Anatomy: Thoracic cavity, Pleura and Lungs Flashcards
The thoracic cavity has ___ divisions: _________________.
3 divisions:
1 mediastinum (central)
2 pulmonary cavities (left & right)
The mediastinum contains what structures?
1) Heart
2) Root of great vessels
(superior vena cava, ascending aorta, pulmonary trunk)
Pulmonary cavities contain which major structures?
Lungs and pleurae
The mediastinum is divided into the __________ and __________ by the __________ along the ___________.
Superior and inferior mediastinum by the sternal angle (@ level of T4/5) along the trans-sternal plane
The inferior mediastinum is further divided into _______________________, all of which are relative to which organ?
Anterior middle and posterior
The heart (middle mediastinum)
The pleura is a ___________ membrane derived from the embryonic _________. It is lined by __________.
double-layered membrane
derived from mesoderm
lined by single layer of mesothelial cells
What are the different layers of the pleura?
Visceral (deep)
- covers lungs and fissures between lobes
Parietal (Superficial)
- lines pulmonary cavities
What is the space between the layers of pleura, what does it contain, and what is its function?
Pleural cavity
- contains serous pleural fluid
- lubricant during respiratory movement
What are the 2 pleural recesses and their clinical significance?
1) Costo-diaphragmatic recess
- allows for lung expansion in inspiration
- used for pleural fluid aspiration in diagnosis
2) Costo-mediastinal recess
- anterior borders of lungs slide in & out during inspiration
Why are surface markings of the lines of pleural reflection important?
Incision and puncture along the lines can cause a pneumothorax or hemothorax
Reflection of the parietal pleura:
1) Cervical pleura on both sides extend into root of neck ____________.
2) Trace downwards and they meet ________ at ______ and continue till they reach _____
3) At __________, left diverges _______________ while right ___________.
4) Curves ________ and reaches (i)_______ at _______, (ii)___________ at _________, and (iii)_______ and _______.
1) Cervical in root of neck 2cm above clavicle
2) Meet behind sternal angle @ 2nd costal cartilage continue until 4th
3) At 6th costal cartilage, left diverge 1cm from sternum, right just stop/emerging from beneath
4) Curve laterally and reaches
i) 8th rib @ mid-clavicular
ii) 10th rib @ mid-axillary
iii) 12th rib @ para-vertebral
What are the 4 parts of the parietal pleura?
1) Cervical
2) Costal
3) Diaphragmatic
4) Mediastinal
Limits of the lung (+ visceral pleura)
- Upper limits of lung follow more or less outline of _______:
_______ above clavicle to behind sternal angle at ________ and continue to lie until ______
- Lower limits of lung are ______ above parietal pleura at midclavicular, midaxillary and parvertebral lines
- Upper limits same as parietal pleura:
2cm above clavicle, meet behind sternal angle @ 2nd costal cartilage until 4th(L)/6(R) - Lower limits are 2 ribs above parietal pleura:
6th @ midclavicular
8th @ midaxillary
10th @paravertebral
Each lung has:
__surfaces (______________)
__ borders (______________)
3 surfaces: Costal (front), Mediastinal (inward), Diaphragmatic
3 borders: Anterior, Inferior, Posterior
The right lung has ____lobes while the left has _____. These are formed/defined by _________.
Right: 3; Left: 2
defined by fissures (both have oblique, only R horizontal)
The ______ lung is larger, heavier and higher than the other due to _________.
Right
Right hemidiaphragm is slightly higher due to liver
What are the neurovascular tissues that are part of the root of the lung?
a) 1 Main bronchus
b) 1 Pulmonary artery
c) 2 Pulmonary veins
d) Bronchial vessels
e) Nerves
f) Lymphatic vessels
The neurovascular tissue in the root of the lung pass through the ______ of the lung.
hilum
What are the 2 types of arteries that supply the lung and what are their respective functions?
1) Bronchial artery (supply lung tissue w nutrients)
2) Pulmonary artery (gas exchange/carry deoxygenated blood)
What is a pneumonectomy?
An operation to remove an entire/part of a lung
What is a lobectomy?
Removal of a lobe of the lung
Which group of blood vessels supply the lungs?
(type of circulation)
Pulmonary circulation
Which group of blood vessels supply part of the body other than the lungs?
(types of circulation)
Systemic circulation
True or false: Blood is pumped into both the pulmonary and systemic circulations simultaneously.
True
Which pulmonary vessel carries deoxygenated blood?
Pulmonary artery
Which pulmonary vessel carries oxygenated blood?
Pulmonary veins
What is a pulmonary embolism?
A blood clot that develops elsewhere in the body (often leg), then travels to and blocks the pulmonary artery, which can cause life-threatening problems including death
What is the hilum of the lung and where is it?
It is the area through which structures enter/leave the lung
On the mediastinal surface of the lung
What is the root of a lung and where is it found?
It is a short tubular connection of structures, surrounded by the mediastinal pleura that emerge at the hilum of each lung.
What are the components of the root of a lung?
a) Main bronchus
b) 2 Pulmonary veins
c) 1 Pulmonary artery
True or false: The lung resides within the visceral pleura, which is within the parietal pleura.
False
Lung is not within, but surrounded by pleural sac
Which is the order of main vessels passing through the root of the RIGHT lung? (superior to inferior)
Bronchus
Artery
Vein
Which is the order of main vessels passing through the root of the LEFT lung? (superior to inferior)
Artery
Bronchus
Vein
The cardiac notch is found on which lung above the _________ (between the oblique fissure and cardiac notch)
left lung above lingula
What are the important relations at the apex of the LEFT lung?
1) 1st thoracic spinal nerve
2) Sympathetic trunk
3) Phrenic nerve
What are the important relations at the hilar region of the LEFT lung?
1) Heart*
2) Oesophagus*
3) Thoracic Aorta*
4) Aortic arch + branches*
5) L subclavian artery
6) L common carotid artery
7) Brachiocephalic artery
What are the important relations at the hilum of the right lung?
1) Heart
2) Oesophagus
3) Azygos vein
4) Both vena cava
The phrenic nerves run _______to the roots of the lungs while the vagus nerves run _______ to the roots of the lungs.
Phrenic run anterior
Vagus run posterior
The phrenic nerve arises from which spinal segments?
C3-5
The network of sympathetic and parasympathetic nerve fibres supply the thoracic viscera with ____________ fibres, contained in _________________________
motor and sensory
contained in (i) cardiac (ii) pulmonary (iii) oesophageal plexuses
The visceral pleura and lungs receive _________ innervation from the __________.
visceral pleura and lung receive visceral afferent (autonomic)
from pulmonary plexus
Are the visceral pleura and lungs sensitive to pain?
No (supplied by visceral afferent/autonomic)
The parietal pleura receives ____________ innervation from ___________________________.
Parietal pleura receives somatic afferent from:
i) Intercostal nerves (T1-11): cervical and costal pleurae
ii) Phrenic nerves (C3-5): mediastinal and diaphragmatic pleurae
Is the parietal pleura sensitive to pain?
Yes (supplied by somatic afferent from intercostal and phrenic nerves)
Where are the dermatomes of the spinal nerves that give rise to the phrenic nerve?
C3: base of neck to clavicle
C4: clavicle to shoulder
C5: lateral over shoulder till elbow
Where would pain from the parietal pleura be referred to?
The skin over the neck and shoulder
How does pain from the parietal pleura get referred?
Pain pathways from the skin surface supplied by C3-5 spinal nerves (over neck and shoulder) AND those from parietal pleura pass very close to e/o @ dorsal root. Ephatic transmission causes brain to mistake pain from visceral parietal pleura for pain from the skin
At which levels does the trachea begin and end?
C6-T4/5 (sternal angle)
What type of cartilage forms the C-shaped rings lining the trachea?
Hyaline cartilage
What tissue forms the interconnections between tracheal rings?
Fibroelastic tissue
What is the function of tracheal rings?
Maintain mechanical stability of trachea:
- keeps trachea open/prevent collapse under negative pressures of respiratory cycle
What happens to the amount of cartilage and smooth muscle as the trachea extends distally?
Cartilage reduces and disappears (no cartilage in bronchioles)
Smooth muscles increase in abundance
What are the important anterior relations of the trachea?
1) Sternum
2) L Brachiocephalic Vein & Trunk
3) L Common Carotid Artery
4) Aortic arch
What are the important posterior relations of the trachea?
1) Oesophagus
2) L recurrent laryngeal nerve
What are the important right lateral relations of the trachea?
1) Azygos vein
2) R Vagus nerve
What are the important left lateral relations of the trachea?
1) Aortic arch
2) L common carotid
3) L subclavian arteries
4) L vagus & phrenic nerves
Where in the airway do the bronchi split into the different lobes of each lung?
Lobar bronchi
In which airway are foreign bodies more likely to the trapped?
Right main bronchus (wider, short, more vertical than left)
Which bronchi supply the bronchopulmonary segments?
Segmental bronchi
Each bronchopulmonary segment has their own _____ supply, whilst the _________ vessels pass through intervening septae that separate segments.
Each have own arterial supply
venous and lymphatic vessels pass through intervening septae
True or false: A bronchopulmonary segment can be surgically removed without disrupting venous supply
False (venous and lymphatic supply is shared between segments, only arterial isn’t)
What does inspection of the chest wall do?
Shows the range of respiratory movements & any inequalities
What does palpation in a chest examination do?
Confirm impression from inspection (esp of respiratory movements)
What does percussion in a chest examination do?
Produce vibrations that extend through tissue to assess the resonance of tissue
What does auscultation in a chest examination do?
Listen for breath sounds (vesicular/collapsed; wheeze & stridor0
What are the 6 things to note in a chest X-ray?
A-F
1) Airway
2) Bones
3) Cardiac outline
4) Diaphragm
5) Effusions
6) Fields
What is a pneumothorax and what is associated radiological appearance?
Entry of air into pleural cavity
- Hyperluscency and absent vascular markings
What is a pleural effusion and what is the associated radiological appearance?
Pleural effusion/Hydrothorax: accumulation of fluid into pleural cavity
(if blood: hemothorax)
- costophrenic angle absent
Is the costophrenic angle present in hemidiaphragm paralysis?
Yes
How do you landmark the triangle of safety for a chest tube insertion?
Define boundaries:
1) Lateral edge of pectoralis major
2) Base of axilla
3) 5th ICS
4) Lateral edge of latissimus dorsi muscle
How do you place an incision in a chest tube insertion?
1) Identify upper border of rib prior to prevent injury to neurovascular bundle
2)Use a finger sweep to ensure correct location and relieve any adhesions
What is a bronchogram?
Radiological examination of the bronchus and its branches
What is a bronchoscopy?
Examination of the bronchus by an illuminated scope
