2. Thorax II Flashcards
What are Pleural Membranes?
Fine Serous Membrane that lines the Thoracic Cavity and envelops the Lungs.
What is a Serous Membrane?
Any of the Smooth, Moist, Delicate membranes
That line the closed cavities of the body and secrete a Watery Exudate.
What are the two layers of Pleura around the Lungs?
- Parietal Pleura
2. Visceral Pleura
What is the Pleural Cavity?
The Pleural Cavity is normally a potential enclosed space,
Between the Parietal and Visceral Layers of Pleura,
Kept moist by a small volume of Pleural Fluid.
It is at Sub - Atmospheric pressure.
How many Pleural Cavities are there in the Thoracic Cavity?
There are two Pleural Cavities within the Thoracic Cavity,
Each quite separate and containing no structures.
What does the Parietal Pleura cover?
The Parietal Pleura is attached to the Chest Wall,
And covers the inside of the Thorax, Mediastinum, and Diaphragm.
What is the Cervical Pleura?
The Parietal Pleura extends beyond the apex of the Lung and into the neck.
This is a region of Parietal Pleura known as Cervical Pleura.
How is the Parietal Pleura split into regions?
Parietal Pleura is a Continuous Membrane,
But different areas of it receive different names based on their relationship to parts of the Thoracic Cavity.
What are the 4 regions of the Parietal Pleura?
- Costal
- Diaphragmatic
- Cervical
- Mediastinal
What is the Innervation of the Parietal Pleura?
The Parietal Pleura is innervated by the Intercostal and the Phrenic Nerves.
Why might a stab wound in the neck lead to a Collapsed Lung?
Because the stab may clip the cervical part of the Parietal Pleura,
Damaging it and causing air to accumulate in the Pleural Space between the Lung and the chest wall.
This causes the pressure at the Pleural Space to be higher than the pressure in the Lungs,
Leading to a collapsed Lung/Pneumothorax
What does the Visceral Pleura cover?
The Visceral Pleura covers the surface of the Lungs.
What is the Visceral Pleura attached to?
The Visceral Pleura is attached firmly to the Lungs.
It is continuous with the Mediastinal Pleura at the root of the Lung.
What is the Innervation of the Visceral Pleura?
The Visceral Pleura is innervated by the Autonomic Nervous System.
What is the Pulmonary Ligament?
Not a real Ligament but a Fold of Pleural Membrane
Attaching the Lung medially to the Mediastinum.
Lies inferior to the root of the lung
What are the 2 Pleural Recesses?
- Costo - Diaphragmatic Recess
2. Costo - Mediastinal Recess
What are the 4 Surfaces of the Lungs?
- Costal
- Vertebral
- Diaphragmatic
- Cardiac
What are the other major features of the Lungs?
Cardiac Notch
Lingula
What is the Apex of the Lung?
The blunt Superior End of the Lung.
It projects Upwards,
Above the level of the 1st Rib and into the Floor of the Neck.
What is the Base of the Lung?
The Inferior Surface of the Lung,
Which sits on the Diaphragm
Which Lung is larger?
The Right Lung is larger than the Left.
The Left Lung is smaller because of the space taken up by the Heart.
What is the Cardiac Notch?
The Lateral Deflection of the Anterior Border of the Left Lung.
It is produced to accommodate the space taken up by the Heart.
Which Lung has a Lingula?
The Left Lung has a Lingula
What are Lobes and how many does each Lung have?
Each Lung is separated into Lobes branching off the main Bronchus:
- The Right Lung has Three Lobes.
- The Left Lung has only Two Lobes.
Where is the Oblique Fissure found?
On Left and Right Lung.
Oblique Fissure is at the level of Rib 6.
Where is the Horizontal/Transverse Fissure found?
On the Right Lung only.
Horizontal/Transverse Fissure is below the level of Rib 6.
How many Lobes and Fissures are on the Right Lung?
3 Lobes
2 Fissures
How many Lobes and Fissures are on the Left Lung?
2 Lobes
1 Fissure
Which structures form impressions on the Right Lung?
Superior Vena Cava
Arch of Azygos Vein
Which structures form impressions are formed on the Left Lung?
Arch of the Aorta
Left Common Carotid
Subclavian Arteries
What are the 3 structures in the Hilum of the Left Lung?
- Superior: Pulmonary Artery
- Middle/Posterior: Bronchus
- Inferior/Anterior: Pulmonary Vein
What are the 3 structures in the Hilum of the Right Lung?
- Superior/Posterior: Bronchus
- Middle/Anterior: Pulmonary Artery
- Inferior: Pulmonary Vein
How can the Hilum structures be differentiated?
Bronchi contain Hard Cartilage,
While Artery Walls are Thicker and Stronger than Veins.
What is the route of the right phrenic nerve?
Lateral to brachiocephalic artery and SVC.
Anterior to lung root.
What is the route of the left phrenic nerve?
Lateral to the left subclavian artery. Crosses over vagus nerve and is anterior to lung root.
What is the transverse pericardial sinus and what is itโs significance?
Pericardial cavity behind the aorta and pulmonary trunk.
Can be used to clamp the aorta and pulmonary trunk to divert or stop circulation to these arteries during cardiac surgery
What is pericarditis and how is it related to cardiac tamponade?
Pericarditis is inflammation of pericardium (hence the โitisโ suffix)
Causes chest pain and certain inflammatory diseases cause pericardial effusion where fluid escapes from pericardial capillaries into the pericardial cavity
If large volumes of pericardial effusion accumulate prevents heart from expanding fully, limiting inflow to the ventricles
This compression of the heart as a result of effusion into the pericardial cavity = cardiac tamponade
Can be lethal because fibrous pericardium is tough and cannot expand.
This cardiac tamponade reduces cardiac output and circulation of blood.
How is cardiac tamponade treated?
Pericardiocentesis: needle and long thin tube (catheter) are used to remove the fluid
