SVC syndrome is most commonly associated with : fmge september2009

SVC syndrome is most commonly associated with :  fmge september 2009

a.  Mediastinal fibrosis

b.  Lymphoma

c.  Lung cancer

d. TB mediastinitis

answer:c 

Superior vena cava syndrome (SVCS), or superior vena cava obstruction (SVCO), is usually the result of the direct obstruction of the superior vena cava by malignancies such as compression of the vessel wall by right upper lobe tumors orthymoma and/or mediastinal lymphadenopathy. The most common malignancies that cause SVCS is bronchogenic carcinoma.

Approximately 90% of cases are associated with a cancerous tumor that is compressing the superior vena cava, such as bronchogenic carcinoma including small cell and non-small cell lung carcinoma, Burkitt lymphoma, lymphoblastic lymphomas, pre-T-cell lineage acute lymphoblastic leukemia (rare), and other acute leukemias. Syphilis and tuberculosis have also been known to cause superior vena cava syndrome SVCS can be caused by invasion or compression by a pathological process or by thrombosis in the vein itself, although this latter is less common (approximately 35% due to the use of intravascular devices).

among the given options lung cancer is the best choice as it is the most common.

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Cardiac dominance is determined by coronary artery : fmge september2009

Cardiac dominance is determined by coronary artery :   fmge september2009

a. supplying circulation to the SA node

b. Supplying circulation to the inferior portion of the interventricular septum

c. Supplying circulation to the interatrial septum

d. Supplying circulation to the anterior portion of the interventricular septum

answer : b

Coronary artery dominance

The artery that supplies the posterior descending artery (PDA)(a.k.a. posterior interventricular artery) determines the coronary dominance.

• If the posterior descending artery (PDA) (a.k.a. posterior interventricular artery) is supplied by the right coronary artery (RCA), then the coronary circulation can be classified as "right-dominant".
• If the posterior descending artery (PDA) is supplied by the circumflex artery (CX), a branch of the left artery, then the coronary circulation can be classified as "left-dominant".
• If the posterior descending artery (PDA) is supplied by both the right coronary artery (RCA) and the circumflex artery, then the coronary circulation can be classified as "co-dominant".

Approximately 70% of the general population are right-dominant, 20% are co-dominant, and 10% are left-dominant A precise anatomic definition of dominance would be the artery which gives off supply to the AV node i.e. the AV nodal artery. Most of the time this is the right coronary artery.

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Azygous vein drains into: fmge september 2009

 Azygous vein drains into:  fmge september2009

a. Right subcostal vein

b. Superior vena cave

c. Braciocephalic

d. Right ascending lumbar vein

answer: b

explanation:

The Azygos Vein

• The azygos vein connects the superior and inferior venae cavae, either directly by joining the IVC or indirectly by the hemiazygos and accessory hemiazygos veins.
• The azygos vein drains blood from the posterior walls of the thorax and abdomen.

• It ascends in the posterior mediastinum, passing close to the right sides of the bodies of the inferior eight thoracic vertebrae (T4-T12).
• It is covered anteriorly by the oesophagus as it passes posterior to the root of the right lung.
• It then arches over the superior aspect of this root to join the SVC.

• In addition to the posterior intercostal veins, the azygos vein communicates with the vertebral venous plexuses.
• This vein also receives the mediastinal, oesophageal, and bronchial veins.

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Muscles involved in quiet expiration: fmge september2009

 Muscles involved in quiet expiration:     fmge september2009

a. Diaphragm

b. Intercostal muscles

c. Both of the above

d. None of the above

During quiet breathing, there is little or no muscle contraction/relaxation involved in expiration. This process is simply driven by the elastic recoil of the lungs in healthy individuals. In certain conditions the elasticity of the lung can be lost, such as in emphysema. Forced or active expiration occurs in such individuals as well as occurring during exercise. The abdominal muscles and the internal and innermost intercostal muscles help expel air.

The principal muscles are the diaphragm, the external intercostal and the interchondral part of the internal intercostal muscles. Both the external intercostal muscles and the intercondral elevate the ribs, thus increasing the width of the thoracic cavity, while the diaphragm contracts to increase the vertical dimensions of the thoracic cavity, and also aids in the elevation of the lower ribs.

There is some controversy as to which muscles may be considered accessory muscles of inspiration (Kendalll, McCreary, Provance, Rodgers, Romani, 2005). The sternocleidomastoid (elevated sternum) and the scalene muscles (anterior, middle and posterior scalene) are typically considered accessory muscles of breathing ., however the following muscles have also been observed contributing to the breathing:

 serratus anterior, pectoralis major & minor, upper trapezius, latissimus dorsi, erector spinae (thoracic), iliocostalis lumborum, quadratus lumborum, serratus posterior superior and inferior, levatores costarum, transversus thoracis, subclavius (Kendall et al., 2005). 

Abdominal muslces relax which is regarded as a function

Scalene muscle activation coincides with the diaphragm even at rest in most humans, suggesting it could be considered a primary muscle of respiration.

If a breathing pattern disorder exists, as in the event of an asthma attack, the accessory muscles of inspiration may become overused.

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