FMGE 2025 Practice Questions

Q: Which structure is formed by the structure indicated by the arrow?

Nucleus pulposus. ***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.

Q: Identify the nerve roots involved in the condition depicted in the image.

C5 and C6. ***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.

Q: A diabetic worker sustains a stab injury to the central region of his palm. After 3 days, he develops swelling, severe pain, and inability to extend his middle and ring fingers. Pus accumulation is suspected in one of the palmar spaces. Which of the following spaces is most likely involved?

B (Midpalmar space). ***B (Midpalmar space)*** - A stab wound to the central palm directly accesses the **midpalmar space**, which lies deep to the palmar aponeurosis and contains the flexor tendons for the middle, ring, and little fingers. - Infection and pus accumulation in this space lead to **flexor tenosynovitis**, causing severe pain, swelling, and inability to extend the middle and ring fingers, as their tendon sheaths are directly involved. *A (Hypothenar space)* - The **hypothenar space** is located on the ulnar side of the palm and is associated with the intrinsic muscles of the little finger. - An infection in this area would primarily cause swelling and tenderness over the hypothenar eminence and affect the **little finger**, not the middle and ring fingers. *C (Thenar space)* - The **thenar space** is on the radial side of the palm, containing the intrinsic muscles of the thumb and often the flexor tendon sheath of the index finger. - Infection here would cause significant swelling at the base of the thumb (thenar eminence) and primarily affect the function of the **thumb and index finger**. *D (Dorsal subaponeurotic space)* - This space is on the **dorsum (back) of the hand**, whereas the injury occurred on the palm. - While deep palmar space infections can cause significant dorsal swelling due to loose tissue, the primary site of pus collection from a palmar wound is a **palmar space**, not a dorsal one.

Q: Which is the narrowest part of the adult laryngeal airway?

Glottis. ***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.

Q: 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?

Common peroneal nerve. ***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.

Q: Refer to the images. A patient presents with the condition shown in ![img-3.jpeg](img-3.jpeg). Which of the following nerve roots are primarily involved in this type of brachial plexus injury, often termed Erb's palsy, as indicated by Erb's point in the anatomical diagram ![img-2.jpeg](img-2.jpeg)?

C5 and C6. ***C5 and C6*** - Erb's palsy is an injury to the **upper trunk** of the brachial plexus, which is formed by the union of the **C5 and C6** nerve roots at a location known as Erb's point. - This injury classically results in a "**waiter's tip**" deformity, characterized by an adducted and internally rotated shoulder, extended elbow, and pronated forearm, due to paralysis of muscles like the deltoid, biceps, and brachialis. *C6 and C7* - The **C7** nerve root continues alone to form the **middle trunk** of the brachial plexus, while C6 joins C5 to form the upper trunk. - An injury involving C7 would primarily affect the extensors of the wrist and fingers, a different clinical picture than Erb's palsy. *C7 and C8* - The **C7** root forms the **middle trunk**, and the **C8** root contributes to the **lower trunk**, so an injury to both would not correspond to a classic upper plexus lesion. - Deficits would involve a combination of weak wrist/finger extension (C7) and weak finger flexion/intrinsic hand muscles (C8), which is not the presentation of Erb's palsy. *C8 and T1* - Injury to the **C8 and T1** nerve roots involves the **lower trunk** of the brachial plexus and results in a condition known as **Klumpke's palsy**. - This condition is characterized by paralysis of the intrinsic muscles of the hand, leading to a **claw hand** deformity, which is distinct from the "waiter's tip" posture.

Q: The upper part of the uncinate process commonly attaches to?

Middle turbinate. ***Middle turbinate***- The superior free end of the **uncinate process** most commonly attaches to the lateral surface of the body of the **middle turbinate** (occurring in approximately 60-70% of individuals).- This insertion variation is crucial as it determines the relationship between the **ethmoidal infundibulum** and the **frontal recess**.*Superior turbinate*- The **superior turbinate** is situated superiorly and posteriorly, often shielding the posterior ethmoid air cells.- The uncinate process is an anterior ethmoid structure and its attachments occur far inferior to the superior turbinate level.*Inferior turbinate*- The **inferior turbinate** is a separate, large bone that defines the **inferior meatus**, which contains the opening of the nasolacrimal duct.- The uncinate process lies superior to the inferior turbinate and is associated with the middle meatus.*Bulla ethmoidalis*- The **bulla ethmoidalis** is a large, fixed anterior ethmoid air cell located posterior to the **uncinate process**.- The space defined between the uncinate process anteriorly and the bulla ethmoidalis posteriorly is the **hiatus semilunaris**.

Q: A young patient experiences shortness of breath specifically during exercise in winter, which subsides after using salbutamol. What is the most likely explanation for this condition?

Exercise-induced bronchoconstriction triggered by cold air. ***Exercise-induced bronchoconstriction triggered by cold air*** - This patient presents with classic **Exercise-Induced Bronchoconstriction (EIB)**, previously known as exercise-induced asthma - **Key clinical features:** Dyspnea occurring during/after exercise, worsened by cold/dry air, rapid response to beta-2 agonists (salbutamol) [1] - **Pathophysiology:** Exercise increases ventilation → inhalation of cold, dry air → water loss from airway surface → increased osmolarity → mast cell degranulation and inflammatory mediator release → bronchoconstriction - Cold air is a potent trigger as it increases airway heat and water loss - Salbutamol (short-acting beta-2 agonist) provides rapid bronchodilation, confirming bronchospasm as the mechanism *Decreased cardiac output stimulates baroreceptors* - Baroreceptors respond to changes in blood pressure, not directly related to bronchospasm - Would not explain the rapid response to salbutamol - Cardiac dysfunction would present with different symptoms (fatigue, peripheral edema) [1] *Hyperventilation-induced respiratory alkalosis* - While exercise increases respiratory rate, respiratory alkalosis causes paresthesias, lightheadedness, not primarily dyspnea - Does not explain the seasonal (winter) pattern - Would not respond specifically to bronchodilators *Vagal stimulation due to cold air exposure* - Cold air can trigger vagal reflexes, but this would cause bradycardia and peripheral vasoconstriction - Vagal bronchomotor tone increases airway resistance but doesn't fully explain the exercise + cold air synergy - The dramatic response to salbutamol indicates beta-2 receptor-mediated bronchodilation is the primary mechanism

Q: What best describes step 3 in the given diagram?

Efflux of K ions. ***Efflux of K ions*** - Step 3 represents the **repolarization** phase of the action potential. This is caused by the opening of voltage-gated **K+ channels** and the inactivation of voltage-gated Na+ channels. - The opening of these channels allows a rapid **efflux** (outward flow) of positively charged K+ ions, which makes the membrane potential decrease from its positive peak back towards the negative resting potential. *Efflux of Na ions* - An efflux of Na+ ions is primarily driven by the **Na+/K+ pump** to maintain the resting potential over time, not to cause the rapid repolarization seen in step 3. - The significant movement of Na+ during the action potential is an **influx** during depolarization (step 2), not an efflux. *Influx of Na ions* - The influx of Na+ ions through voltage-gated channels is responsible for the **depolarization** phase (step 2), the rapid rising phase of the action potential. - During step 3, the voltage-gated **Na+ channels are inactivated**, preventing the influx of Na+ ions and allowing repolarization to occur. *Influx of K ions* - K+ ions move **outward** (efflux) during repolarization, not inward. - An influx of K+ would make the membrane potential more negative, but this is not the mechanism of repolarization in step 3.

Q: During an explosion, a patient sustains a crushed lower limb injury by collapse of a building. What type of blast injury does this represent?

Quaternary. ***Quaternary*** - This category includes all injuries not caused by primary, secondary, or tertiary mechanisms, such as **crush injuries**, burns, and toxic exposures. - The patient's crushed lower limb from a collapsing building is a classic example of a **quaternary blast injury**. *Primary* - Primary blast injuries are caused by the direct effect of the **blast wave overpressure** on the body. - They typically affect gas-containing organs, leading to conditions like **tympanic membrane rupture** or **blast lung**, which are not described here. *Secondary* - Secondary blast injuries result from being struck by **flying debris or fragments** (shrapnel) propelled by the explosion. - This mechanism causes penetrating or blunt trauma from projectiles, not crush injuries from a structural collapse. *Tertiary* - Tertiary blast injuries occur when the victim is thrown by the **blast wind** and impacts a solid object like a wall or the ground. - This results in blunt force trauma and fractures from the impact, which is different from being crushed by a falling structure.

Question 1

Which structure is formed by the structure indicated by the arrow?

Accepted Answer

Nucleus pulposus

Answer

Annulus fibrosus

Answer

Septum transversum

Answer

Neural tube

Question 2

Identify the nerve roots involved in the condition depicted in the image.

Accepted Answer

C5 and C6

Answer

C6 and C7

Answer

C7 and C8

Answer

C8 and T1

Question 3

A diabetic worker sustains a stab injury to the central region of his palm. After 3 days, he develops swelling, severe pain, and inability to extend his middle and ring fingers. Pus accumulation is suspected in one of the palmar spaces. Which of the following spaces is most likely involved?

Accepted Answer

B (Midpalmar space)

Answer

A (Hypothenar space)

Answer

D (Dorsal subaponeurotic space)

Answer

C (Thenar space)

Question 4

Which is the narrowest part of the adult laryngeal airway?

Accepted Answer

Glottis

Answer

Supraglottic region

Answer

Trachea

Answer

Subglottic region

Question 5

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?

Accepted Answer

Common peroneal nerve

Answer

Tibial nerve

Answer

Femoral nerve

Answer

Deep peroneal nerve

Question 6

Refer to the images. A patient presents with the condition shown in ![img-3.jpeg](img-3.jpeg). Which of the following nerve roots are primarily involved in this type of brachial plexus injury, often termed Erb's palsy, as indicated by Erb's point in the anatomical diagram ![img-2.jpeg](img-2.jpeg)?

Accepted Answer

C5 and C6

Answer

C6 and C7

Answer

C7 and C8

Answer

C8 and T1

Question 7

The upper part of the uncinate process commonly attaches to?

Accepted Answer

Middle turbinate

Answer

Superior turbinate

Answer

Bulla ethmoidalis

Answer

Inferior turbinate

Question 8

A young patient experiences shortness of breath specifically during exercise in winter, which subsides after using salbutamol. What is the most likely explanation for this condition?

Accepted Answer

Exercise-induced bronchoconstriction triggered by cold air

Answer

Decreased cardiac output stimulates baroreceptors

Answer

Vagal stimulation due to cold air exposure

Answer

Hyperventilation-induced respiratory alkalosis

Question 9

What best describes step 3 in the given diagram?

Accepted Answer

Efflux of K ions

Answer

Efflux of Na ions

Answer

Influx of Na ions

Answer

Influx of K ions

Question 10

During an explosion, a patient sustains a crushed lower limb injury by collapse of a building. What type of blast injury does this represent?

Accepted Answer

Quaternary

Answer

Tertiary

Answer

Primary

Answer

Secondary

FMGE 2025

Anatomy

Internal Medicine

Physiology

Surgery