📚 Question Bank

The middle cardiac veins lie in the posterior interventricular groove and not the posterior atrioventricular groove.

Option A: The opening of the coronary sinus may be guarded by a semilunar valve of the coronary sinus, the Thebesian valve.

Option C: The great cardiac vein accompanies the anterior interventricular artery (left anterior descending artery) in the anterior interventricular groove.

Option D: The venae cordis minimae / Thebesian veins open into all cardiac chambers.

The anterior cardiac vein drains directly into the right atrium and not into the coronary sinus, hence, they might remain normal in coronary sinus thrombosis.

Small cardiac vein does not open into the sinus venarum. It opens into the coronary sinus.

Superior vena cava, coronary sinus, and the inferior vena cava open into the sinus venarum or the smooth posterior part of the right atrium.

The sympathetic innervation of the heart is by T1-T5.

The preganglionic sympathetic nerves to the heart arise from T1-T5. Some of these synapse in the upper thoracic sympathetic ganglia and some synapse in the cervical ganglia. The postganglionic fibres from these ganglia form the sympathetic cardiac nerves and innervate the heart.

The cardiac ganglion of Wrisberg is present in the superficial cardiac plexus immediately below and slightly in front of the arch of aorta to the right of the ligamentum arteriosum.

The internal intercostal muscles are the muscles of expiration.

The device shown in the image is an incentive spirometer. It is a device used to help your lungs recover after surgery or a lung illness.

Latissimus dorsi is not an accessory muscle of inspiration. It is an accessory muscle of expiration. Accessory muscles of inspiration:

• Sternocleidomastoid
• Scalene muscles
• Serratus posterior and anterior
• Errector spinae
• Pectoralis major and minor

Breathing involves changing the thoracic volume by altering the vertical, transverse, and anteroposterior dimensions of the thorax. The diaphragm is the key muscle in respiration.

Serratus posterior superior elevates the ribs, hence aiding in inspiration. Serratus posterior inferior depresses the ribs. It is a muscle aiding in expiration.

Serratus posterior inferior does not elevate the ribs.

The muscles of inspiration help increase the diameters of the thoracic cavity by elevating the ribs. Serratus posterior inferior is an accessory muscle of expiration. The muscles of expiration help in the depression of the ribs.

Mnemonic: SIT-Q depressors that work along with anterior abdominals for expiration:

• Serratus posterior inferior
• Internal intercostals
• Transversus thoracis
• Quadratus lumborum

The trachea starts at the level of the inferior border of the cricoid cartilage at the level of the C6 vertebra.

The trachea bifurcates at the lower border of T4 vertebra. The trachea is 10 - 12 cm long and has 2 parts:

• Upper cervical
• Thoracic(in superior mediastinum)

Note: Although Gray's Anatomy 41st Ed states that the tracheal bifurcation is at T6, we choose to stick with T4 as multiple other textbooks give the answer as T4.

The left bronchus crosses the esophagus at 28 cm from the upper incisor teeth.

Normally esophagus shows 4 constrictions at the following levels measured from upper incisors:

• Junction of the esophagus with cricopharynx (15 cm from the incisor teeth)
• Crossed by arch of aorta (23 cm from the incisor teeth)
• Crossed by left bronchus (28 cm from the incisor teeth)
• It pierces the diaphragm (40 cm from the incisor teeth)

The inferior margin of the pleura in the midaxillary line is at the level of the 10th rib. So, while doing thoracentesis you would not go below this level. It is done in the 8th or 9th intercostal space so as not to damage the surrounding structures.

The surface marking of the oblique fissure of the lung will not touch 4th costal cartilage.

On either side, the upper and lower lobes of the lung are separated by the oblique fissure.

This can be marked by a line that runs anteroinferiorly from the posterior end of the 4th rib (the spinous process of the T3 vertebra), crosses the 5th rib in the midaxillary line, continues inferiorly, crossing either the 6th intercostal space/ 7th rib on the right or the 5th rib/ 5th intercostal space on the left, on both sides at the midclavicular line.

The left oblique fissure is located at a higher level and courses more vertically than the right oblique fissure.

The lower border of the lung in the midclavicular line is at the level of the 6th rib. Hence, if the entry wound is below this level, the lung is probably not injured.

The dome-shaped layer of parietal pleura lining the cervical extension of the pleural cavity is called cervical pleura/pleural cupola/dome of pleura.

The pain from mediastinal pleura is referred to the side of the neck.

Pleura

Costaland peripheral diaphra gmatic pleura

Mediastinaland Central diap hragmatic pleura

Innervation Intercostal nerves

Phrenic nerve (C3, C4, and C 5)

Pain referred to

Thoracic or abdominal wall

Lateral neck and supraclavic ular region

Superior vena cava is related to the mediastinal part of the right lung.

The vagus nerve is posterior to the root of the lung.

The roots of the lung are at the level of T5-T7 vertebral bodies. The phrenic nerve is anterior to the root of the lung.

The area marked 'A' is where the azygos vein arches over the hilum of the right lung.

The diagram shown is of the right lung, identified by the presence of hyparterial and eparterial bronchus at the hilum.

The sequence of structures at the left hilum superior to inferior is: (Mnemonic: 'ABV')

• Pulmonary artery,
• Principal (hyparterial) bronchus
• Inferior pulmonary vein

The sequence of structures at the right hilum superior to inferior is: (Mnemonic: 'BABV')

• Superior lobar (eparterial) bronchus
• Pulmonary artery
• Principal bronchus
• Inferior pulmonary vein

The inferior most structure of the right hilum is the inferior pulmonary vein.

The sequence of structures at the right hilum superior to inferior is: (Mnemonic - 'BABV')

• Superior lobar (eparterial) bronchus
• Pulmonary artery
• Principal bronchus
• Inferior pulmonary vein

Lingula is not a lobe. It is a small process that is usually present at the lower end of the cardiac notch of the left lung.

The right lung has 3 lobes:

• Superior
• Middle
• Inferior

The left lung has 2 lobes:

• Superior
• Inferior

Note: The azygos vein may sometimes course in a more lateral position, within a four-layered pleural septum within the superior lobe, creating an ‘azygos lobe’. This is not a true lobe, but a separated portion of the superior lobe that lacks its own bronchi, arteries, or veins.

Both the lungs have 10 bronchopulmonary segments each.

The functionally independent unit of lung tissue is called a bronchopulmonary segment. Each segment is a separate respiratory unit.

The eparterial bronchus supplies the right upper lobe, which includes the segments: apical, posterior, and anterior. Hence, these segments will have decreased airflow.

The bronchopulmonary segments are aerated by tertiary bronchi (3°).

Principal bronchi (1°) ---gt; lobar bronchi (2° - right into 3, left into 2) ---gt; segmental bronchi

(3°)