Thorax 2 Flashcards
label the 5 divisions of the mediastinum
Where does the trachea bifurcate?
At the level of the sternal angle into the bronchi - carina t4/5
what are the 5 lobes and fissures of the lungs?
which lung does not have a middle lobe and why?
left
apex of heart (ventricle) projects to the left
what is lung cardiac notch and lingula?
a concave impression molded to accommodate the shape of the heart
The lingula is not technically a lobe, but is the left lung equivalent of the right lung’s middle lobe.
How and why are the costal surfaces separated from the ribs?
Serous lining
Prevent damage during respiration
What is a bronchopulmonary segment?
What is the clinical significance of a bronchopulmonary segment?
How many bronchopulmonary segments do we have?
label them
An area of lung supplied by a segmental (tertiary) bronchus and accompanying pulmonary artery branch + pulmonary vein
Smallest, functionally independent unit of a lung and smallest area that can be isolated and removed without affecting adjacent regions
10 in each lung (8-10 in left) as some of them fuse in the left lung
Give the 3 sites of potential fusion in the left lung
-Fusion between apical and posterior segments of the superior lobe
-Fusion between superior and inferior lingular segments
-Fusion between medial and anterior basal; collectively termed as the anteromedial basal
label what u can
what does parietal and visceral pleura line?
what is the pleural cavity?
whats in it?
parietal - thoracic cavity
visceral - organs/ lungs
The pleural cavity is a potential space between the parietal and visceral layers.
pleural fluid
Where do the bronchial arteries originate from?
right bronchial artery x1 = from the posterior 3rd intercostal artery
left bronchial artery x2 = from aorta (descending throacic)
Where do the pulmonary arteries originate from?
Compare the pressure between the bronchial and pulmonary arteries
How do the bronchial and pulmonary arteries join together?
From the heart itself
Much higher pressure in bronchial
-Connection between the two at the capillary bed level, allows for nourishment of pulmonary as bronchial is highly oxygenated
Identify impressions on the lung made by adjacent structures
Right lung: Superior vena cava; arch of azygos vein
o Left lung: Arch of the aorta, left common carotid and subclavian arteries
what is in the hilum? (lung root) and how do they differ in each lung?
Bronchus at the BACK
Artery ABOVE the vein
label the divisions of the parietal pleura
1 - cervical
2 - costal
3 - diaphragmatic
4 - mediastinal
5 - pulmonary ligament
what does the pulmonary ligament do?
- Allows increased
mobility during
respiration
what are the recesses of the pleural cavity? what is occupied during respiration?
Costodiaphragmatic recess:
* Between costal and diaphragmatic parietal pleura
* Occupied by lungs during inspiration
- Costomediastinal recess:
- Between costal and mediastinal parietal pleura
- Occupied by anterior border of lungs during inspiration
Where do important nerves pass in relation to the lung root?
Vagus nerve passes immediately posterior to root
Phrenic nerve immediately anterior
Locate the pulmonary arteries, veins and bronchi in the hilum of the lungs
Explain the difference in bronchus branching between the 2 lungs
Right: the lobar bronchus to the superior lobe branches from the main bronchus in the root
Left: branches within the lung itself
Give the 4 layers of the trachea
MSCA
*Mucosa - goblet cells (mucin)
*Submucosa
*Fibrocartilage
*Adventitia - binds trachea to adjacent structures in the neck and mediastinum
What is the function of mucous and serous glands in the trachea?
Secretions of mucous and serous glands moisten the air, which protects the alveoli from desiccation
How is the trachea kept patent (open and unobstructed) ?
U-shaped rings of hyaline cartilage
What is the importance of the trachealis muscle?
Oesophagus expansion during swallowing
Where does the trachea begin? and while we r here, where does the eosophogus begin and end?
cricoid cartilage (C6) to
c6 to t11 (not t10 - thsi where it pierces diaphragm)
What are the 3 components of the carotid sheath?
Carotid artery, internal jugular vein and vagus nerve
Compare the main bronchi
Right main bronchus is wider and shorter (2.5cm length)
Left is narrower and longer and more horizontal (5cm length)
Foreign bodies more likely to go in right lung into middle/lower lobe bronchi
What structures can we examine in bronchoscopy?
Give 2 functions of a bronchosopy
Trachea to carina
View segmental and lobar bronchi
Biopsy of mucous membrane
Removal of inhaled foreign bodies
Give the 6 divisions of the trachea
Explain the innervation of the different surfaces of the parietal pleura
SOMATIC nerve supply:
*Costal pleura by intercostal nerves
*Mediastinal pleura by phrenic nerve (C3-C5)
*Central diaphragmatic pleura by phrenic nerve
*Peripheral diaphragmatic pleura by lower 6 intercostal nerves
Response to touch, temperature and pressure (PAIN)
How is the visceral pleura innervated?
What does the visceral pleura respond to?
ANS: pulmonary plexus from sympathetic trunk and vagus nerve
Distension, not sensitive to pain
Difficult to diagnose visceral pain therefore
What is pleural effusion?
Collection of pleural fluid in the pleural cavity
Can occur during infections or cardiac surgery
Causes collapsed lung
What is a pneumothorax?
Air in the pleural cavity
Collapsed lung
Why are the lungs more resistant to infarction (lack of blood flow)?
Dual blood supply from bronchial and pulmonary arteries
How many bronchial arteries are there in each lung?
2 in left lung (superior and inferior)
1 in right lung
Where does the right bronchial artery arise from?
Where does the left bronchial artery arise from?
3rd posterior intercostal artery
Directly from the aorta
How does the right bronchial vein drain?
How does the left bronchial vein drain?
Azygous then SVC
Accessory hemiazygous vein then Azygous then SVC
Give the 5 groups of lymph nodes in the lungs
*Pre-tracheal and paratracheal nodes are located anterior to, and along the sides of the trachea (respectively);
*Superior tracheobronchial nodes, are seen at the superior border of the bifurcation of the trachea;
*Bronchopulmonary or hilar nodes, are located in the hilum of the lungs where the main-stem bronchi enter the lungs,
*Pulmonary or intrapulmonary nodes, are just deep to the hilum and surround the bronchi;
*Inferior tracheobronchial or subcarinal nodes are inferior to the carina of the trachea.
Transverse thoracic plane - level
T4-T5
how does a surgeon isolate the pulmonary trunk and ascending aorta
Transverse pericardial sinus (the pericardial cavity behind aorta and pulmonary trunk)
- During cardiac surgery, the transverse pericardial sinus allows a surgeon to isolate the pulmonary trunk and ascending aorta and apply a temporary ligature or clamp.
Tension pneumothorax
Air in the pleural cavity has pushed the heart and left lung over to the right (a tension pneumothorax). Tension pneumothorax is a life-threatening condition.
