The Respiratory System Flashcards
What are the requirements to maximise diffusion?
Large surface area to volume ratio
Short diffusion distance
Steep diffusion gradient
What is the function of cartilage?
Keeps airways open
Rings allow flexibility
What is the function of goblet cells?
Produce and secrete mucus
What is the function of ciliated epithelia?
Synchronised wafting
Moves mucus across cell surface
What is the function of smooth muscle?
Wrapped around airways to contract to reduce lumen size
Influence volume of air that enters and leaves the lungs
What is the function of elastic fibres?
Stretch and recoil in alveolar walls to help with exhalation
Compresses in airways when smooth muscle contracts and recoil when muscle relaxes to dilate lumen
Where is cilliated epithelia found?
In the trachea, bronchi and bronchioles
Where are goblet cells found?
In the trachea, bronchi and a few in the bronchioles
Where is cartilage found?
In the trachea and bronchi
Where is smooth muscle found?
In the trachea, bronchi and bronchioles
Where are elastic fibres found?
In the trachea, bronchi, bronchioles and alveoli
Where are squamous epithelial cells found?
In the alveoli
How is the problem of gas exchange solved in large organisms?
By breaking large cells into many smaller ones
By having specialised gas exchange surfaces
Internalising gas exchange surfaces to reduce water loss due to evaporation from the moist surface required
How are the lungs adapted to having a short diffusion distance?
Alveolar wall is one cell thick
Cells are squamous epithelial
Capillary walls are one cell thick (endothelium)
How are the lungs adapted to have a large surface area to volume ratio?
Many alveoli
Each alveoli is highly folded
How are the lungs adapted to maintain a steep diffusion gradient for the respiratory gases?
Diffused gases are constantly carried in to high end of diffusion gradient (by ventilation or blood flow)
Diffused gases are constantly removed from the low end of the diffusion gradient
How does the spirometer work?
Subject breathes in and out, drawing air from the air chamber in the spirometer
Nose clip prevents invalid results from breathing through the nose
Carbon dioxide is absorbed using soda lime
What precautions must one take when using the spirometer?
Subject must have no known heart or breathing problems Mouth piece must be disinfected Soda lime needs renewal frequently Check for air leaks Mouth piece must be dis
What is ventilation?
When air is drawn in and out of the lungs to renew oxygen supply and remove carbon dioxide
How can pressure in the cavity be changed?
By changing the volume of the chest/lungs
By changing the position of the diaphragm
By changing the position of the rib cage
What changes occur to the respiratory system during inhalation?
Intercostal muscles contract Ribs move UP AND OUT Diaphragm muscles contract Diaphragm is lowered Volume of thorax increases Pressure in thorax falls Air is drawn in down the pressure gradient
What changes occur to the respiratory system during exhalation?
Diaphragm muscles and intercostal muscles relax
Elastic fibres that were stretched during inhalation recoil
Volume of thorax falls
Pressure in thorax increases
Air flows out down the pressure gradient
What is the spirometer trace used for?
To calculate volume and rate of breathing
What is the soda lime for in the spirometer?
To absorb any carbon dioxide that might cause the subject to hyperventilate
