects to the superior mesenteric vein, distant from esophageal circulation. - Lacks the anatomical connections required for **portosystemic anastomoses** at the gastroesophageal junction where varices develop.
Question 24: Injury to which part causes difficulty in dorsiflexion of the foot?
- A. B (Correct Answer)
- B. D
- C. C
- D. A
Explanation: ***B*** - This arrow points to the **head and neck of the fibula**. The **common fibular (peroneal) nerve** wraps around the fibular neck, making it susceptible to injury in this location. - Damage to the common fibular nerve results in paralysis of the muscles in the anterior and lateral compartments of the leg, leading to **foot drop**, which is the inability to dorsiflex and evert the foot. *A* - This arrow points to the **medial condyle of the femur**. Injury to this area typically affects the knee joint, potentially damaging ligaments like the MCL or the medial meniscus. - It does not directly involve the nerves responsible for foot dorsiflexion, which are located more laterally and distally. *C* - This arrow indicates the **shaft of the femur**. A fracture of the femoral shaft is a severe injury but does not typically cause isolated difficulty with foot dorsiflexion. - Foot drop could occur if the **sciatic nerve** is injured proximally in the thigh, but this would result in a more widespread neurological deficit affecting both plantarflexion and dorsiflexion. *D* - This arrow points to the **lateral condyle of the femur**. Similar to the medial condyle, an injury here would primarily compromise the structures of the knee joint itself, such as the LCL or lateral meniscus. - The course of the common fibular nerve is posterior to the lateral femoral condyle before it wraps around the fibular neck, so an isolated condylar fracture is unlikely to cause foot drop.
Question 25: A 30-year-old man came with choking episodes after ingestion of fish bone while eating. The fishbone got impacted at the level of T4 in the esophagus. Which is the most likely site of obstruction?
- A. Arch of aorta (Correct Answer)
- B. Diaphragm
- C. Left bronchus
- D. Cricopharyngeus
Explanation: ***Arch of aorta*** - The esophagus has three principal anatomic constrictions where foreign bodies, such as swallowed fish bones, commonly lodge; the second constriction occurs at the level of **T4/T5** where the **arch of the aorta** passes anteriorly. - This large anatomical structure compresses the esophagus against the vertebral column, creating a localized narrowing precisely matching the T4 level described for the obstruction [1]. *Left bronchus* - The **left main bronchus** also crosses anterior to the esophagus and contributes significantly to the formation of the **middle esophageal constriction** at the T4/T5 level. - However, in standard radiological and endoscopic visualization, the compression caused by the arch of the aorta is often considered the dominant landmark at this specific location [1]. *Cricopharyngeus* - This structure forms the initial and **uppermost esophageal constriction** (upper esophageal sphincter), located at the level of the **C6 vertebra** (cervical spine). - Obstruction at the cricopharyngeus would occur in the neck, which is anatomically much higher than the reported **T4 (thoracic spine)** impaction site. *Diaphragm* - The passage of the esophagus through the **esophageal hiatus** of the diaphragm forms the **third and lowest physiological constriction**, typically located at the vertebral level of **T10**. - This site of potential foreign body obstruction is significantly distal and caudal to the T4 level described in the clinical case. Management of such objects often involves careful endoscopy under general anesthesia to prevent perforation [2].
Question 26: A man fell on his shoulder with his head pushed in the opposite direction. He presented with the following deformity. Which nerve root values are most likely affected?
- A. C7 and C8
- B. C6 and C7
- C. C5 and C6 (Correct Answer)
- D. C8 and T1
Explanation: ***C5 and C6*** - The clinical presentation of an adducted, internally rotated arm with an extended elbow and pronated forearm is known as the "**waiter's tip**" or "**porter's tip**" position. This is the classic sign of an upper brachial plexus injury, specifically **Erb's Palsy**. - This type of injury typically occurs from trauma that increases the angle between the neck and shoulder, such as a fall or during childbirth, affecting the **C5 and C6** nerve roots. This leads to paralysis of shoulder abductors (deltoid), external rotators (infraspinatus), and elbow flexors (biceps brachii). *C6 and C7* - An injury involving the **C7** root would predominantly cause weakness in the extensors of the elbow, wrist, and fingers, a condition often referred to as "**wrist drop**". - While the C6 root is involved, the primary features of the "waiter's tip" deformity (loss of shoulder abduction and external rotation) are most characteristic of a C5-C6 lesion, not a C6-C7 lesion. *C7 and C8* - A lesion of the **C7 and C8** nerve roots would primarily affect the muscles responsible for finger extension and wrist flexion. - This pattern of weakness does not align with the observed posture, which is defined by deficits in shoulder and elbow movements controlled by C5 and C6. *C8 and T1* - Injury to the **C8 and T1** roots results in a lower brachial plexus injury, known as **Klumpke's Palsy**, which typically occurs from a hyperabduction injury of the arm. - This condition affects the intrinsic muscles of the hand, leading to a "**claw hand**" deformity, which is clinically distinct from the deformity shown in the image.
Question 27: Which structure is formed by the structure indicated by the arrow?
- A. Nucleus pulposus (Correct Answer)
- B. Annulus fibrosus
- C. Septum transversum
- D. Neural tube
Explanation: ***Nucleus pulposus*** - The arrow indicates the **notochord**, a midline mesodermal rod that serves as the basis of the axial skeleton. Its postnatal remnant is the **nucleus pulposus**. - The **nucleus pulposus** is the gelatinous inner core of the intervertebral disc, responsible for providing shock absorption and flexibility to the vertebral column. *Annulus fibrosus* - The **annulus fibrosus** is the strong, fibrocartilaginous outer layer of the intervertebral disc that surrounds the nucleus pulposus. - It is derived from the **sclerotome** portion of the somites, not the notochord. *Neural tube* - The **neural tube**, shown as the large purple structure dorsal to the notochord, develops into the central nervous system (brain and spinal cord). - It is formed from the folding of the **neuroectoderm**, a process induced by the underlying notochord, but it is a distinct structure. *Septum transversum* - The **septum transversum** is a mass of mesodermal tissue that develops more cranially and ventrally in the embryo. - It is a major embryonic precursor to the central tendon of the **diaphragm** and does not originate from the notochord.
Question 28: Identify the nerve roots involved in the condition depicted in the image.
- A. C6 and C7
- B. C7 and C8
- C. C5 and C6 (Correct Answer)
- D. C8 and T1
Explanation: ***C5 and C6*** - The image displays a "waiter's tip" or "porter's tip" posture, which is the classic presentation of **Erb's palsy** (or Erb-Duchenne palsy). - This condition results from an injury to the **upper trunk** of the brachial plexus, which is formed by the union of the **C5 and C6** nerve roots, leading to paralysis of shoulder abductors/external rotators and elbow flexors. *C6 and C7* - An injury involving the C7 nerve root, which forms the **middle trunk**, primarily results in weakness of the wrist and finger extensors, a condition known as **wrist drop**. - While C6 is involved in Erb's palsy, the classic "waiter's tip" deformity is not seen with a C7 lesion. *C7 and C8* - A lesion affecting C7 and C8 would involve the middle and part of the lower trunk, leading to a combination of weak wrist extension and weak finger flexion. - This pattern of injury does not correspond to a recognized brachial plexus syndrome and would not produce the specific posture shown. *C8 and T1* - Injury to the C8 and T1 nerve roots affects the **lower trunk** of the brachial plexus, causing **Klumpke's palsy**. - This condition presents with paralysis of the intrinsic muscles of the hand, leading to a **"claw hand"** deformity, which is distinct from the posture seen in the image.
Question 29: Which is the narrowest part of the adult laryngeal airway?
- A. Glottis (Correct Answer)
- B. Supraglottic region
- C. Trachea
- D. Subglottic region
Explanation: ***Glottis***- In adults, the **glottis** (the level of the true vocal cords) is the point of the smallest cross-sectional area in the larynx, crucial for regulating airflow and phonation [1].- This region is formed by the mobile **vocal folds** and the space between them (rima glottidis), making it the most critical constriction point. *Supraglottic region*- The **supraglottic region** (above the vocal folds) is generally wider than the glottis due to the location of the expansive **epiglottis** and aryepiglottic folds.- Its primary function is protective, and its diameter is larger than the narrow aperture created by the vocal cords. *Subglottic region*- While the **subglottic region** (at the level of the cricoid cartilage) is the narrowest part in *children*, in adults, its diameter usually exceeds that of the glottis [1].- It is supported by the complete ring of the **cricoid cartilage**, which provides a relatively unyielding but generally wider structure compared to the mucosal space between the vocal cords. *Trachea*- The **trachea** is positioned distal to the larynx and is markedly wider than any part of the laryngeal airway.- Its large diameter, maintained by **C-shaped cartilage rings**, ensures low resistance for air passage to the bronchi and lungs.
Question 30: A man sustained trauma on the lateral side of his right knee. Two days later, he complains of difficulty in walking, as his toes keep dragging on the ground. He also notices numbness over the upper lateral aspect of the leg and dorsum of the foot. Which nerve is most likely injured?
- A. Common peroneal nerve (Correct Answer)
- B. Tibial nerve
- C. Femoral nerve
- D. Deep peroneal nerve
Explanation: ***Common peroneal nerve***- The **common peroneal nerve** (fibular nerve) curves superficially around the neck of the **fibula**, making it the most vulnerable nerve in the lower extremity to direct trauma on the lateral side of the knee.- Injury to the common peroneal nerve results in paralysis of the muscles responsible for **dorsiflexion** (deep peroneal branch) and **eversion** (superficial peroneal branch), leading to the characteristic 'foot drop' and difficulty clearing the toes, as well as sensory loss over the dorsum of the foot.*Tibial nerve*- The **tibial nerve** innervates the **plantarflexors** and **invertors** of the foot; injury would present as difficulty standing on the toes (calcaneovalgus deformity), which is opposite to the symptoms described.- Sensory loss from tibial nerve injury involves the **sole of the foot** and is unrelated to the dorsum or upper lateral aspect of the leg.*Deep peroneal nerve*- The **deep peroneal nerve** innervates the dorsiflexors, causing foot drop if injured, but its sensory distribution is limited to the web space between the **first and second toes**.- This isolated injury would not explain the numbness observed over the upper lateral aspect of the leg and the general dorsum of the foot, which is supplied by the superficial peroneal nerve (a branch of the common peroneal nerve).*Femoral nerve*- The **femoral nerve** innervates the **quadriceps muscle** (knee extensors) and provides sensation to the anterior thigh and medial leg via the saphenous nerve.- Injury primarily leads to difficulty with **knee extension** and instability when climbing stairs, not foot drop or numbness in the described lateral distribution.