Intro to Resp Flashcards
What defines pressure
force/unit area exerted on a surface by gas next to it
What’s the kinetic theory of gases
the more frequent and harder the collisions the higher the pressure
What does Boyle’s law tell us?
How can we relate Boyle’s law to the respiratory system?
Pressure is inversely proportional to volume.
When bronchioles and alveoli expand the volume increases and pressure decreases: generating a pressure gradient. Since pressure moves from high –> low, air is drawn into the alveoli
What is the partial pressure of O2 in alveoli?
13.3 kPa
What does Charle’s Law tell us?
Absolute temperature is proportional pressure.
Temperature increases velocity which increases collision which increases pressure!
What generates saturated vapour pressure?
Which factor does it depend on?
Moles leaving water and going to gas exert this pressure, depends on temperature
What is the universal gas law?
Pressure X Volume = R (Ideal gas constant) X Temperature
what defines ‘tension’
The pressure exerted as gas molecules enter water
What 2 factors are equal at equilibrium? What does this tell us?
Partial pressure and tension of gas in a mixture, should tell you how readily the gas will leave the liquid.
What determines the amount of gas that enters a liquid? (and establishes a tension)
Solubility of the gas
How much oxygen should 5L of blood pick up per min at rest. What feature of the airways ensures this is able to happen?
12 mmol, large SA of small compartments (alveoli) surrounded by capillaries
How many lobes are in the R and L lung?
3 in the right, 2 in the left
Name a characteristic difference between bronchi and bronchioles
Bronchi have cartilage in their walls, bronchioles have smooth muscle
What is the typical pulmonary arterial pressure?
Why does no fluid form in the lungs under normal circumstances?
14-18 mmHg
No fluid forms (without the presence of disease) as there is low pressure and low resistance in the pulmonary circulation
Explain Ventilation Perfusion Matching
Matching the amount of air that reaches the alveoli with a sufficient amount of blood that carries it away
What two forces interact to balance the amount of fluid that stays and leaves the vessels?
Hydrostatic and Oncotic pressure
Name the ‘respiratory’ and ‘conducting’ components of the resp system
Conducting:
- Upper resp tract: mouth/nose, larynx
- Lower resp tract: trachea, lungs, bronchi, bronchioles and terminal bronchioles
Respiratory: alveolar ducts and alveoli
Which epithelia are specific to the nose? What’s their function?
Olfactory epithelia: have olfactory neurones that are able to sense smell
At what point in the resp tract do goblet cells cease? What replaces them and what is their function?
Present until the terminal bronchioles, replaced by Clara cells; thin the mucus and have immune functions
What is the function of the oropharynx?
A passageway under the nasopharynx for food moving from mouth - esophagus and air moving to and from the nasal cavity
What type of epithelium lines most of the resp tract?
Pseudostratified ciliated columnar
What are 3 things the larynx do?
- Vocal cords
- Protect airways from choking on material in the throat
- Regulates flow of air into lungs
What happens to the epithelium as the diameter of the resp tract decreases?
Columnar epithelium becomes more cuboidal
What are the 3 types of cells found in the alveoli? What are their functions?
- Simple squamous: provide a short barrier for gas diffusion
- Cuboidal surfactant secreting cells: surfactant decreases the surface tension so alveoli can inflate easier
- Macrophages: scavenge small debris that reaches the alveoli
