Week 3: Introduction to the Respiratory System Flashcards
What is the conducting zone and whats it made up by?
- Is the region where no gas exchange occurs - It is made up of the trachea, bronchi and bronchioles (they are highway systems for air)
Whats the respiratory zone and whats it made up by?
- Is the actual site of gas exchange within the body - It includes the respiratory bronchioles, alveolar ducts and alveoli (bulk of gas exchange occurs in the alveoli)
What are the 2 main zones in the respiratory system?
Conducting and respiratory zone
What is the function of the conducting zone?
- Conducts air (it moves it) 2. Warms the air 3. Humidifies air 4. Cleans the air (it does this through the nasal hairs and nasal turbinates as we breath it in)
What is the first line of defence from preventing foreign particles from getting into the lungs?
Nasal hairs which work along side mucous.
What are the conchae and their function?
extensions within the nasal passage which increase the surface area of the nasal passage. This serves to increase the amount of nasal hairs and mucous that can clean, whilst also increasing the surface area of the capillaries (which allow water and heat exchange).
Particles only less than ___ can enter the lungs due to the first line of defence.
6 micrometers
What happens to particles 1-5 and under 1 micrometers when they make it passed the first line of defence in the upper respiratory system?
Trapped by bronchi by the mucous that lines it and particles smaller than 1 micrometer will end up in alveoli but will be engulfed by alveoli macrophages.
What are the 3 mechanisms which maintain airway patency?
- structural - c shaped cartilage rings which line trachea. 2. radial traction - relies on elastin and type 4 collagen (fibres pull the airway open like springs) 3. Pressure gradients - pressure inside greater than pressure outside
Structural mechanisms maintain patency of the __ and ___ whilst radial tension and pressure gradients maintain patency of the ___ and below
Structural mechanisms maintain patency of the trachea and bronchi, whilst radial tension and pressure gradients maintain the patency of the bronchioles and below
Explain boyles law in terms of how we breath
In order to breath in, we increase the volume of the chest volume, decreasing the chest pressure and thus drawing air into the lungs
What is an important feature of the pleura which helps the lungs to increase its volume when taking a breath?
there is a slight negative pressure that sucks the lungs out and holds the intercostal space.
What would happen when taking a breath if there is air accumulating in the pleural space?
The chest would move when taking a breath but the lungs wouldn’t.
What is intrapulmonary pressure
Pressure inside the lung
Explain the mechanism of inhalation
- Diaphragm contracts and thus moves inferiorly - External intercostals contract and thus moves ribs out and up - Both of these actions increase the volume of the lung, thus creating negative intrapulmonary pressure - Air flows in - Lungs increase in volume
Explain the mechanism of expiration
- There is elastic recoil - Lungs decrease in volume - There is positive intrapulmonary pressure - Air therefore flows out - (Note: expiration is passive at rest)
What is eupnea?
passive expiration from elastic recoil
what is hyperpnoea?
Increase in breathing