Bronchi, lungs, pleura and diaphragm Flashcards
Where should the trachea be located
Central
If not- indication of pathology
Swallowing and breathing can also cause positional shifts.
Describe the trachea
Extends from vertebral level C6 to T4/5
Held open by C-shaped cartilage rings
Lowest ring has a hook – carina (keel of ship)
The oesophagus continues into the posterior mediastinum
Describe the relations of the trachea to other structures
As the trachea passes through the superior mediastinum, they are crossed laterally by the azygos vein (right) and arch of aorta (left)
Describe the primary bronchi
formed at T4/5, with the right wider and more vertical (STERNAL ANGLE) - inhaled objects likely to enter right lung as more vertical and wider.
Describe the lobar (secondary bronchi)
formed within lungs to supply lobes (2 on left, 3 on right)
Supply the lobes
Describe the segmental bronchi
supply the bronchopulmonary segments (further subdivisions to supply independent units of lung tissues known as bronchopulmonary segments)
Describe the bronchial tree
Trachea divides into two main bronchi at vertebral level T4/5:
Right and left main (primary) bronchi divide into:
Lobar (secondary) bronchi - supplying the lobes (2 left, 3 right)
The lobar bronchi further subdivide into segmental (tertiary) bronchi supplying self-contained independent units of lung tissue named bronchopulmonary segments
What is meant by the bronchial tree
Branching pattern of trachea into main, lobar and segmental bronchi
What is C7
Prominent vertebrae- can be palpated
What happens to the segmental bronchi
The segmental bronchi give rise to multiple generations, ultimately bronchioles, which further subdivide and supply the respiratory surfaces.
The walls of the bronchi are held open by discontinuous elongated plates of cartilage, but these are not present in bronchioles
Why is the trachea open posteriorly
To allow the oesophagus to expand (e.g when eating)
What is meant by a bronchopulmonary segment
smallest functionally independent region of the lung so can remove one without affecting others/upstream
Has its own blood supply (pulmonary artery), innervation and airway
Tributaries of the pulmonary vein tend to pass intersegmentally around the margins of the segment..
How many bronchopulmonary segments are there
10 in each lung- however some fuse in the left lung
Describe the lungs
essential respiration organs situated in thorax and separated by mediastinum; each lies freely in pleural cavity (lined by pleural membranes held together by tension of fluid) apart from attachment to heart via pulmonary vessels and trachea and lung room (hilum)
Describe the shape of the lungs
The lungs are conical in shape
Describe the base of the lungs
concave
rests on convex surface of diaphragm
Describe the apex of the lungs
thoracic inlet oblique - apex rises 3-4 cm above
level of first costal cartilage- into root of neck.
Describe the surfaces of the lungs
The surfaces of the lungs relate to the structures that the lungs are sat in.
Costal- lies immediately adjacent to the ribs and intercostal spaces
Mediastinal surface- lies against the mediastinum anteriorly and vertebral column posteriorly- contains hilum
Inferior- diaphragm
Describe the borders (edges) of the lungs
Inferior border- sharp, separates base from the costal surface
Anterior and posterior- separate costal surfaces from the medial surface- smooth and rounded.
What does the diaphragm separate
right lung from right lobe of liver
left lung from left lobe of the liver, stomach & spleen