Thorax Practice Questions

Q: Which of the following is TRUE about bronchopulmonary segments?

Pulmonary veins are intersegmental. Detailed knowledge of lung anatomy is essential for thoracic surgery. ***Pulmonary veins are intersegmental*** - The **pulmonary veins** run in the connective tissue septa **between** the bronchopulmonary segments, making them **intersegmental** [1]. - This anatomical arrangement allows surgeons to ligate the veins without affecting adjacent segments during a segmentectomy. *Spherical in shape* - Bronchopulmonary segments are typically **pyramid-shaped** or cone-shaped, with their apices directed towards the hilum [1]. - Their irregular, wedge-like structure allows them to fit together within the lung. *Artery is intersegmental* - The **bronchial arteries** and **pulmonary arteries** are **intrasegmental**, meaning they run **within** the bronchopulmonary segment alongside the bronchi. - Each segment has its own arterial supply, allowing for independent blood flow. *Non resectable* - Bronchopulmonary segments are considered **functionally and surgically independent units**, making them **resectable** [1]. - This allows for the removal of diseased segments while preserving healthy lung tissue, such as in cases of **lung cancer** or localized infection.

Q: Which are the most commonly fractured ribs during Cardio Pulmonary Resuscitation?

2nd-7th rib. ***2nd-7th rib*** - The **anterior and lateral aspects of the middle ribs (particularly 3rd-7th, extending to the 2nd rib)** are most commonly fractured during CPR due to their position and the direct forces applied to the sternum and rib cage during chest compressions. - These ribs are relatively thin and fixed to the sternum, making them vulnerable to fracture under sustained mechanical stress from repeated compressions. - **This range encompasses the area where CPR compressions are applied** over the lower half of the sternum. *7th-10th rib* - While these ribs can be fractured, they are **less frequently involved** compared to the more central ribs during typical CPR hand placement. - They are somewhat protected by overlying muscle and the costal margin, and lie below the typical compression point. *10th-12th rib* - These are the **floating ribs** and are **rarely fractured during CPR**. - Their free anterior ends provide considerable flexibility, and they are located lower on the torso, well below the area of sternal compressions. *1st & 2nd rib* - The **first rib is extremely well-protected** by the clavicle, scapula, and thick musculature of the shoulder girdle, making it rarely fractured during CPR. - The **second rib**, while more protected than the middle ribs, can occasionally be involved in the fracture pattern, but is **much less commonly fractured** than ribs 3-7. - Isolated fractures of ribs 1-2 typically require very significant force such as severe blunt trauma.

Q: Tubercles of Montgomery are present in

Breast. ***Breast*** - **Tubercles of Montgomery** are sebaceous glands found on the **areola**, the pigmented area surrounding the nipple [1]. - They become more prominent during pregnancy and lactation, producing an oily secretion that helps lubricate and protect the nipple and areola [1]. *Lung* - The **lungs** are responsible for gas exchange and contain structures like bronchi, bronchioles, and alveoli. - There are no anatomical structures within the lung parenchyma or airways referred to as Tubercles of Montgomery. *Duodenum* - The **duodenum** is the first part of the small intestine, primarily involved in digestion and absorption. - Its inner surface is characterized by plicae circularis, villi, and crypts, none of which are known as Tubercles of Montgomery. *Liver* - The **liver** is a large organ with diverse metabolic functions, composed of hepatocytes arranged in lobules. - While it has a complex anatomical structure, it does not contain any Tubercles of Montgomery.

Q: Dislocation of the vertebra is uncommon in the thoracic region because:

The articular processes are interlocked. ***The articular processes are interlocked*** - The **articular processes** in the thoracic spine are oriented coronally (in the frontal plane) and interlock, which provides significant stability and limits rotational movement, thus preventing dislocation. - This anatomical arrangement makes it inherently difficult for one vertebra to slide past another, serving as the primary mechanism preventing thoracic vertebral dislocation. *The rib cage provides additional stability* - While the **rib cage** does provide significant additional stability to the thoracic spine through costovertebral and costotransverse joints, this is a contributing factor rather than the primary anatomical reason. - The rib articulations create a semi-rigid thoracic cage, but the question asks for the primary vertebral feature preventing dislocation. *Spinous process is long and pointed* - The **long, pointed spinous processes** of the thoracic vertebrae (especially T5-T8) limit extension through mechanical overlap but do not primarily prevent dislocation of the vertebral bodies. - These processes can fracture under significant trauma, and their role in preventing dislocation is secondary compared to the facet joint orientation. *Anterior longitudinal ligament is strong* - The **anterior longitudinal ligament** reinforces the anterior aspect of the vertebral column and helps prevent hyperextension. - While it provides important ligamentous support, the primary structural stability against dislocation comes from the bony articulation and interlocking of the facet joints, not ligamentous structures alone.

Q: A patient is admitted with a stab wound in the left anterior chest wall in the parasternal line. Which cardiac chamber is most likely to be injured?

Right ventricle. Right ventricle - The **right ventricle** lies most anteriorly in the chest, directly behind the sternum and ribs, making it the most vulnerable chamber to direct anterior stab wounds [1]. - Its position makes it more susceptible to injury from penetrating trauma to the **parasternal region** [1]. *Aorta* - The **aorta** is located more posteriorly and to the left in the mediastinum, making it less likely to be injured by an anterior stab wound unless the penetrating object is very long and deep. - Injury to the aorta would typically present with more severe and immediate **hemorrhage** and hemodynamic collapse. *Left ventricle* - The **left ventricle** is located more posteriorly and to the left, and is largely covered by the right ventricle, making it less exposed to direct anterior penetrating trauma. - A stab wound would need to be more lateral or deeper to reach the left ventricle directly. *Right atrium* - The **right atrium** is located to the right and superior to the right ventricle, but also somewhat posterior to the most anterior aspect of the right ventricle. - While it can be injured, the right ventricle typically presents the largest surface area directly behind the parasternal area.

Q: Diaphragm paralysis occurs due to damage to which nerve?

Phrenic. Phase 1: Phrenic - The **phrenic nerve** is crucial for respiration as it provides the sole motor supply to the **diaphragm** [1], [2]. - Damage to the phrenic nerve leads to **diaphragmatic paralysis**, impairing breathing [1]. *Intercostal* - **Intercostal nerves** innervate the **intercostal muscles**, which assist in rib cage movement during breathing [2]. - While important for respiration, damage to these nerves alone does not typically cause complete **diaphragm paralysis** [1]. *Vagus* - The **vagus nerve** (cranial nerve X) plays a role in parasympathetic innervation of various organs, including the heart, lungs, and digestive tract [1]. - It does not directly innervate the **diaphragm** for motor function, so damage would not cause diaphragm paralysis. *Hypoglossal* - The **hypoglossal nerve** (cranial nerve XII) primarily controls the movements of the **tongue**. - Damage to this nerve affects speech and swallowing but has no direct impact on **diaphragm function** or breathing.

Q: The physician identifies a palpable mass in one breast, and the patient is scheduled for a "Lumpectomy." The breast is anatomically organized into multiple lobes, each containing a separate duct system with connecting lobules, which is important for understanding breast structure and surgical approaches. The normal breast usually contains how many lobes?

15 to 25. ***15 to 25*** - The **mammary gland** is composed of approximately **15 to 25 lobes** arranged radially around the nipple [1]. - Each lobe contains **lobules** that produce milk and drain into a **lactiferous duct** that opens onto the nipple [1]. *10 to 12* - This range is too low for the typical number of **lobes** found in a normal breast. - While it represents a significant number, it does not fully encompass the normal anatomical variability. *2 to 3* - This number is significantly too low and does not reflect the complex anatomical structure of the **breast**, which is designed for milk production and secretion. - A breast with only 2-3 lobes would be highly abnormal and functionally impaired. *5 to 7* - This range also underestimates the typical number of **lobes** present in a healthy breast. - A limited number of lobes would restrict the breast's functional capacity and overall glandular tissue.

Q: Base of heart is formed by

RA + LA. ***RA + LA*** - The **base of the heart** is primarily formed by the **left atrium** and a portion of the **right atrium** [1]. - This posterior aspect of the heart receives the great veins (SVC, IVC, pulmonary veins) and is oriented towards the vertebral column [1]. *RV* - The **right ventricle** forms the majority of the **anterior surface** of the heart, underlying the sternum. - It does not primarily contribute to the anatomical base. *LV* - The **left ventricle** forms the **apex** of the heart and much of the **left border**, but not the anatomical base. - It is responsible for pumping oxygenated blood to the systemic circulation. *LV + RV* - While both ventricles contribute significantly to the bulk of the heart, together they form the **apex** and the **anterior/inferior surfaces**, not the anatomical base. - The base is specifically the posterior aspect formed by the atria.

Q: The most common passage for foreign body aspiration is:

Right main bronchus. ***Right main bronchus*** - The **right main bronchus** is wider, shorter, and more vertically aligned with the trachea compared to the left main bronchus. - This anatomical configuration makes it the path of least resistance for aspirated foreign bodies. *Left main bronchus* - The **left main bronchus** branches off the trachea at a more acute angle and is narrower and longer. - These anatomical features make aspiration into the left main bronchus less common. *Bronchioles* - While foreign bodies can eventually reach the **bronchioles**, the initial aspiration typically occurs into the larger main bronchi. - Smaller foreign bodies might pass further down, but the primary entry point is usually a main bronchus. *Alveoli* - Foreign bodies are highly unlikely to directly reach the **alveoli** upon aspiration due to their small size and the extensive branching of the tracheobronchial tree. - Aspiration usually lodges in larger airways before reaching such distal structures.

Q: During resuscitation, fractured ribs most commonly involve:

4th -6th ribs. ***4th -6th ribs*** - During **cardiopulmonary resuscitation (CPR)**, compressions are typically applied to the **sternum**, leading to direct pressure on the adjacent ribs. - The **middle ribs**, particularly the 4th, 5th, and 6th, are most susceptible to fracture due to their anatomical position and lever arm during compressions. *3rd -5th ribs* - While these ribs can be fractured during CPR, the **3rd rib** is less commonly affected than the 4th-6th due to its more superior position and attachment. - The range does not fully encompass the ribs most consistently subjected to maximum stress during typical chest compressions. *2nd -4th ribs* - Fractures of the **2nd rib** are relatively uncommon during CPR, as it is more protected by the clavicle and shoulder girdle. - This range largely excludes the **5th and 6th ribs**, which are frequently implicated in CPR-related fractures. *5th -7th ribs* - The **7th rib** is less commonly fractured than the 4th-6th ribs because compressions are generally focused higher on the sternum. - This range includes the 7th rib, which is often below the primary point of maximum force during CPR.

Question 1

Which of the following is TRUE about bronchopulmonary segments?

Accepted Answer

Pulmonary veins are intersegmental

Answer

Spherical in shape

Answer

Artery is intersegmental

Answer

Non resectable

Question 2

Which are the most commonly fractured ribs during Cardio Pulmonary Resuscitation?

Accepted Answer

2nd-7th rib

Answer

7th-10th rib

Answer

10th-12th rib

Answer

1st & 2nd rib

Question 3

Tubercles of Montgomery are present in

Accepted Answer

Breast

Answer

Lung

Answer

Duodenum

Answer

Liver

Question 4

Dislocation of the vertebra is uncommon in the thoracic region because:

Accepted Answer

The articular processes are interlocked

Answer

The rib cage provides additional stability

Answer

Spinous process is long and pointed

Answer

Anterior longitudinal ligament is strong

Question 5

A patient is admitted with a stab wound in the left anterior chest wall in the parasternal line. Which cardiac chamber is most likely to be injured?

Accepted Answer

Right ventricle

Answer

Aorta

Answer

Left ventricle

Answer

Right atrium

Question 6

Diaphragm paralysis occurs due to damage to which nerve?

Accepted Answer

Phrenic

Answer

Intercostal

Answer

Vagus

Answer

Hypoglossal

Question 7

The physician identifies a palpable mass in one breast, and the patient is scheduled for a "Lumpectomy." The breast is anatomically organized into multiple lobes, each containing a separate duct system with connecting lobules, which is important for understanding breast structure and surgical approaches. The normal breast usually contains how many lobes?

Accepted Answer

15 to 25

Answer

10 to 12

Answer

2 to 3

Answer

5 to 7

Question 8

Base of heart is formed by

Accepted Answer

RA + LA

Answer

RV

Answer

LV

Answer

LV + RV

Question 9

The most common passage for foreign body aspiration is:

Accepted Answer

Right main bronchus

Answer

Left main bronchus

Answer

Bronchioles

Answer

Alveoli

Question 10

During resuscitation, fractured ribs most commonly involve:

Accepted Answer

4th -6th ribs

Answer

3rd -5th ribs

Answer

2nd -4th ribs

Answer

5th -7th ribs

Thorax — MCQs

Thorax — MCQs

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