Thorax and Breathing Flashcards
(34 cards)
What are the boundaries of the thorax?
Sternum to vertebral column (T1 to T12)
What are the superior and inferior boundaries of the lungs?
Superior = point above the clavicle Inferior = diaphragm
Why is the medial surface of the lungs slightly concave?
To allow for other viscera to fit in thorax
Where do the primary bronchi and blood vessels enter the lung?
At the hilum
What type of control is the diaphragm under?
Mostly involuntary but can be overridden
Which nerve supplies the diaphragm?
Phrenic nerve: C 3, 4, 5
What type of muscle is the diaphragm?
Skeletal
What is the top of the lung called?
The apex (the top of the cone shaped structure) Projects above the clavicle
How many lobes does each lung have?
Right lung has 3 lobes - superior, middle and inferior
Left lung has 2 lobes - superior and inferior
Which fissures are present in the right lung?
Oblique and horizontal fissures separate 3 lobes
Which fissures are present in the left lung?
Oblique fissure separates 2 lobes
What do fissures in the lungs enable?
Increase the surface area -> allow for more gas exchange
What is the pulmonary ligament made up of?
Folds of the parietal and visceral pleura
What does the parietal pleura line?
Lines the whole of the thoracic cavity
Adheres to internal surface of the ribs and superior face of the diaphragm
Partitions off the mediastinum
What is the mesothelium?
Very thin layer of endothelium
Pleura is made up of mesothelium
What does the visceral pleura line?
Visceral pleura lies against the parietal pleura and covers the outer surface of the lung
What is between the 2 layers of pleura (parietal and visceral pleura)?
Pleural fluid
What is the purpose of pleural fluid?
Prevents friction between the 2 pleural layers
Where can fluid build up in lung disease?
The costodiaphragmatic recess
Why does the aorta not pass through the diaphragm?
Would get compressed during breathing
What do internal intercostal muscles do in respiration?
Depress the ribs
What do external intercostal muscles do in respiration?
Elevate the ribs
What effect does the diaphragm have on the thorax as it contracts and moves downwards?
Enlarges the thorax
What does the quadratus lumborum do?
Depresses the last rib
