Session 1 (and BL recap) Flashcards
How many ribs are there in total?
24
Which ribs are directly attached to the sternum via their costal cartilage?
The first 7
- Ribs 8 to 12 are known as false ribs (3 of which share a common cartilagenous connection to sternum and last 2 are floating)
Pleural sacs are comprised of 2 layers. Name them:
Parietal and visceral serosa
Fluid can be drained from the pleural cavity via use of a wide bore needle. What needs to be avoided when doing this?
The neurovascular bundle that runs under each rib
The respiratory tract is made up of a conducting and respiratory portion. What is the conducting portion comprised of?
Nasal cavity, pharynx, larynx, trachea, primary bronchi, secondary bronchi, bronchioles, terminal bronchioles
The respiratory tract is made up of a conducting and respiratory portion. What is the respiratory portion comprised of?
Respiratory bronchioles, alveolar ducts, alveoli
What epithelia line the nasal cavity to the secondary bronchi?
Pseudostratified ciliated columnar, with presence of goblet cells
What epithelia line the bronchioles and terminal bronchioles?
Simple columnar epithelium with cilia and Clara cells, no goblet cells
What epithelia line the respiratory bronchioles and alveolar ducts?
Simple cuboidal epithelium with Clara cells
What epithelia line the alveoli?
Simple squamous
Does the cartilage of trachea completely surround lumen?
No it is C shaped - allows for the oesophagus to expand.
How is the cartilage of primary bronchi arranged?
Ring structure
The secondary bronchi down to bronchioles have irregular crescent plates of cartilage. True or false?
True
Bronchioles have no cartilage or glands. True or false?
True
What keeps bronchioles open?
Surrounding alveoli
What do Clara cells secrete?
A surfactant lipoprotein - prevents walls of bronchioles sticking together during expiration
CF sufferers do not have the ion channel molecule CFTR - what impact does this have?
Chloride ion transport across membrane compromised, water does not leave epithelium to hydrate mucus -> viscous mucus less readily removed
What type of fibres surround alveoli?
Elastic
Alveolar cells are…
Type I pneumocytes, type II pneumocytes
What is the role of type I pneumocytes?
permit gas exchange with capillaries, predom cell type (90%)
What is role of type II pneumocytes?
Produce surfactant
What is emphysema?
Destruction of alveolar walls, permanent enlargement of air spaces. Alveolar walls hold bronchioles open, allowing air to leave in expiration. If damaged, difficult for lungs to empty
What is the major factor that influences the volume of thorax?
Movement of diaphragm
During inspiration, what happens to diaphragm?
Contracts and flattens, increasing vertical diameter of thoracic cavity -> pressure in cavity decreases and air drawn in
What innervates the diaphragm?
Phrenic nerve C3, C4, C5
Describe the movement of the chest wall during breathing, in relation to the ribs
1) Bucket handle movement: ribs move up to increase lateral dimension of thorax
2) Pump handle movement: sternum moves anteriorly and up
What are the 3 layers of intercostal muscles?
External, internal and innermost
Where is the external intercostal muscle deficient?
Anteriorly
Where are the internal intercostals deficient?
Posteriorly
Where are the innermost intercostal muscles mostly present?
Lateral aspect
Are intercostals important in normal tidal breathing?
No, mainly for forced ventilation
In what direction do the external intercostal fibres run, how do they impact ribs?
Run infero-medially (hands in pockets). When contract they pull ribs up
-> muscles for inhalation (forced)
In what direction do the internal and innermost intercostal fibres run, how do they impact ribs?
Run at right angles to external (supero-medially to insert on rib above). Pull ribs down and backwards.
-> muscles for expiration (forced)
There are 3 main structures that pass through diaphragm. What are they and at what level do they pass through?
1) Vena cava T8
2) Oesophagus T10
3) Aortic hiatus T12
An inhaled foreign body will usually go down which bronchus?
The right - more vertical and wider
How many lobes does the right lung have?
3
The intercostal neurovascular bundle runs between what layers of intercostal muscles?
Internal and innermost
Blood from the intercostal spaces is drained into what system?
Azygos venous system - drains into SVC
