Thorax 2 - Lungs & Pleura Flashcards
lungs; neurovasculature; lymphatics (59 cards)
what structure separates the thoracic cavity from the abdominal cavity and forms the inferior border of the lungs?
diaphragm
where are the lungs located in relation to the mediastinum?
the lungs are located on either side of the mediastinum, flanking the heart
what is the functional unit of respiration in the lungs?
alveoli - allows oxygen to diffuse into the blood & CO2 to diffuse out
how far do the lungs extend (from apex to inferior border)?
apex extends above the 1st rib into the root of the neck
inferior border of lungs reaches the costal margin
what are the two layers of the pleura? how do they differ?
visceral pleura - adheres close to the lung surface
parietal pleura - lines the ribcage & diaphragm (internal surface of the thoracic cavity)
what are the 4 divisions of the parietal pleura associated with the lungs?
cervical
diaphragmatic
costal
mediastinal
what are the 4 divisions of the parietal pleura? where are they located?
- diaphragmatic - covers the superior surface of the diaphragm
- cervical - extends above the 1st rib into the root of the neck
- costal - lines the inner surface of the ribs
- mediastinal - covers the lateral surface of the mediastinum (near the heart)
what is the thickened portion of the cervical parietal pleura called? what is its significance?
suprapleural membrane - provides structural support and protection to the cervical parietal pleura as it extends into the root of the neck
the suprapleural membrane is a thickening of WHAT pleura?
cervical parietal pleura - provides structural support & protection to the apex of the lung as it extends into the root of the neck
what is the pleural cavity?
pleural cavity is the small space between the visceral & parietal pleural layers
why is the pleural cavity important for lung function?
- negative pressure space; allows the lungs to expand and contract smoothly during breathing
- secretes lubricating pleural fluid & reduces friction between lungs and thoracic cavity
what would happen if the pleural cavity were compromised (e.g., due to a pneumothorax)?
the lungs may collapse due to the loss of negative pressure that allows them to inflate - impairs gas exchange
what is a haemothorax?
when blood enters the pleural cavity - causes loss of negative pressure & lungs may collapse
what are the two recesses of the pleural cavity?
costomediastinal recess
costodiaphragmatic recess
what are pleural recesses?
areas of the pleural cavity not completely filled with lung tissue
WHEN do pleural recesses become occupied by lung tissue?
occupied with lung tissue during INSPIRATION - remain empty during expiration
what happens to the costomediastinal recess during inspiration?
becomes occupied by lung tissue (especially the anterior border of the lungs)
where is the costodiaphragmatic recess located?
at the base of the pleural cavity - where the diaphragm meets the thoracic wall
what part of the lung occupies the costodiaphragmatic recess during inspiration - the base or apex of the lung?
base of the lung
primary function of pleural recesses?
provide additional space for lung expansion during deep inspiration
how are the pleural recesses affected during pleural effusion? which recess is more clinically significant in this case?
accumulate excess fluid - costodiaphragmatic recess is a common site for fluid accumulation & can be accessed for treatment
how many lobes & fissures does the right lung have?
3 lobes (superior, middle & inferior)
2 fissures (horizontal & oblique)
how many lobes & fissures does the left lung have?
2 lobes (superior & inferior)
1 fissure (oblique fissure)
what are the 3 surfaces of the lungs?
- costal surface - faces inner surface of ribcage
- diaphragmatic surface - contacts diaphragm
- mediastinal surfaces - faces mediastinum