Lungs, Pleura, and the Mechanics of Ventilation Flashcards
The lungs are divided into bronchopulmonary segments (BP), how many BP are there for each lung?
10
Each BP segment is served by a
Segmental (tertiary) bronchus and a pulmonary artery and vein
Bronchopulmonary segments can also be projected to the
Chest wall
The trachea bifurcates at the level of the
Sternal angle (T4-T5)
More vertical and slightly larger in diameter
Right bronchus
The fetus is surrounded by excessive amniotic fluid. This is referred to as
Polyhydramnios
Does not allow the fetus to swallow amniotic fluid, causing polyhydramnios
Tracheoesophageal fistula
The developing lungs evaginate into the pleural cavities and become covered with
Pleura
The arrangement of the lung in the pleural cavities, the heart in the pericardial cavity, and the organs in the abdominal cavity is the
Same
The apex of the lungs is superior to the
Medial 1/3 of the clavicle
Parietal pleura turns back on itself and forms
Reflections
Some of these reflections are at very acute angles so that during quiet breathing the lungs do not enter these areas. This is called a
Recess
Since their is no lung tissue in these recesses, during quiet breathing, which two things touch?
Parietal pleura touch eachother
Boyle’s law requires a constant
Teperature
Boyles law says that at a constant temperature
P1V1 = P2V2
This pressure-volume relationship governs
Normal and pathologic respiratory function
Allows all three dimensions of the thoracic cavity to be increased
Muscular action
The most important muscle for ventilation
Diaphragm
Contraction of the diaphragm increases the superior-inferior dimensions of the
Thoracic cavity
Pivot during respiration to increase the anterior-posterior dimensions of the thoracic cavity
Ribs 2-6
During this process, the anterior ends of ribs 2-6 move
Up and down
During this process, the sternum moves
Anteriorly
This is referred to as the “pump handle” movement caused by the
External intercostal muscles
Ribs 7-10 pivt on an axis through the head of the rib and sternocostal joint to increase the
Transverse Dimension of the thoracic cavity
This is the “bucket handle” movement and is caused by contraction of the
Diaphragm
Promotes the “bucket handle” movement of the ribs by acting as a platform for the diaphragm to push against
Lives