Week 11 Questions Semester 1 Anatomy Ta Questions

1. A 3 year old boy was brought into the ED because he had swallowed a lego. If the lego had not gone down the esophagus, but instead obstructed his airway, where would you most likely find the lego?

Left Bronchus

Right bronchus

Right tertiary bronchi

Left secondary bronchi

The right airway is most likely because it has a more vertical orientation than the left bronchus. So from the trachea it would more easily lodge into the right bronchus. Depending on the size of the lego, it may go further to the lower lobe of the right lung.

Explanation

The right airway is most likely because it has a more vertical orientation than the left bronchus. So from the trachea it would more easily lodge into the right bronchus. Depending on the size of the lego, it may go further to the lower lobe of the right lung.

2. A 2 year old boy is brought into the emergency room by his mother because she saw him stick a few marbles in his nose and now the marbles are missing. If the boy did indeed aspirate the marbles, where would you expect them to most likely be?

Left main bronchus

Lingular segment of the left lung

Medial basal segmental bronchus of the left inferior lobe

Terminal bronchiole of the left inferior lobe

Right main bronchus

aspiration of foreign bodies usually get stuck in the right main bronchus because it is shorter, straighter, and wider.

Explanation

aspiration of foreign bodies usually get stuck in the right main bronchus because it is shorter, straighter, and wider.

3. A 5-year-old boy is presents to the emergency room coughing. You are told by his father that he had been playing with some M&Ms and he thinks the boy may have aspirated one (gotten it into his airway). Where would you most likely expect to find the M&M?

Apicoposterior segmental bronchus of left lung

Right main bronchus

Lingular segment of left lung

Left main bronchus

Terminal bronchiole of right lung, lower lobe

As the lumen of the right main bronchus is more vertical and of slightly wider in diameter than the left main bronchus, aspirated material is more likely to end up in this bronchus or one of its subsequent bifurcations (depending on the size of the aspirated particle).

Explanation

As the lumen of the right main bronchus is more vertical and of slightly wider in diameter than the left main bronchus, aspirated material is more likely to end up in this bronchus or one of its subsequent bifurcations (depending on the size of the aspirated particle).

4. Main drainage of the heart is through -

Middle cardiac vein

Coronary Sinus

Anterior cardiac veins

Oblique vein

The main drainage of the heart is through the coronary sinus. The coronary sinus is a large vein located on the posterior surface of the heart. It receives deoxygenated blood from the cardiac veins, including the middle cardiac vein, anterior cardiac veins, and oblique vein. The coronary sinus then empties into the right atrium, allowing the blood to return to the systemic circulation for oxygenation.

Explanation

The main drainage of the heart is through the coronary sinus. The coronary sinus is a large vein located on the posterior surface of the heart. It receives deoxygenated blood from the cardiac veins, including the middle cardiac vein, anterior cardiac veins, and oblique vein. The coronary sinus then empties into the right atrium, allowing the blood to return to the systemic circulation for oxygenation.

5. You are attending an operation to remove a thymic tumor from the superior mediastinum. The surgeon asks, "What important nerve lying on and partly curving posteriorly around the arch of the aorta should we be careful of as we remove this mass?" Seeing that you are an astute anatomist, your correct answer would be what?

Left phrenic

Left sympathetic trunk

Left vagus

Right phrenic

Right sympathetic trunk

The left vagus nerve enters the thorax between left common carotid artery and left subclavian artery and descends on the aortic arch. It gives rise to the left recurrent laryngeal nerve, which hooks around the aortic arch to the left of the ligamentum arteriosum (derivative of the 6th pharyngeal arch) and ascends between the trachea and esophagus. The left vagus further continues and enters the abdomen as the anterior vagal trunk in the esophageal hiatus of the diaphragm. Comparatively, the right vagus nerve gives rise to the right recurrent laryngeal nerve, which hooks around the proximal right subclavian artery (derivative of the 4th pharyngeal arch) and ascends into the neck between the trachea and esophagus. The right vagus further continues and enters the abdomen as the posterior vagal trunk in the esophageal hiatus of the diaphragm

Explanation

The left vagus nerve enters the thorax between left common carotid artery and left subclavian artery and descends on the aortic arch. It gives rise to the left recurrent laryngeal nerve, which hooks around the aortic arch to the left of the ligamentum arteriosum (derivative of the 6th pharyngeal arch) and ascends between the trachea and esophagus. The left vagus further continues and enters the abdomen as the anterior vagal trunk in the esophageal hiatus of the diaphragm. Comparatively, the right vagus nerve gives rise to the right recurrent laryngeal nerve, which hooks around the proximal right subclavian artery (derivative of the 4th pharyngeal arch) and ascends into the neck between the trachea and esophagus. The right vagus further continues and enters the abdomen as the posterior vagal trunk in the esophageal hiatus of the diaphragm

6. Which of the following arteries supplies the right atrium, SA & AV nodes and posterior part of IVS?

Right marginal

Posterior Intervenricular

Left Coronary

Right Coronary

The right coronary artery supplies the right atrium, SA and AV nodes, and the posterior part of the interventricular septum. This artery is responsible for delivering oxygenated blood to these specific areas of the heart. The other options, such as the right marginal artery, posterior interventricular artery, and left coronary artery, do not supply these specific regions of the heart.

Explanation

The right coronary artery supplies the right atrium, SA and AV nodes, and the posterior part of the interventricular septum. This artery is responsible for delivering oxygenated blood to these specific areas of the heart. The other options, such as the right marginal artery, posterior interventricular artery, and left coronary artery, do not supply these specific regions of the heart.

7. Blockage of which of the following arteries would lead to ischemia of the apex of the heart?

Anterior interventricular (descending)

Left circumflex

Posterior interventricular (descending)

Right marginal

Right coronary

Anterior interventricular (descending)
The anterior interventricular artery is a branch of the left coronary artery. It supplies both ventricles as well as the interventricular septum. It also reaches the apex, supplying that area as well. The left circumflex artery is the other major branch of the left coronary artery. It supplies the posterior surface of the left ventricle, but does not reach the apex of the heart.
The right coronary artery has two major branches: the right marginal and the posterior interventricular artery. (The right coronary also gives off two smaller branches to the SA node and the AV node.) The right marginal artery supplies the right ventricle, while the posterior IV artery supplies the interventricular septum and the two ventricles. Neither of these arteries provides a major source of blood to the apex of the heart.

Explanation

Anterior interventricular (descending)
The anterior interventricular artery is a branch of the left coronary artery. It supplies both ventricles as well as the interventricular septum. It also reaches the apex, supplying that area as well. The left circumflex artery is the other major branch of the left coronary artery. It supplies the posterior surface of the left ventricle, but does not reach the apex of the heart.
The right coronary artery has two major branches: the right marginal and the posterior interventricular artery. (The right coronary also gives off two smaller branches to the SA node and the AV node.) The right marginal artery supplies the right ventricle, while the posterior IV artery supplies the interventricular septum and the two ventricles. Neither of these arteries provides a major source of blood to the apex of the heart.

8. Which compartment of the heart has the highest risk of injury due to an object piercing the esophagus ( ex: fish bone ) ?

Right atrium

Left atrium

Left ventricle

Right ventricle

slide 8 Dr. Kirera’s Posterior Mediastinum lecture shows possible relationships

Explanation

slide 8 Dr. Kirera’s Posterior Mediastinum lecture shows possible relationships

9. A 78-year-old female presented with edema of the left upper limb due to poor venous return. Examination revealed an aneurysm of the ascending aorta that was impinging on a large vein lying immediately anterosuperior to it, most likely the:

Azygos v.

Internal thoracic v

Left brachiocephalic v

Left superior intercostal v

Right brachiocephalic v.

Remember that the ascending aorta is the short part of the aorta emerging from the heart before the aortic arch. The left brachiocephalic vein is the only vein listed which is anterosuperior to that part of the aorta. It crosses horizontally through the mediastinum to join with the right brachiocephalic vein and form the superior vena cava. The right brachiocephalic vein stays on the right side of the chest and would not be affected by the aortic aneurysm (the IVC could be). The azygos vein is also on the right side of the chest, and it lies deep in the thoracic cavity. The internal thoracic vein lies on the interior surface of the anterior wall of the chest. Although it drains into the brachiocephalic vein, it would not be affected by the aneurysm. The left superior intercostal vein crosses the aortic arch laterally, but its blockage would only affect drainage of intercostal spaces 2-4 on the left side.

Explanation

Remember that the ascending aorta is the short part of the aorta emerging from the heart before the aortic arch. The left brachiocephalic vein is the only vein listed which is anterosuperior to that part of the aorta. It crosses horizontally through the mediastinum to join with the right brachiocephalic vein and form the superior vena cava. The right brachiocephalic vein stays on the right side of the chest and would not be affected by the aortic aneurysm (the IVC could be). The azygos vein is also on the right side of the chest, and it lies deep in the thoracic cavity. The internal thoracic vein lies on the interior surface of the anterior wall of the chest. Although it drains into the brachiocephalic vein, it would not be affected by the aneurysm. The left superior intercostal vein crosses the aortic arch laterally, but its blockage would only affect drainage of intercostal spaces 2-4 on the left side.

10. A patient involved in an automobile accident presents with a sharp object puncture of the middle of the sternum at about the level of the 4th or 5th costal cartilage. If the object also penetrated pericardium and heart wall, which heart chamber would most likely be damaged?

Left atrium

Left ventricle

Right atrium

Right ventricle

The right ventricle forms most of the anterior wall of the heart and extends from approximately the right border of the sternum to approximately 2 inches to the left of the sternum at the level of the fourth intercostal space. The right atrium forms the right border of the heart. Its anterior surface is on the right side of the sternum from approximately the third rib to the sixth rib. The left atrium forms the posterior wall of the heart. The only portion of the left atrium seen on the anterior surface of the heart is the left auricular appendage, which is at the level of the second intercostal space on the left. The left ventricle forms most of the left border of the heart and the diaphragmatic surface of the heart. It forms the anterior wall of the heart in a region from approximately 2-3 inches from the left border of the sternum from the third to the fifth intercostal space.

Explanation

The right ventricle forms most of the anterior wall of the heart and extends from approximately the right border of the sternum to approximately 2 inches to the left of the sternum at the level of the fourth intercostal space. The right atrium forms the right border of the heart. Its anterior surface is on the right side of the sternum from approximately the third rib to the sixth rib. The left atrium forms the posterior wall of the heart. The only portion of the left atrium seen on the anterior surface of the heart is the left auricular appendage, which is at the level of the second intercostal space on the left. The left ventricle forms most of the left border of the heart and the diaphragmatic surface of the heart. It forms the anterior wall of the heart in a region from approximately 2-3 inches from the left border of the sternum from the third to the fifth intercostal space.

11. Which one of the following structures will be deficient in a child who has a Neural Crest Cell migration problem?

Ductus Arteriosis

Smooth part of Right Atria

Aortic/Pulmonic trunks

Oblique Sinus

NCC are responsible for the correct partitioning of the outflow tracks.

Explanation

NCC are responsible for the correct partitioning of the outflow tracks.

12. Melanie presents to the clinic with a pounding headache. She has a strong carotid pulse, yet her femoral and dorsalis pedis pulses are extremely weak. After further investigation, her doctor tells her that she has coarctation of her aorta. Where is the coarctation likely located?

Coarctation of the aorta before the branching of the brachiocephalic trunk

Coarctation of the aorta before the branching of the left sublclavian artery

Coarctation of the aorta slightly past the branching of the left subclavian

Coarctation of the ascending aorta

Coarctation of the aorta just after the branching of the left sublcavian artery would force extra blood through the branches of the aorta that supply the upper limbs and head (hence the strong carotid pulse and headache). Blood would not be able to flow through the thoracic and descending aorta as strongly (hence the weak femoral and dorsalis pedis pulse).

Explanation

Coarctation of the aorta just after the branching of the left sublcavian artery would force extra blood through the branches of the aorta that supply the upper limbs and head (hence the strong carotid pulse and headache). Blood would not be able to flow through the thoracic and descending aorta as strongly (hence the weak femoral and dorsalis pedis pulse).

13. The right atria receives blood from the lower body by way of the IVC, if a patient has a developmental defect in which the L. Supracardinal Vein does not regress completely (inferior portions persists), what will be the effect on the embryo?

Double IVC

Rib notching

Lack of IVC

Double Azygous system

Cyanosis

Persistence of the L. Supracardinal vein results in Double IVC.

Explanation

Persistence of the L. Supracardinal vein results in Double IVC.

14. The minor (horizontal) fissure separates:

The lower lobe from the lingula

The upper lobe from the lingula

The lower lobe from both the middle and upper lobes

The lower lobe from the middle lobe

The middle lobe from the upper lobe

The horizontal fissure cuts across the right lung in such a way as to separate the middle lobe from the upper lobe. The oblique fissure separates the lower lobe from both the middle and upper lobes. Remember that the lingula is only on the left lung, and it is part of the superior lobe.

Explanation

The horizontal fissure cuts across the right lung in such a way as to separate the middle lobe from the upper lobe. The oblique fissure separates the lower lobe from both the middle and upper lobes. Remember that the lingula is only on the left lung, and it is part of the superior lobe.

15. Cardiothoracic surgeons must be familiar with bronchopulmonary segments since individual segments of the lung can be removed, leaving the rest of the lung intact and functional. Which of the following is a correct characterization of bronchopulmonary segments?

They are arranged with their bases directed toward the hilum of the lung

They are separated by parietal pleura

The arterial supply is located in the periphery of each segment

Each segment is supplied by a secondary or lobar bronchus

Veins may be used to localize the planes between segments

Veins may be used to localize the planes between segments. Although the segmental bronchus and artery tend to be centrally located (answer C), the veins do not accompany the arteries, but tend to be located subpleurally and between bronchopulmonary segments. Indeed, at surgery the intersegmental veins are useful in defining intersegmental planes. Bronchopulmonary segments, the anatomic and functional units of the lung, are roughly pyramidal in shape, have apices directed toward the hilum of the lung (answer a), and are separated from each other by connective tissue septa. Each bronchopulmonary segment is supplied by one tertiary or segmental bronchus (answer D), along with a branch of the pulmonary artery. The parietal pleura (answer B) only covers the ends of the bronchopulmonary segments.

Explanation

Veins may be used to localize the planes between segments. Although the segmental bronchus and artery tend to be centrally located (answer C), the veins do not accompany the arteries, but tend to be located subpleurally and between bronchopulmonary segments. Indeed, at surgery the intersegmental veins are useful in defining intersegmental planes. Bronchopulmonary segments, the anatomic and functional units of the lung, are roughly pyramidal in shape, have apices directed toward the hilum of the lung (answer a), and are separated from each other by connective tissue septa. Each bronchopulmonary segment is supplied by one tertiary or segmental bronchus (answer D), along with a branch of the pulmonary artery. The parietal pleura (answer B) only covers the ends of the bronchopulmonary segments.

16. You have a patient with a failure of right-sided looping during development. They are, luckily, asymptomatic; however, they were recently in an accident wherein a piece of steel penetrated their anterior ribcage, parasternal in the left 5^th intercostal space. What vascular structure is most likely compromised?

Thoracic duct

SVC

Descending aorta

Atria

The patient described has Situs Inversus, basically all the structures are reversed. Therefore, the correct answer would be the atria, all others are in the posterior mediastinum.

Explanation

The patient described has Situs Inversus, basically all the structures are reversed. Therefore, the correct answer would be the atria, all others are in the posterior mediastinum.