FMGE 2023 - Anatomy Practice Questions

Q: If the division in the zygote occurs between 9-12 days after fertilization, which of the following twins is expected?

Monochorionic monoamniotic. ***Monochorionic monoamniotic*** - Division of the inner cell mass (ICM) occurring between **9 and 12 days** after fertilization results in a twin pregnancy where both fetuses share a single **chorion** and a single **amnion**.- This stage marks division after the amnion has formed (around day 8) but before complete differentiation, leading to high risks like **cord entanglement**. *Dichorionic diamniotic* - This pattern results from division occurring very early, typically within the first **3 days** (2-cell stage to morula stage).- Since separation happens before the differentiation of the trophoblast and inner cell mass, both the **chorion** and the **amnion** are separate. *Conjoint twins* - Conjoint twins (Siamese twins) occur when the separation is delayed beyond the **13th day** after fertilization.- The division is incomplete, as it occurs *after* the formation of the **embryonic disc**. *Monochorionic diamniotic* - This type of twinning arises from division occurring between **4 and 8 days** after fertilization, typically during the blastocyst stage.- It leads to the sharing of the **chorion** but the development of separate **amnions**.

Q: Identify the segment marked in red in the image below.

a.V. ***a.V*** - The highlighted area represents **Segment V** of the liver according to the **Couinaud classification**. It is located in the inferior portion of the **right anterior section**. - It lies inferior to **Segment VIII** and is separated from the medial segment (IVb) by the **middle hepatic vein**. *b.IVa* - **Segment IVa** is part of the **left medial section** and is located superiorly, just inferior to the diaphragm. - The structure shown is in the **right lobe** of the liver, not the left medial section. *c.VII* - **Segment VII** is located in the superior part of the **right posterior section** of the liver. - The highlighted segment is in the **anterior section**, separated from the posterior section by the **right hepatic vein**. *III* - **Segment III** is part of the **left lateral section** of the liver, located anteriorly and inferiorly within that section. - The highlighted structure is part of the **right lobe**, well to the right of the falciform ligament and middle hepatic vein.

Q: Identify the rib highlighted in the X-ray.

3rd rib posterior part. ***3rd rib posterior part*** - On a posteroanterior (PA) chest X-ray, the **posterior ribs** are more prominent and have a more horizontal orientation as they articulate with the thoracic vertebrae, which matches the highlighted structure. - When counting from the top, the first rib is the highest and most curved. The highlighted rib is clearly the third one down from the apex of the thorax, confirming it as the **3rd posterior rib**. *3rd rib anterior part* - The **anterior parts** of the ribs are more difficult to visualize and course downwards and medially towards the sternum. The highlighted rib is oriented horizontally. - Anterior ribs connect to the sternum via **costal cartilage**, which is not as radiopaque as bone and thus appears less distinct on an X-ray than the highlighted structure. *4th rib anterior part* - This option is incorrect as the highlighted structure is a **posterior rib**, not an anterior one, based on its orientation. - Additionally, counting reveals the rib to be the third, not the fourth. The **fourth rib** would be located inferior to the highlighted one. *1st rib anterior part* - The **1st rib** is the most superior and has a very sharp curvature, often partially obscured by the clavicle. The highlighted rib is located below the first and second ribs. - This is also incorrect because the image highlights the **posterior aspect** of a rib, not the anterior aspect.

Q: Identify the structure marked in the image given below.

Internal Capsule. ***Internal Capsule***- The **internal capsule** is a V-shaped structure of densely packed white matter tracts situated deep within the cerebral hemispheres.- It contains crucial ascending and descending fibers, including the **corticospinal tract** (motor fibers) and **thalamocortical projections** (sensory fibers).*External capsule*- The **external capsule** is a thin sheet of white matter located *lateral* to the **lenticular nucleus** (putamen and globus pallidus).- It separates the **putamen** from the **claustrum**.*Caudate nucleus*- The **caudate nucleus** is a C-shaped component of the **basal ganglia**, typically situated medial to the internal capsule and forming the lateral wall of the anterior horn of the **lateral ventricle**.- Damage to this structure is often implicated in **Huntington's disease**.*Putamen*- The **putamen** is the larger, more lateral gray matter structure of the **lenticular nucleus**, located lateral to the internal and external capsules.- It is a core component of the **basal ganglia**, involved primarily in controlling learned motor movements.

Q: Identify the type of pelvis in the given image.

Gynecoid pelvis. ***Gynecoid pelvis***- The **Gynecoid pelvis** is considered the classic female pelvis, characterized by a **round** or slightly oval pelvic inlet and a well-curved sacrum.- This type is optimal for vaginal delivery, featuring straight side walls, a spacious midpelvis, and a **wide subpubic angle** (arch of 90 degrees or more).*Android pelvis*- The **Android pelvis** possesses a characteristic **heart-shaped** or triangular pelvic inlet because the sacrum is pushed forward, leading to converging side walls.- This shape is typically associated with the male structure and increases the likelihood of obstructed labor due to a **narrow subpubic arch**.*Anthropoid pelvis*- The **Anthropoid pelvis** has an oval shape where the **anteroposterior diameter** is significantly longer than the transverse diameter (long, narrow oval).- The fetal head often engages in the occipito-anterior or occipito-posterior position, which may increase the chance of difficulty with rotation to the transverse diameter.*Platypelloid pelvis*- The **Platypelloid pelvis** (or flat pelvis) is characterized by a severely flattened, transversely oval or **kidney-shaped** inlet, meaning the transverse diameter is much greater than the AP diameter.- It frequently prevents the fetal head from properly engaging or rotating, often leading to transverse arrest and necessity for **cesarean section**.

Q: Which of the following structures passes through the foramen marked by the arrow? ![img-53.jpeg](img-53.jpeg)

Thoracic duct. ***Thoracic duct*** - The arrow in the image points to the **aortic hiatus**, which is the most posterior of the three major openings in the diaphragm, located at the vertebral level of **T12**. - This hiatus provides passage for the **aorta**, the **thoracic duct**, and the **azygos vein** from the thorax into the abdomen. *Oesophagus* - The oesophagus passes through its own opening, the **oesophageal hiatus**, which is located more anteriorly and superiorly at the **T10** vertebral level within the muscular part of the diaphragm. - This opening is formed by the fibers of the **right crus** of the diaphragm and also transmits the **vagal trunks**. *Inferior vena cava* - The inferior vena cava traverses the diaphragm through the **caval opening**, the most anterior and superior opening, situated at the **T8** vertebral level. - This foramen is located within the **central tendon** of the diaphragm and also allows passage for branches of the **right phrenic nerve**. *Sympathetic trunk* - The sympathetic trunk does not pass through any of the major apertures but rather descends posterior to the diaphragm. - It typically passes behind the **medial arcuate ligament** or pierces the **crus of the diaphragm** to enter the abdomen.

Q: Identify the nerve indicated by the arrow in the image.

Ulnar nerve. ***Ulnar nerve*** - The arrow points to the area posterior to the **medial epicondyle** of the humerus, which is the location of the **cubital tunnel**. - The **ulnar nerve** passes superficially through this tunnel, making it susceptible to compression or injury, and is commonly known as the "funny bone". *Radial nerve* - The **radial nerve** travels down the posterior aspect of the humerus in the **radial groove** and then crosses the elbow joint anterior to the **lateral epicondyle**. - It is primarily responsible for innervating the **extensor muscles** of the forearm and hand. *Median nerve* - The **median nerve** descends through the **anterior compartment** of the arm and passes through the **cubital fossa**, which is anterior to the elbow joint. - It innervates most of the **flexor muscles** of the forearm and the **thenar muscles** of the hand. *Musculocutaneous nerve* - The **musculocutaneous nerve** is found in the **anterior compartment** of the arm, where it pierces the coracobrachialis muscle and runs between the biceps brachii and brachialis muscles. - It supplies the **flexor muscles** of the arm and provides sensory innervation to the **lateral forearm**.

Q: Which nerve can be injured when a fracture is sustained in the area marked with the red arrow in the image? ![img-54.jpeg](img-54.jpeg)

Ulnar nerve. ***Ulnar nerve*** - The arrow points to the **medial epicondyle** of the humerus. The ulnar nerve runs in a groove on the posterior surface of the medial epicondyle, making it vulnerable to injury in this location. - A fracture of the medial epicondyle can cause direct trauma or entrapment of the ulnar nerve, leading to numbness and tingling in the fourth and fifth digits and weakness of the intrinsic hand muscles. *Radial nerve* - The radial nerve is most commonly injured in fractures of the **mid-shaft of the humerus**, where it travels in the **radial groove**. - Injury to the radial nerve typically results in **wrist drop**, characterized by the inability to extend the wrist and fingers. *Median nerve* - The median nerve is most at risk with **supracondylar fractures** of the humerus, as it passes anterior to the elbow joint. - This nerve is also famously associated with **carpal tunnel syndrome** when compressed at the wrist. *Musculocutaneous nerve* - The musculocutaneous nerve is located in the **anterior compartment** of the arm and is not in close proximity to the medial epicondyle. - Injury to this nerve, which is rare from fractures, results in weakness of elbow flexion (**biceps brachii** and **brachialis**) and sensory loss over the lateral forearm.

Q: The condition seen in the image results from failure of fusion of:

Medial nasal prominence and maxillary prominence. ***Medial nasal prominence and maxillary prominence*** - The upper lip is formed embryologically by the fusion of the two **medial nasal prominences** (which form the central philtrum) and the two **maxillary prominences** (which form the lateral parts of the upper lip). - Failure of these prominences to fuse results in a **cleft lip** (cheiloschisis), as depicted in the image, which can be unilateral or bilateral. *Lateral nasal prominence and maxillary prominence* - The fusion of the **lateral nasal prominence** and the **maxillary prominence** forms the side of the face and the nasolacrimal duct. - Failure of these structures to fuse results in an **oblique facial cleft**, a rare condition extending from the upper lip to the eye. *Lateral nasal prominence and mandibular prominence* - These two prominences do not fuse during facial development. The **lateral nasal prominence** forms the alae (wings) of the nose. - The **mandibular prominence** forms the lower jaw and the lower lip, which is anatomically separate from the nasal structures. *Medial nasal prominence and mandibular prominence* - The **medial nasal prominence** contributes to the upper lip and nose, while the **mandibular prominence** forms the lower lip and jaw. - These structures are located superior and inferior to the developing mouth, respectively, and do not fuse with each other.

Q: Identify the given histology slide:

Pancreas. ***Pancreas*** - The image displays a classic histological feature of the pancreas: a pale-staining cluster of endocrine cells, known as an **Islet of Langerhans**. - This islet is surrounded by more intensely stained, basophilic **acinar cells**, which constitute the exocrine component of the pancreas responsible for producing digestive enzymes. *Lymph node* - A lymph node has a distinct architecture with a **cortex** containing **lymphoid follicles** (often with germinal centers) and a **medulla**, which is not seen in this image. - The predominant cells would be lymphocytes, which appear as small, dark-staining cells, unlike the larger glandular cells shown here. *Glomerulus* - A glomerulus is a capillary tuft surrounded by **Bowman's capsule**, located within the renal cortex of the kidney. - The surrounding tissue would be composed of **renal tubules** (proximal and distal convoluted tubules), not the acinar cells seen in the slide. *Spleen* - The spleen is characterized by its division into **red pulp** (containing sinusoids and erythrocytes) and **white pulp** (lymphoid tissue surrounding a central artery). - The organized structure of islets and acini is distinct from the splenic architecture of lymphoid follicles and blood-filled sinuses.

Question 1

If the division in the zygote occurs between 9-12 days after fertilization, which of the following twins is expected?

Accepted Answer

Monochorionic monoamniotic

Answer

Dichorionic diamniotic

Answer

Monochorionic diamniotic

Answer

Conjoint twins

Question 2

Identify the segment marked in red in the image below.

Accepted Answer

a.V

Answer

c.VII

Answer

b.IVa

Answer

d.III

Question 3

Identify the rib highlighted in the X-ray.

Accepted Answer

3rd rib posterior part

Answer

4th rib anterior part

Answer

3rd rib anterior part

Answer

1st rib anterior part

Question 4

Identify the structure marked in the image given below.

Accepted Answer

Internal Capsule

Answer

External capsule

Answer

Putamen

Answer

Caudate nucleus

Question 5

Identify the type of pelvis in the given image.

Accepted Answer

Gynecoid pelvis

Answer

Android pelvis

Answer

Platypelloid pelvis

Answer

Anthropoid pelvis

Question 6

Which of the following structures passes through the foramen marked by the arrow? ![img-53.jpeg](img-53.jpeg)

Accepted Answer

Thoracic duct

Answer

Oesophagus

Answer

Sympathetic trunk

Answer

Inferior vena cava

Question 7

Identify the nerve indicated by the arrow in the image.

Accepted Answer

Ulnar nerve

Answer

Radial nerve

Answer

Musculocutaneous nerve

Answer

Median nerve

Question 8

Which nerve can be injured when a fracture is sustained in the area marked with the red arrow in the image? ![img-54.jpeg](img-54.jpeg)

Accepted Answer

Ulnar nerve

Answer

Radial nerve

Answer

Musculocutaneous nerve

Answer

Median nerve

Question 9

The condition seen in the image results from failure of fusion of:

Accepted Answer

Medial nasal prominence and maxillary prominence

Answer

Lateral nasal prominence and mandibular prominence

Answer

Lateral nasal prominence and maxillary prominence

Answer

Medial nasal prominence and mandibular prominence

Question 10

Identify the given histology slide:

Accepted Answer

Pancreas

Answer

Lymph node

Answer

Spleen

Answer

Glomerulus

FMGE 2023 — Anatomy