Mechanisms of ventilation Flashcards
What are the three parts of the pharynx
Nasopharynx
Oropharynx
Laryngopharynx
What are the roles of the superior concha and the inferior concha
Increase SA
Help filtrate air thats Brought in
What is the epiglottis
Protects airways
When you swallow, epiglottis closes the airway so the food and airway goes into the oesphagus and not the trachea
How do we breathe
At rest, diaphragm relaxed
- Muscles of respiration contract to expand thoracic cavity (mainly diaphragm)
- THis increases thoracic volume/decreases intrathoracic pressure
- Air drawn into lungs from outside (where pressure is greater)
- Air passes into terminal bronchioles/alveoli to oxygenate blood
- Diaphragm relaxes, lungs recoil, thoracic volume decreases, intrathoracic pressure increases and air expelled
What is the main muscle of respiration when relaxed
Diaphragm
What is the diaphragm innervated by
Phrenic nerve C3-5
What does the diaphragm anteriorly attach to
Xiphoid process and costal margin
What does the diaphragm laterally attach to
ribs 6-12
What does the diaphragm posteriorly attach to
T12 vertebra
What is the most important intercostal muscle
External
What does the contraction of external and internal fibers do
Raises each rib toward the rib above, to raise the rib cage
What do the innermost and internal intercostal muscles do
Depress each rib to the rib below, to lower the rib cage
What is the direction of the external intercostal muscles
Hands in the pockets
What are the accessory muscles of respiration
Trapezius
Pectorals
Scalenous anterior
SCM
What does the trapezius do
Fix the pectoral girdle to raise the rib cage
What does the scaleous anterior do
Attach to rib 1 tubercle and helps raise rib 1 to aid respiration
What does the SCM do
-Where does it attach
Raises sternum to aid respiration
-manubrium and clavicle
What are the lungs covered by when they go above the first rib
Suprapleural membrane
What is the parietal pleura continuous with
Visceral pleura
What does the parietal pleura line
Mediastinum
Diaphragm
Inside of the ribcage
Mediastinum again
What can babies only breathe via
abdominal breathing (only diaphragm contraction) -can't use pump/bucket handle movements
What muscles are weak in babies
Intercostals
What are babies at high risk of and why
Reliance on the diaphragm for breathing means there is a risk for respiratory failure if the diaphragm is not able to contract
When are children nasal breathers
Until 4-6 week
What is larger in children than adults and why might this be a problem
Tongue in proportion to the mouth
-More likely to obstruct airway if child unconscious so higher chance for respiratory distress
What else is also higher in children than adults
Respiratory rate
How do you do an examination of the airways
Bronchoscopy
What is the carina
Point where trachea splits into two
What is a sign of respiratory distress
Use of accessory muscles while at rest (because lungs fail to provide enough oxygen to a person’s body)
What are the two main types of respiratory distress
Neonatal respiratory distress syndrome which affects newborn babies
Acute respiratory distress syndrome (ARDS) which can affect people regardless of age
Symptoms of respiratory distress
Blue colored extremities
Rapid and shallow breathing
Rapid heart rate
Who is more at risk of neonatal respiratory distress
Premature because lungs are not developed properly
What causes pneumothorax
When you get air in pleural cavity to get a ‘real’ space
How can air get in pleural cavity to cause pneumothorax
Perforate parietal pleura
What are the two types of pneumothorax
- Non-tension pneumothorax
- Tension pneumothorax
Whats the difference between non-tension and tension pneumothorax
non-tension- When theres a hole in pleural cavity but air can still get in and out. Theres a flap which allows air to go in and out
tension- air can’t get out, but can only come in (big medical emergency)
How does a tension pneumothorax look different to a non-tension in an X-ray
Non-tension= mediastinum is at midline, hemidiaphragms at equal length
Tension- mediastinum is deviated (is more outwards) so pushes into heart and will cause heart failure, hemidiaphragms not at equal length
What is emphysema
In a group of diseases called chronic obstructive pulmonary disease
Dust accumulates in lung tissue which results in an inflammatory response, the over-inflated alveoli do not allow effective gas exchange
How can you see emphysema in an x ray
Lungs stay inflated so unoxygenated blood stays there and less oxygenated blood comes in
