bronchi, lungs, pleura and the diaphragm Flashcards
what does the bronchial tree consist of?
- trachea - primary bronchi - secondary bronchi - tertiary bronchi - bronchioli
describe the trachea ?
- C shaped incomplete cartilage rings - the lowest tracheal ring is the carina
where does the trachea start and end?
starts at C6 - ends at T4 this is where is biFOURCATES
where is the primary bronchi?
T4/5
compare the right and left bronchi?
the right is wider and vertical than the left also a bit shorter
label a diagram of the trachea moving into the bronchi?
where are the secondary bronchi and what do they supply?
they are formed within the lungs
- they supply the lobes
how many lobes does the right and left lung have?
right = 3
left = 2
what do the tertiary bronchi supply?
they supply the bronchopulmonary segments
- self contained independent units of lung tissue
what are bronchopulmonary segments?
they are the smallest functionally independent regions of the lung
how many bronchopulmonary segments do the right and left lung have?
right = 10
left = 8 or 9
how do the compositions of substances change down the airway?
what is the pleura?
- a thin layer of flattened cells supported by connective tissue that lines each pleural cavity and covers the exterior the lungs
what are the two types of pleura?
what do they do?
- the parietal pleura:
lines the inner surface of the chest walls
- the visceral pleura:
covers the surface of the lungs
it is shiny
how do the pleura connect?
they are continuous with one another at the lung root = the hilum
what is the pleural cavity?
- this is potential space between the visceral and parietal pleura
- this contains a thin layer of serous fluid
- this allows the lungs to glide
what does the costodiaphragmatic recess of the pleura mean?
- this means the lung tissue is not normally present except on max inspiration
- this is where the fluid first accumulates
what is the purpose of a chest drain?
what are the borders of a safe triangle?
- to collect fluid, air, blood from the pleural space
- the borders of the safe triangle are
Posterior: latissimus dorsi
Anterior: pectoralis major
Superior: apex of axilla
Inferior: 5th ICS at MAL
the needle will insert superior to the superior border of the rib to avoid the neuromuscular bundle
label the lobes and the fissures on the lungs?
what are some important surface land marks?
sternoclavicular joint
sternal angle
sternal border
oblique fissure
horizontal fissure
- 2-3cm above medial 3rd of the clavicle = sternoclavicular joint
- 2nd costal cartilage at the sternal angle
- 6th costal cartilage at sternal border
oblique fissure : from T3 posteriorly to 6th CC
horizontal fissure : from 4th CC on the right to meet oblique fissure at MAL
what are the two circulations of the lungs?
- pulmonary
supplies the lung with deoxygenated blood needed to oxygenate it
- bronchial (systemic)
provides the lungs with oxygenated blood to meet its metabolic needs
how are the lungs innervated?
by sympathetic and parasympathetic nerves?
PSNS: vagus nerve, increases secretions, contraction of the smooth muscle of the airways so that the airways are smaller and less air can come through
SNS: from the sympathetic trunks, relaxes the smooth muscle so more air flows through
how does the lymphatic drainage of the lungs work?
- lymphatics of the lungs and the visceral pleura drain to the
bronchopulmonary lymph nodes –> tracheobronchial nodes
–>bronchomediastinal trunk
what are the surfaces of the lungs?
- costal surface
convex
- mediastinal surface
- diaphragmatic surface
concave
what does the margin of the diaphragm attach to?
- costal margin
- xiphroid process
- ribs 11/12
- lumbar vertebrae
how far does the dome of the diaphragm extend?
- much higher than the costal margin
- abdominal organs
at what level is the
IVC
oesophagus
aorta
IVC: T8
Esophagus: T10
Aorta: T12
out of the IVC, oesophagus, aorta which pierces the diaphragm?
only the oesophagus and aorta are thick enough the pierce the diaphragm
the IVC does not pierce the diaphragm
what happens to the diaphragm, chest wall, intercostal muscles and lungs during inspiration?
intercostal muscles contract
the diaphragm contracts
the ribs move up and out
the chest wall expands
the pressure decreases
what happens to diaphragm, chest wall, intercostal muscles and lungs during inspiration?
- the internal intercostal muscles contract
- the external intercostal muscles relax
- the ribs move in and downwards
- the diaphragm relaxes
- the chest cavity gets smaller
- pressure increases
what is the mechanism of breathing?
- pleural cavity expands during inhalation
- elastic lungs also expand during inhalation
Reduced pressure inside lungs vs environment
Air flows in
how do the ribs move during breathing?
Ribs move in 2 directions with 2 ‘mechanisms’
-
Bucket handle: increases transverse diameter (lateral expansion)
Pump handle: increases antero-posterior diameter
overall this increases the volume of the chest
what does the contraction of the diaphragm result in?
Diaphragm contraction increases volume of thoracic cavity
–> Pressure on abdominal viscera
further contraction causes the costal margin the raise
- the increased thoracic capacity causes reduced intrapleural pressure
what innervates the diaphragm?
what supplies the diaphragm?
Innervated by phrenic nerve
supplied by inferior phrenic arteries
what does quiet expiration rely on?
- it is passive
- it relies on the elastic recoil of the lungs elastic tissue and ribcage
what does forced expiration rely on?
- abdominal wall muscles contract
- this results in an increase in intra-abdominal pressure which forces diaphragm upwards
- this also pulls the ribs down
