FMGE 2025 — Anatomy
33 Previous Year Questions with Answers & Explanations
A 45-year-old woman presented with tingling sensation of lateral 3 digits with loss of sensation of base of thumb on the dorsal aspect of the hand. Which is the nerve involved?
What is the type of cartilage present in the histology section given below?
A renal biopsy image is shown. Identify the cells marked in the histological section.
Identify the lymphatic structure from the histology section given below?
Which of the following images displays the characteristic histology of the Thymus?
Which among the following is a pressure epiphysis?
Identify the level of lymph nodes indicated in the marked region of the neck in the given anatomical image.
Identify the structure marked in the image.
A patient presents with loss of sensation on the posterior surface of the ear along with a lesion. Which structure is most likely involved?
What is the most common type of ventricular septal defect?
FMGE 2025 - Anatomy FMGE Practice Questions and MCQs
Question 1: A 45-year-old woman presented with tingling sensation of lateral 3 digits with loss of sensation of base of thumb on the dorsal aspect of the hand. Which is the nerve involved?
- A. Median nerve
- B. AIN
- C. Radial nerve (Correct Answer)
- D. Ulnar nerve
Explanation: ***Radial nerve*** - The **superficial branch of the radial nerve** provides sensory innervation to the dorsal aspect of the hand, including the dorsal surface of the thumb, index, middle, and the radial half of the ring finger up to the nail beds [1]. - The patient's symptoms of sensory loss at the **dorsal base of the thumb** (anatomical snuffbox) and tingling in the lateral digits are classic signs of superficial radial nerve involvement [1]. *Ulnar nerve* - The **ulnar nerve** provides sensation to the medial one and a half digits (the little finger and the medial half of the ring finger) on both the palmar and dorsal sides [1]. - Involvement of the ulnar nerve would not cause sensory changes in the lateral three digits or the thumb. *Median nerve* - The **median nerve** supplies sensation to the palmar aspect of the lateral three and a half digits and the nail beds on the dorsal side [1]. - It does not supply the dorsal aspect of the hand or the base of the thumb, which is a key localizing feature in this case. Common entrapment leads to **carpal tunnel syndrome** [2]. *AIN* - The **Anterior Interosseous Nerve (AIN)** is a purely **motor** branch of the median nerve [2]. - An injury to the AIN would result in motor weakness, specifically an inability to flex the thumb and index finger to make an 'OK' sign, but would not cause any sensory loss [2].
Question 2: What is the type of cartilage present in the histology section given below?
- A. Articular cartilage
- B. Hyaline cartilage (Correct Answer)
- C. Fibrocartilage
- D. Elastic cartilage
Explanation: ***Hyaline cartilage*** - The image displays a **homogenous, glassy matrix** with **chondrocytes** residing in spaces called **lacunae**. This appearance is due to the presence of fine **Type II collagen** fibrils that are not visible with a standard light microscope. - A **perichondrium**, the layer of dense connective tissue seen on the left, is typically present and provides nourishment. This type of cartilage is found in the **trachea**, **larynx**, and **articular surfaces of bones**. *Elastic cartilage* - This cartilage is characterized by a matrix containing abundant **elastic fibers**, which would appear as dark, branching lines, giving it a less homogenous look. These fibers are not visible in the provided slide. - It is found in structures that require flexibility and the ability to recoil, such as the **epiglottis** and the **external ear** (pinna). *Articular cartilage* - While histologically a type of hyaline cartilage, articular cartilage specifically covers the ends of bones in **synovial joints** and is distinguished by its **lack of a perichondrium**. - The image clearly shows a perichondrium on the left side, making it more likely to be hyaline cartilage from a location like the respiratory tract rather than a joint surface. *Fibrocartilage* - Fibrocartilage has a distinct, fibrous appearance due to thick, parallel bundles of **Type I collagen** within its matrix, which is absent in this image. - It is a transitional tissue between dense connective tissue and hyaline cartilage, found in areas requiring great tensile strength, like the **intervertebral discs** and **pubic symphysis**.
Question 3: A renal biopsy image is shown. Identify the cells marked in the histological section.
- A. Podocytes
- B. Lacis cells (Correct Answer)
- C. Juxtaglomerular (JG) cells
- D. Macula densa
Explanation: ***Lacis cells*** - The highlighted cells are **extraglomerular mesangial cells**, also known as Lacis cells, located in the triangular space between the afferent arteriole, efferent arteriole, and macula densa at the vascular pole of the glomerulus. - They are part of the **juxtaglomerular apparatus (JGA)** and are thought to play a role in transmitting signals from the macula densa to the juxtaglomerular cells, contributing to **tubuloglomerular feedback**. *Macula densa* - These are specialized, densely packed epithelial cells in the wall of the **distal convoluted tubule** where it contacts the glomerulus. The highlighted cells are situated outside of any tubule. - Macula densa cells function as **chemoreceptors** that monitor the **sodium chloride** concentration in the tubular fluid, regulating renin release and glomerular filtration rate. *Juxtaglomerular (JG) cells* - These are modified smooth muscle cells located primarily in the wall of the **afferent arteriole**. The cells in the image are not within an arteriolar wall. - JG cells synthesize, store, and secrete **renin**, and they function as **mechanoreceptors** by sensing changes in blood pressure within the afferent arteriole. *Podocytes* - These are specialized cells located **inside Bowman's capsule**, wrapping around the glomerular capillaries. The highlighted cells are distinctly **extraglomerular** (outside the glomerulus). - Podocytes form **filtration slits** with their interdigitating foot processes (**pedicels**), which are a critical component of the glomerular filtration barrier.
Question 4: Identify the lymphatic structure from the histology section given below?
- A. Spleen
- B. Lymph node
- C. Tonsil
- D. Thymus (Correct Answer)
Explanation: ***Thymus*** - The histology shows lymphoid tissue organized into **lobules** separated by connective tissue septa, with each lobule having a darkly stained outer **cortex** and a paler inner **medulla**. - The medulla contains **Hassall's corpuscles**, which are pathognomonic for the thymus, and the cortex lacks the germinal centers found in other lymphoid organs. *Tonsil* - Tonsils are characterized by an overlying **stratified squamous epithelium** that invaginates to form deep **tonsillar crypts**, neither of which is present in this image. - They contain numerous lymphoid follicles with prominent germinal centers but lack the distinct lobulated cortico-medullary architecture of the thymus. *Lymph node* - A lymph node has a distinct architecture with a **subcapsular sinus**, a cortex with B-cell follicles, a paracortex, and a medulla with medullary cords and sinuses, which is structurally different from the image provided. - The lobulated pattern with clear cortico-medullary differentiation within each lobule is a key feature of the thymus, not a lymph node. *Spleen* - The spleen's parenchyma is divided into **red pulp** (containing sinusoids) and **white pulp** (lymphoid tissue), an organization not seen in this section. - Splenic white pulp is characterized by a **central arteriole** surrounded by a **periarteriolar lymphoid sheath (PALS)**, a feature absent in the image.
Question 5: Which of the following images displays the characteristic histology of the Thymus?
- A. Image of Spleen
- B. Image of Thymus (Correct Answer)
- C. Image of Lymph node
- D. Image of Tonsil
Explanation: ***Image of Thymus*** - The image correctly illustrates the key histological features of the thymus, including the division of thymic lobules into a dark outer **cortex** and a lighter inner **medulla**. - A pathognomonic feature shown is the presence of **Hassall's (thymic) corpuscles**, which are whorls of epithelial reticular cells found exclusively in the thymic medulla. *Image of Tonsil* - Tonsillar histology is characterized by deep invaginations called **tonsillar crypts** and numerous **lymphoid follicles** with prominent germinal centers, neither of which are depicted in the image. - Tonsils are covered by **stratified squamous epithelium** (in palatine and lingual tonsils) or pseudostratified columnar epithelium (in pharyngeal tonsils), a feature not seen in the thymus. *Image of Lymph node* - A lymph node has a distinct architecture with a **cortex** containing **lymphoid follicles**, a **paracortex**, and a **medulla** with medullary cords and sinuses, which is structurally different from the image provided. - Lymph nodes are surrounded by a capsule with afferent lymphatic vessels and a **subcapsular sinus**, features that are absent in the thymus. *Image of Spleen* - Splenic histology is organized into **red pulp** and **white pulp**. The white pulp consists of **lymphoid follicles** and **periarteriolar lymphoid sheaths (PALS)** surrounding a central arteriole, which is not shown. - The red pulp, which makes up the majority of the spleen, contains **splenic sinusoids** and the **cords of Billroth**, structures for filtering blood that are absent in the thymus.
Question 6: Which among the following is a pressure epiphysis?
- A. Elbow joint
- B. Head of Humerus (Correct Answer)
- C. Sternum
- D. Wrist joint
Explanation: ***Head of Humerus*** - **Pressure epiphyses** are located at the ends of long bones where they transmit weight-bearing forces and facilitate movement across joints - The **head of humerus** is a classic example of a pressure epiphysis, articulating with the glenoid cavity of the scapula at the glenohumeral joint - It transmits forces from the upper limb and bears the load during various shoulder movements - Other examples include femoral head, humeral head, and tibial condyles *Elbow joint* - The elbow is a **synovial hinge joint**, not an epiphysis - While the joint contains epiphyses (distal humerus, proximal radius and ulna), the joint itself is not an epiphysis - Joints are articulations between bones, whereas epiphyses are the rounded ends of long bones *Sternum* - The sternum is a **flat bone** in the anterior chest wall, not a long bone - It does not have typical epiphyses like long bones - Flat bones ossify differently through intramembranous ossification, not endochondral ossification with distinct epiphyseal plates *Wrist joint* - The wrist is a **complex synovial joint** (radiocarpal joint), not an epiphysis - It is formed by articulation of the distal radius with carpal bones - Like the elbow, it contains epiphyseal regions but is not itself an epiphysis
Question 7: Identify the level of lymph nodes indicated in the marked region of the neck in the given anatomical image.
- A. Level Ib
- B. Level II (Correct Answer)
- C. Level Ia
- D. Level IV
Explanation: **Level II** - The arrow points to the **upper deep cervical lymph nodes**, also known as the **upper jugular nodes**, which correspond to **Level II** in the neck lymph node classification. - This level is located in the upper third of the neck, extending from the base of the skull down to the **hyoid bone**, and is a common site for metastasis from cancers of the oral cavity, pharynx, and larynx. *Level Ia* - **Level Ia** represents the **submental nodes**, located in the midline triangle between the anterior bellies of the digastric muscles and inferior to the chin. - The indicated region is lateral and superior to the location of **Level Ia**. *Level Ib* - **Level Ib** corresponds to the **submandibular nodes**, situated within the submandibular triangle, bounded by the mandible and the digastric muscles. - The arrow points to a region posterior and superior to the **submandibular triangle**. *Level IV* - **Level IV** represents the **lower deep cervical lymph nodes** or **lower jugular nodes**, located along the lower third of the internal jugular vein, extending from the cricoid cartilage down to the clavicle. - The marked area is in the upper part of the neck, significantly superior to **Level IV**.
Question 8: Identify the structure marked in the image.
- A. Cystic duct
- B. Cystic artery
- C. Hepatic duct
- D. Right Hepatic artery (Correct Answer)
Explanation: ***Right Hepatic artery*** - The marked structure is the **Right Hepatic artery**, a branch of the **proper hepatic artery**, which supplies arterial blood to the right lobe of the liver. - As depicted, the **cystic artery**, which supplies the gallbladder, commonly originates from the right hepatic artery within the triangle of Calot. *Cystic artery* - The **cystic artery** is a smaller branch that is shown originating from the marked vessel and running towards the gallbladder (green structure); the pointer is on the parent artery. - This artery is a critical structure to identify and ligate during a **cholecystectomy** (gallbladder removal) to prevent bleeding. *Hepatic duct* - The **hepatic ducts** are part of the biliary system (colored yellow/orange) and function to drain bile from the liver, not supply blood to it. - These ducts converge to form the **common hepatic duct**, which is distinct from the arterial system (colored red). *Cystic duct* - The **cystic duct** is the channel that connects the gallbladder to the common hepatic duct, allowing bile to flow in and out of the gallbladder. - It is a component of the biliary tract, not a blood vessel like the marked artery.
Question 9: A patient presents with loss of sensation on the posterior surface of the ear along with a lesion. Which structure is most likely involved?
- A. External Carotid Artery
- B. External Jugular Vein
- C. Internal Jugular Vein
- D. Greater Auricular Nerve (Correct Answer)
Explanation: ***Greater Auricular Nerve***- The **Greater Auricular Nerve (GAN)**, originating from the cervical plexus (C2, C3), provides sensory innervation to the **skin over the mastoid process** and the **posterior surface of the auricle (ear)**.- Damage (lesion involvement) to this nerve results specifically in **sensory loss (anesthesia)** in its distribution area, matching the patient's presentation.*Internal Jugular Vein*- This is a large deep vein responsible for major **venous drainage** of the head and neck, not sensory innervation.- Involvement would cause **venous congestion** or potentially severe complications related to thrombosis, not isolated sensory loss.*External Jugular Vein*- This is a superficial vein responsible for minor **venous drainage** of the face and head, running lateral to the sternocleidomastoid muscle.- Any compromise to this vein affects the circulatory system (**venous return**) and does not lead to sensory deficits.*External Carotid Artery*- This is a major artery supplying the extracranial structures of the head; its primary function is **blood supply (perfusion)**.- Lesions would typically cause signs of **ischemia** or hemorrhage in its distribution, not an isolated nerve-related sensory loss on the posterior ear.
Question 10: What is the most common type of ventricular septal defect?
- A. Incomplete fusion of the septum
- B. Non-development of the perimembranous part of the septum
- C. Muscular defect
- D. Membranous defect (Correct Answer)
Explanation: ***Membranous defect***- This type of defect, also known as **perimembranous VSD**, is the most common form, accounting for approximately 70-80% of all ventricular septal defects [1].- It is located just below the aortic valve, involving the **proximal third** of the septum and is defined by its relationship to the fibrous trigones [1].*Muscular defect*- **Muscular VSDs** (or trabecular VSDs) are less common than membranous defects and can be found anywhere within the thick muscular portion of the septum.- These defects often have a higher rate of **spontaneous closure**, especially the small, multiple defects referred to as 'Swiss cheese' VSDs.*Non-development of the perimembranous part of the septum*- While the failure of complete septation of the **membranous portion** is the underlying embryological cause, the specific anatomical diagnosis defining the common VSD type is the *membranous defect*. - This phrasing is descriptive of the etiology but **membranous defect** identifies the most common resulting structure.*Incomplete fusion of the septum*- This is a generic description of the mechanism leading to VSD development (failure of the septal components to fuse correctly), but it does not specify the **most common anatomical location**.- The most critical and common fusion failure involves the development of the **membranous septum**, which results in the named *membranous defect*.