SCID 242 - Disease Quiz - Quiz & Trivia

1. After a blunt injury to the left anterior shoulder region, a young man was told by an examining physician that he had a muscle tear that resulted directly from the superolateral distraction of a fractured coracoid process. Which muscle was torn?

Subclavius

Serratus anterior

Pectoralis major

Pectoralis minor

Deltoid

Of the muscles listed, pectoralis minor is the only one which is attached to the coracoid process.

Explanation

Of the muscles listed, pectoralis minor is the only one which is attached to the coracoid process.

2. After being thrown from a motorcycle moving at high speed, a 15-year-old female was found to have a paralyzed right pectoralis major muscle. Which set of movements at the shoulder joint would be found greatly weakened?

Abduction and extension

Abduction and lateral rotation

Adduction and flexion

Lateral rotation and extension

Pectoralis major flexes, adducts, and medially rotates the arm. It is innervated by the lateral and medial pectoral nerves, from the lateral and medial cords of the brachial plexus.

Explanation

Pectoralis major flexes, adducts, and medially rotates the arm. It is innervated by the lateral and medial pectoral nerves, from the lateral and medial cords of the brachial plexus.

3. In lymphatic drainage of the breast, the major portion (about 75%) enters eventually into which group of nodes?

Central axillary

Deltopectoral

Lateral axilllary

Parasternal

Subscapular

About 75% of the lymph draining the breast goes to the axillary lymph nodes, via the pectoral lymph nodes. All of this lymph from the pectoral lymph nodes must drain to the central lymph nodes as well. This is why it is so important to examine all these groups of axillary lymph nodes when performing a breast exam.

Explanation

About 75% of the lymph draining the breast goes to the axillary lymph nodes, via the pectoral lymph nodes. All of this lymph from the pectoral lymph nodes must drain to the central lymph nodes as well. This is why it is so important to examine all these groups of axillary lymph nodes when performing a breast exam.

4. While observing a mastectomy on a 60-year-old female patient, a medical student was asked by the surgeon to help tie off the arteries that supply the medial side of the breast. The artery that gives origin to these small branches is the:

Thoracoacromial

Superior epigastric

Posterior intercostal

Musculophrenic

Internal thoracic

Small branches from the internal thoracic artery, known as medial mammary branches, supply the medial side of the mammary gland. The lateral side of the mammary gland is supplied by the lateral thoracic artery.

Explanation

Small branches from the internal thoracic artery, known as medial mammary branches, supply the medial side of the mammary gland. The lateral side of the mammary gland is supplied by the lateral thoracic artery.

5. In the axilla, the pectoralis minor is a landmark, being closely related to all of the following structures except:

Second part of the axillary artery

Cords of the brachial plexus

Medial pectoral nerve

Lateral thoracic artery

Cephalic vein

The cephalic vein is the only structure listed that does not have a special relationship to pectoralis minor. The cords of the brachial plexus are found deep to pectoralis minor. The second part of the axillary artery is defined as the segment of the axillary artery which is covered by the pectoralis minor muscle. So, branches of the second part of the axillary artery, including the lateral thoracic artery, lie deep to pectoralis minor. The medial pectoral nerve pierces pectoralis minor to reach pectoralis major.

Explanation

The cephalic vein is the only structure listed that does not have a special relationship to pectoralis minor. The cords of the brachial plexus are found deep to pectoralis minor. The second part of the axillary artery is defined as the segment of the axillary artery which is covered by the pectoralis minor muscle. So, branches of the second part of the axillary artery, including the lateral thoracic artery, lie deep to pectoralis minor. The medial pectoral nerve pierces pectoralis minor to reach pectoralis major.

6. In the process of doing an axillary lymph node dissection in a 50 year-old patient, the surgery resident cleans the space between the pectoralis major and minor muscles, in an attempt to remove all of the lateral pectoral lymph nodes. Upon recovery it is noted that the patient's lower pectoralis major is paralyzed. The nerve most likely injured is the:

Thoracodorsal

Suprascapular

Medial pectoral

Lateral pectoral

Axillary

Since the medial pectoral nerve pierces pectoralis minor to reach pectoralis major, it seems likely for this nerve to be injured from trauma to the space between pectoralis minor and major. Also, remember that the medial pectoral nerve innervates the inferior part of pectoralis major, while the lateral pectoral nerve innervates the superior part of pectoralis major.

Explanation

Since the medial pectoral nerve pierces pectoralis minor to reach pectoralis major, it seems likely for this nerve to be injured from trauma to the space between pectoralis minor and major. Also, remember that the medial pectoral nerve innervates the inferior part of pectoralis major, while the lateral pectoral nerve innervates the superior part of pectoralis major.

7. The prognosis in breast cancer is poorer as more proximal lymph nodes are found to have cancerous cells in them. Spread of cancer to which of the following axillary nodes would indicate the worst prognosis?

Apical

Central

Lateral

Pectoral

Subscapular

As lymph drains from the breast into the axillary system, it moves from pectoral, lateral, and subscapular nodes to the central nodes, and then to the apical nodes. If cancer is found in the apical axillary nodes, this is a sign that the cancer has spread through the regional lymphatic system and may have metastasized to the rest of the body.

Explanation

As lymph drains from the breast into the axillary system, it moves from pectoral, lateral, and subscapular nodes to the central nodes, and then to the apical nodes. If cancer is found in the apical axillary nodes, this is a sign that the cancer has spread through the regional lymphatic system and may have metastasized to the rest of the body.

8. Breast cancer cells can spread directly to the cranial cavity and brain via the vertebral venous plexus. Through which route can they reach this plexus?

Axillary lymph nodes

Internal thoracic vein

Intercostal veins

Parasternal lymph nodes

Thoracoacromial artery

Hematogenous spread through the intercostal veins is the easiest way for breast cancer to reach the internal vertebral venous plexus. It is true that the axillary lymph nodes drain 75% of the lymph from the breast, and the parasternal lymph nodes drain most of the remaining lymph. However, these lymphatic channels are not the major way that cancer would be transmitted to the internal vertebral venous plexus.

Explanation

Hematogenous spread through the intercostal veins is the easiest way for breast cancer to reach the internal vertebral venous plexus. It is true that the axillary lymph nodes drain 75% of the lymph from the breast, and the parasternal lymph nodes drain most of the remaining lymph. However, these lymphatic channels are not the major way that cancer would be transmitted to the internal vertebral venous plexus.

9. Common routes for metastasis of breast cancer include hematogenous spread and lymphatic spread. Which route is more likely for metastases from breast tissue to ribs and other bones?

Hematogenous spread

Lymphatic spread

Option 3

Option 4

The most likely route for breast cancer to reach the bones is hematogenous spread via the intercostal veins.

Explanation

The most likely route for breast cancer to reach the bones is hematogenous spread via the intercostal veins.

10. A 45-year-old patient with breast cancer subsequently develops metastases in her vertebral column. The most direct route for spread of the tumor to the vertebral column was via:

Branches of the cephalic vein

Branches of the lateral thoracic vein

Branches of the thoracoacromial veins

Ymphatic vessels draining into the axilla

Branches of the intercostal veins

he most likely route for the cancer to reach the vertebral column is through the intercostal veins, i.e. hematogenous spread. The cephalic vein and thoracoacromial vein would not be draining the breast, and the lateral thoracic vein would not be directing blood toward the vertebral column. Lymphatic vessels may carry some tumor cells to the axillary lymph nodes and may participate in the spread of the cancer, but this isn't the best answer for this question. The most direct way for the cancer to spread to the vertebral column is through the venous system.

Explanation

he most likely route for the cancer to reach the vertebral column is through the intercostal veins, i.e. hematogenous spread. The cephalic vein and thoracoacromial vein would not be draining the breast, and the lateral thoracic vein would not be directing blood toward the vertebral column. Lymphatic vessels may carry some tumor cells to the axillary lymph nodes and may participate in the spread of the cancer, but this isn't the best answer for this question. The most direct way for the cancer to spread to the vertebral column is through the venous system.

11. Which one do you like?

Option 1

Option 2

Option 3

Option 4

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Explanation

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