lungs

Question 1

Explain the parts and features of right and left lungs

Answer 1

• Apex
• Base
• Three borders * Anterior
• Posterior * Inferior
• Two surfaces. * Costal
• Medial (Anterior mediastinal and posterior vertebral)

Question 2

Apex

Answer 2

-rounded, and extends into the root of the neck, 2.5 to 4 cm above the level of the sternal end of first rib.
* Covered by cervical pleura and supra pleural membrane.

Question 3

Base

Answer 3

-broad, concave, and rests upon the diaphragm,
-which separates the right lung from the right lobe of the liver and the left lung from the left lobe of the liver, stomach and spleen.
* As the diaphragm extends higher on the right than on the left side, the concavity on the base of the right lung is deeper than that on the left.

Question 4

Borders

Answer 4

• Anterior border- thin, it is vertical on the right side and shows cardiac notch on the left side below 4th costal cartilage.
• Posterior border - thick and ill defined.
• Inferior border - separates the base from the costal and mediastinal surfaces.

Question 5

Surfaces

Answer 5

Costal
* Medial (Anterior mediastinal and posterior vertebral)

Question 6

costal surface

Answer 6

-smooth, convex, in contact with the costal pleura and presents, grooves corresponding with the overlying ribs.
* Related to lateral thoracic wall
* Separated by costal pleura and
endothoracic facia
* Upper 6 ribs in midclavicular line, 8 in mid axillary line and 10 in mid scapular line

Question 7

medial surface

Answer 7

divided into a vertebral part, and mediastinal part.
* The vertebral part lies in contact with the sides of the thoracic vertebrae and intervertebral discs, the posterior intercostal vessels, and the splanchnic nerves.
* The mediastinal part is concave, because it is adapted to the heart(the cardiac impression). this is larger and deeper on the left lung than on the right lung.
* It presents the hilum, where various structures enter or leave the lung.
* Mediastinal part is in contact with the mediastinal pleura.

Question 8

Hilum

Answer 8

-structures which form the root of the lung enter and leave.
* Hilar structures-principal bronchus, pulmonary artery, pulmonary veins, bronchial artery, bronchial vein, nerves & lymphatics.
* VAB - Anterior to posterior

Question 9

Fissures

Answer 9

• Oblique fissure
• Left and right
• Downwards and forward
• Horizontal fissure * Right lung only
• Forms middle lobe * 4th costal cartilage

Question 10

Fissures(Surface Marking)

Answer 10

Oblique fissure:
* Roughly corresponds to medial border of the scapula in the fully abducted position of the arm
* 2cm lateral to the T3 spine
* Posterior border 6cm below the apex
* 5th rib in mid axillary line
* Reaches 6th costal cartilage 7-8 cm lateral to the midline (6th costochondral junction)
* Inferior border 5cm from midline Horizontal fissure:
* Right 4th costal cartilage
* Meet the oblique fissure in midaxillary line

Question 11

lobes

Answer 11

r:3
l:2

Question 12

Fissures

Answer 12

• Oblique fissure
• Left and right
• Downwards and forward
• Horizontal fissure *
  Right lung only
• Forms middle lobe
• 4th costal cartilage

Question 13

Fissures surface marking

Answer 13

oblique fissure:
* Roughly corresponds to medial border of the scapula in the fully abducted position of the arm
* 2cm lateral to the T3 spine
* Posterior border 6cm below the apex
* 5th rib in mid axillary line
* Reaches 6th costal cartilage 7-8 cm lateral to the midline (6th costochondral junction)
* Inferior border 5cm from midline

Horizontal fissure:
* Right 4th costal cartilage
* Meet the oblique fissure in midaxillary line

Question 14

Blood Supply-Arteries

Answer 14

• Left side - 2 bronchial arteries arising from descending thoracic aorta.
• Right side - 1 bronchial artery arising from posterior intercostal artery.

Question 15

Vein

Answer 15

• 2 bronchial veins on both sides.
• Left side drains into left superior intercostal vein or hemiazygos vein.
• Right side drains into azygos vein.

Question 16

Lymphatics

Answer 16

-two sets of lymphatics, drain into the bronchopulmonary nodes.
* Superficial vessels drain the peripheral lung tissue lying beneath the pulmonary pleura.
* Deep lymphatics drain the bronchial tree, the pulmonary vessels and the connective tissue septa.
* They run towards the hilum where they drain into the bronchopulmonary nodes

Question 17

Nerve Supply

Answer 17

• Parasympathetic nerves are derived from the vagus.
• These fibres are:
• Motor to the bronchial muscles, and on
  stimulation cause bronchospasm.
• Secretomotor to the mucous glands bronchial tree.
• Sensory fibres are responsible for the stretch reflex of the lungs, and for the cough reflex.

Question 18

Difference between lobes

Question 19

Common medical terminologies

Answer 19

Bronchitis - Inflammation of the bronchi.
* Eupnea - Normal respiratory rate and rhythm.
* Apnea- Cessation of breathing.
* Hyperpnea - Deeper and more vigorous breathing but with unchanged respiratory rate.
* Dyspnea - Difficult or labored breathing
* Anoxia - Deficiency of oxygen.
* Hypoxia - Condition in which tissue oxygen supply is inadequate.
* Asthma - Lung disease characterized by bronchoconstriction.

Question 20

Clinical Relevance

Answer 20

Accessory lobe
* The most common “accessory” lobe is the azygos lobe, which appears in the right lung in approximately 1% of people. In these cases, the azygos vein arches over the apex of the right lung and not over the right hilum, isolating the medial part of the apex as an azygos lobe.

• Auscultation of the lungs (assessing air flow through the tracheobronchial tree into the lung with a stethoscope) and percussion of the lungs (tapping the chest over the lungs with the finger) always include the root of the neck to detect sounds in the apices of the lungs.
• Percussion helps establish whether the underlying tissues are air-filled (resonant sound), fluid-filled (dull sound), or solid (flat sound).
  serious lung infections cause localised necrosis of tissue leading to formation of a lung abscess.
• Most lung abscesses are caused by inhalation of infective material from infected sinuses (sinusitis), tonsillitis, or dental infection.
• Amongst bacterial infections of the lungs, pulmonary tuberculosis is an important chronic infection which when untreated can lead to cavities and abcess formation. The most common site to be affected by tuberculosis is the posterior segment of the right upper lobe leading to decreased air entry in the upper lobe.

Question 21

bronchial Asthma

Answer 21

• Spasm of the smooth muscle in the wall of the bronchioles. This particularly reduces the diameter of the bronchioles during expiration, usually causing the asthmatic patient to experience great difficulty in expiring

Question 22

Loss of Lung Elasticity

Answer 22

s emphysema and pulmonary fibrosis, destroy the elasticity of the lungs, and thus the lungs are unable to recoil adequately, causing incomplete expiration.

Question 23

emphysema

Answer 23

In some cases chronic respiratory obstruction leads to considerable dilatation of alveoli. Large spaces may be formed in the lung parenchyma. This condition is called emphysema. This condition may lead to a barrel-shaped chest.

Question 24

Loss of Lung Elasticity

Answer 24

• Many diseases of the lungs, such as emphysema and pulmonary fibrosis, destroy the elasticity of the lungs, and thus the lungs are unable to recoil adequately, causing incomplete expiration.

Question 25

chronic respiratory obstruction

Answer 25

leads to considerable dilatation of alveoli. Large spaces may be formed in the lung parenchyma. This condition is called emphysema. This condition may lead to a barrel-shaped chest.