What is the most common site of congenital diaphragmatic hernia?
Q2
Identify the labeling correctly
Q3
Structure preventing vertical descent of spleen
Q4
A 46-year-old male presents in consultation for weight loss surgery. He is 6’0” and weighs 300 pounds. He has tried multiple dietary and exercise regimens but has been unsuccessful in losing weight. The surgeon suggests a sleeve gastrectomy, a procedure that reduces the size of the stomach removing a large portion of the stomach along the middle part of the greater curvature. The surgeon anticipates having to ligate a portion of the arterial supply to this part of the stomach in order to complete the resection. Which of the following vessels gives rise to the vessel that will need to be ligated in order to complete the resection?
Q5
A 54-year-old woman comes to the physician because of a 3-month history of upper midthoracic back pain. The pain is severe, dull in quality, and worse during the night. Ten months ago, she underwent a modified radical mastectomy for invasive ductal carcinoma of the right breast. Physical examination shows normal muscle strength. Deep tendon reflexes are 2+ in all extremities. Examination of the back shows tenderness over the thoracic spinous processes. An x-ray of the thoracic spine shows vertebral osteolytic lesions at the levels of T4 and T5. The patient's thoracic lesions are most likely a result of metastatic spread via which of the following structures?
Q6
A 35-year-old obese man presents to the office complaining of chronic heartburn and nausea for the past 6 months. These symptoms are relieved when he takes 20 mg of omeprazole twice a day. The patient was prompted to come to the doctor when he recently experienced difficulty breathing and shortness of breath, symptoms which he believes underlies a serious health condition. The patient has no cardiac history but is concerned because his father recently died of a heart attack. Imaging of the patient’s chest and abdomen would most likely reveal which of the following?
Q7
A 75-year-old man presents to the clinic for chronic fatigue of 3 months duration. Past medical history is significant for type 2 diabetes and hypertension, both of which are controlled with medications, as well as constipation. He denies any fever, weight loss, pain, or focal neurologic deficits. A complete blood count reveals microcytic anemia, and a stool guaiac test is positive for blood. He is subsequently evaluated with a colonoscopy. The physician notes some “small pouches” in the colon despite poor visualization due to inadequate bowel prep. What is the blood vessel that supplies the area with the above findings?
Q8
An 18-year-old man is brought to the emergency department 30 minutes after being stabbed in the chest during a fight. He has no other injuries. His pulse is 120/min, blood pressure is 90/60 mm Hg, and respirations are 22/min. Examination shows a 4-cm deep, straight stab wound in the 4th intercostal space 2 cm medial to the right midclavicular line. The knife most likely passed through which of the following structures?
Q9
An 8-year-old boy is brought to the emergency department because of shortness of breath and dry cough for 2 days. His symptoms began after he helped his father clean the basement. He is allergic to shellfish. Respirations are 26/min. Physical examination shows diffuse end-expiratory wheezing and decreased inspiratory-to-expiratory ratio. This patient's symptoms are most likely being caused by inflammation of which of the following structures?
Q10
A 24-year-old man presents to the emergency room with a stab wound to the left chest at the sternocostal junction at the 4th intercostal space. The patient is hemodynamically unstable, and the trauma attending is concerned that there is penetrating trauma to the heart. Which cardiovascular structure is most likely to be injured first in this stab wound?
Thorax/Abdomen US Medical PG Practice Questions and MCQs
Question 1: What is the most common site of congenital diaphragmatic hernia?
A. Central tendon
B. Posterolateral (Correct Answer)
C. Crural
D. Anterolateral
E. Esophageal hiatus
Explanation: ***Posterolateral***
- The **posterolateral** region, specifically the foramen of Bochdalek, is the most common site for congenital diaphragmatic hernia (CDH).
- This type of hernia accounts for approximately 80-90% of all CDH cases and usually occurs on the **left side**.
*Central tendon*
- Hernias through the **central tendon** are extremely rare and are distinct from the more common forms of CDH.
- Defects in the central tendon are often associated with **pericardial defects** rather than typical diaphragmatic hernias which allow abdominal contents into the thoracic cavity.
*Crural*
- Hernias involving the **crura** of the diaphragm are typically **hiatal hernias** (e.g., sliding or paraesophageal), which are different in origin and presentation from CDH.
- These are usually acquired and involve the stomach moving into the mediastinum, rather than a congenital defect leading to abdominal viscera migrating into the chest.
*Anterolateral*
- While congenital diaphragmatic hernias can occur **anterolaterally** through the foramen of Morgagni, these are much less common than posterolateral hernias.
- Morgagni hernias account for a small percentage of CDH cases (around 2-5%) and are typically located on the right side, often containing omentum or colon.
*Esophageal hiatus*
- The **esophageal hiatus** is the normal opening in the diaphragm through which the esophagus passes.
- While hiatal hernias can occur at this site, these are typically **acquired hernias** in adults, not congenital diaphragmatic hernias.
- Congenital CDH refers to developmental defects in the diaphragm itself, not enlargement of normal openings.
Question 2: Identify the labeling correctly
A. A - Ascending aorta, B - Pulmonary trunk, C - Superior vena cava, D - Descending aorta (Correct Answer)
B. A - Ascending aorta, B - Superior vena cava, C - Pulmonary trunk, D - Descending aorta
C. A - Superior vena cava, B - Pulmonary trunk, C - Ascending aorta, D - Descending aorta
D. A - Pulmonary trunk, B - Ascending aorta, C - Superior vena cava, D - Descending aorta
E. A - Ascending aorta, B - Pulmonary trunk, C - Descending aorta, D - Superior vena cava
Explanation: ***A - Ascending aorta, B - Pulmonary trunk, C - Superior vena cava, D - Descending aorta***
- **A** points to the **ascending aorta**, the initial segment of the aorta emerging from the left ventricle.
- **B** indicates the **pulmonary trunk**, which originates from the right ventricle and carries deoxygenated blood to the lungs.
- **C** correctly identifies the **superior vena cava**, responsible for draining deoxygenated blood from the upper body into the right atrium.
- **D** is correctly labeled as the **descending aorta**, the portion of the aorta that descends through the thorax and abdomen.
*A - Ascending aorta, B - Superior vena cava, C - Pulmonary trunk, D - Descending aorta*
- This option incorrectly identifies **B as superior vena cava** and **C as pulmonary trunk**. B is clearly emerging from the right ventricle, characteristic of the pulmonary trunk, while C is positioned where the superior vena cava would be.
- The superior vena cava (C) would be located to the right and anterior to the ascending aorta, while the pulmonary trunk (B) is anterior to the ascending aorta, emerging from the right ventricle.
*A - Superior vena cava, B - Pulmonary trunk, C - Ascending aorta, D - Descending aorta*
- This option incorrectly labels **A as superior vena cava** and **C as ascending aorta**. A is clearly the large vessel emerging from the left side of the heart, consistent with the ascending aorta.
- The ascending aorta (A) would be the largest vessel emerging from the left ventricle, and the superior vena cava (C) would be entering the right atrium.
*A - Pulmonary trunk, B - Ascending aorta, C - Superior vena cava, D - Descending aorta*
- This option incorrectly identifies **A as pulmonary trunk** and **B as ascending aorta**. A is the large vessel originating from the left ventricle, which is the ascending aorta.
- The pulmonary trunk (B) arises from the right ventricle and is usually anterior to the ascending aorta (A).
*A - Ascending aorta, B - Pulmonary trunk, C - Descending aorta, D - Superior vena cava*
- This option incorrectly swaps **C and D**, labeling C as descending aorta and D as superior vena cava. C is positioned in the superior mediastinum where the superior vena cava enters the right atrium, not in the posterior mediastinum where the descending aorta would be located.
- The descending aorta (D) runs posteriorly in the thorax, while the superior vena cava (C) is an anterior structure draining into the right atrium.
Question 3: Structure preventing vertical descent of spleen
A. Ligamentum teres
B. Ligamentum flavum
C. Hepatogastric ligament
D. Phrenocolic ligament (Correct Answer)
E. Lienorenal ligament
Explanation: ***Phrenocolic ligament***
- The **phrenocolic ligament** is a fold of peritoneum that extends from the left colic (splenic) flexure of the colon to the diaphragm.
- It forms a shelf or sling underneath the spleen, providing crucial support and preventing its **vertical descent**.
*Ligamentum teres*
- The **ligamentum teres hepatis** is the remnant of the obliterated umbilical vein, found in the free margin of the falciform ligament.
- It connects the umbilicus to the liver and plays no role in supporting the spleen.
*Ligamentum flavum*
- The **ligamentum flavum** is a series of elastic ligaments connecting the laminae of adjacent vertebrae in the spinal column.
- It is a component of the vertebral column and has no anatomical or functional relationship with the spleen.
*Hepatogastric ligament*
- The **hepatogastric ligament** is part of the lesser omentum, extending from the liver to the lesser curvature of the stomach.
- Its primary function is to contain the **gastric arteries** and connect these organs, not to support the spleen.
*Lienorenal ligament*
- The **lienorenal ligament** (splenorenal ligament) connects the hilum of the spleen to the anterior surface of the left kidney.
- While it provides **lateral support** to the spleen, it does not prevent **vertical descent** as effectively as the phrenocolic ligament.
Question 4: A 46-year-old male presents in consultation for weight loss surgery. He is 6’0” and weighs 300 pounds. He has tried multiple dietary and exercise regimens but has been unsuccessful in losing weight. The surgeon suggests a sleeve gastrectomy, a procedure that reduces the size of the stomach removing a large portion of the stomach along the middle part of the greater curvature. The surgeon anticipates having to ligate a portion of the arterial supply to this part of the stomach in order to complete the resection. Which of the following vessels gives rise to the vessel that will need to be ligated in order to complete the resection?
A. Right gastroepiploic artery
B. Splenic artery (Correct Answer)
C. Left gastric artery
D. Gastroduodenal artery
E. Right gastric artery
Explanation: ***Splenic artery***
- A sleeve gastrectomy involves resecting a large portion of the **greater curvature of the stomach**. This portion is primarily supplied by the **short gastric arteries** and the **left gastroepiploic artery**.
- The **splenic artery** is the main vessel that gives rise to the **short gastric arteries** and the **left gastroepiploic artery**, which originate from the distal portion of the splenic artery prior to its terminal branches. Therefore, ligation of branches from the splenic artery would be necessary.
*Right gastroepiploic artery*
- The **right gastroepiploic artery** primarily supplies the distal part of the greater curvature and arises from the **gastroduodenal artery**.
- While it contributes to the vascular supply of the greater curvature, the bulk of the vessels needing ligation for a *sleeve gastrectomy* are the short gastrics and left gastroepiploic, which stem from the **splenic artery**.
*Left gastric artery*
- The **left gastric artery** primarily supplies the lesser curvature of the stomach near the cardia and arises directly from the **celiac trunk**.
- Its branches would not be the primary vessels ligated in a procedure focused on the **greater curvature**.
*Gastroduodenal artery*
- The **gastroduodenal artery** arises from the **common hepatic artery** and typically supplies the pylorus, duodenum, and head of the pancreas, giving rise to the **right gastroepiploic artery**.
- It is not the main source of arterial supply to the proximal and middle greater curvature resected during a sleeve gastrectomy.
*Right gastric artery*
- The **right gastric artery** typically arises from the **common hepatic artery** or **proper hepatic artery** and primarily supplies the lesser curvature of the stomach.
- Its role in the robust blood supply to the **greater curvature** is minimal, and its ligation would not be central to a sleeve gastrectomy focused on this region.
Question 5: A 54-year-old woman comes to the physician because of a 3-month history of upper midthoracic back pain. The pain is severe, dull in quality, and worse during the night. Ten months ago, she underwent a modified radical mastectomy for invasive ductal carcinoma of the right breast. Physical examination shows normal muscle strength. Deep tendon reflexes are 2+ in all extremities. Examination of the back shows tenderness over the thoracic spinous processes. An x-ray of the thoracic spine shows vertebral osteolytic lesions at the levels of T4 and T5. The patient's thoracic lesions are most likely a result of metastatic spread via which of the following structures?
A. Lateral axillary lymph nodes
B. Azygos vein (Correct Answer)
C. Thyrocervical trunk
D. Thoracic duct
E. Intercostal artery
Explanation: ***Azygos vein***
- The **vertebral venous plexus** communicates with both the intercostal veins (draining the chest wall and ultimately the breast) and the azygos vein system, providing a direct pathway for **hematogenous spread** to the spine without passing through the portal or caval systems.
- The **Batson venous plexus**, a valveless system within the vertebral venous plexus, allows for easy retrograde flow of cancer cells from breast cancer to the thoracic spine due to changes in intra-abdominal or intrathoracic pressure.
*Lateral axillary lymph nodes*
- While **axillary lymph nodes** are the primary site of lymphatic spread for breast cancer, they would typically lead to spread to other lymphatic structures or secondary hematogenous spread via systemic circulation, not direct metastasis to the spine.
- Lymphatic spread to axillary nodes typically causes **lymphadenopathy** in the axilla and can be a prognostic indicator, but it is not the direct pathway for vertebral osteolytic lesions.
*Thyrocervical trunk*
- The **thyrocervical trunk** is an artery that supplies structures in the neck and shoulder, such as the thyroid gland and scapular muscles.
- It is an **arterial structure** and is not a common pathway for the metastatic spread of breast cancer to the thoracic spine.
*Thoracic duct*
- The **thoracic duct** is the main lymphatic vessel of the body, collecting lymph from the lower body, left arm, and left side of the head and neck, eventually draining into the left subclavian vein.
- While breast cancer can spread via lymphatics, the thoracic duct is not the typical or direct route for metastasis to the **thoracic vertebrae**.
*Intercostal artery*
- **Intercostal arteries** supply blood to the intercostal spaces, chest wall, and pleura.
- As an **arterial structure**, it is involved in blood supply to the region but is not a primary pathway for the metastatic spread of cancer cells to the bones.
Question 6: A 35-year-old obese man presents to the office complaining of chronic heartburn and nausea for the past 6 months. These symptoms are relieved when he takes 20 mg of omeprazole twice a day. The patient was prompted to come to the doctor when he recently experienced difficulty breathing and shortness of breath, symptoms which he believes underlies a serious health condition. The patient has no cardiac history but is concerned because his father recently died of a heart attack. Imaging of the patient’s chest and abdomen would most likely reveal which of the following?
A. Cardiomegaly with pulmonary effusion
B. Lung hypoplasia due to a defect in the diaphragm
C. Widened mediastinum with evidence of esophageal rupture
D. "Hourglass stomach" due to upward displacement of the gastroesophageal junction
E. Protrusion of fundus of the stomach through the diaphragm into the thoracic cavity (Correct Answer)
Explanation: ***Protrusion of fundus of the stomach through the diaphragm into the thoracic cavity***
- The patient's symptoms of chronic heartburn, nausea, and relief with omeprazole are classic for **Gastroesophageal Reflux Disease (GERD)**, which is frequently caused or exacerbated by a **hiatal hernia**.
- A hiatal hernia involves the **fundus of the stomach** protruding through the esophageal hiatus of the diaphragm into the chest cavity, leading to reflux and potentially respiratory symptoms due to compression or irritation of surrounding structures.
*Cardiomegaly with pulmonary effusion*
- While an obese patient could have **cardiac issues**, his symptoms, particularly the response to omeprazole, do not primarily point to cardiomegaly or pulmonary effusion.
- This option suggests a **cardiac origin** for shortness of breath, which is less likely given the prominent GI symptoms.
*Lung hypoplasia due to a defect in the diaphragm*
- **Lung hypoplasia** typically occurs in infancy or childhood due to conditions like congenital diaphragmatic hernia, not in a 35-year-old presenting with chronic heartburn.
- It describes **underdevelopment of the lungs**, which wouldn't be the primary finding in an adult with these symptoms.
*Widened mediastinum with evidence of esophageal rupture*
- A **widened mediastinum** with **esophageal rupture** (Boerhaave syndrome) is an acute, life-threatening condition associated with severe pain, vomiting, and shock, not chronic heartburn and gradual onset shortness of breath.
- This condition is typically an **acute surgical emergency**, and the patient's presentation does not fit this high-acuity scenario.
*"Hourglass stomach" due to upward displacement of the gastroesophageal junction*
- An **"hourglass stomach"** usually refers to a severe stricture or narrowing of the mid-stomach, often due to chronic ulcers or malignancy, not just upward displacement of the gastroesophageal junction.
- While it can be associated with GI symptoms, it doesn't directly explain the **fundic protrusion** characteristic of a hiatal hernia, which is more consistent with the chronic reflux.
Question 7: A 75-year-old man presents to the clinic for chronic fatigue of 3 months duration. Past medical history is significant for type 2 diabetes and hypertension, both of which are controlled with medications, as well as constipation. He denies any fever, weight loss, pain, or focal neurologic deficits. A complete blood count reveals microcytic anemia, and a stool guaiac test is positive for blood. He is subsequently evaluated with a colonoscopy. The physician notes some “small pouches” in the colon despite poor visualization due to inadequate bowel prep. What is the blood vessel that supplies the area with the above findings?
A. Ileocolic artery
B. Superior mesenteric artery
C. Inferior mesenteric artery (Correct Answer)
D. Middle colic artery
E. Right colic artery
Explanation: ***Inferior mesenteric artery***
- The patient's **microcytic anemia** and **positive stool guaiac test** indicate chronic gastrointestinal blood loss, highly suggestive of **diverticulosis** presenting as "small pouches" in the colon.
- Diverticulosis commonly affects the **descending colon** and **sigmoid colon**, which are primarily supplied by branches of the **inferior mesenteric artery**.
*Ileocolic artery*
- The ileocolic artery is a branch of the **superior mesenteric artery** and supplies the **ileum**, **cecum**, and **ascending colon**.
- Diverticula are less commonly found in these regions compared to the left colon.
*Superior mesenteric artery*
- The superior mesenteric artery supplies the **midgut derivatives**, including the **small intestine** and the **right half of the large intestine** (up to the distal transverse colon).
- While it supplies a large portion of the GI tract, the typical location of diverticulosis (descending and sigmoid colon) is outside its primary distribution.
*Middle colic artery*
- The middle colic artery is a branch of the **superior mesenteric artery** and supplies the **transverse colon**.
- While diverticula can occur in the transverse colon, it is not the most common location, and the inferior mesenteric artery supplies the areas most frequently affected.
*Right colic artery*
- The right colic artery is a branch of the **superior mesenteric artery** and supplies the **ascending colon**.
- Diverticula are less frequently found in the ascending colon compared to the descending and sigmoid colon.
Question 8: An 18-year-old man is brought to the emergency department 30 minutes after being stabbed in the chest during a fight. He has no other injuries. His pulse is 120/min, blood pressure is 90/60 mm Hg, and respirations are 22/min. Examination shows a 4-cm deep, straight stab wound in the 4th intercostal space 2 cm medial to the right midclavicular line. The knife most likely passed through which of the following structures?
A. Serratus anterior muscle, pleura, inferior vena cava
B. External oblique muscle, superior epigastric artery, azygos vein
C. Pectoralis minor muscle, dome of the diaphragm, right lobe of the liver
D. Intercostal muscles, internal thoracic artery, right heart
E. Pectoral fascia, transversus thoracis muscle, right lung (Correct Answer)
Explanation: ***Pectoral fascia, transversus thoracis muscle, right lung***
* The stab wound is in the **4th intercostal space**, 2 cm medial to the right midclavicular line, placing it over the anterior chest wall. This trajectory would first penetrate the **pectoral fascia**.
* Deeper structures in this region include the **transversus thoracis muscle** and, given the depth, the **right lung** as it extends superiorly behind the anterior chest wall.
* *Serratus anterior muscle, pleura, inferior vena cava*
* The **serratus anterior muscle** is more laterally positioned, typically covering the side of the rib cage.
* The **inferior vena cava** is located more medially and posteriorly within the mediastinum, deep to the diaphragm, making it an unlikely target for an anterior 4th intercostal stab.
* *External oblique muscle, superior epigastric artery, azygos vein*
* The **external oblique muscle** is part of the abdominal wall and would not be penetrated in the 4th intercostal space.
* The **superior epigastric artery** is lower, typically extending into the abdominal wall, and the **azygos vein** is in the posterior mediastinum, not in the path of this superficial anterior stab wound.
* *Pectoralis minor muscle, dome of the diaphragm, right lobe of the liver*
* The **pectoralis minor muscle** is located deep to the pectoralis major, which would be penetrated. However, a stab at the 4th intercostal space would be too high to directly involve the **dome of the diaphragm** or the **right lobe of the liver**, which are typically below the 5th intercostal space, especially in forced expiration.
* *Intercostal muscles, internal thoracic artery, right heart*
* The **intercostal muscles** would certainly be traversed.
* However, the **internal thoracic artery** runs paramedially (about 1-2 cm from the sternum), and getting to the **right heart** would require a more medial and deeper trajectory, potentially causing immediate tamponade or severe hemorrhage.
Question 9: An 8-year-old boy is brought to the emergency department because of shortness of breath and dry cough for 2 days. His symptoms began after he helped his father clean the basement. He is allergic to shellfish. Respirations are 26/min. Physical examination shows diffuse end-expiratory wheezing and decreased inspiratory-to-expiratory ratio. This patient's symptoms are most likely being caused by inflammation of which of the following structures?
A. Pleural cavity
B. Terminal bronchioles (Correct Answer)
C. Respiratory bronchioles
D. Alveoli
E. Distal trachea
Explanation: ***Terminal bronchioles***
- The combination of **shortness of breath**, **dry cough**, **diffuse end-expiratory wheezing**, and decreased inspiratory-to-expiratory ratio in an allergic child points strongly to **bronchiolar inflammation** and **bronchoconstriction**, characteristic of asthma.
- The **terminal bronchioles** are the primary site of airway obstruction in asthma, where inflammation, mucus plugging, and smooth muscle constriction lead to the classic wheezing sound upon expiration.
*Pleural cavity*
- Inflammation or fluid in the **pleural cavity** (e.g., pleurisy, pleural effusion) typically causes **sharp pleuritic chest pain** and diminished breath sounds, not diffuse wheezing.
- While it can cause shortness of breath, the hallmark signs like wheezing and decreased I:E ratio are not characteristic of pleural involvement.
*Respiratory bronchioles*
- While respiratory bronchioles are involved in gas exchange and can be affected by some lung diseases, the **terminal bronchioles** are the main site of **bronchoconstriction** and airflow obstruction responsible for the wheezing seen in asthma.
- Inflammation primarily affecting respiratory bronchioles might lead to more insidious symptoms or **bronchiolitis obliterans**, not acute, widespread wheezing as described.
*Alveoli*
- Inflammation of the **alveoli** (e.g., pneumonia, pulmonary edema) leads to impaired gas exchange, often presenting with **crackles**, consolidation, or hypoxemia.
- It does not typically cause **diffuse wheezing** or a decreased inspiratory-to-expiratory ratio, which are signs of airway obstruction.
*Distal trachea*
- Inflammation or narrowing of the **distal trachea** can cause stridor or a monophonic wheeze, but typically affects both inspiration and expiration equally (not predominantly end-expiratory).
- It would not typically present with the diffuse, widespread wheezing characteristic of **small airway obstruction** seen in this patient.
Question 10: A 24-year-old man presents to the emergency room with a stab wound to the left chest at the sternocostal junction at the 4th intercostal space. The patient is hemodynamically unstable, and the trauma attending is concerned that there is penetrating trauma to the heart. Which cardiovascular structure is most likely to be injured first in this stab wound?
A. Left ventricle
B. Aorta
C. Right ventricle (Correct Answer)
D. Right atrium
E. Left atrium
Explanation: ***Right ventricle***
- The **right ventricle** lies most anteriorly in the chest, directly behind the sternum and costal cartilages, making it the most likely chamber to be injured in an anterior stab wound.
- Its anatomical position makes it vulnerable to penetrating trauma at the sternocostal junction, especially at the **4th intercostal space**.
*Left ventricle*
- The **left ventricle** is located more posteriorly and to the left of the midline, making it less susceptible to a central anterior stab wound.
- While possible, it would typically require a stab wound further to the left or a deeper penetration.
*Aorta*
- The **aorta** is a very deep, large vessel located posterior to the heart, making it generally protected from isolated anterior stab wounds to the sternocostal junction.
- Injury to the aorta typically occurs with more extensive, high-energy trauma or deeper penetration.
*Right atrium*
- The **right atrium** is located to the right and slightly posterior to the right ventricle, so it is less exposed to a direct anterior stab wound than the right ventricle.
- Although it is a relatively anterior structure, its position is slightly less exposed than the right ventricle.
*Left atrium*
- The **left atrium** is the most posterior chamber of the heart, nestled against the esophagus, and is therefore very well protected from anterior penetrating trauma.
- Injury to the left atrium is extremely rare with an anterior stab wound and would suggest a very severe and deep injury.
