HS2-15 Lungs and Pleura Flashcards
Describe the process of gas exchange in the lungs.
deoxygenated blood from heart enters lungs via pulmonary trunk + pulmonary arteries
oxygenated blood flows from lungs to heart via pulmonary vein
Compare the size and weight of the two lungs.
right lung is wider and heavier than left
What fissures are found on the right lung?
oblique
horizontal
What lobes are found in the right lung?
superior
middle
inferior
Which lung is taller?
left lung
What fissures are found on the left lung?
only oblique fissure
What lobes are found on the left lung?
superior (featuring cardiac notch + lingula)
inferior
Impressions on the lung are found on which lung?
left lung (cardiac + aortic impressions)
What structures are found in the hilum, the root of the lung? (5)
bronchi
pulmonary arteries/veins
bronchial arteries/veins
pulmonary plexus
lymph vessels/nodes
Describe the arrangement of structures in the left lung hilum. Draw a diagram.
1 pulmonary artery superior to 1 main bronchus
pulmonary veins anterior and inferior to bronchus and artery
Describe the arrangement of structures in the right lung hilum. Draw a diagram.
1 lobar bronchus superior to main bronchus
2 pulmonary arteries, one slightly superior and anterior to each bronchus
pulmonary veins anterior and inferior to bronchi and arteries
What is the hierarchy of bronchi?
principal = main
secondary = lobar
tertiary = segmental
Why are inhaled objects more likely to get stuck in the right bronchus?
because the right bronchus is wider, shorter, and more vertically oriented
How many secondary/lobar bronchi are there?
2 left
3 right
What is the function of bronchial arteries?
supply oxygenated blood to lung tissue
How many bronchial arteries are there?
2 from thoracic aorta (supply left lung)
1 from first intercostal artery -or- superior left bronchial artery (supplies right lung)
What is the function of the bronchial veins?
drain deoxygenated blood from lung tissue
The bronchial veins drain into
azygos vein (right)
hemiazygos vein (left)
What are the two layers of pleura?
parietal
visceral
The parietal pleura covers
parts of the thoracic wall, and some of the thoracic contents
What are the subtypes of parietal pleura found in the thoracic cavity? (4)
costal
mediastinal
diaphragmatic
cervical (a.k.a. cupola)
Describe the features of cervical pleura. (3)
covers apex of lung
extends an inch above clavicle, therefore reaching into neck
also called the cupola
The visceral pleura covers
lungs
The visceral pleura is continuous with
the parietal pleura at the root of the lung
What is the pleural cavity?
space between parietal and visceral pleura
What is the function of the pleural fluid found in the pleural cavity? (2)
reduces friction
produces surface tension that keeps parietal and visceral pleural stuck to each other
What are lines of pleural reflection?
where one type of parietal pleura becomes continuous with another (ie. changes surfaces)
What are pleural recesses?
areas where two layers of parietal pleura are not separated by lung during quiet respiration
What are the three functionally significant pleural recesses?
right costodiaphragmatic recess
left costodiaphragmatic recess
left costomediastinal recess
What is the significance of the right and left costodiaphragmatic recesses?
can accommodate inferior margins of lungs
What is the significance of the left costomediastinal recess? (2)
exists due to leftward bulge of heart
accommodates lingula of left lung
What is the innervation to the visceral pleura?
autonomic innervation from vagus + sympathetic trunk
(T/F) The visceral pleura are insensitive to pain.
True
What is the innervation to the parietal pleura? (1, +2)
somatic innervation:
costal pleura = intercostal nerves
diaphragmatic + mediastinal pleura = phrenic nerve
Describe how the vertical plane of the thorax changes during respiration.
diaphgram contracts and moves inferiorly
Describe how the transverse plane of the thorax changes during respiration. (2)
ribs 2-10 elevate in bucket handle motion
lateral edges of ribs move away from midline
Describe how the anteroposterior plane of the thorax changes during respiration.
sternum moves superiorly in pump handle motion
anterior ends of ribs 2-6 elevate
What are the muscles associated with quiet inspiration?
diaphragm
What are the muscles associated with forced inspiration? (1 +3, 1 +3)
primary = external intercostals, scalenes, sternocleidomastoid
secondary = pectoralis major/minor, serratus anterior, serratus posterior superior/inferior
What are the muscles associated with quiet expiration? (2)
relaxation of diaphragm
elastic recoil of lung tissue
What are the muscles associated with forced expiration?
contraction of internal + innermost intercostal muscles
Describe the mechanism of forced expiration.
contraction of internal and innermost intercostal muscles pulls ribs and sternum inferiorly
increase in abdominal pressure causes diaphragm to move superiorly
What are the three common views of chest x-rays?
PA (posterior anterior) = frontal view, standing
lateral = lateral view, standing
AP (anterior posterior) frontal view, supine
How is the heart imaged in the AP view?
because the heart is positioned further from the director, it is artifically magnified in size
What is echocardiography?
ultrasound of the heart
What is mammography?
specialized radiographic technique used to image the breast
What are the bronchi?
main two stems of the trachea
What is the carina?
branching point of main stem bronchi
What is main stem bronchus intubation?
placement of an endotracheal tube that preferrably ends up in the mid trachea, proximal to the carina
Where do malpositioned endotracheal tubes most commonly end up?
right main stem bronchus (for the same reason that inhaled objects tend to end up in the right main stem bronchus)
How can a right main stem bronchus intubation affect the left lung?
can cause left lung collapse due to lack of ventilation on the left side caused by malpositioned tube in right side
Differentiate between the left and right hilums in chest radiography.
left hilum is slightly higher than right hilum on chest x-ray
Describe the visualization of right middle lobe pneumonia on chest x-ray.
abnormal, triangularly-shaped opacity that demonstrate’s the right middle lobe’s characteristic triangular shape
Which type of chest x-ray is best for visualizing right middle lobe pneumonia?
lateral CXR
What is pneumothorax?
presence of air in pleural space
What is the effect of pneumothorax on the visceral and parietal pleura?
air occupies pleural space and pushes visceral pleura away from parietal pleura
(T/F) In its normal state, the visceral pleura is visualizable on CXR.
False. That’s why if you do actually see the visceral pleura on CXR, something is not normal (such as pneumothorax).
Where on a CXR is pneumothorax most easily visualized?
in the superior thorax/apical region
In what patient position is pneumothorax most easily visualized on CXR?
patient in upright position
Write out a table that shows where the lungs and parietal pleura end at the midclavicular, midaxillary, and midscapular lines.
Where does the costodiaphragmatic recess extend to, posteriorly?
12th rib @ midscapular line
Where does the costodiaphragmatic recess extend to, laterally?
extends to 10th rib @midaxillary line
Where does the costodiaphragmatic recess extend to, anteriorly?
extends to 8th rib @ midclavicular line
Which of the costodiaphragmatic recesses are best seen on CXR?
lateral and posterior
Where does fluid preferentially accumulate in the pleural cavity of the thorax?
the lateral and posterior costodiaphragmatic recesses, because they are the most inferior regions of the thorax
How is pleural fluid typically seen on CXR?
homogeneous opacity that “blunts” the typical costodiaphragmatic angle and has a concave meniscus
Describe the movement of air after the trachea.
trachea
↓
principal/main bronchi
↓
secondary/lobar bronchi
↓
tertiary/segmental bronchi
↓
bronchopulmonary segments
